Utilization by sheep of dried pig faeces containing a high concentration of copper

Abstract

Seven groups of three sheep were given pelleted diets as follows: A, 97% hay + 3% molasses; B, C, D, 82% hay + 3% molasses + 15% dried pig faeces; E, F, G, 67% hay + 3% molasses + 30% dried pig faeces. In an attempt to counteract potential toxic effects of copper in the pig faeces (613 mg/kg dry matter), molybdenum was added to diets C and F at the rate of 90 mg/kg diet, and to diets D and G at the rate of 175 mg/kg diet. Sulphate was included in all diets at the rate of 1.08% of diet. Measurements were made of digestibility, copper retention, and plasma glutamic oxaloacetic transaminase (GOT) values during a 70-day feeding period, after which the animals were slaughtered. Dry matter digestibility coefficients were : diet A, 49.2; diets B, C, D, 44.4; diets E, F, G, 42.5, from which the coefficient for pig faeces alone is calculated to be < 30. Mean copper retention over the 70 days ranged from 210 mg for diet A to 1225 mg for diet G (excluding diet E which showed an aberrant retention of 53 ± 185 mg). Plasma GOT values fluctuated between diets and between sheep with a maximum value of 182 units/ml. Mean liver copper concentrations ranged from 718 mg/kg dry matter for diet A to 1740 mg/kg for diet E. Necrotic lesions occurred in some livers. Kidneys were apparently normal. There were no clear differences in copper status of animals receiving 15% versus 30% pig faeces except for a tendency for liver damage to be greater in the latter. There were no apparent effects of additions of molybdenum. The pig faeces were poorly utilized and, because of the high copper content, potentially hazardous to the health of the sheep.