**2. Tools and protocols before parturition**

Proper management of hyperprolific sows in order to optimize piglet survival and sow's reproductive health starts before parturition. The aim is to improve mammary gland development and colostrum production as well as to prevent birth complications and puerperal diseases. In order to do so, optimizing environment, management, and nutrition is highly important. **Table 1** provides a checklist for preventive measures.


#### **Table 1.**

*Checklist for prevention of birth complications and puerperal diseases as well as for improving mammary gland development and colostrum production.*

*Animal Reproduction in Veterinary Medicine*

**1.2 Colostrum and piglet survival**

husbandry during the week(s) before parturition.

mary gland development is low and/or parturition is prolonged.

**1.3 Postpartum dysgalactia syndrome and sows' fertility**

nest-building behavior, is an important cause of primary uterine inertia [10]. Other causes are nutritional factors, e.g., diets low in fiber and high in energy leading to constipation and obesity [11]. Secondary uterine inertia is more common than primary inertia, usually occurring because of a prolonged farrowing particularly associated with a large litter size [12]. Idiopathic dystocia may occur because of the

Sufficient mammary gland development is important for optimal colostrum production and therefore prevention of piglet mortality [13]. Pre-weaning piglet mortality rate was 7.1% (reference value: <11%), when piglets ingested more than 200 g of colostrum, and increased to 43.4% when intake was less than 200 g [14]. Thus, piglets need at least 200 g of good quality (>50 mg IgG/ml) colostrum. Unfortunately, colostrum yield is highly variable, averaging 3.5 kg and ranging between 1.5 and 6.0 kg [15, 16]. This means that some sows will not produce enough colostrum for their piglets. Further, even though the average yield might be enough for a litter of average size (about 17–18 piglets), it can be difficult for many sows to adequately nurse more than 10–11 piglets without human assistance (such as assisted suckling, cross fostering, movement to a nurse sow, split or suckling assistance) [17]. Thus, factors affecting mammary gland development and colostrum production need to be identified and optimized [13]. One of these factors is the hormonal status of the sow, which can be because of stress, suboptimal feeding, and

Besides the production of a sufficient amount of good quality colostrum, there are further challenges. One of them is the length of the colostral phase. Colostrum is produced only during the first day after the start of parturition. Already after the first 6 h, the IgG content in colostrum is halved [18]. Since large litters can easily extend farrowing beyond 6 h [1], many piglet are born too late in order to get an appropriate amount of good quality colostrum. Therefore, the goal at each parturition is not only to optimize colostrum production by the sow but also the colostrum uptake by neonate piglets. Neonate piglets must acquire a sufficient amount of immunoglobulins from ingested colostrum for energy and passive immune protection [19]. The concentration of immunoglobulins in the plasma of piglets shortly after birth correlates positively with their survival rate [20]. Thus, it is necessary to assess colostrum quality and colostrum intake by piglets throughout parturition in order to reduce piglet pre-weaning mortality. This is especially important if mam-

PDS is the most important puerperal disease and is characterized by insufficient colostrum and milk production by the sow during the first days of lactation [21]. As consequence, colostrum and milk intake by piglets is reduced, and therefore their mortality increased [21]. Further, PDS negatively affects subsequent reproductive health of the sow [4]. Unspecific symptoms for PDS include fever (>40°C), loss of appetite, and lethargy [21]. Specific symptoms are dysgalactia and vulvar discharge syndrome [21]. Causes of the vulvar discharge syndrome are vaginitis, endometritis, and cystitis [22].

use of prostaglandin F2α and oxytocin to induce or control parturition [12]. Thus, in order to prevent birth complications, the needs of the sow must be fulfilled, stress must be avoided, and nutrition must be optimized. If not, hormonal imbalance will result into weak uterine contraction and subsequently dystocia. Therefore, active birth management starts before birth in order to prevent this and continues during birth when proper response to hormonal imbalance is needed.

**90**

#### **2.1 Environment and stress**

Modern housing and production systems have promoted the confinement of sows in crates during farrowing. In crates, the sow's movement is severely restricted, and bedding and rooting material is often limited. Consequently, nest-building behavior is reduced or does not occur at all. The lack of space and absence of nest-building materials and behavior are important stressors in sows [27]. This promotes the release of opioids and results into decreased oxytocin secretion and reduced uterine contractility [10, 28]. Thus, the lack of space and bedding material can prolong parturition due to uterine inertia. Considering that a large litter itself can prolong parturition [1, 12], hyperprolific sows need access to space and rooting material in order to prevent birth complications. Allowing the sow to move freely before and during farrowing reduces the duration of farrowing by an average of 100 min, thereby reducing the risk of stillborn piglets and birth of piglets with low vitality [12].

Besides an increase in oxytocin secretion, proper nest-building behavior increases prolactin [29], which is essential for colostrum production. The prepartum decrease in progesterone leads to an increase in prolactin [30]. Delays in progesterone decrease and in prolactin increase relative to the onset of parturition were associated with a strongly reduced yield of colostrum [31]. Thus, as with farrowing duration and prevention of birth complications, studies have found a positive effect of provision of space and nest-building material on oxytocin and prolactin release and therefore colostrum production and maternal nursing behavior [32].

#### **2.2 Management and hygiene**

Proper management, especially hygiene, is highly important for the prevention of PDS and therefore piglet mortality and decreased fertility in sows [21]. The current hypothesis is that interactions between endotoxins produced by Gram-negative bacteria in the gut, mammary gland, and/or urogenital tract and alterations in the immune and endocrine functions play a central role in the development of PDS [21]. This is supported by a study where periparturient sows were challenged with lipopolysaccharide (LPS) endotoxin of *E. coli*, in which sows generated symptoms similar to PDS [33]. *E. coli* originates from the environment or can already be present in the urogenital tract of prepartum sows or enter during or after parturition. Predominantly, *E. coli* followed by *Staphylococcus* spp. and *Streptococcus* spp. are isolated from the urogenital tract in case of cystitis, endometritis, and mastitis [34, 35]. Considering that these are unspecific bacteria originating from feces and environment, it is important to keep hygiene before and during parturition at a high level [36]. Risk factors for PDS are the use of unslatted floor, no washing of sows and no use of disinfectants in the farrowing rooms [36].

Besides hygiene, alterations in the immune and endocrine functions play a central role in the development of PDS [21]. Considering that parturition itself decreases immunity and causes significant inflammatory changes [23], all other factors affecting immunity and endocrinology need to be kept at a minimum level. The most important factor is stress, as described above. Stress needs to be reduced as much as possible. Stress due to restricted space in farrowing crates and lack of nest-building material is discussed above [21]. Other stressors are high ambient temperature and abrupt change from group housing during gestation to restraint in crates a few days before farrowing [37, 38].

#### **2.3 Nutrition and body condition**

Nutrition and body condition are important to prepare the sow for farrowing and the production of colostrum and milk. The sow should have an optimal body

**93**

*Tools and Protocols for Managing Hyperprolific Sows at Parturition: Optimizing Piglet Survival…*

condition around parturition. Obesity needs to be avoided [11]. The fatter the sow, the longer the duration of parturition. It is possible that the fat deposition stores lipid-soluble steroids such as progesterone. In this case, the prepartum decline in progesterone may be delayed which in turn affects oxytocin receptor activation [10, 12]. Low concentration of oxytocin receptors will result in weak uterine contractions and colostrum let-down. Higher backfat and progesterone lead also to lower colostrum quality and production [39, 40]. If possible, backfat should be

Besides body condition, there is a negative correlation between constipation and farrowing duration [11]. The more constipated the sow, the longer the duration of parturition. One reason may be that constipation can cause a physical obstruction to the passage of the piglets [12]. Another reason may be that constipation may result in higher concentrations of LPS. LPS can be absorbed from the gut and affect normal endocrine changes associated with farrowing [41]. A third explanation may be that the discomfort and pain associated with constipation affect hormonal changes associated with parturition [12]. Studies have found that pain releases opioids, which inhibit oxytocin secretion during parturition [28, 42]. Therefore, pain due to prolonged constipation, or any other source of pain, can reduce myometrial contractions and therefore cause birth complications. Constipation can be evaluated using a constipation index [43]. Constipation index should be two or higher, i.e.,

In order to prevent constipation and obesity, ad libitum feeding in the last third, especially in the last week, of gestation should be avoided. Restricted feeding supports the birth process, mammary gland development, and colostrum production [44]. There were positive associations between colostrum yield and plasma concentrations of urea, creatinine, and free fatty acids [45]. Further, there was a positive association between backfat loss in the last third of gestation and colostrum yield [46]. These results show that feed restriction with protein and fat mobilization for metabolism has positive effects on colostrum production [30]. Nevertheless, this can probably only be recommended for sows that have reached a good body condition (>18 mm) at the end of gestation. Unfortunately, sows usually receive high-energy concentrated diet low in fiber during late gestation [47]. Such diets can promote obesity and constipation, leading to poor mammary gland development [30], low colostrum quality [48], birth complication [11], and PDS [21, 49]. Late pregnancy diets should contain at least up to 7–10% fiber [43]. A good fiber source can also be provided by offering different types of roughage, e.g., straw or hay, or adding any other feedstuffs with high levels of fiber such as sugar beet pulp [50]. Besides amount and composition of feed, the feeding intervals are important. A short time-lapse between the last meal prior to the onset of the expulsion stage and the onset considerably shortens the duration of farrowing [51]. Farrowing duration, odds for farrowing assistance, and odds for stillbirth were low, intermediate, and high when the time between the last meal and onset of parturition was less than 3,

In addition to improving mammary gland development by means of management, environment, and nutrition, the mammary gland needs to be evaluated before each parturition. It is important to assess the number and morphology of functional teats and the degree of edema. The number of functional teats available per piglet is positively associated with piglet survival [52]. If piglets had access to less than one functional teat, mortality increased to more than 14% [52]. If more than one teat was available, mortality was reduced to below 8% [52]. Besides the number of

*DOI: http://dx.doi.org/10.5772/intechopen.91337*

feces should be present, pellet-shaped, and not dry [11].

3–6, and more than 6 h, respectively [51].

**2.4 Prepartum assessment of mammary gland**

between 16 and 20 mm [11].

### *Tools and Protocols for Managing Hyperprolific Sows at Parturition: Optimizing Piglet Survival… DOI: http://dx.doi.org/10.5772/intechopen.91337*

condition around parturition. Obesity needs to be avoided [11]. The fatter the sow, the longer the duration of parturition. It is possible that the fat deposition stores lipid-soluble steroids such as progesterone. In this case, the prepartum decline in progesterone may be delayed which in turn affects oxytocin receptor activation [10, 12]. Low concentration of oxytocin receptors will result in weak uterine contractions and colostrum let-down. Higher backfat and progesterone lead also to lower colostrum quality and production [39, 40]. If possible, backfat should be between 16 and 20 mm [11].

Besides body condition, there is a negative correlation between constipation and farrowing duration [11]. The more constipated the sow, the longer the duration of parturition. One reason may be that constipation can cause a physical obstruction to the passage of the piglets [12]. Another reason may be that constipation may result in higher concentrations of LPS. LPS can be absorbed from the gut and affect normal endocrine changes associated with farrowing [41]. A third explanation may be that the discomfort and pain associated with constipation affect hormonal changes associated with parturition [12]. Studies have found that pain releases opioids, which inhibit oxytocin secretion during parturition [28, 42]. Therefore, pain due to prolonged constipation, or any other source of pain, can reduce myometrial contractions and therefore cause birth complications. Constipation can be evaluated using a constipation index [43]. Constipation index should be two or higher, i.e., feces should be present, pellet-shaped, and not dry [11].

In order to prevent constipation and obesity, ad libitum feeding in the last third, especially in the last week, of gestation should be avoided. Restricted feeding supports the birth process, mammary gland development, and colostrum production [44]. There were positive associations between colostrum yield and plasma concentrations of urea, creatinine, and free fatty acids [45]. Further, there was a positive association between backfat loss in the last third of gestation and colostrum yield [46]. These results show that feed restriction with protein and fat mobilization for metabolism has positive effects on colostrum production [30]. Nevertheless, this can probably only be recommended for sows that have reached a good body condition (>18 mm) at the end of gestation. Unfortunately, sows usually receive high-energy concentrated diet low in fiber during late gestation [47]. Such diets can promote obesity and constipation, leading to poor mammary gland development [30], low colostrum quality [48], birth complication [11], and PDS [21, 49]. Late pregnancy diets should contain at least up to 7–10% fiber [43]. A good fiber source can also be provided by offering different types of roughage, e.g., straw or hay, or adding any other feedstuffs with high levels of fiber such as sugar beet pulp [50].

Besides amount and composition of feed, the feeding intervals are important. A short time-lapse between the last meal prior to the onset of the expulsion stage and the onset considerably shortens the duration of farrowing [51]. Farrowing duration, odds for farrowing assistance, and odds for stillbirth were low, intermediate, and high when the time between the last meal and onset of parturition was less than 3, 3–6, and more than 6 h, respectively [51].

#### **2.4 Prepartum assessment of mammary gland**

In addition to improving mammary gland development by means of management, environment, and nutrition, the mammary gland needs to be evaluated before each parturition. It is important to assess the number and morphology of functional teats and the degree of edema. The number of functional teats available per piglet is positively associated with piglet survival [52]. If piglets had access to less than one functional teat, mortality increased to more than 14% [52]. If more than one teat was available, mortality was reduced to below 8% [52]. Besides the number of

*Animal Reproduction in Veterinary Medicine*

of stillborn piglets and birth of piglets with low vitality [12].

Besides an increase in oxytocin secretion, proper nest-building behavior increases prolactin [29], which is essential for colostrum production. The prepartum decrease in progesterone leads to an increase in prolactin [30]. Delays in progesterone decrease and in prolactin increase relative to the onset of parturition were associated with a strongly reduced yield of colostrum [31]. Thus, as with farrowing duration and prevention of birth complications, studies have found a positive effect of provision of space and nest-building material on oxytocin and prolactin release

and therefore colostrum production and maternal nursing behavior [32].

Proper management, especially hygiene, is highly important for the prevention of PDS and therefore piglet mortality and decreased fertility in sows [21]. The current hypothesis is that interactions between endotoxins produced by Gram-negative bacteria in the gut, mammary gland, and/or urogenital tract and alterations in the immune and endocrine functions play a central role in the development of PDS [21]. This is supported by a study where periparturient sows were challenged with lipopolysaccharide (LPS) endotoxin of *E. coli*, in which sows generated symptoms similar to PDS [33]. *E. coli* originates from the environment or can already be present in the urogenital tract of prepartum sows or enter during or after parturition. Predominantly, *E. coli* followed by *Staphylococcus* spp. and *Streptococcus* spp. are isolated from the urogenital tract in case of cystitis, endometritis, and mastitis [34, 35]. Considering that these are unspecific bacteria originating from feces and environment, it is important to keep hygiene before and during parturition at a high level [36]. Risk factors for PDS are the use of unslatted floor, no washing of sows and no use of disinfectants in the farrowing rooms [36]. Besides hygiene, alterations in the immune and endocrine functions play a central role in the development of PDS [21]. Considering that parturition itself decreases immunity and causes significant inflammatory changes [23], all other factors affecting immunity and endocrinology need to be kept at a minimum level. The most important factor is stress, as described above. Stress needs to be reduced as much as possible. Stress due to restricted space in farrowing crates and lack of nest-building material is discussed above [21]. Other stressors are high ambient temperature and abrupt change from group housing during gestation to restraint in

Nutrition and body condition are important to prepare the sow for farrowing and the production of colostrum and milk. The sow should have an optimal body

Modern housing and production systems have promoted the confinement of sows in crates during farrowing. In crates, the sow's movement is severely restricted, and bedding and rooting material is often limited. Consequently, nest-building behavior is reduced or does not occur at all. The lack of space and absence of nest-building materials and behavior are important stressors in sows [27]. This promotes the release of opioids and results into decreased oxytocin secretion and reduced uterine contractility [10, 28]. Thus, the lack of space and bedding material can prolong parturition due to uterine inertia. Considering that a large litter itself can prolong parturition [1, 12], hyperprolific sows need access to space and rooting material in order to prevent birth complications. Allowing the sow to move freely before and during farrowing reduces the duration of farrowing by an average of 100 min, thereby reducing the risk

**2.1 Environment and stress**

**2.2 Management and hygiene**

crates a few days before farrowing [37, 38].

**2.3 Nutrition and body condition**

**92**

#### **Figure 1.**

*Severe prepartum edema of the mammary gland. Visual inspection (A) reveals dimpled skin with persistent marks of the floor, swollen teats, and indistinguishable gland complexes. Ultrasonographic image (B) shows shadowing, thickened dermal tissue, hyperechoic lobuloalveolar tissue, and enlarged blood vessels, lymphatic ducts, and milk ducts. Images taken by Stefan Björkman.*

functional teats, also the morphology is important. Piglets tend to suck first from teats that are close to the abdominal midline and have longer inter-teat distances [53]. Thus, a functional teat with short inter-teat distance and/or long distance between teat base and abdominal midline may be unusable for the piglet [54].

Furthermore, severe edema of the mammary gland before parturition will have a negative impact on teat accessibility, reduce colostrum quality, and increase the risk of PDS [48, 49]. The degree of mammary gland edema can be graded visually or via ultrasound [48, 49, 55]. At visual inspection, sows with severe udder edema have dimpled skin with persistent marks of the floor (**Figure 1A**). Further, teats are swollen and mammary glands are indistinct (**Figure 1A**) [48, 49]. Ultrasound of the mammary glands shows thickened dermal and subdermal tissues, hyperechoic lobuloalveolar tissue with enlarged blood vessels, and severe shadowing (**Figure 1B**) [48, 49, 55]. Also at the end of lactation, the assessment of the mammary gland, as described above, is crucial and should be used for the decision of removing the sow from the herd.
