Effect of Late Gestation and Early Postpartum Concentrate Supplementation on Milk Production, Milk Composition and Reproductive Performances of HF × Boran Dairy Cows

Abstract

A study was carried out to evaluate the effect of late gestation and early postpartum concentrate supplementation on milk yield, milk composition and reproductive performances of HF × Boran crossbred dairy cows in randomized complete block design with three treatments. The treatments were control (hay and concentrate from agro-industrial by-products), T₂ (hay and concentrate from agro-industrial by-products plus ruminant premix) and T₃ (hay and concentrate mixture from agro-industrial by-products plus commercial dairy concentrate plus ruminant premix). As a result of variations in treatment diets, the crude protein contents of treatments during the late gestation and early postpartum periods were 26.5, 14.1, 14.3 and 26.5, 15.4, 15.6% for T₁, T₂ and T₃, respectively. The metabolizable energy contents of treatments were 11.1, 10.4, 10.7 and 11.1, 11.5 and 11.8 MJ/kg DM for T₁, T₂ and T₃, respectively. During late gestation period cows on the control diet had a higher (P<0.001) daily energy intake (91.0 MJ) than T₂ (88.0 MJ) and T₃ (86.2 MJ) per cow. The daily protein intake for T₁ (2699.2 g) was also higher (P<0.0001) than T₂ (1456.0 g) and T₃ (1430.8 g), respectively but not different (P>0.05) among parities. Total daily DM intake during early post-calving period for T₂ (14.5 kg) was significantly (P<0.0001) varied from T₁ (13.2 kg) and T₃ (13.1 kg). There was significant variation in nutrient intake among treatments and parities in the early postpartum period and daily energy intake per cow in T₂ (141.1 MJ) was higher (P<0.0001) than T₃ (129.3 MJ/) and T₁ (121.0 MJ). But the daily CP intake per cow was higher (P<0.0001) for T₁ (3499.3 g) than T₂ (2229.6g) and T₃ (2039.3 g). Daily milk yield per cow was 15.8 l, 14.2 l and 11.0 l for T2, T3 and T1, respectively. Milk composition did not vary (P>0.05) because of diet and parity differences. Body condition score (BCS) at calving and day 60, calving to first heat intervals (CFHI), calving to first service intervals (CFSI), calving to conception intervals (CCI) and calving interval (CI) was statistically different (P<0.05) among treatments and cows in T₂ and T₃ were better than T₁. Therefore, from the results it can be concluded that formulating ration according to the cow requirement, stage of production improves milk production and reproductive performances. Furthermore, agro-industrial by-products alone are appropriate feed sources in formulating dairy ration.

Keywords: agro-industrial by-products, hay, milk, milking cows, reproductive performances, supplementation