Influence of isobutyric acid supplementation on nutrient intake, its utilization and growth performance of crossbred calves fed low protein and urea containing rations

Abstract

The present experiment was conducted to observe the beneficial effect of dietary supplementation of sodium salt of isobutyric acid in low protein and urea containing wheat straw (WS) based diets. Eighteen crossbred growing calves, divided into 3 similar groups, were fed a basal diet consisting of wheat straw, concentrate mixture and green oat fodder in 40:40:20 proportion (T₁), basal diet + isobutyric acid (BCFA) @0.75% of basal diet (T₂) and basal diet +BCFA+ Urea to replace 1/3rd of dietary nitrogen (T₃) for 120 days. The average DMI (kg/100kg BW) was higher in T₃ (2.55) as compared to Tr (1.95) and T₂ (1.95). The dietary supplementation of isobutyric acid improved the DM, OM and CF digestibilities by 8.6, 8.0 and 13.2% over T1. The DCP content of experimental rations was similar in all the groups. However, the DCP intake (g/day and g/kg W^0.75) was higher in T3 (304.55 and 6.70) as compared to T₁ (217.90 and 5.01) and T₂ (226.94 and 5.52). Similarly TDN intake (g/day and g/kg W^0.75) was also higher (P<0.05) in T₃ (2.63 and 58.20) as compared to T₁ (1.80 and 41.80) and T₂ (1.90 and 43.95). However, the TDN content of both the BCFA supplemented rations was significantly (P<0.01) higher (64.35 and 63.23%) as compared to T₁ (59.60). The total gain in livc weight in T₂ and T₃ was higher by 15.94 and 30.02%, respectively, over T₁. The average daily gain and efficiency of feed conversion were also higher in BCFA supplemented groups i.e., T₂ and T₃ calves by 13.38 and 26.71; and 12.48 and 22.16%, respectively, over T₁ The dietary supplementation of isobutyric acid improved the digestibility of nutrients and growth performance of calves.