ABSTRACT
Effect of chromium propionate supplementation on lactation performance and blood parameters of Simmental cows in mid-lactation under heat stress

Blagoje Stojkovic1*, Bojan Stojanovic1, Vesna Davidovic1, Aleksandra Ivetic2, Stefan Simunovic3, Aleksandar Ignjatovic1, and Ivana Grujicic1
 
Nutritional management of high-producing dairy cows under heat stress conditions presents a significant challenge due to the increasing issue of global warming. The study aimed to explore the effects of Cr supplementation in the form of chromium propionate (CrP) on feed intake, lactation performance, and selected biochemical serum parameters in mid-lactation Simmental dairy cows under heat stress conditions. The experiment was conducted during July and August and lasted for 8 wk. The average temperature-humidity index (THI) was 76.45 ± 2.80 during the experimental period, indicating that the cows were under heat stress. The added CrP provided 0.34 mg Cr kg-1 DM of used ration. The supplementation of diet with CrP increased DM intake (4.11%, P < 0.01) and the yield of milk (4.48%, P < 0.01), 4% fat-corrected milk (4.08%, P < 0.01), milk fat (4.46%, P < 0.01), protein (4.21%, P < 0.01), lactose (3.79%, P < 0.01), and total solids (3.51%, P < 0.01). Additionally, CrP supplementation increased blood glucose concentrations (8.39%, P < 0.01), while reducing blood urea N (BUN) levels (14.85%, P < 0.05) and beta-hydroxybutyrate (BHB) levels (17.14%, P < 0.05). The use of CrP as additional dietary source of Cr significantly improved productive performances of dairy cows under heat stress conditions. It was indicated that supplemented Cr could have positive effect on glucose and N metabolism, as well as on energy metabolism of lactating cows at moderately high THI values.
Keywords: Cattle, chromium propionate, lactation performance, temperature-humidity index.
1University of Belgrade, Faculty of Agriculture, 11080 Belgrade, Serbia.
2Institute for Science Application in Agriculture, 11108 Belgrade, Serbia.
3Institute of Meat Hygiene and Technology, 11040 Belgrade, Serbia.
*Corresponding author (blagoje.stojkovic@agrif.bg.ac.rs).