**2. Farm animals**

#### **2.1 Cattle and small ruminants**

Ruminants belong to the order Cetartiodactyla, which encompasses numerous species, and only a minority has been domesticated including cattle, sheep, and goats. Although these are suited to different habitats, in intensive farming systems, domestication has led to exposure to different stressors potentially responsible of pathologies.

For centuries, cattle have been grown in a traditional manner, within small farms, mainly grazing. Since the second half of the nineteenth century, the continuous demand of protein products and the availability of grains and protein sources to low costs led to an intensive, highly specialized production system, where animals are "adapted" to meet the constraints caused by their housing conditions and the management practices [5], thus restricting their natural behaviors. Furthermore, individual selection for enhanced production traits has placed an even greater metabolic demand on these animals.

The microenvironment experienced by cattle in houses, on open feedlots or at pasture is determined by the *microclimate*. Beef cattle can tolerate and adapt to a wide range of air temperatures, and metabolic heat production increases with increasing feed intake. Microclimate changes (e.g., inadequate ventilation, extreme temperatures, high relative humidity, ammonia concentration, etc.), affect the animal's immune response resulting in **respiratory and enteric diseases**, the major welfare problems in beef cattle [6].

The *housing system* could play an important role in cattle welfare [7]. Loose housing systems allow more freedom of movement than tether systems, also offering the animals the possibility of experiencing more natural social behaviors. The resting area is one of the most important areas, especially in a cow facility. Lying down is a basic requirement, and repeated deprivation is aversive to cows. Lying times are lower and standing times are higher when dairy cattle are forced to use hard surfaces. Particularly, in dairy cow, the poor hygiene and the materials of the bedding leads to **udder problems**, as manure may compromise cow comfort and increase the risk of intramammary infections. The type of flooring on which animals walk has been found to affect their welfare by impairing locomotion and increasing the occurrence of **hoof disorders and lameness**, which represent a major concern for the dairy industry because it negatively affects milk production. Beef cattle kept on slatted floors show a higher incidence of abnormal standing and lying movements and also a higher incidence of injuries than animals kept on concrete floor with fully or partially straw-bedded areas. A long duration of grazing periods, associated with frequent manure removal during the housing period, is probably a key factor for limiting the occurrence of podal lesions.

As far as *social interactions* are concerned, mixing and regrouping of cattle increase the incidence of agonistic behaviors and have also disadvantages from a health perspective. Older and more aggressive animals may cause trauma and continuous and severe stress to lower ranking calves (bullers). Small and young animals are more prone to diseases if kept with larger and older animals. For these reasons, groups should be made up with animals of similar age, weight, and sex [5]. Moreover, overcrowding and the reduced space at the manger are one of the most critical factors negatively affecting cattle welfare by increasing competition among pen-mates, causing the buller steer syndrome, decreasing the feed intake, reducing the time spent resting, eating, and ruminating, and increasing lesions, such as trauma on bones and joints, osteoarthropathies, prepuce injury, and tail-tip necrosis. In most intensive farming systems, the separation of the dairy calves from their

**131**

and beef cattle [9].

*The Disturbed Habitat and Its Effects on the Animal Population*

mother in the period immediately after birth may have negative consequences for the health and welfare of cows and calves. Particularly, the socialization of calves

in the prevalence of stress responses and physical injuries [8]. In fact, a positive attitude of the stockperson in handling and taking care of the animals seems to improve cattle welfare. The age of the farmers is also responsible for the less efficient management and consequently poor welfare of the animals. Not well-trained

*Husbandry practices* can have a tremendous effect on cattle provoking an increase

Furthermore, the welfare of any animal clearly depends on the provision of sufficient food to supply principally energy (Net Energy [NE]), proteins, amino acids, fatty acids, minerals, and vitamins, which are essential for the functions of life (maintenance, growth, activity, and reproduction). Failure to provide sufficient NE and optimal amounts of specific nutrients can lead to severe loss of body condition, infertility, and severe metabolic disorders. Growing beef cattle, housed, yarded or on feedlots, and presented with high energy and low fiber rations *ad libitum* are at risk of **digestive disorders** (**Figure 3A**). The most common of these ones is subacute ruminal acidosis, which occurs when the fermentation rate and hence the volatile fatty acid production exceed the buffering capacity of the rumen, but it is possible to observe also fatty liver, ketosis, displaced abomasum, liver abscesses, and laminitis. Unnatural foraging regimes, possibly exacerbated by restrictive environments, are thought to elicit stereotypic oral behavior in cattle, such as

For all the reasons stated above, the authors hypothesize that the stress related to the intensive livestock farming could also represent a mechanotransduction-promoting factor of subclinical pathological changes such as **coronary arteriosclerosis** (**Figure 3B**), which has been frequently reported at slaughterhouse in both calves

Basically, the major farming systems of small ruminants are those based on pasture (extensive-grazing), the indoor ones (intensive-industrial), and the semiintensive. The negative impact of intensification of breeding systems can be observed at several levels and is very similar to what has been discussed above for the cattle. However, limited studies on the small ruminant welfare have been carried out, since they are considered very rustic animals able to cope with prohibitive environmental conditions and inadequate management practices, without harming their welfare and productive performances. This aspect has been overrated for many years considering that also in sheep and goats, stress can impair growth rate, wool growth, and feed conversion efficiency, also leading to the development of multi-factorial diseases such as **mastitis, laminitis, and metabolic disorders,** and increasing the frequency of abnormal behaviors (aggressive behavior), stereotypies, and vocalizations [10]. The *microclimate* is fundamental in preventing **respiratory diseases**. Indeed, animals allocated in hot and dusty environments are more prone to develop bacterial or viral pneumonia. Additional stressors could be found in the extensive systems, such as climatic extremes, that may evoke a **decrease in feed intake efficiency** and utilization, disturbances in water, protein, energy, and mineral bal-

ances, enzymatic reactions, hormonal secretions, and blood metabolites.

ment practices are important in either type of system.

The *housing system* is fundamental for small ruminant welfare too: only few animals are reared in extensive production systems in which animals are free to move and perform their physiological and behavioral functions; most of them are housed only during the night and in the periods when grazing is not feasible. In any case, it is fundamental to understand that maintenance of good hygiene conditions, correct dimensioning of structural parameters, and adoption of proper manage-

may profit from staying with the dam, preferentially in a group [5].

milkers may produce **teats injuries** that predispose to mastitis.

tongue-rolling, object-licking, chain-chewing, or bar-biting [6].

*DOI: http://dx.doi.org/10.5772/intechopen.84872*

#### *The Disturbed Habitat and Its Effects on the Animal Population DOI: http://dx.doi.org/10.5772/intechopen.84872*

*Habitats of the World - Biodiversity and Threats*

Ruminants belong to the order Cetartiodactyla, which encompasses numerous species, and only a minority has been domesticated including cattle, sheep, and goats. Although these are suited to different habitats, in intensive farming systems, domestication has led to exposure to different stressors potentially responsible of

For centuries, cattle have been grown in a traditional manner, within small farms, mainly grazing. Since the second half of the nineteenth century, the continuous demand of protein products and the availability of grains and protein sources to low costs led to an intensive, highly specialized production system, where animals are "adapted" to meet the constraints caused by their housing conditions and the management practices [5], thus restricting their natural behaviors. Furthermore, individual selection for enhanced production traits has placed an even greater

The microenvironment experienced by cattle in houses, on open feedlots or at pasture is determined by the *microclimate*. Beef cattle can tolerate and adapt to a wide range of air temperatures, and metabolic heat production increases with increasing feed intake. Microclimate changes (e.g., inadequate ventilation, extreme temperatures, high relative humidity, ammonia concentration, etc.), affect the animal's immune response resulting in **respiratory and enteric diseases**, the major

The *housing system* could play an important role in cattle welfare [7]. Loose housing systems allow more freedom of movement than tether systems, also offering the animals the possibility of experiencing more natural social behaviors. The resting area is one of the most important areas, especially in a cow facility. Lying down is a basic requirement, and repeated deprivation is aversive to cows. Lying times are lower and standing times are higher when dairy cattle are forced to use hard surfaces. Particularly, in dairy cow, the poor hygiene and the materials of the bedding leads to **udder problems**, as manure may compromise cow comfort and increase the risk of intramammary infections. The type of flooring on which animals walk has been found to affect their welfare by impairing locomotion and increasing the occurrence of **hoof disorders and lameness**, which represent a major concern for the dairy industry because it negatively affects milk production. Beef cattle kept on slatted floors show a higher incidence of abnormal standing and lying movements and also a higher incidence of injuries than animals kept on concrete floor with fully or partially straw-bedded areas. A long duration of grazing periods, associated with frequent manure removal during the housing period, is probably a key factor for

As far as *social interactions* are concerned, mixing and regrouping of cattle increase the incidence of agonistic behaviors and have also disadvantages from a health perspective. Older and more aggressive animals may cause trauma and continuous and severe stress to lower ranking calves (bullers). Small and young animals are more prone to diseases if kept with larger and older animals. For these reasons, groups should be made up with animals of similar age, weight, and sex [5]. Moreover, overcrowding and the reduced space at the manger are one of the most critical factors negatively affecting cattle welfare by increasing competition among pen-mates, causing the buller steer syndrome, decreasing the feed intake, reducing the time spent resting, eating, and ruminating, and increasing lesions, such as trauma on bones and joints, osteoarthropathies, prepuce injury, and tail-tip necrosis. In most intensive farming systems, the separation of the dairy calves from their

**2.1 Cattle and small ruminants**

metabolic demand on these animals.

welfare problems in beef cattle [6].

limiting the occurrence of podal lesions.

**2. Farm animals**

pathologies.

**130**

mother in the period immediately after birth may have negative consequences for the health and welfare of cows and calves. Particularly, the socialization of calves may profit from staying with the dam, preferentially in a group [5].

*Husbandry practices* can have a tremendous effect on cattle provoking an increase in the prevalence of stress responses and physical injuries [8]. In fact, a positive attitude of the stockperson in handling and taking care of the animals seems to improve cattle welfare. The age of the farmers is also responsible for the less efficient management and consequently poor welfare of the animals. Not well-trained milkers may produce **teats injuries** that predispose to mastitis.

Furthermore, the welfare of any animal clearly depends on the provision of sufficient food to supply principally energy (Net Energy [NE]), proteins, amino acids, fatty acids, minerals, and vitamins, which are essential for the functions of life (maintenance, growth, activity, and reproduction). Failure to provide sufficient NE and optimal amounts of specific nutrients can lead to severe loss of body condition, infertility, and severe metabolic disorders. Growing beef cattle, housed, yarded or on feedlots, and presented with high energy and low fiber rations *ad libitum* are at risk of **digestive disorders** (**Figure 3A**). The most common of these ones is subacute ruminal acidosis, which occurs when the fermentation rate and hence the volatile fatty acid production exceed the buffering capacity of the rumen, but it is possible to observe also fatty liver, ketosis, displaced abomasum, liver abscesses, and laminitis. Unnatural foraging regimes, possibly exacerbated by restrictive environments, are thought to elicit stereotypic oral behavior in cattle, such as tongue-rolling, object-licking, chain-chewing, or bar-biting [6].

For all the reasons stated above, the authors hypothesize that the stress related to the intensive livestock farming could also represent a mechanotransduction-promoting factor of subclinical pathological changes such as **coronary arteriosclerosis** (**Figure 3B**), which has been frequently reported at slaughterhouse in both calves and beef cattle [9].

Basically, the major farming systems of small ruminants are those based on pasture (extensive-grazing), the indoor ones (intensive-industrial), and the semiintensive. The negative impact of intensification of breeding systems can be observed at several levels and is very similar to what has been discussed above for the cattle. However, limited studies on the small ruminant welfare have been carried out, since they are considered very rustic animals able to cope with prohibitive environmental conditions and inadequate management practices, without harming their welfare and productive performances. This aspect has been overrated for many years considering that also in sheep and goats, stress can impair growth rate, wool growth, and feed conversion efficiency, also leading to the development of multi-factorial diseases such as **mastitis, laminitis, and metabolic disorders,** and increasing the frequency of abnormal behaviors (aggressive behavior), stereotypies, and vocalizations [10].

The *microclimate* is fundamental in preventing **respiratory diseases**. Indeed, animals allocated in hot and dusty environments are more prone to develop bacterial or viral pneumonia. Additional stressors could be found in the extensive systems, such as climatic extremes, that may evoke a **decrease in feed intake efficiency** and utilization, disturbances in water, protein, energy, and mineral balances, enzymatic reactions, hormonal secretions, and blood metabolites.

The *housing system* is fundamental for small ruminant welfare too: only few animals are reared in extensive production systems in which animals are free to move and perform their physiological and behavioral functions; most of them are housed only during the night and in the periods when grazing is not feasible. In any case, it is fundamental to understand that maintenance of good hygiene conditions, correct dimensioning of structural parameters, and adoption of proper management practices are important in either type of system.

#### **Figure 3.**

*(A) Beef cattle—abomasitis due to improper nutrition. (B) Beef cattle—heart. Arteriosclerotic alterations: diffuse intimal hyperplasia (\*), medial smooth muscle cells reoriented and with disseminated vacuolar degeneration of the cytoplasm, moderate medial hypertrophy/hyperplasia (\*\*). Histological section stained with H & E. Original magnification 20×. (C) Goat—udder. Traumatic teat injuries caused by milking. (D) Pig—lung. Pulmonary sequestration due to Actinobacillus pleuropneumoniae infection. (E) Pig—tail-biting lesions. (F) Pig—gastric ulcer due to improper nutrition.*

With regard to *social interactions*, separation of goats/sheep from the group and re-introduction (e.g., for shearing or milking) and introduction of goats/sheep into established groups are stressful. One measure to reduce the effects of separation and reintroduction is to enable the (separated) goat/sheep to still hear and smell the other goats.

As seen above for cattle, *human-animal interaction* is a key factor also in the welfare of small ruminants too, and it is not unusual to find shepherds who have no specific skills or are not aware of the welfare standards of the animals [3]. An inadequate milking may produce teat injuries (**Figure 3C**) which is why specific training of farm crews should therefore be encouraged. Finally, an inadequate pasture in terms of quality and quantity can lead to **nutritional unbalance** with **liver disease, enzootic ataxia, pregnancy toxemia, hypocalcaemia, diarrhea,** and **enterotoxaemia**.

**133**

*The Disturbed Habitat and Its Effects on the Animal Population*

Genetic selection in domestic pigs has been widely exploited in order to achieve specific phenotypic characteristics. Many pigs are raised in intensive conditions and thus strongly conditioned by the environment where they live. Moreover, even free-ranging domestic pigs and wild boars may be strongly influenced by human activities. Several signs of suffering in swine have been described and they can be quantified using animal-based measures (ABMs) [11, 12]. Furthermore, researches on pig welfare and ABMs led to the identification of "iceberg indicators" such as body injuries and ear and tail lesions. These indicators can be a proxy of "disturbed

habitat" which is strongly influenced by microclimate and/or management. *Microclimate* heavily affects the stress conditions for pigs, particularly in intensive farming where different age groups require different microclimate standards (air, temperature, and humidity). If ventilation and air quality are not optimal, respiratory disorders, such as pneumonia (**Figure 3D**) and/or pleuritis from opportunistic pathogens, may occur, thus increasing the mortality. Variations in temperature and humidity (outside the thermal comfort) result in abnormal behaviors. For example, distressed pigs show increased huddling due to excessive cold weather and panting due to excessive hot weather [11]. Proper *management* is the key to maintain suitable habitat conditions for both intensive and extensive pig farming. Housing systems affect both animal behavior and physical conditions. In the intensive farming, floor types (e.g., slatted or solid), space allowance, and availability of bedding material influence incidence of bursitis, erosions, lameness, and shoulder ulcers. Moreover, the type of flooring directly affects the hygiene of the pig's body and the risk of developing enteric disorders. In the extensive farming, pigs must always have access to proper shelters; otherwise, outbreaks of severe enteric and respiratory disorders will occur increasing also the mortality rating. Appropriate structures and adequate space allowance for activities such as resting, feeding, and drinking are directly related to social behavior and interactions. Indeed, the environment in which pigs are confined influences the *degree of social interactions*. When a new group of pigs is formed, a stable social hierarchy is usually established in 1 or 2 days. During this initial phase, negative interactions arise and their outcomes may be observed mainly as wounds on the body. Once the hierarchy is established, negative interactions drastically subside while positive interactions (e.g., grooming, sniffing, nosing, and liking) and exploratory behaviors become prevalent [12, 13]. Nevertheless, rearing conditions typical of intensive housing systems can exacerbate inappropriate behaviors such as stereotypies (e.g., sham chewing) and negative interactions (e.g., ear and tail biting) (**Figure 3E**) [14]. *Human influence* on genetic selection and daily management is one of the most important variables which can exacerbate consequences of "disturbed habitat." Indeed, daily management errors, such as improper nutrition or feeding, may lead to severe conditions like gastric ulcers (**Figure 3F**) or toxic states (e.g., salt poisoning) which can cause high mortality [15]. Clear differences in the body condition scores of pigs of the same age are also a direct consequence of inadequate feeding. Genetic selection has led to great production results improving parameters such as reproductive performances, meat production, daily weight gain, and feed conversion ratio. However, this intense selection has made pigs less able to adapt to certain environmental situations (e.g., thickness of the subcutaneous fat layer), with organs at the limit of physiological potentiality (e.g., heart), leading to an increased risk of pathologies such as hernias and mulberry heart disease [16]. Pigs are also selected to be more prolific but, without adequate assistance, there is a drastic increase of newborn piglet mortality. Finally, human influence on pig management has repercussions on infectious diseases, which negatively affect pig health, such as colibacillosis, polyserositis,

*DOI: http://dx.doi.org/10.5772/intechopen.84872*

**2.2 Pigs**

*The Disturbed Habitat and Its Effects on the Animal Population DOI: http://dx.doi.org/10.5772/intechopen.84872*

#### **2.2 Pigs**

*Habitats of the World - Biodiversity and Threats*

With regard to *social interactions*, separation of goats/sheep from the group and re-introduction (e.g., for shearing or milking) and introduction of goats/sheep into established groups are stressful. One measure to reduce the effects of separation and reintroduction is to enable the (separated) goat/sheep to still hear and smell the other goats. As seen above for cattle, *human-animal interaction* is a key factor also in the welfare of small ruminants too, and it is not unusual to find shepherds who have no specific skills or are not aware of the welfare standards of the animals [3]. An inadequate milking may produce teat injuries (**Figure 3C**) which is why specific training of farm crews should therefore be encouraged. Finally, an inadequate pasture in terms of quality and quantity can lead to **nutritional unbalance** with **liver disease, enzootic ataxia, pregnancy toxemia, hypocalcaemia, diarrhea,** and **enterotoxaemia**.

*lesions. (F) Pig—gastric ulcer due to improper nutrition.*

*(A) Beef cattle—abomasitis due to improper nutrition. (B) Beef cattle—heart. Arteriosclerotic alterations: diffuse intimal hyperplasia (\*), medial smooth muscle cells reoriented and with disseminated vacuolar degeneration of the cytoplasm, moderate medial hypertrophy/hyperplasia (\*\*). Histological section stained with H & E. Original magnification 20×. (C) Goat—udder. Traumatic teat injuries caused by milking. (D) Pig—lung. Pulmonary sequestration due to Actinobacillus pleuropneumoniae infection. (E) Pig—tail-biting* 

**132**

**Figure 3.**

Genetic selection in domestic pigs has been widely exploited in order to achieve specific phenotypic characteristics. Many pigs are raised in intensive conditions and thus strongly conditioned by the environment where they live. Moreover, even free-ranging domestic pigs and wild boars may be strongly influenced by human activities. Several signs of suffering in swine have been described and they can be quantified using animal-based measures (ABMs) [11, 12]. Furthermore, researches on pig welfare and ABMs led to the identification of "iceberg indicators" such as body injuries and ear and tail lesions. These indicators can be a proxy of "disturbed habitat" which is strongly influenced by microclimate and/or management. *Microclimate* heavily affects the stress conditions for pigs, particularly in intensive farming where different age groups require different microclimate standards (air, temperature, and humidity). If ventilation and air quality are not optimal, respiratory disorders, such as pneumonia (**Figure 3D**) and/or pleuritis from opportunistic pathogens, may occur, thus increasing the mortality. Variations in temperature and humidity (outside the thermal comfort) result in abnormal behaviors. For example, distressed pigs show increased huddling due to excessive cold weather and panting due to excessive hot weather [11]. Proper *management* is the key to maintain suitable habitat conditions for both intensive and extensive pig farming. Housing systems affect both animal behavior and physical conditions. In the intensive farming, floor types (e.g., slatted or solid), space allowance, and availability of bedding material influence incidence of bursitis, erosions, lameness, and shoulder ulcers. Moreover, the type of flooring directly affects the hygiene of the pig's body and the risk of developing enteric disorders. In the extensive farming, pigs must always have access to proper shelters; otherwise, outbreaks of severe enteric and respiratory disorders will occur increasing also the mortality rating. Appropriate structures and adequate space allowance for activities such as resting, feeding, and drinking are directly related to social behavior and interactions. Indeed, the environment in which pigs are confined influences the *degree of social interactions*. When a new group of pigs is formed, a stable social hierarchy is usually established in 1 or 2 days. During this initial phase, negative interactions arise and their outcomes may be observed mainly as wounds on the body. Once the hierarchy is established, negative interactions drastically subside while positive interactions (e.g., grooming, sniffing, nosing, and liking) and exploratory behaviors become prevalent [12, 13]. Nevertheless, rearing conditions typical of intensive housing systems can exacerbate inappropriate behaviors such as stereotypies (e.g., sham chewing) and negative interactions (e.g., ear and tail biting) (**Figure 3E**) [14]. *Human influence* on genetic selection and daily management is one of the most important variables which can exacerbate consequences of "disturbed habitat." Indeed, daily management errors, such as improper nutrition or feeding, may lead to severe conditions like gastric ulcers (**Figure 3F**) or toxic states (e.g., salt poisoning) which can cause high mortality [15]. Clear differences in the body condition scores of pigs of the same age are also a direct consequence of inadequate feeding. Genetic selection has led to great production results improving parameters such as reproductive performances, meat production, daily weight gain, and feed conversion ratio. However, this intense selection has made pigs less able to adapt to certain environmental situations (e.g., thickness of the subcutaneous fat layer), with organs at the limit of physiological potentiality (e.g., heart), leading to an increased risk of pathologies such as hernias and mulberry heart disease [16]. Pigs are also selected to be more prolific but, without adequate assistance, there is a drastic increase of newborn piglet mortality. Finally, human influence on pig management has repercussions on infectious diseases, which negatively affect pig health, such as colibacillosis, polyserositis,

enzootic pneumonia, post weaning multisystemic wasting syndrome, and porcine reproductive and respiratory syndrome.

#### **2.3 Equines for meat production**

Equine meat consumption depends on cultural and traditional customs. Since it is a niche product, scientific community has made little efforts to define the main factors responsible for a "disturbed habitat" in this category. Equine breeds specifically selected for meat production do not exist and genetic selection focused more upon preserving and improving traits related to horses' morphology and performance. Therefore, although equines' domestication dates back to 5000 years ago, these species still retain the ancestral characteristics of their progenitors and feral equine populations can provide information about many aspects of equine behavior (e.g., social and foraging behavior). Considering the most important *microclimate factors* that negatively affect the equine habitat, insufficient ventilation and inadequate air quality may cause an increased exposure to gaseous ammonia and airborne dust that contain high levels of organic particulates including mite debris, microbes and vegetative material with varying content of endotoxins. The inhalant exposure to those irritant factors is implicated in the pathogenesis of **chronic inflammatory pulmonary disorders** such as inflammatory airway diseases (IAD) and recurrent airway obstruction (RAO) [17].

Equines reared for meat production are housed in conditions that markedly differ from those in which they evolved. As a consequence, those animals attempt to adapt to the conditions in which they are kept performing functionless and repetitive activity known as **stereotypic behaviors** that include crib-biting, wind sucking, box walking, and weaving [18]. Therefore, using equine stereotypies as welfare indicators should lead to perform management changes to enhance equine's welfare.

Bedding is an essential component in the *housing of the equine stabled. Bedding* should be dry, clean and not dusty, providing comfort, allowing animals to express their natural behavior of lying and resting and also avoiding the risk of **hoofs and skin lesions** [19].

Regarding the equines' opportunity to perform normal behaviors, it is important to guarantee an adequate space allowance to prevent aggressive reactions that might lead to stress competition for resources and for hierarchy establishment with consequent **physical injuries**. Indeed, wild horses live in relatively stable harem bands, so the overcrowding and the high rates of regrouping of intensively farmed horse may cause an increase in aggressiveness and injuries [20]. On the contrary, in nature, donkeys adapt easily, and their social organization depends on the availability of food and water resources. Therefore, the competition in the stabled donkeys, probably, could be increased if the available resources are not accessible to all, but their behaviors in farmed conditions need to be further studied.

Equines are grazing herbivores adapted to eating a forage-based diet. In nature, horses and donkeys spend about 16 hours per day foraging over wide distances, and this is essential for the health of their gastrointestinal tract and for their behavioral needs. On the contrary, equines in the breeding farms are fed high-energy, low-fiber concentrates, and this lack of foraging opportunity along with the high amount of concentrate feedstuff has been directly linked to the onset of **gastrointestinal disorders such as** gastric ulcerations (**Figure 4A**) and colic [19]. Equine gastric ulcer syndrome (EGUS) is reported in domesticated horses mainly involved in athletic endeavors. EGUS prevalence and severity have been correlated with the type of training and management practice. Common known risk factors have been identified in intense exercise, high grain-low roughage diet, water deprivation, fasting, hospitalization, and overdose of NSAIDs. In particular, excessive ingestion

**135**

**2.4 Poultry**

**Figure 4.**

*of stress and opportunistic infections.*

*The Disturbed Habitat and Its Effects on the Animal Population*

of carbohydrates causes a rapid proliferation of the hindgut gram-positive bacteria *Streptococcus bovis* and *Streptococcus lutetiensis* that lead to very acidic conditions with pH lower than 4. Low pH in the large intestine causes the death and lysis of a large number of bacteria and the release of the toxic components which are absorbed from the gut into the bloodstream and may cause the development of **laminitis** [21].

*(A) Horse—gastric ulcer due to improper nutrition. (B) Chicken—footpad dermatitis. (C) Chicken—ascites. (D) Sea bream (Sparus aurata)—peduncle mutilation caused by bite in overcrowding breeding conditions. (E) Sturgeon (Acipenser spp.)—skin erosion caused by an inappropriate and traumatic manipulation. (F) Sturgeon (Acipenser spp.)—dark color and a skin whitish patch due to Flavobacterium spp. infection. Evidence* 

The concept of "disturbed habitat" in poultry farming can be almost entirely related to the continuously increasing production levels of the breeding programs,

*DOI: http://dx.doi.org/10.5772/intechopen.84872*

#### **Figure 4.**

*Habitats of the World - Biodiversity and Threats*

reproductive and respiratory syndrome.

**2.3 Equines for meat production**

airway obstruction (RAO) [17].

**skin lesions** [19].

enzootic pneumonia, post weaning multisystemic wasting syndrome, and porcine

Equine meat consumption depends on cultural and traditional customs. Since it is a niche product, scientific community has made little efforts to define the main factors responsible for a "disturbed habitat" in this category. Equine breeds specifically selected for meat production do not exist and genetic selection focused more upon preserving and improving traits related to horses' morphology and performance. Therefore, although equines' domestication dates back to 5000 years ago, these species still retain the ancestral characteristics of their progenitors and feral equine populations can provide information about many aspects of equine behavior (e.g., social and foraging behavior). Considering the most important *microclimate factors* that negatively affect the equine habitat, insufficient ventilation and inadequate air quality may cause an increased exposure to gaseous ammonia and airborne dust that contain high levels of organic particulates including mite debris, microbes and vegetative material with varying content of endotoxins. The inhalant exposure to those irritant factors is implicated in the pathogenesis of **chronic inflammatory pulmonary disorders** such as inflammatory airway diseases (IAD) and recurrent

Equines reared for meat production are housed in conditions that markedly differ from those in which they evolved. As a consequence, those animals attempt to adapt to the conditions in which they are kept performing functionless and repetitive activity known as **stereotypic behaviors** that include crib-biting, wind sucking, box walking, and weaving [18]. Therefore, using equine stereotypies as welfare indicators should lead to perform management changes to enhance equine's welfare. Bedding is an essential component in the *housing of the equine stabled. Bedding* should be dry, clean and not dusty, providing comfort, allowing animals to express their natural behavior of lying and resting and also avoiding the risk of **hoofs and** 

Regarding the equines' opportunity to perform normal behaviors, it is important to guarantee an adequate space allowance to prevent aggressive reactions that might lead to stress competition for resources and for hierarchy establishment with consequent **physical injuries**. Indeed, wild horses live in relatively stable harem bands, so the overcrowding and the high rates of regrouping of intensively farmed horse may cause an increase in aggressiveness and injuries [20]. On the contrary, in nature, donkeys adapt easily, and their social organization depends on the availability of food and water resources. Therefore, the competition in the stabled donkeys, probably, could be increased if the available resources are not accessible to all, but

Equines are grazing herbivores adapted to eating a forage-based diet. In nature, horses and donkeys spend about 16 hours per day foraging over wide distances, and this is essential for the health of their gastrointestinal tract and for their behavioral needs. On the contrary, equines in the breeding farms are fed high-energy, low-fiber concentrates, and this lack of foraging opportunity along with the high amount of concentrate feedstuff has been directly linked to the onset of **gastrointestinal disorders such as** gastric ulcerations (**Figure 4A**) and colic [19]. Equine gastric ulcer syndrome (EGUS) is reported in domesticated horses mainly involved in athletic endeavors. EGUS prevalence and severity have been correlated with the type of training and management practice. Common known risk factors have been identified in intense exercise, high grain-low roughage diet, water deprivation, fasting, hospitalization, and overdose of NSAIDs. In particular, excessive ingestion

their behaviors in farmed conditions need to be further studied.

**134**

*(A) Horse—gastric ulcer due to improper nutrition. (B) Chicken—footpad dermatitis. (C) Chicken—ascites. (D) Sea bream (Sparus aurata)—peduncle mutilation caused by bite in overcrowding breeding conditions. (E) Sturgeon (Acipenser spp.)—skin erosion caused by an inappropriate and traumatic manipulation. (F) Sturgeon (Acipenser spp.)—dark color and a skin whitish patch due to Flavobacterium spp. infection. Evidence of stress and opportunistic infections.*

of carbohydrates causes a rapid proliferation of the hindgut gram-positive bacteria *Streptococcus bovis* and *Streptococcus lutetiensis* that lead to very acidic conditions with pH lower than 4. Low pH in the large intestine causes the death and lysis of a large number of bacteria and the release of the toxic components which are absorbed from the gut into the bloodstream and may cause the development of **laminitis** [21].

#### **2.4 Poultry**

The concept of "disturbed habitat" in poultry farming can be almost entirely related to the continuously increasing production levels of the breeding programs, which are focused on increasing the growth rates and decreasing the feed conversion ratios of the animals. These *management procedures* lead to remarkable imbalances between the high potential productivity of birds (as a result of the targeted genetic selection) and their ability to physiologically adapt. These imbalances are frequently associated with homeostatic dysregulation and pathological changes of organs that supply the energy for production and maintenance (liver and cardiovascular system) or muscle tissue severely forced to obtain a fast weight increase. The other "disturbed habitat" conditions may strictly depend on microclimate alterations or management defects related to housing system and degree of social interactions.

With regard to the *microclimate* alterations, heat stress is the most common physical environmental stressor that can lead to alterations in the intestinal epithelium integrity and microbiota composition (with development of necrotic enteritis), hyperthermia, heat exhaustion, and death [22, 23]. Multiple behavioral, physiological, and health issues, such as reduced feed consumption, neuroendocrine disorders, electrolyte imbalance, and systemic immune dysregulation, which in turn will negatively affect nutrient uptake and utilization, growth, and survival rate, are also frequently observed. Modern broiler hybrids seem to be particularly susceptible to heat stress, since the high body heat resulting from their great metabolic activity may exacerbate this phenomenon [23]. Metabolic disorders resulting from other microclimate alterations (such as cold, hypoxia, and light/dark hour changes) are less frequent and quite nonspecific [22].

Management defects related to *housing conditions* and *social interactions* among animals are strictly related to each other. One of the most frequent welfare problems in broiler chickens is **contact dermatitis** (i.e., hock burns, breast burns, and foot pad dermatitis), which is caused by continuing contact and pressure of the skin of the breast, hocks, and feet against humid and soiled bedding. In particular, **footpad dermatitis** (FPD) has the greatest relevance (**Figure 4B**). It is also known as pododermatitis and represents a condition that is characterized by inflammation and necrotic lesions, ranging from superficial to deep on the plantar surface of the footpads and toes. Deep ulcers may also lead to abscesses and thickening of underlying tissues and structures. Several environmental factors such as litter material, moisture depth and amendments, drinker design and management, and stocking density may influence FPD development. Indeed, a straw, wet, thin, and acidifier-added litter and small drinker cups and higher stocking densities have been reported to be associated with a greater incidence of FPD [24]. **Feather-pecking**, which is defined as a nonaggressive behavior whereby birds peck at and/or pull out the feathers of conspecifics, represents one of the most significant welfare concerns in laying hens resulting in feather damage, feather loss, wounds, pain, cannibalistic pecking, and death. Development of feather-pecking has been associated with different causative factors, one of the most important being the inhibition of foraging behaviors (such as groundpecking or lack of environmental stimuli) and lack of early life access to litter [25].

The selection procedures focused on a high growth rate may cause specific diseases of the energy-supplying organs (in particular the intestine and the liver), as a result of the developing imbalances between oxygen supply and oxygen requirement. In particular, **fatty liver-hemorrhage syndrome** (FLHS) is frequently observed in laying hens, while broiler chicken gut may show malabsorption syndrome [26]. High growth rates, as well as high body weights and low levels of activity, are also frequently associated with the development of lameness of various degrees of severity. It is most prominent in rapidly growing males, with **leg deformities** such as angular bone deformity (valgus-varus), dyschondroplasia, and spondylolisthesis (kinky back) accounting for 65–80% of the noninfectious causes of lameness in broiler chickens. Modern fast-growing strains may also present an increase in skeletal muscle myopathies, such as **white striping** and **wooden breast**. In turkeys, focal avascular

**137**

*The Disturbed Habitat and Its Effects on the Animal Population*

or ischaemic necrosis (osteochondrosis) of articular cartilage, avulsion fractures and ligament damage at the intertarsal joint or femorotibial joints, and spontaneous fracture of the femur may also occur [21]. Finally, **pulmonary arterial hypertension** (PAH, also known as ascites syndrome and pulmonary hypertension syndrome) is one of the most common diseases observed worldwide in fast growing broilers (**Figure 4C**). This disease can be attributed to the fast growth-related imbalances between cardiac output and the anatomical capacity of the pulmonary vasculature to accommodate ever-increasing rates of blood flow, as well as to an inappropriate degree of constriction maintained by the pulmonary arterioles. Other common **cardiovascular diseases** associated with rapid growth are the sudden death syndrome (SDS) in broilers and hypertrophic cardiomyopathy (HCM), spontaneous turkey cardiomyopathy (STC), and aortic dissecting aneurysm in turkeys [22].

Fish class is the biggest and the most differentiated among vertebrates. Fishes are adapted to different extreme situations as their evolutional success depends on their ability to thrive in a variable medium: water. One of the most remarkable examples of the strict connection between fishes and water is the fishes' inability to regulate their internal temperature (ectothermic animals). Nowadays aquaculture is one of the more sustainable and economically favorable sources of animal protein. Studies on the effect and pathological results of the fishes' "disturbed habitat" are well known due to common compromised (naive) situations. Considering wild habitats, we must sentence that they are strongly impacted by human activity (pollution, overfishing, and introduction of non-indigenous organisms), and this makes it difficult to define what is to be considered normal, not normal, or sub-normal for fishes in a specific situation. In farmed animals, the effect of "disturbed habitat" can sometimes become more evident and dramatic than into the wild [27]. Moreover, the severity of a given disease is dependent on the intricate interaction of numerous variables of the host, the pathogen, and the environment, among which the environment is the less-known factor [28]. In addition, early signs of suffering in fishes are difficult to relate to a specific disease by inexperienced staff. Commonly, acute stressed fishes show color changes because the melanin pigmentation in skin is under neuroendocrine control in fish and it is thus affected by hormones such as epinephrine involved in the first step of stress reaction. If a stress factor persists for a longer time, other hormones, such as cortisol, become dominant (chronic stress). The chronic stress induces immunodeficiency that causes a higher incidence of opportunistic disease outbreaks. Despite the difficulties explained above, in the following section, we will focus on the main stress factors that can impact fish welfare. Among *abiotic ambient factors,* there are all the physical and chemical water parameters such as temperature, conductivity, salinity, turbidity, hardness, dissolved oxygen and other gasses, pH, ammonia and other nitrogen compounds, metals, pesticides, etc. Fishes can handle an open range of variations for each parameter without showing recognizable signs of disease or suffering, thus accumulating chronic stress. Out of these ranges, water quality parameters can influence acute stress along with **high mortality** showing or not respiratory symptoms. More frequently, considering the synergistic effect of water-quality parameters, only subclinical evidences like a **reduction of productivity and reproduction, dissimilarity of age classes** (for wild stocks), or a higher impact of some **infectious agents or tumors** (if a carcinogenic pollutant is suspected) can be noted [29]. Focusing on the farm self-pollution, due to organic wastewater and nitrogen compound discharge (e.g., ammonia), a direct **damage at the fish gills** (acute gill disease) is evident due to a decreased dissolved oxygen. This acute gill disease is easily detected in fishes with an acute respiratory

*DOI: http://dx.doi.org/10.5772/intechopen.84872*

**2.5 Fish**

#### *The Disturbed Habitat and Its Effects on the Animal Population DOI: http://dx.doi.org/10.5772/intechopen.84872*

or ischaemic necrosis (osteochondrosis) of articular cartilage, avulsion fractures and ligament damage at the intertarsal joint or femorotibial joints, and spontaneous fracture of the femur may also occur [21]. Finally, **pulmonary arterial hypertension** (PAH, also known as ascites syndrome and pulmonary hypertension syndrome) is one of the most common diseases observed worldwide in fast growing broilers (**Figure 4C**). This disease can be attributed to the fast growth-related imbalances between cardiac output and the anatomical capacity of the pulmonary vasculature to accommodate ever-increasing rates of blood flow, as well as to an inappropriate degree of constriction maintained by the pulmonary arterioles. Other common **cardiovascular diseases** associated with rapid growth are the sudden death syndrome (SDS) in broilers and hypertrophic cardiomyopathy (HCM), spontaneous turkey cardiomyopathy (STC), and aortic dissecting aneurysm in turkeys [22].

### **2.5 Fish**

*Habitats of the World - Biodiversity and Threats*

which are focused on increasing the growth rates and decreasing the feed conversion ratios of the animals. These *management procedures* lead to remarkable imbalances between the high potential productivity of birds (as a result of the targeted genetic selection) and their ability to physiologically adapt. These imbalances are frequently associated with homeostatic dysregulation and pathological changes of organs that supply the energy for production and maintenance (liver and cardiovascular system) or muscle tissue severely forced to obtain a fast weight increase. The other "disturbed habitat" conditions may strictly depend on microclimate alterations or management

With regard to the *microclimate* alterations, heat stress is the most common physical environmental stressor that can lead to alterations in the intestinal epithelium integrity and microbiota composition (with development of necrotic enteritis), hyperthermia, heat exhaustion, and death [22, 23]. Multiple behavioral, physiological, and health issues, such as reduced feed consumption, neuroendocrine disorders, electrolyte imbalance, and systemic immune dysregulation, which in turn will negatively affect nutrient uptake and utilization, growth, and survival rate, are also frequently observed. Modern broiler hybrids seem to be particularly susceptible to heat stress, since the high body heat resulting from their great metabolic activity may exacerbate this phenomenon [23]. Metabolic disorders resulting from other microclimate alterations (such as cold, hypoxia, and light/dark hour

Management defects related to *housing conditions* and *social interactions* among animals are strictly related to each other. One of the most frequent welfare problems in broiler chickens is **contact dermatitis** (i.e., hock burns, breast burns, and foot pad dermatitis), which is caused by continuing contact and pressure of the skin of the breast, hocks, and feet against humid and soiled bedding. In particular, **footpad dermatitis** (FPD) has the greatest relevance (**Figure 4B**). It is also known as pododermatitis and represents a condition that is characterized by inflammation and necrotic lesions, ranging from superficial to deep on the plantar surface of the footpads and toes. Deep ulcers may also lead to abscesses and thickening of underlying tissues and structures. Several environmental factors such as litter material, moisture depth and amendments, drinker design and management, and stocking density may influence FPD development. Indeed, a straw, wet, thin, and acidifier-added litter and small drinker cups and higher stocking densities have been reported to be associated with a greater incidence of FPD [24]. **Feather-pecking**, which is defined as a nonaggressive behavior whereby birds peck at and/or pull out the feathers of conspecifics, represents one of the most significant welfare concerns in laying hens resulting in feather damage, feather loss, wounds, pain, cannibalistic pecking, and death. Development of feather-pecking has been associated with different causative factors, one of the most important being the inhibition of foraging behaviors (such as groundpecking or lack of environmental stimuli) and lack of early life access to litter [25]. The selection procedures focused on a high growth rate may cause specific diseases of the energy-supplying organs (in particular the intestine and the liver), as a result of the developing imbalances between oxygen supply and oxygen requirement. In particular, **fatty liver-hemorrhage syndrome** (FLHS) is frequently observed in laying hens, while broiler chicken gut may show malabsorption syndrome [26]. High growth rates, as well as high body weights and low levels of activity, are also frequently associated with the development of lameness of various degrees of severity. It is most prominent in rapidly growing males, with **leg deformities** such as angular bone deformity (valgus-varus), dyschondroplasia, and spondylolisthesis (kinky back) accounting for 65–80% of the noninfectious causes of lameness in broiler chickens. Modern fast-growing strains may also present an increase in skeletal muscle myopathies, such as **white striping** and **wooden breast**. In turkeys, focal avascular

defects related to housing system and degree of social interactions.

changes) are less frequent and quite nonspecific [22].

**136**

Fish class is the biggest and the most differentiated among vertebrates. Fishes are adapted to different extreme situations as their evolutional success depends on their ability to thrive in a variable medium: water. One of the most remarkable examples of the strict connection between fishes and water is the fishes' inability to regulate their internal temperature (ectothermic animals). Nowadays aquaculture is one of the more sustainable and economically favorable sources of animal protein. Studies on the effect and pathological results of the fishes' "disturbed habitat" are well known due to common compromised (naive) situations. Considering wild habitats, we must sentence that they are strongly impacted by human activity (pollution, overfishing, and introduction of non-indigenous organisms), and this makes it difficult to define what is to be considered normal, not normal, or sub-normal for fishes in a specific situation. In farmed animals, the effect of "disturbed habitat" can sometimes become more evident and dramatic than into the wild [27]. Moreover, the severity of a given disease is dependent on the intricate interaction of numerous variables of the host, the pathogen, and the environment, among which the environment is the less-known factor [28]. In addition, early signs of suffering in fishes are difficult to relate to a specific disease by inexperienced staff. Commonly, acute stressed fishes show color changes because the melanin pigmentation in skin is under neuroendocrine control in fish and it is thus affected by hormones such as epinephrine involved in the first step of stress reaction. If a stress factor persists for a longer time, other hormones, such as cortisol, become dominant (chronic stress). The chronic stress induces immunodeficiency that causes a higher incidence of opportunistic disease outbreaks. Despite the difficulties explained above, in the following section, we will focus on the main stress factors that can impact fish welfare.

Among *abiotic ambient factors,* there are all the physical and chemical water parameters such as temperature, conductivity, salinity, turbidity, hardness, dissolved oxygen and other gasses, pH, ammonia and other nitrogen compounds, metals, pesticides, etc. Fishes can handle an open range of variations for each parameter without showing recognizable signs of disease or suffering, thus accumulating chronic stress. Out of these ranges, water quality parameters can influence acute stress along with **high mortality** showing or not respiratory symptoms. More frequently, considering the synergistic effect of water-quality parameters, only subclinical evidences like a **reduction of productivity and reproduction, dissimilarity of age classes** (for wild stocks), or a higher impact of some **infectious agents or tumors** (if a carcinogenic pollutant is suspected) can be noted [29]. Focusing on the farm self-pollution, due to organic wastewater and nitrogen compound discharge (e.g., ammonia), a direct **damage at the fish gills** (acute gill disease) is evident due to a decreased dissolved oxygen. This acute gill disease is easily detected in fishes with an acute respiratory

distress shown by a higher frequency of gill opercula movements. On the contrary, in case of prolonged mild problems, fishes develop a "chronic gill disease" characterized by a fusion of secondary lamellae [30] and a typical fish silhouette called "snake head shape" due to the contrast between a large and triangular head, deformed for the enlarged opercula, and a thin body. In fact, the low level of oxygen blood saturation causes a growth failure for the inability to optimally metabolize food nutrients.

The *housing system* in aquaculture management must take into consideration the different biology, ecology, and natural behaviors of individual fish species. The space, design, composition material for tanks, pools, basins and nets, water source, flow and change, lighting and photoperiod, etc. must be taken into account. An inappropriate housing system determines lower growth performances and a higher incidence of **opportunistic diseases** due to chronic stress [31]. The *degree of social interaction* among fishes, with the main critical point of the animal density, is different in extensive farming when compared to the intensive one: the first is closer to a wild condition while the second is richer of health-limiting conditions. In nature, high animal density happens only for short times (i.e., migration for the reproduction or for feed) but in farmed fishes is a constant need. Over-density causes **traumatic lesions by bite** (skin erosion, ulcers, and body mutilation) (**Figure 4D**) and fast deterioration of water-quality parameters. Similar consequences can be observed as a result of *husbandry practices*, such as selection, artificial reproduction, handling, transport, and net confinement, especially if carried out without suitable tools or by unskilled workers (**Figure 4E**). **Infections** caused by opportunistic bacteria or fungi (Oomycetes) such as *Flavobacterium* spp., *Columnaris* disease (fin or skin rot), or *Saprolegnia* spp. (water mold infection) can develop into skin or gill injuries (**Figure 4F**). Sometimes, if fish density is high and the water quality and exchange low, **parasites** such as barnacles or motile ciliates can also provoke a massive outbreak with evident skin hemorrhages and erosions. At the same time, also common aquatic bacteria such as motile *Aeromonas* spp*., Pseudomonas* spp., or *Vibrio* spp. can cause septicaemia characterized by skin, gills, and internal organ hemorrhages, pop eyes, and skin ulcerations. Regarding feeding, as fish are ectothermic, periods of food deprivation may be less detrimental than in endotherms. For this reason, temporary starvation prior to transport, treatment of disease, or any other kind of handling procedures is highly recommended to reduce physiological stress [27]. However, an inappropriate food composition or feeding procedure can generate **gut problems** like enteritis and **size inhomogeneity** in the fish stock [32].
