Effect of heat and nutritional stress on growth and testicular HSP70 expression in goats

Abstract

A study was conducted to assess the combined effects of heat and nutritional stress on body weight changes and HSP70 gene expressionin Osmanabadi goats. Twenty four adult Osmanabadi bucks were divided into four groups of six animals each viz. C (control), HS (heat stress), NS (nutritional stress) and CS (combined stress). The C and HS bucks had ad libitum access to their feed while NS and CS bucks were subjected to restricted feed (30% intake of C bucks) to induce nutritional stress. The HS and CS bucks were exposed to heat stress in outside environment for six hours a day between 10:00 h to 16:00 h. Both C and HS groups showed significantly higher (P<0.01) body weight and body condition scoring as compared to NS and CS groups. The highest plasma growth hormone (P<0.01) was recorded in CS group and the lowest in all stress groups (C, HS and NS). The higher (P<0.05) expression of testicular Heat Shock Protein 70 (HSP70) mRNA was reported in HS groups. It can be concluded from this study that when nutrition is not compromised Osmanabadi goats were able to withstand heat stress without compromising production.