Effects of dietary protein supplementation on the performance of West African dwarf (WAD) goats infected with Haemonchus contortus and Trichostrongylus colubriformis

Twenty worm-free male West African dwarf (WAD) goats, 7-8 months of age, were used to study the effect of dietary protein on their response to mixed infections of trychostrongyles. The goats were divided into 4 groups (A-D), each containing 5 animals. Groups A and B were fed forages with concentrate feed containing 17.06% crude protein, whereas Groups C and D were fed forages alone. An escalating infection of 500 infective larvae (L3), 1000 L3, 2000 L3, and 4000 L3 was given consecutively at weeks 0, 1, 2, and 3, respectively, for 4 weeks to groups A and D. Patency and level of infection were monitored by carrying out fecal egg counts (FECs) twice weekly. All of the animals were humanely sacrificed 42 days after infection, and the abomasum and intestines were recovered and processed for worm recovery. The results showed that there was a positive correlation between the dietary protein and body weight gain and body condition score. However, the dietary protein had no significant (P > 0.05) effect on the packed cell volume (PCV), total serum protein, and serum albumin levels. The supplemented goats shed significantly fewer helminth eggs in the feces and harbored lighter burdens of the 2 worm species compared to unsupplemented goats. There was a negative significant correlation between the worm burden and the body weight and body condition scores. The correlation between the worm burden and PCV was also negative but not significant, while that between the worm burden and FEC was positive and significant. Infection significantly affected the feed intake but did not affect water intake. These results therefore demonstrate that nutritional supplementation enhances the resistance of WAD goats to mixed infections of H. contortus and T. colubriformis and results in their improved performance.