# Association of Temperament with Growth Performance in Nili Ravi Buffalo Heifers

## TL;DR

Calm Nili Ravi buffalo heifers grow faster than nervous ones in early life, suggesting temperament affects growth performance and could influence breeding strategies.

## Contribution

Demonstrates a novel link between buffalo temperament and early growth rates, with implications for breeding and management practices.

## Key findings

- Calm heifers had higher average daily gains than nervous heifers during early growth phases (4–6 and 6–12 months).
- Calm heifers showed numerically lower cortisol levels compared to nervous heifers.
- The growth advantage of calm heifers was not observed in later stages (18–24 months).

## Abstract

This study explored the relationship between temperament and growth performance in Nili Ravi buffalo heifers. A total of 84 heifers, aged 18 to 24 months, were assessed for temperament using chute score and exit velocity. Based on these measurements, heifers were classified as either calm or nervous. Retrospective growth data, including average daily gain, were obtained from farm records, and blood samples were analyzed for cortisol levels. Results showed that 48 heifers were classified as calm, while 36 were nervous. Calm heifers had significantly higher average daily gains than nervous heifers, particularly during early growth phases (4–6 months: +240 g/day; 6–12 months: +190 g/day). However, this advantage was not observed at 18–24 months. Additionally, calm heifers have numerically lower cortisol levels (0.96 vs. 1.27 μg/dL). These findings emphasize the importance of temperament in improving growth performance, highlighting its potential role in breeding and management strategies for dairy buffalo.

This study investigated the association between temperament and retrospective growth rates in 84 Nili Ravi buffalo heifers aged 18 to 24 months. Temperament was assessed using chute score and exit velocity, measured twice at a seven-day interval, and classified as calm (≤3) or nervous (>3). Retrospective average daily weight gain data were retrieved from farm records, and blood samples were collected to measure cortisol levels. ANOVA was used to analyze data, considering temperament, age group, season, and year of birth as fixed effects, with birth weight as a covariate. Results showed that 48 heifers were calm and 36 were nervous. Calm heifers exhibited significantly higher average daily gains than nervous heifers during the post-weaning period, with an increase of 240 g/day from 4 to 6 months and 190 g/day from 6 to 12 months (p < 0.001). However, this difference was not significant at 18–24 months (p = 0.144). Calm heifers have numerically lower cortisol levels (0.96 vs. 1.27 μg/dL; p = 0.11). These findings suggest that calmer heifers grow faster in early life, emphasizing the importance of temperament in breeding programs aimed at improving growth performance and welfare.