ABSTRACT
The current study aimed at development of breeding objectives and estimation of the economic values for traits of economic importance to various dairy goat breeders associations. This was achieved through the development of a bio-economic model to derive economic values for the selected traits. The input and output parameters used represented the average performance of Saanen, Toggenburg and Alpine breeds. The gross margin was estimated using the R software. Economic values for milk yield (MY, kg), pre-weaning survival rate (PrSr, %), post-weaning survival rate, (PoSR, %), doe survival rate, (DoSR, %), and kidding rate, (Kr, %) were estimated based on fixed flock size and fixed feed resources scenarios. The findings indicate varied gross margin across the breeds; Saanen (US$ 116.17), Toggenburg (US$ 68.21) and Alpine (US$ -1.11). In both scenarios, the economic values in selected traits were positive for the three breeds except for milk yield in Alpine, which was negative in both fixed flock and fixed feed resources. The positive economic values of selected traits indicated a unit increase in genetic merit of these traits. The developed bio-economic model was able to estimate the gross margin of Saanen, Toggenburg and Alpine breeds represented by Nyanza Dairy Goat Breeders Association (NDGA), Meru Dairy Goat Breeders Association (MDGA) and Dairy Goat Association of Kenya (DGAK), respectively, reared under semi-intensive production system. The study offers an opportunity to evaluate genetic and economic merit of alternative strategies for dairy goats reared in semi-intensive production systems managed by various dairy goat breeders associations.
Subject(s)
Goals , Goats , Animals , Kenya , Goats/genetics , Milk , PhenotypeABSTRACT
This study aimed at determining factors influencing response of Sahiwal cows/heifers to fixed time artificial insemination protocol in pastoral systems in Kenya. Available cows/heifers were inspected for conformity to Sahiwal breed characteristics, parity, body condition score, and subsequently rectal palpation to determine pregnancy status, ovarian structures, and estimated ovarian diameter. Consequently, these animals were injected with 100 µg of gonadotrophin-releasing hormone. On days 7 and 9, only responsive cows/heifers were injected with 500 µg of cloprostenol and 100 µg of gonadorelin Acetate, respectively. On day 10, animals were inseminated and separated from bulls for 45 days and pregnancy diagnosis done after 90 days. Analysis of variance was performed to determine the effects of production system, parity, and ovarian structures on ovary diameters pre- and post-hormonal treatment. Logistic regression was used fitting a logit function to account for the binomial distribution of conception. Overall, 56.2%, 23.1%, and 20.7% of the animals had follicles (F), corpus luteum (CL), and corpus albicans (CA), respectively, at day 0, and 16.6%, 68.6%, and 14.8%, respectively, at day 7. Human and environmental factors had no influence on conception. Among the animal factors, only the ovarian structures at day 7 had a significant effect on conception. Ovaries with CL at this time were about 6 times significantly more likely to conceive than those with F. For higher conception rates, animals with ovaries with CL should be recruited into the FTAI program as they are significantly more likely to conceive than those with other ovarian structures.
