Effect of different levels of energy on milk composition in crossbred lactating cows

Twelve crossbred (HF x Gir) lactating cows, divided in to the two groups of six each, with same stage of lactation and average daily milk production. Group-I (control) received basal ration comprising green and dry fodder and concentrate mixture (60% TDN). Group - II (Experimental) received concentrate mixture containing 5% higher energy (TDN) than control. Both the groups received same roughages comprising of green (maize) and dry fodder. Average daily DM intake in groups I and II was 12.09 and 12.15 kg, respectively, and the variation between the groups was nonsignificant. Supplementation of extra 5% energy in the form of TDN for period of 13 weeks in group II, resulted in significantly higher milk fat percentage than control. The average specific gravity and total ash percentage of milk revealed non-significant difference among the treatments. However, total solid, solid not fat and protein percentage of the milk were significantly lower in treatment group than control, group. It may be concluded that for improving performance in respect of milk fat, in early lactating crossbred cows, the energy content of routinely used concentrate mixture (containing 60% TDN) can be increased by 5%.