Estimates of genetic parameters for Boran, Friesian, and crosses of Friesian and Jersey with the Boran cattle in the tropical highlands of Ethiopia: milk production traits and cow weight

Abstract

Breed additive and non-additive effects plus heritabilities and repeatabilities for milk yield per lactation (LMY), milk yield per day (DMY), lactation length (LL), annual milk yield (AMY), annual milk yield per metabolic body weight (AMYBW) and cow weight at calving (BW) were estimated for 5464 lactation records collected from purebred Boran (B), Friesian (F), and crosses of Friesian and Jersey (J) breeds with the Boran breed raised in the tropical highlands of Ethiopia. Single trait analysis was carried out by using two equivalent repeatability animal models. In the first model the genotype was fitted as a fixed group effect, while in the second model the genotype was substituted by breed additive, heterotic and recombination effects fitted as fixed covariates. Both the F and J breed additive effects, measured as a deviation from the B breed were significant (p < 0.01) for all traits, except for BW of the J. The F and J additive contributions were 2774 ± 81 and 1473 ± 362 kg for LMY, 7.1 ± 0.2 and 4.8 ± 0.8 kg for DMY, 152 ± 7 and 146 ± 31 days for LL, 2345 ± 71 and 1238 ± 319 kg for AMY, 20.6 ± 0.9 and 18.9 ± 4.3 kg for AMYBW, and 140 ± 4 and )21 ± 22 kg (p > 0.05) for BW. The heterotic contributions to the crossbred performance were also positive and significant (p < 0.01) for all traits. The F 1 heterosis expressed as a deviation from the mid-parent values were 22 and 66% for LMY, 11 and 20% for DMY, 29 and 29% for LL, 21 and 64% for AMY, 42 and 42% for AMYBW, and 2% (p < 0.05) and 11% for BW for the F · B and J · B crosses, respectively. The recombination effect estimated for the F · B crosses was negative and significant for LMY ()526 ± 192 kg, p < 0.01), DMY ()3.0 ± 0.4 kg, p < 0.001), AMY ()349 ± 174 kg, p < 0.05) and BW ()68 ± 11 kg, p < 0.001). For the J · B crosses the recombination loss was significant and negative only for DMY ()2.2 ± 0.7 kg, p < 0.05) and BW ()33 ± 17 kg, p < 0.05). The direct heritabilities (h 2 ) estimated for LMY, DMY, LL, AMY and AMYBW were 0.24 ± 0.04, 0.19 ± 0.03, 0.13 ± 0.03, 0.23 ± 0.04 and 0.17 ± 0.05, respectively. Based on the genetic parameters estimated, the best breeding strategy to increased milk production under highland Ethiopian conditions is to apply selection on purebred base populations (Boran and Friesian) and then crossing them to produce F 1 dairy cows. However, for breeding decision based on total dairy merit, further investigations are needed for traits such as milk quality, reproduction, longevity and survival. ZusammenfassungSchä tzung genetischer Parameter fü r Boran, Friesian und Kreuzungen von Friesian und Jersey mit Boran im tropischen Hochland von Ä thiopien: Milchproduktionsmerkmale und Kuhgewichte Additive Rasseneffekte, nicht additive Effekte, Heritabilitäten und Wiederholbarkeiten fü r Milchmenge pro Laktation (LMY), Milchmenge pro Tag (DMY), Laktationsdauer (LL), jährliche Milchmenge (AMY), jährliche Milchmenge pro metabolischem Kö rpergewicht (AMYBW) und Kuhgewichte zur Kalbung (BW) wurden anhand von 5464 Laktationsdatensätzen von reinrassigen...

Genetic evaluation of Ethiopian Boran cattle and their crosses with Holstein Friesian in central Ethiopia: milk production traits

“…Given the non-significant effect of calving season on milk production performance in the present study, it could be inferred that an improved management in the herds might have caused improvement in the performance traits. This result agrees well with other studies (Million and Tadelle, 2003;Demeke et al, 2004).…”

“…For example, 50% Holstein crosses had a fourfold increase over the Ethiopian Boran breed in terms of LYD, 305YD, DM and LTYD; they were also milked for 97 more days than Ethiopian Boran. Except for the magnitude of differences, the superior performance of crossbred progeny compared with the Ethiopian Boran for milk production traits is as expected and is in agreement with comparative results reported for Bos indicus and their crosses with European dairy breeds in the tropics (IAR, 1982;Kiwuwa et al, 1983;Thorpe et al, 1993;Rege et al, 1994;Udo et al, 1995;Demeke et al, 2004). When the crosses were compared, it was observed that as the exotic inheritance level increased, LYD, 305YD and DM showed an increasing trend.…”

“…0.05) was recorded between the second and subsequent parities. Significant changes in milk production for parity effect were also reported by Thorpe et al (1993), Rege et al (1994) and Demeke et al (2004).…”

“…Data collected for a long time on crossbreeding studies by different institutions has not been -E-mail: a.haile@cgiar.org systematically analyzed and documented to help in the design of sound and sustainable breeding program. Indeed, some studies compared indigenous cattle breeds with their contemporary crosses for dairy performance in Ethiopia (IAR, 1982;Kiwuwa et al, 1983;Haile-Mariam et al, 1993;Negussie et al, 1998;Demeke et al, 2004). Some workers (Haile-Mariam et al, 1993;Demeke et al, 2004) also estimated genetic parameters for the economic traits.…”

“…In Ethiopia, however, limited studies (Demeke et al, 2004;Million and Tadelle, 2004) estimated these crossbreeding parameters. Documented information on crossbreeding is scarce to base sound and sustainable breeding programs.…”