Effects of original source of dairy cows, season and age on milk production in Botswana
2011
Mpapho, G.S. | Dambe, L. | Nsoso, Shalaulani James
The objective of the study was to determine the effects of animal and environmental factors on milk yield of Holstein dairy cows kept under intensive system in Botswana. A total of 768 monthly records of 27 Holstein cows of different parities were recorded over 5 years (2004- 2008) at Botswana College of Agriculture (BCA) dairy farm were used. The data was analyzed using General Linear Model of Statistical Analysis System. Higher (p<0.05) higher milk yield was recorded in spring (14.42±0.36 kg/d) than in winter (11.27±0.35 kg/d) with other seasons being intermediate. Third parity cows produced more milk (14.65±1.03 kg/d) than first calvers (11.60±0.66 kg/d). Although not significantly (p>0.05) different, the third parity corresponded with greater lactation yield than the others. Lactation length for third parity was 369.91±57.20days. Milk yield was significantly higher at 4 years of age (16.02±0.51 kg/d) than at 9 years (10.96±0.79 kg/d) and 10 years of age (5.85± 1.15 kg/d). Although the amount of milk produced by cows that were sourced from South African farms (15.26±1.52 kg/d) was higher than those sourced from Botswana College of Agriculture (11.89±1.16 kg/d) and Animal Production Research Unit (11.19. ±1.20 kg/d), these did not differ significantly. Farms should have more cows lactating in spring and at parities and ages that maximize milk yield.
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