Influence of Breed, Season, Age and Body Condition Score (Bcs) on Litter Size of Goats Reared in Mubi, the Guinea Savanah Zone of Nigeria

Abstract

A two year study was conducted to investigate the effects of breed, year, season, age and body condition score on litter sizes of goats reared in Mubi, guinea savannah zone of Nigeria. Data was collected on fetuses recovered, and the grafian follicles as well as the presence of corpus luteum, which are direct measures of litter size from female Sahel and Sokoto Red goats of different age groups and body condition scores across four seasons for two years. It was discovered that, there were significant (P<0.001) effects of breed, season, age, year and body condition score variations on the litter sizes. The Sahel has higher number of litters than the Sokoto Red does. Season has highly significant (P < 0.001) effect on the litter sizes where early dry and late wet seasons ranked highest. Measurement of the litter size based on the number of matured follicles and the presence of corpora lutea shows similar trend. There are differences in the number of litter size in the does based on the year, as year 2016 recorded the highest number of matured follicles and corpora lutea. The highest number of ovarian parameters for both the right and the left were recorded among does aged ≥ 3 years with body condition score (BCS5). The combined effects of breed x season on litter sizes was significantly ((P < 0.01) higher during the early dry and late wet seasons in both breeds, but was better in the Sahel in both seasons. Since breed, season, age and BCS has significant influence on the litter sizes as measured using fetal recovery and ovulation rate in does of both breeds, and with the ovaries being active all year round, selection and breeding exercise should be carefully carried out based on the records obtained. This indicates that breed or individual animals that have the best parameter values should be selected for breeding using the available measured index.