National Centre for Agrarian Sciences, BG-1373 Sofia, Bulgaria
STOIKOV, A., 2003. Effect of fattening of entire male pigs on environmental safety. Bulg. J. Agric. Sci., 9: 77–80
A balance trial was carried out with two groups of Shumen hybrid pigs in accordance with Oslage methodology (1962). It encompassed an equal number of boars (group I) and male castrates (group II) of similar origin and body weight. During fattening from 30 kg to 100 kg, they were fed a mixture containing 13.2 MJ/kg digestible energy, 143.5 g protein, 0.68% lysine, 0.75% calcium and 0.64% phosphorus.
Comparative data showed that feed consumption per 1 kg gain in boars was 2.950 kg and in castrates – 3.150 kg. Entire males reached 100 kg body weight 8.2 days earlier than castrates. Boars deposited 16.45% 18.63% less fat and energy, respectively (P ≤ 0.01). Protein retention in young entire male pigs was 126 g and in castrates – 119 g/day and that of fatty tissue – 258.4 g and 300.9 g, respectively. Young boars assimilated minerals 6.25% better than castrates. The results were of major economic and environmental importance.