Effect of Somatotropin (pST) on Some More Important Fattening and Slaughter Traits in Hybrid Pigs

1 Agricultural Institute, BG-9700 Shumen, Bulgaria
2 Episkop K. Preslavski University, BG-9700 Shumen, Bulgaria


SLANEV, S., and A. DRAGOEVA, 2003. Effect of somatotropin (pST) on some more important fattening and slaughter traits in hybrid pigs. Bulg. J. Agric. Sci., 9: 81–88

The effect of somatotropin pST applied in comparatively low dose (3 mg/day) during the second (finishing) phase of fattening on the fattening and slaughter qualities and economic results in female and male castrated pigs from Shumen double-cross hybrid was investigated. In pigs treated with pST the feed intake decreases by 4.0%, the feed efficiency per 1 kg gain increases by 7.0 (P ≤ 0.001) and per 1 kg meat by 9.2% (P ≤ 0.01). The meat with bones content in the half carcass increases by 3.2% and the fat thickness (ΣCKL2) decreases by 23.0%. The differences compared to the controls are significant.
The analysis of the results according to the animals' sex established higher effect of hormonal treatment in the male castrated pigs. In these animals, the feed conversion per 1 kg gain is lower by 9.7% (P ≤ 0.001) and per 1 kg meat with bones – by 11.8% (P ≤ 0.01). The meat with bones content in the right half is higher by 3.8% (P ≤ 0.05) and the prime gain cost is lower by 8.8% (P ≤ 0.001) compared to the controls. In the female pigs these results have the following values: 4.4%, 6.6%, 2.5% (P ≤ 0.05) and 4.3% respectively. The final result is that the profit is higher by 4.6 levs in the male castrated pigs than the profit in the female pigs.

Key words: somatotropin, meat, back fat thickness, feed conversion