Effect of feed quality restriction on changes in body measurements and carcass characteristics of West African dwarf sheep

Abstract

Twenty seven West African Dwarf (WAD) sheep were used for the 120 day feeding trial to determine the effects of feed quality restriction on changes in body measurements and carcass characteristics. The animals were divided into three groups of nine animals each, the control group(C), the restricted group one (R1) and the restricted group two (R2). The sheep in the control group were fed dried guinea grass (Panicum maximum) and concentrate diet for the whole period of the experiment. The R1 and R2 animals were fed dried grass for a period of 30 days and 60 days, respectively before the inclusion of concentrate diet for 60 days. The live weight was measured weekly and body measurements every two weeks. Data obtained were analyzed using one way analysis of variance. Results showed that the average values for chest girth were significantly (P< 0.05) affected by duration of feed quality restriction with R2 group sheep having the highest value of 58.67 ± 1.16 cm and R1 group sheep having the lowest mean value of 53.85 ± 0.65 cm. The average values for testes girth and total dry matter intake were significantly (P< 0.05) affected by duration of feed quality restriction with C group sheep having the highest values 11.33 ± 0.26 cm and 346.80 ± 0.26 g, respectively. The C group sheep also had significantly higher (P< 0.05) values for live weight, withers height, shoulder width, thigh bone weight, dressing percentage and liver weight (12.75 ± 0.73 kg, 55.88 ± 0.00 cm, 19.05 ± 0.42 cm, 0.18 ± 0.03 kg, 60.47 ± 4.76 % and 0.22 ± 0.01 kg, respectively) during realimentation. In conclusion, feed restriction negatively affected live weight, total dry matter intake, chest and testes girth and it was recommended that feed supplementation during periods of feed scarcity be encouraged so as to allow animals maximise their growth and breeding potentials because animals fed grass and concentrate (C group) performed better than those fed grass only for specific periods (R1 and R2 groups).