Selective myostatin inhibitor - P AH-A: effects of in ovo administration on skeletal muscle development in chickens

Abstract

The commercial meat industry is a valuable component of the United States economy, and scientists have spent decades investigating methods for improving muscle production in agricultural animals. A breakthrough in the exploration of muscle development occurred in 1997 with the identificat ion of myostatin, a negative regulator of skeletal muscle growth (McPherron et ai, 1997). Inhibition of myostatin through genetic alteration, the use of monoclonal anti-myostatin antibodies, and treatments of a soluble form of the activin type II receptor protein are effective methods for increasing muscle production in mice and poultry. The purpose of our study was to investigate effects of Pfizer Animal Health-Compound A (PAH-A), a selective myostatin inhibitor, on skeletal muscle production in broiler chickens. We hypothesized that in ova administration of PAH-A would favorably increase muscle development by means of hypertrophy. We analyzed mean body mass gain (BMG) and cross-sectional area (CSA) of broiler pectoralis major samples nine treatments groups on post-hatch days 3 (D3) and 14 (DI4). Our results revealed a positive correlation between the CSA and body mass (BM) of control birds (R = 0.96) and showed significant differences (p < 0.05) in mean CSA between D3 and DI4 tissue samples. Our results did not support our hypothesis because we failed to observe significant differences in BMG or CSA between control and PAH-A groups. Additional studies are required for accurate evaluation of PAH-A as a myostatin inhibitor. In addition to improvements in agricultural meat production, future applications of PAH-A and other myostatin inhibitors could become successful methods for reversing the effects of muscle degenerative diseases in humans.