Abstract #257

# 257
Effects of sodium bicarbonate and chromium propionate supplementation on growth performance, blood and rumen indices of Beetal bucks under heat stress conditions.
M. A. Rashid*1, A. Jamal1, M. I. Malik1, A. B. Nisar1, Z. A. Qamar1, H. Rehman2, M. S. Yousaf2, 1Department of Animal Nutrition, University of Veterinary and Animal Sciences, Lahore, Pakistan, 2Department of Physiology, University of Veterinary and Animal Sciences, Lahore, Pakistan.

Objectives of current experiment were to determine the effects of sodium bicarbonate (SBC) and chromium propionate (Cr) supplementation on intake, growth performance, feed sorting, rumen pH, and blood indices under hot and humid conditions. Twenty-eight Beetal bucks were randomly assigned to 4 treatments (n = 7 bucks/treatment): Control (C) without supplementation, sodium bicarbonate (SBC); at 1.5% of DM, chromium propionate (Cr); at 1.5 mg chromium/animal/d), and (SBC+Cr) diet containing SBC at 1.5% of DM + Cr at 1.5 mg chromium/animal/d. Total duration of experiment was 8 wk. Animals were housed individually, fed on iso-nitrogenous TMR (30% oat silage and 70% concentrate) to ensure 10% daily refusal, and given free access to water. Temperature and humidity values were recorded thrice daily at 0800, 1400 and 2000 h. Feed sorting, body weights and body measurements were conducted weekly. Rumen samples (n = 4 bucks/treatment) were collected on fortnightly basis using oral tube to determine rumen pH. Weekly measures including ADG, DMI, feed sorting, rumen pH and blood metabolites were analyzed using Mixed Model of SAS. Data of live BW, structural measurements, and FE were analyzed using one way ANOVA and declared significant at P < 0.05. During entire experiment, mean daily THI (85.3 ± 1.94) remained above the threshold level of THI (72–75) for ruminants. Mean daily DMI was higher (P < 0.05) in the SBC and SBC+Cr (1227, 1258 g/d) compared with the C and Cr (928, 962 g/d). Additionally, ADG was higher in the SBC+Cr (P < 0.05) compared with the C and Cr (185 vs. 124 and 136 g/d). Feed sorting behavior, body measurements, blood metabolites and feed efficiency were not affected (P > 0.05) by the treatments. However, rumen pH was higher in the SBC and SBC+Cr (P < 0.05) than in the C and Cr treatments. In conclusion, combination of SBC at 1.5% of DM and Cr at 1.5 mg/animal/d improved DMI and ADG without any negative impact on rumen and blood indices.

Key Words: heat stress, growth, Beetal buck