**3.2. Ensiling legume crops/fodder**

quality, quantity available and climatic conditions, and then to store it properly to reduce losses. Silage made from grasses and cereals is dark yellowish green in color, while it is blackish green when made of legumes. A good silage is friable, non-sticky and free from mold/ fungal growth and should have an acceptable and pleasant aroma (fruity odor) and mild acidic taste. It should have a pH < 4.5; the lactic acid should be higher than other acids with a low butyric acid content (0.2–0.5%) and ammoniacal N not higher than 9–15% of total N.

**Figure 1.** Silage pits lined with plastic sheet to prevent seepage.

14 Ruminants - The Husbandry, Economic and Health Aspects

**Figure 2.** Packing of fodder in plastic bag for silage making.

Farmers' friendly ensiling process has been developed in many countries for its wider adaptation, which is relatively simple, can be performed manually, is flexible in handling and feedout according to needs and does not require much input. Dry tree forages, less palatable fallen tree leaves, less preferable stovers and mature crop residues can be mixed with high moisture

Current restrictions on the use of animal-based protein supplements coupled with increasing demand for soya protein concentrates put pressure on the livestock farmers and researchers to consider alternative home-grown protein-rich forage crops as supplements to grass silage for sustaining production. Ensiling legumes is a good way of providing a cheaper, non-animalbased and traceable home-grown protein that may improve the efficiency of production system in any livestock farms. Also, legume silages with low DM and WSC contents are generally more resistant to aerobic deterioration than cereal silages [6]. There are also some unidentified microbial inhibitors that prevent the growth of spoilage microorganisms [7]. But, most legumes undergo butyric acid fermentation when ensiled without additives at low DM content due to low WSC and high buffering capacity [8]. Furthermore, severe degradation of proteins may devalue the protein quality due to inefficient N utilization.

content makes sour silage. Additionally, the critical pH value for clostridial growth varies directly with the moisture content of the plant material, and unless WSC levels are exceptionally high, ensiling wet crops encourages clostridial fermentation, resulting in high losses and reduced nutritive value. Moreover, many high CP legume foliages can be difficult to ensile successfully, because they tend to have low WSC, high buffering capacity and low DM con-

DM and high lactic acid contents. Legumes that have low WSC and high buffer capacity do not produce good quality silage [8]. High N-containing leguminous fodder also includes tree forages and browses that are rich in plant secondary metabolites (PSM). Many times these phytochemicals may become adverse to fermentation process (e.g. antimicrobial effects of alkaloids, essential oils, etc.) and put forth additional challenges to step up microbial fermentative activity. Further, degradation of protein during ensiling process produces volatile organic acids with higher pKa values, and thus, the silages may have higher pH, unfavorable aroma, less aerobic stability and greater spoilage. Further, the relationship between weekly growth rate and change in quality parameters is differed among species and functional groups, i.e., grasses and legumes, and therefore, quantifying the impact of delaying the harvest date of grass-legume mixtures and assessing the relationships between productivity and

Tannins in ruminants can induce beneficial effects attributable to tannin-protein complexes, which lead to increased rumen escape of dietary protein and increase in microbial protein outflow. High N fertilized grasses are more degradable, which are hydrolyzed extensively during ensiling and are rapidly degraded in rumen resulting in more excretory loss. Decreased proteolysis and slower fermentation of proteins and NPN are particularly important in silages for uniform N availability to ruminal microbial synthesis and thus optimizing its usage. Forage legumes with PSM are considered to be less susceptible to proteolysis than other legumes, which improve silage quality. The legume sainfoin has been shown to contain tannins of particularly beneficial composition for ruminant nutrition. Adding tannins during ensiling holds key both at ensiling and at rumen level to check N degradation and decrease its excretion.

Plant phenolic compounds and flavonoids are the largest and best-studied natural phenols that possess a series of biological properties and act on biological systems, such as antioxidants, antimicrobials and immunostimulants, which in turn, are associated with a reduction in the incidence of various human diseases. The shift in research to feedstuff endogenous factors, which influence proteolysis and lipolysis, may have a significant contribution on ruminant products (meat, milk) and their transmission to human food chain. Any qualitative variation in ruminant food products with naturally rich conjugated linoleic/linolenic acid (CLA) and other ω3 fatty acids (FA) can thus be influenced by animal's diet. Ruminal biohydrogenation is heavily influenced by PSM, which includes polyphenol oxidase (PPO), FA oxidation and tannins, and the effect is a complex set of mechanisms directly affected by PPO or indirectly by passage rate, lipid encapsulation, shift in the ruminal microbial population,


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Silage for Climate Resilient Small Ruminant Production http://dx.doi.org/10.5772/intechopen.74667

The characteristics of good silage should have pH values of 4.2 or less, NH3

tent when directly harvested [8].

components of feed quality are important.

*3.3.1. Phytochemical-rich forages*

Besides, stage of maturity and DM content of the crop at ensiling, wilting and rate of drying markedly reduce proteolysis in the silo [9]. Rapid and extensive wilting (DM > 500 g/kg) improved protein value and reduced CP degradability. Moreover, due to the reversible proteinbinding properties of tannin, species containing tannin have shown to undergo less protein degradation during ensiling than that do not contain tannin. Since protein degradation in the silo is widely recognized to be the most limiting factor in legume silage, intrinsic protein protection by mixing tannin-containing forages may contribute to reducing the rate and the extent of NPN formation in silages, thereby improving N usage. Fraser et al. [10] compared the nutritive value of a range of ensiled forage legumes from late second-cut lotus (*Lotus corniculatus*), first-cut sainfoin (*Onobrychis viciifolia*) and both early and late second-cut red clover (*Trifolium pratense*) and lucerne and found high intake potential of all the legume silages. The taniferous lotus silage recorded higher intake and N utilization compared to less/non-tannin legumes, clover and lucerne, while low N digestibility appears to limit the nutritional value of sainfoin. In silages made from the beginning of ripening stage, where most of the protein was localized in the seed, the level of proteolysis was reduced and a good fermentation was observed in peas ensiled after a short wilting period [11]. Possible approaches include the adoption of harvesting techniques that reduce field wilting time, the use of protein protection agents during ensiling such as tannins or the choice of natural tannin-containing legume species.

#### **3.3. Alternate plant biomass for silage making**

Industrialization of food production has produced large quantities of food wastes, viz. (i) crop waste and residues, (ii) grain and legume by-products; (iii) distillery and brewery byproducts; (iv) fruit and vegetables by-products; (v) sugar, starch and confectionary industry by-products and (vi) oil industry by-products. Fruit and vegetable processing by-products/ co-products are promising sources of valuables such as phytochemicals (carotenoids, phenolics, flavonoids), antioxidants, antimicrobials, vitamins or dietary fats that have favorable technological activities or nutritional properties and have traditionally been used as feed ingredients, and their effect on animal performance has been extensively studied [12–14].

**Key determinants while selecting unconventional resources:** Moisture content is the most important factor in silage making, with a recommendation at 65–75% [15] depending on the means of storage, the degree of compression and the amount of water that will be lost in storage. Effluent is produced when moisture is above 75%, with the amount of effluent increasing with increasing silo height due to increasing pressure. In general, forage with high moisture content makes sour silage. Additionally, the critical pH value for clostridial growth varies directly with the moisture content of the plant material, and unless WSC levels are exceptionally high, ensiling wet crops encourages clostridial fermentation, resulting in high losses and reduced nutritive value. Moreover, many high CP legume foliages can be difficult to ensile successfully, because they tend to have low WSC, high buffering capacity and low DM content when directly harvested [8].

The characteristics of good silage should have pH values of 4.2 or less, NH3 -N contents <100g/kg DM and high lactic acid contents. Legumes that have low WSC and high buffer capacity do not produce good quality silage [8]. High N-containing leguminous fodder also includes tree forages and browses that are rich in plant secondary metabolites (PSM). Many times these phytochemicals may become adverse to fermentation process (e.g. antimicrobial effects of alkaloids, essential oils, etc.) and put forth additional challenges to step up microbial fermentative activity. Further, degradation of protein during ensiling process produces volatile organic acids with higher pKa values, and thus, the silages may have higher pH, unfavorable aroma, less aerobic stability and greater spoilage. Further, the relationship between weekly growth rate and change in quality parameters is differed among species and functional groups, i.e., grasses and legumes, and therefore, quantifying the impact of delaying the harvest date of grass-legume mixtures and assessing the relationships between productivity and components of feed quality are important.
