Age, Sex and Season Related Changes in Growth Hormone and Cortisol Level of Black Bengal Goats during Pre-pubertal Growth Period

In present changing climatic conditions, the study of growth dynamics is of great significance as the demand for meat is always increasing due to increasing population. Improvement of functional longevity in goats is becoming highly relevant and is of great economic importance. Hence, determining animal growth and their inter-relationship and correlation with endocrine parameters in different seasons is imperative for determining the genetic potential and adaptation of the black Bengal breed for higher meat production. The goal of the present study was to find out the effect of sex and season on growth hormone and cortisol levels during different periods of pre-pubertal growth in summer and winter-born black Bengal kids of either sex reared under a free-range rearing system. Statistical analysis was done by using the software IBM-SPSS (Version 20.0). The general linear model technique repeated over age, groups and seasons was considered for all parameters under the study. The major finding of this study is that growth hormone was positively correlated (P <
0.01) with growth parameters height, heart girth and linear length during summer and winter seasons. Cortisol was significantly (P≤ 0.01) higher in the kids born in summer than in winter. Summer-born kids are more susceptible to stress. The levels of growth hormone can be predicted which were positively explained by age irrespective of sex. Due to climatic change, the effects of multiple environmental stressors on prepubertal growth are likely to increase. Hence, it is very critical to identify and protect agro-ecological zone-specific climate-resilient thermo-tolerant animals to sustain livestock production.