The effects of ovariectomy on meat performance and expression of GH/IGF-I in young goats

Zhang, L., Wang, Y.-y., Fu, M.-z., Li, G., An, N., Li, S.-y. and Zhou, Z.-q. 2014. The effects of ovariectomy on meat performance and expression of GH/IGF-I in young goats. Can. J. Anim. Sci. 94: 619–626. Experiments were carried out to investigate the effects of ovariectomy on meat production efficiency and to explore the expression of GH/IGF-I in young goats. Animal performance, meat quality, levels of serum growth hormone (GH) and insulin-like growth factor 1 (IGF-I), and mRNA levels of three key genes [GH Receptor (GHR), IGF-I and IGF-I Receptor (IGF-IR)] in longissimus dorsi and biceps femoris muscles were measured. The results show that carcass weight, net meat mass, fat weight and loin eye area of ovariectomized goats were higher than those of the controls, and ovariectomized goats lost 0.40 kg of bone weight (P<0.05). There was no statistically valid difference for the color, pH, water-holding capacity, or cooking rate of meat (P>0.05) between the two groups, except for the shear value, which was significantly lower in the Ovx group than in the control group (P<0.05). The results of this research show for the first time a significant trend (P<0.05) for serum GH and IGF-I in the direction of increasing in ovariectomized goats. Furthermore, the mRNA levels of GHR, IGF-I and IGF-IR in muscle were all up-regulated, except for the IGF-I gene in biceps femoris, by ovariectomy. In summary, ovariectomy showed a beneficial promotion in animal performance, but did not reduce meat quality, and increased serum GH and IGF-I and mRNA expression levels of GHR, IGF-I and IGF-IR in young female goats.