Srobana Sarkar, R.S. Bhatt, R.L. MeenaICAR- Central Sheep and Wool Research Institute, Avikanagar, Rajasthan, India
Livestock sector plays a valuable role in socio-economic development and food security of a considerable population in developing countries. However, due to inadequacy and non availability of quality feeds and fodders the productivity of farm animals is generally low in most tropical countries. The availability of green fodders from various sources is only 40% of the basic requirement hence there is 60% shortage of green fodder. Considering the huge scarcity of green fodder and quality dry matter along with decreasing land availability, it is essential to intensify forage production through improved high yielding crops and better management practices. Moreover, conventional feed resources for animal production are highly expensive which further necessitates the identification and inclusion of alternative feed resources. One such promising fodder source for livestock feeding is hegde lucerne (Desmanthus virgatus). Hegde lucerne is a perennial legume fodder with an annual green fodder yield of 90-100 (t/ha/year) which can be an alternative protein source to conventionally used oilcakes in the diet of livestock. It can be cultivated throughout the year under irrigated conditions and during monsoon under rainfed conditions. Hedge lucerne is nutritious and palatable to grazing animals throughout the growing season so it is economical and sustainable to bridge the gap between demand and supply of fodder for up surging animal population.
Nutritional value of hedge Lucerne
The nutrient and phytochemical constituents present in hedge lucerne are shown in Table 1. Like several other legume forages, hedge lucerne contains high amount of protein and the leaves have a higher protein content than the stems. The empty pods contain much less protein than whole plant or the leaves. Desmanthus virgatus have average crude protein content (18% DM vs. 25% DM for Leucaena leucocephala, a legume fodder tree) and NDF content of ~50% DM. The biomass yield per acre for six cuttings of hedge lucerne is approximately 40 tons and the total digestible nutrient and metabolizable energy content is around 59% and 5.6 MJ/kg, respectively. It is moderately rich in lignin (7% DM), and contains high amount of saponins like other legume forages along with negligible amount of tannins. Hedge lucerne is recently used as reference forage in studies assessing potential of other forages.
Table 1. Nutrient and phytochemical composition of hedge lucerne
|Chemical composition||% dry matter basis|
|Neutral detergent fiber||52|
|Acid detergent fiber||41|
|Plant bioactive compounds|
|Total phenols %||1.34|
|Total tannins %||0.48|
|Condensed tannins %||0.08|
|Hydrolysable tannins %||0.40|
Effect on livestock performance
Hedge lucerneis palatable to animals but its relative palatability depends on the variety and its hay can be successfully included in compound feeds. In case of cattle the in vivo digestibility of dry matter and protein are around 48 and 44%, respectively. Feeding of dried hedge lucerne leaves at the rate of 3.0/kg/cow/day as protein supplement in roughage based ration for dairy cows improved milk yield but reduced milk fat content. Inclusion up to 50% hedge lucerne to replace concentrate in diet of goats improves growth performance and increases net profit of Osmanabadi goat production. Supplementation of Acacia nilotica pods up to 5% in hedge lucerne silage improved the quality of silage for feeding of goats. Hedge lucerne hay added up to 200 g/day along with 600 g/day Astrebla hay had beneficial effects on wool growth, intake and body weight in sheep due to high protein and sulphur content. However, in case of pigs hedge lucerne leaf meal beyond 17% of the diet is unsuitable as an alternative protein source. In case of pullets feeding of hedge lucerne meal at the rate of 6% of layer diet produced no adverse effects on egg quality and laying performance while enhancing egg yolk coloration but use of hedge lucerne seeds is detrimental in broilers and inclusion up to 5% level causes severe growth depression. In case of rabbits, fresh hedge lucerne is used as promising green forage in the southern states of India (Tamil Nadu and Telangana) for growing rabbits or breeding does. Hedge lucerne foliage produced higher body weight gains in rabbits than conventional tree foliages like Leucaena leucocephala, Artocarpus heterophyllus, Mangifera indica and Morus alba. In growing rabbits, ad libitum supplementation of fresh hedge lucerne with 50 to 70 g / head/ day concentrate mixture is sufficient to meet their dry matter requirements and growth rate. Therefore, hedge lucerne can be considered as a nutritious round the year available green fodder for ruminants and rabbits.