Mercy, A DRuby, AugustianKAU2020-11-062020-11-062008172786https://krishikosh.egranth.ac.in/handle/1/5810154602MVScA study was conducted to assess the effect of energy supplementation in the form of maize and rumen protected fat in early lactating cows under the field condition. Thirty, early lactating cross bred cows were selected and divided into three groups uniformly with regard to days in milk, the average days in milk being 40 days. The animals were randomly allotted to the dietary treatments T1, T2 and T3. The concentrate mix made in the semi liquid form and paddy straw formed the T1 ration. The animals of T2 and T3 were supplemented with 1 kg ground maize and 100 g of rumen protected fat respectively, over and above the control ration. The animals maintained on the three dietary treatments T1, T2 and T3 showed an average milk production of 15.38, 14.58 and 13.01 kg respectively during the 90 day period of the experiment. Statistical analysis showed no significant difference (P>0.05) in milk yield between the three treatment groups. The average daily DMI and DMI/100 kg body weight remained similar for all the three groups. The TDN intake was up to the requirement in animals maintained on T3 ration while T1 and T2 rations could not meet the requirements of the animals of the respective groups. The DCP intake was optimum from the three rations. The energy supplementation did not affect milk composition such as percentage of total solids, milk fat, solids not fat (SNF) and milk protein, and milk urea nitrogen (MUN). The 4 per cent FCM yield, total yield of milk fat and protein remained unaffected by energy supplementation. Animals in all the three groups showed similar blood parameters such as haemoglobin, plasma glucose, plasma urea nitrogen and plasma Ca and P. The digestibility of EE, DM, NDF and ADF was higher for the T3 ration than that of T1 and T2. The digestibility of crude protein (CP) was higher for T2 than T1 and T3 rations. Animals maintained on T3 ration showed earlier post partum heat. The cost of feed for producing 1 kg milk was higher for the dietary treatments T2 and T3. An overall assessment of the results obtained in the present study showed that energy supplementation in the form of either maize or rumen protected fat could not influence dry matter intake, milk yield and 4 per cent FCM yield. There was no change in the composition of milk and blood parameters studied, among the experimental animals. However, energy supplementation in the form of protected fat could meet the energy requirement of early lactating animals, improved the digestibility of EE, DM, NDF and ADF and positively influenced the first post partum heat.EnglishThesis