Estimation of 305-day yields from total milk yields in Bunaji and Friesian-Bunaji crosses
Malau-Aduli, A.E.O., and Abubakar, B.Y. (1991) Estimation of 305-day yields from total milk yields in Bunaji and Friesian-Bunaji crosses. In: Proceedings of the 16th Annual Conference of the Nigerian Society for Animal Production. p. 75. From: 16th Annual Conference of the Nigerian Society for Animal Production, 10-14 March 1991, Sokoto, Nigeria.
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Abstract
Lactation data of 207 cows comprising 91 Bunaji and 116 Friesian x Bunaji crosses milking for over 305 days were collected and analysed on the basis of the following variables: Average daily yield (ADY), actual 305-day yield (305-Y), total yield (TY) and lactation length (LL). The objective was to fit a suitable equation that would estimate 305-day yield from TY and to develop estimation factors. The linear regression equations for estimating 305-day yield from TY are Y = 185.229 + 0.804TY (R2 = 0.971) and Y = 366.176 + 0.775TY (R2 = 0.827) for Bunaji and Friesian x Bunaji cows respectively. Various combinations of TY, ADY and LL were used in multiple regressions to estimate 305-day yield with R2 values of over 90%. Factors for the estimation of weight records at birth, and at 3, 6, 9 and 12 months of age of half Friesian-Bunaji cows that calved over a twenty-three year (1967-1989) were computed. Least squares means ± S.E. of LL, TLY, 305DY, DDRY, AFC and CI were 250.563 ± 5.8 days, 1988.695 ± 108.7 kg, 2420.756 ± 93.8 kg, 102.333 ± 2.5 days, 35.638 ± 2.3 months and 390.312 ± 3.7 days, respectively. Parity, season and year of calving significantly affected LL, TLY (P<0.01) and 305DY (P<0.05), but not CI. DDRY was only affected by season of calving (P<0.01). Year of birth was highly significant (P<0.01) in affecting body weights at all ages, while month of birth was not. Season of birth was significant (P<0.05) for birth weight and body weights at 3 and 6 months of age.
Item ID: | 54950 |
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Item Type: | Conference Item (Abstract / Summary) |
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Date Deposited: | 09 Aug 2018 01:13 |
FoR Codes: | 07 AGRICULTURAL AND VETERINARY SCIENCES > 0702 Animal Production > 070201 Animal Breeding @ 100% |
SEO Codes: | 83 ANIMAL PRODUCTION AND ANIMAL PRIMARY PRODUCTS > 8303 Livestock Raising > 830302 Dairy Cattle @ 100% |
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