Administration of chromium picolinate and meloxicam alleviates regrouping stress in dairy heifers

¹Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Science, College of Agriculture and Life Sciences, Seoul National University, Gwanak-gu, Seoul 08826, Korea
²Institutes of Green Bio Science Technology, Seoul National University, Pyeongchang-gun, Gangwon 25354, Korea

Correspondence: Myunggi Baik, Tel: +82-02-880-4809, Fax: +82-02-873-2271, Email: mgbaik@snu.ac.kr

Received: 22 February 2024 • Revised: 21 March 2024 • Accepted: 28 March 2024

Abstract

Objective
This research was performed to investigate effect of administering chromium (Cr) and meloxicam (MEL) on growth performance, cortisol and blood metabolite, and behaviors in young regrouped heifers.
Methods
Fifty Holstein dairy heifers (body weight (BW) 198 ± 32.7 kg and 6.5 ± 0.82 months of age) were randomly assigned to non-regrouped group or four regrouped groups. Non-regrouped animals were held in the same pen throughout entire experimental period (NL: non-regrouping and administration of lactose monohydrate (LM; placebo). For regrouping groups, two or three heifers maintained in four different pens for 2 weeks were regrouped into a new pen and assigned to one of four groups: regrouping and LM administration (RL); regrouping and Cr administration (RC); regrouping and MEL administration (RM), and regrouping and Cr and MEL administration (RCM). LM (1 mg/kg BW), Cr (0.5 mg Cr picolinate/kg dry matter intake), and MEL (1 mg/kg BW) were orally administered immediately before regrouping. Blood was collected before regrouping (0 h) and at 3, 9, and 24 h and 7 and 14 d thereafter. Behaviors were recorded for 7 consecutive days after regrouping.
Results
Average daily gain was lower (P < 0.05) in RL than NL heifers, but was higher (P < 0.05) in RM, RC, and RCM than RL heifers. RL heifers had higher (P < 0.05) cortisol than NL heifers on d 1 after regrouping. The cortisol concentrations in RC, RM, and RCM groups were lower (P < 0.05) than in RL treatment 1 d after regrouping. Displacement behavior was greater (P < 0.05) in RL group than all other groups at 2, 3, and 6 d after regrouping.
Conclusion
Regrouping caused temporal stress, reduced growth performance, and increased displacement behavior in heifers. Administering Cr and MEL recovered the retarded growth rate and reduced displacement behavior, thereby alleviating regrouping stress.

Keywords: Chromium; Displacement Behavior; Heifer; Meloxicam; Regrouping Stress