ADVANCE PRINCIPLES OF FEEDING WITH USE OF CROP AND CROP RESIDUES FOR GOATS

Pashu Sandesh, 03 Aug 2022

Neha Sisodia, MVSc Scholar, Department of Livestock Production & Management, LUVAS, Hisar, Haryana, 125004

Dipin Chander Yadav, Scientist, Department of Livestock Production & Management, LUVAS, Hisar, Haryana, 125004

The scavenging image of small ruminants cannot be relied on to provide adequate nutrients for optimal livestock production. Thus, it is important to ensure adequate feeding in order to enhance the productivity of the stock. The abundance of crop residues and agro-industrial by-products make them cheap sources of nutrients for small ruminants. One of the major constraints identified is the generally low nutritive value of these crop residues. They have low nitrogen, and high fibre contents and are poorly digested such that they barely meet the maintenance requirements of adult goats and sheep. They need to be upgraded by treatment or appropriate supplementation in order to exploit fully the role they could play in goat nutrition.

Four main categories of feed resources are potentially available for use in smallholder crop–animal systems. 

1. Pastures 

Native and improved grasses, herbaceous legumes and multi-purpose trees. Crops, including forages, explicitly grown for ruminants represent a relatively small component of the available feed resources on mixed farms.

2. Crop residues - Cereal straws and stovers are by far the most important crop residues.

3. Agro-industrial by-products (AIBPs) - AIBPs are less fibrous, have relatively more digestible nutrients, and are often high in protein. Examples of AIBPs are oilseed cakes and meals (e.g., copra cake, rice bran, cottonseed meal and oil palm kernel cake)

4. Non-conventional feed resources (NCFRs) - are identified separately and include all those products that have not been used traditionally in animal feeding. These feeds are perse and include cocoa pod husks, rubber seed meal, distiller solubles, shrimp waste, leather shavings and poultry litter

Rice and wheat straws alone contribute about 57% of total availability, and if maize, millet and sorghum are included the contribution would increase further to about 78%. Although NCFRs contribute about 38% of total availability, with approximately 80% of these feeds mostly suitable for ruminants, they are currently grossly underutilised in farming practice

Three main production systems for goats 

(i) low-input extensive or subsistence system based on free grazing of roadside forages complemented with kitchen wastes, crop residues and by-product supplements when available. 

(ii) Intensive cut and carry feeding of confined or tethered animals on grasses, browse crop residues and by-products.

(iii) Commercial grazing of sheep flocks that may also benefit from crop residue and by-product feeding.

Crops

1. Annual food crop 

In India, the green fodder yields of summer forage crops, planted before wet season rice, ranged from 7–24 t/ha. In a rice-wheat–cowpea cropping sequence, 11.5 t/ha of grain, 17.2 t/ha of straw and 24.0 t/ha of green fodder were produced, whilst oats, berseem and lucerne planted after rice harvest resulted in dry matter yields of 6.4, 6.5 and 5.2 t/ha, respectively (Hedge and Pandey, 1989). Sun hemp, as an intercrop in mung bean and pigeon pea, can produce grain and forage yields of 5.0 and 12.0 t/ha, respectively (Miah and Carangal, 1987; Rebancos et al., 1991).

2. Tree crop

Coconut tree crop for goats.

3. Trees and shrubs

Crop Residues

It is important to keep the concept of crop residues in perspective. Each residue, and even each fraction of certain residues, is different in terms of its availability, its nutritive value and its potential impact in relation to the overall feeding system. We can distinguish one major group of residues, the fibrous crop residues (FCRs), which have in common their high biomass, and their low crude protein and high crude fibre contents, of approximately 3-4% and 35-48% respectively. These FCRs form the base of feeding systems for ruminants throughout the developing countries and include all cereal straws, sugarcane tops, bagasse, cocoa pod husks, pineapple waste and coffee seed pulp. Complementary to FCRs are those crop residues that are more nutritious and can therefore be used judiciously to improve the overall diet. This category includes a variety of oilseed cakes and meals, such as coconut cake, palm kernel cake, cottonseed cake and sweet potato vines, which are often used as dietary supplements. Among crop residues, cereal straws have been at the forefront of research and development efforts. 

Eight crop residues i.e., sorghum {Sorghum bicolour) straw, maize (Zea mays) straw, cotton (Gossypium Sp.) straw, sunflower (Helianthus Sp.) straw, cotton (Gossypium Sp.) seed hulls, 6, groundnut (Arachis hypogaea) hulls, maize (Zea mays) cobs, sugarcane (Saccharum Officinarum) bagasse and two forest dry grasses Heteropogan contorts and Sehima nervosuin. Sorghum straw, maize straw, Heteropogan grass and Sehima grass were subjected to three processing methods 1, chopping (2-3 cm), 2, grinding (8 mm) and steam pelleting (8-10 mm die holes). In contrast, the remaining crop residues were subjected to grinding and pelleting.

The bulk density of chopped/unprocessed material increased by grinding and further increased by pelleting. The increased bulk density on grinding was due to decreased particle size and further increase on pelleting was due to compaction in the pelleting process. Grinding increased the bulk density of chopped/ unprocessed material. Molasses absorbability was highest with cotton seed hulls and least with maize cobs. The presence of lint on cottonseed hulls has helped for increased molasses absorbability. The particle size of maize cobs was compact, smooth and heavy like solid grits compared to other roughages and this might have resulted in low molasses absorbability. The molasses absorbability of any ground material is the amount of molasses absorbed by 100 kg of these materials. Palatability is good with cotton seed hulls but very low with sorghum straw, maize straw and maize cobs in goats. 

Limitations with crop residues

Crop residues have less nutritive value as compared to fresh green fodders. For example, straws have only 4-5% average crude protein and 1.5-1.6 Mcal/kg ME. If we talk about fresh leaves of vegetables, especially cabbage, cauliflower, potatoes, and carrot, we can find an average of 16-17% crude protein (as % of their DM) and 1.8-1.9 Mcal/kg ME, which is sufficient for maintenance requirement of animals. It will be a good idea to use vegetable fresh leaves as alternatives to fodder in feed shortage times. In the matter of crop residues. Animals face problems when we offer feed to them without calculation. Same in the case of crop residues, leaves of some leguminous plants may cause metabolic disorders like bloat (Wadhwa and Bakshi, 2013; Njidda, 2010; Soetan and Oyewole, 2009). Most of the residues possess anti-nutritional factors. Some crops have mineral deficiencies, i.e., the Brassica family is deficient in Iodine. It is a goitrogenic crop if we will not offer iodine supplements with them. Sometimes, ruminants graze on turnip, tuber, bulbs and maize cobs (Wadhwa et al., 2006; Cassida et al., 1994). These large pieces of food are stuck into the oesophagus and block the digestive pathway. In Table 1, we have summarized some anti-nutritional factors in various crops and their effects on animals.

Available technologies to improve the nutritive value of crop residues 

Increasing the efficiency with which crop residues are utilised by livestock has been a major theme of technology development since the 1970s. In the case of cereal straws, the central objective has been to overcome the inherent nutritional limitations of low digestibility, low crude protein, poor palatability and sheer bulk. These include chemical treatment and the use of supplementation (energy, nitrogen and minerals). 

1. Chemical treatment 

Chemical treatment is an effective way of improving the nutritive value of straws. Various wet and dry processes have been tried using sodium hydroxide. Ammonia is less hazardous than sodium hydroxide and contributes toward the nitrogen enhancement of the straw as well as increasing the energy value. The variables affecting the efficiency of treatment include the length of the straw (unchopped or chopped), its moisture content and the level and method (spraying or impregnation) of chemical application. The value of the treated straw to livestock will depend on the feeding regime (with or without additional ingredients), the species of animals and the objective of the production system. 

2. Supplementation

 Feeding cereal straws alone results in perpetual poor productivity in animals on small farms in Asia. Several alternative supplementation strategies have been pursued, the commonest being the use of purchased protein supplements such as cottonseed and oilseed cakes, and the installation of multi-nutrient blocks as licks, often consisting of molasses, urea and minerals. Supplements serve two essential functions. They promote efficient microbial growth in the rumen & increase protein supply for digestion in the small intestine through the provision of by-pass or rumen non-degradable proteins. 

References:

Singh, Amit. (2018). Feeding management of goat.

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Goetsch, Arthur. (2019). Recent advances in the feeding and nutrition of dairy goats. Asian-Australasian Journal of Animal Sciences. 32. 10.5713/ajas.19.0255.

Bhandari, Bal & Bahadur, (2019). CROP RESIDUE AS ANIMAL FEED. 10.13140/RG.2.2.20372.04486.