**8. Extrudates and extrusion process**

*Livestock Health and Farming*

and not conclusive [59].

with saponins [28, 59].

**7. Other feedstuffs**

ruminal methane emission.

encapsulate probiotic bacteria.

**7.1 Probiotics**

plants and are composed of 27 carbon atoms in the central skeleton of its molecule (e.g., spirostanol and furostanol). Otherwise, triterpenoids are composed mainly of aglycones with 30 carbon atoms in its molecule (e.g., oleanane) [58]. These are the most common types of saponins, especially in legumes [59]. Methanogenic action of saponins occurs by protozoa defaunation which is associated to methanogens. Moreover, saponins enhance production of propionate, a natural competitor of methane in hydrogen capture [58]. Nevertheless, some studies affirm that methane inhibition action by saponins is dose and time dependent

III.**Flavonoids**. Flavonoids are phenolic compounds (like tannins); however, these contain only 15 carbon atoms linked to 2 aromatic rings connected through a 3-carbon bridge [60]. These metabolites are particularly studied for human purposes, and their biological benefits to health correlated to their consumption [61]. Almost all flavonoids are conjugated to glycosides and are common to find hydroxyl groups in carbons with four, five, and seven positions [60]. In addition, flavonoids stimulate microbial metabolism and reduce methane production through enhancing acetogenesis pathway and increasing hydrogen capture in propionate anabolism, in a similar way as described earlier

Since the 1970s, ruminal microbes and their effect on ingested nutrients have been subject of intensive research [27]. Ruminal microorganisms are crucial for the digestive performance of animals. Addition of feedstuffs in diets of ruminants has led to investigate their effects on the absorption and utilization of nutrients as well as the ruminal environment and conditions. Genetically modified *Escherichia coli* showed a ruminal methanogenesis mitigation effect in sheep [62]. Other researches [63] reported that *Lactococcus lactis* produces nisin, which has demonstrated antimicrobial activity against Gram-positive bacteria, resulting in a mitigation effect on

β1–β4 galacto-oligosaccharides (GOS), along with glucose, fructose, and starch, present in the rumen are used by *Bifidobacterium* and *Lactobacillus* as substrates to produce lactate and acetate. Lactate is one of the main transitional compounds during propionate production, which competes against methanogens for available hydrogen.

As a result, methane production can be decreased by GOS consumption [64].

Probiotics are commonly defined as "live micro-organisms which, when administered in adequate amounts, confer a health benefit on the host." Other authors indicate that a probiotic food carries 106–107 CFU/g viable probiotic cells, until the shelf life of the product is reached [65]. Probiotic foods contain sensitive ingredients, such as probiotic cells that require protection against oxidative stress, high acidity, freezing, shear stress, and other undesirable factors. Although microencapsulation has been primarily used to protect bioactive ingredients due to its advantages [66], co-extrusion technology has become an emerging alternative to

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### **8.1 The use of the extrusion process in the supplementation of probiotics**

Extrusion processing using oil and alginate solutions to create emulsions as core medium [67] has found a favorable survival of probiotic *L. acidophilus* at 4°C for 50 days. Over the years and because of technological advances, extrusion has become an almost unlimited cooking processing alternative due its inherent versatility. Multiple studies had focused on designing and evaluating the incorporation of biomass, distillery by-products, fruit pomaces, agro-industrial by-products, and dairy residues [68]. One of the main advantages of the thermal and pressure conditions during extrusion is the inactivation of antinutritional factors, elimination of pathogens, improved digestibility, reduced level of toxins, as well as the bitterness of some oil plants (flax, cotton, peanut, and sunflower) while achieving the desired organoleptic characteristics by properly adjusting residence times, specific energy absorbed, and pressure effects on the raw materials [67]. Other authors extruded rye whole meal to decrease microbial contamination and used it as cultivation medium for the evaluation of supplementation of dairy cow ration with *P. pentosaceus* BaltBio02 (9.6 log10 CFU g<sup>−</sup><sup>1</sup> head<sup>−</sup><sup>1</sup> day<sup>−</sup><sup>1</sup> ) [69]. Obtained results showed an increase (P < 0.05) of milk yield but did not affect milk composition or ruminal fermentation parameters. *Lactobacillus sakei* KTU 05-6 (9.6 log10 CFU g<sup>−</sup><sup>1</sup> head<sup>−</sup><sup>1</sup> day<sup>−</sup><sup>1</sup> ) was also analyzed but showed no significant impact on yield or ruminal parameters.

On the other hand, a different study evaluated the effect of different doses of probiotic containing 1.6 × 109 CFU/g of *Bacillus licheniformis* and 1.6 × 109 CFU/g of *Bacillus subtilis* on in vitro digestibility of concentrates and forages [70]. These authors concluded that 3 g head<sup>−</sup><sup>1</sup> d<sup>−</sup><sup>1</sup> of probiotic increased by 10.9% starch digestibility after 12 h of incubation, indicating a promotion of NDF digestibility in roughages and starch in concentrates, although no significant changes were obtained of acetate, propionate, and butyrate molar ratios, possibly due to negligible changes on H<sup>+</sup> concentrations that affect the environmental pH of ruminal microorganisms [71]. An enhanced VFA production results in a pH reduction and growth inhibition of fermenting fibrous carbohydrate bacteria, which compromise NDF digestibility.

#### **9. Current strategies**

#### **9.1 Methane reduction through improvement of the forage quality**

There is a lot of information about supplementation of secondary metabolites, certain additives, and increasing concentrate fraction in the diet of livestock to abate methane emissions. However, some producers in developing countries are not able to afford these alternatives. Otherwise, methane production in ruminants in developing countries is directly correlated to a poor quality in feedstuffs offered to livestock, by decreasing the efficiency and productivity for productive unit [72]. In this way, the strategies that producers and researchers in developing countries use imply the production of improved forage sources which is cheaper than the acquisition of some supplements. Additionally, the use of these forage sources may increase the fertility in the soil which is desirable for nitrogen fixation. Consequently, by improving the quality and quantity of forage, the productivity will increase, and methane production will be reduced by productive unit.

### **9.2 Vaccination and chemical compounds**

On the other hand, other researchers have focused their efforts on evaluating the inclusion of protected lipids and nitrate compounds [73, 74]. In addition, the use of some nitrate compounds showed no effect on organoleptic and nutritional properties in edible products for ruminants [75]. However, both strategies could be discarded by increases on fiber digestibility and a reduction of dry matter intake. Otherwise, the acquisition and use of these compounds in livestock will substantially increase production costs and market price. In the past decades, chemical compounds were used as inhibitors in methane synthesis through vaccination or the analogue supplementation. Nevertheless, methanogen defaunation is not a viable long-term alternative since microorganisms are easily adaptable to different environments. Additionally, the use of other additives, like ionophores, is forbidden in the USA. In this way, the use of plant extractives and especially metabolites arises as a sustainable alternative; however, there are not conclusive results which lead to a punctual design of dietary strategies. The latter is exposed since some of these metabolites may be present in edible products of ruminants affecting their organoleptic properties [76]. In addition, further studies are required to demonstrate the effectivity of extractable compounds of plants which are well perceived by the population as an alternative for chemical compound supplementation.

### **10. Conclusions**

Methane and GHG mitigation in livestock is possible through different strategies, most of them as dietary alterations. However, it is necessary to carry out conclusive in vivo studies evaluating the use of metabolites and extractable plants' compounds, as well as the use of alternative forage sources which may provide directly these metabolites affecting the presence of ruminal methanogens and protozoa. Moreover, each region or geographic zone has different forage sources even perennial that can be produced locally. The incorporation of these into livestock feeding arises as a viable and sustainable alternative for mitigating GHG emissions, especially methane.

### **Acknowledgements**

The authors would like to acknowledge the National Council of Science and Technology (CONACYT) for indirect support of some researchers. Likewise, the authors would like to acknowledge the Forestry and Wood Industry Institute and Veterinary Medicine and Husbandry Faculty of the UJED, as well as the Durango Institute of Technology and Technological Institute of the Valle del Guadiana for the facilities.

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**Author details**

Pámanes-Carrasco Gerardo1

and Reyes-Jáquez Damián4

*Climate Change Mitigation in Livestock Production: Nonconventional Feedstuffs and Alternative…*

\*, Herrera-Torres Esperanza<sup>2</sup>

1 CONACYT, Durango State Juarez University, Durango, Dgo, Mexico

4 TecNM, Durango Institute of Technology, Durango, Dgo, Mexico

\*Address all correspondence to: gerardo.pamanes@gmail.com

provided the original work is properly cited.

3 Durango State Juarez University, Durango, Dgo, Mexico

2 TecNM, Valle del Guadiana Institute of Technology, Durango, Dgo, Mexico

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

, Murillo-Ortiz Manuel3

*DOI: http://dx.doi.org/10.5772/intechopen.89433*

*Climate Change Mitigation in Livestock Production: Nonconventional Feedstuffs and Alternative… DOI: http://dx.doi.org/10.5772/intechopen.89433*
