Estimation of body tissue gain of entire and castrated male pigs at two feeding levels and three body weights, using energy/nitrogen balance and comparative slaughter technique

Abstract

Rates of tissue gain and body composition of 18 entire (E) and 18 castrated (C) male pigs, fed at one of two levels of feeding (high (H) or low (L)), were investigated in a 2x2 factorial experiment. Calorimetric, energy and nitrogen balances were carried out on each animal at 30, 60 and 90 kg live weight. The animals were slaughtered at 95 kg and their body composition was determined. The higher feeding level resulted in greater (P < 0.001) rates of body weight gain, protein and fat deposition in all treatment combinations Castration was associated with decreased and increased potential for protein and fat deposition, respectively. Mean values of shoulder fat thickness, loin fat and subcutaneous fat (P2) were greater (P < 0.01) for the animals fed at the high compared with those fed at the low level and these fat measurements were greater in the castrated than the entire male pigs. Relative to the slaughter method, the balance method overestimated and underestimated the rates of protein and fat deposition by 0.16 and 0.10, respectively.

Keywords: Tissue gain, calorimetric, balance, slaughter, pigs

Tanzania J. Agric. Sc. (2000) Vol.3 No.1, 47-54