Evaluation of reproduction performance and calf sex ratio of dairy cattle in selected locations of South-East Oromia

• Main Author: Debele Guta (Author)
• Format: Book
• Published: International Journal of Agricultural Science and Food Technology - Peertechz Publications, 2021-04-23.
• Subjects: Thesis
• Online Access: Connect to this object online.

Summary

<p>Dairy farmers in many parts of the world complain about the deviation from the normal calf sex ratio following Artificial Insemination (AI). The prospective and retrospective studies were conducted to compare the sex ratio of the calves born following Artificial Insemination (AI) and Natural Mating (NM) under institutional and smallholder-managed dairy farms. This study also compared the reproductive performance of dairy cattle under institutional management and smallholder systems. The data encompassed farm records maintained between 1996-2014 G.C by dairy farms at Arsi University-Asela, crossbreeding center at Gobe ranch, and Agarfa ATVET College. These farms reared both F1 and crossbreds with higher (>75%) exotic inheritances (grade crosses). The study also considered household and progeny history surveys on smallholder dairy farms (n=90) adjoining to the institutional farms which were randomly selected from Tiyo, Kofele, and Sinana districts. The result indicates that most of the respondents at Tiyo (96.8%) and Kofale (100%) were concerned about the differences in the sex ratio of calves born from AI service and natural mating, while most of the respondents at Sinana (29%) did not report such differences. The respondents in Tiyo and Kofale districts reported higher numbers of male calves (58%) and higher numbers of female calves (58.1%) born from cows inseminated artificially respectively. The Average Age at First Calving (AFC) had no significant difference between genotypes (F1 and grade crosses) reared at the institutional farms. There were significant differences (p<0.05) in AFC across the ranches. The AFC was lower in the institutional farms when compared to those managed at smallholder management conditions. The number of services per conception (NSC) varied p<0.05) across the dairy farms. No significant differences were observed among the sex ratio of the calves born through natural and AI mating systems either at the institutional or smallholder farms. However, differences due to season and year were observed, indicating the effect of non-genetic factors influencing the sex ratio of the calves. In some seasons the numbers of male calves were higher while the reverse was true for some other seasons. Therefore, the reproduction traits of the cattle differed (P<0.05) across the institution and smallholder production systems having lower values observed among the cattle raised at the dairy farms and higher for the F1 crossbred than grade crosses, while production trait of the cattle differed (P<0.05) across the three dairy farms and there were no significant differences in calf sex ratio among the calves born from AI and NM. </p>

DOI

10.17352/2455-815X.000105