. GENET~C AND NON-GENETIC FACTORS AFFECTING TOTAL MilK YJELDJ DAYS OPEN, NUMBER OF SERVICE

Hussein,, K.

doi:10.21608/jappmu.2004.239470

	. GENET~C AND NON-GENETIC FACTORS AFFECTING TOTAL MilK YJELDJ DAYS OPEN, NUMBER OF SERVICE " . PER -CONCEPTION AND AGE At FIRST CALVING OF FRIESIAN COWS tN EGYPT.
Journal of Animal and Poultry Production
Article 3, Volume 29, Issue 12, December 2004, Page 6843-6851 PDF (2.82 MB)
Document Type: Original Article
DOI: 10.21608/jappmu.2004.239470
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Author
K. Hussein,
Dept. of Animal Breeding, Animal Prod. Res. Institute, Ministry of Agric., Egypt.
Abstract
Tatar of "fl394 normal records of Friesian cows in first lactation sired by 146 d buus colrecte~ from Sakha Farm, Ministry of Agriculture. Egypt during the period from 1 ~7O- to 1<993< were used in this study. The data were used to estimate; the effects of non-genetic aad genetic (sire) factors on total milk yield (TMY) and some reproductive _ tFaits, namely days open (DO), number of service per conception (NSPC) and age at - first cawing (AFC), and to estimate genetic and phenotypic parameters for the previous traits. Data were analyzed using linear mixed mode] of Harvey's (1990). The results obtained could be summarized as follows:- The actual means of TMY. DO, NSPC and AFC were 339t.9 kg, 190.7 days. 2.2 service and 31.8 month, respectively. Coefficients of variation of TMY and some reproductive traits (DO, NSPC and AFC) were 42.8% and (34.7%, 59.3% and 16.8%), respectively. Mo:efh,of calving had significant (P< 0.05) effect on days open. while, non significant effeets en numb.er of servlce per conception, age at first calving and total milk yield. Year of calving, had highly significant (P< 0.01) effect on total milk yield and of reproductive traits under the presenf investigation. The sire had highly significant (P< 0.01) effects on total milk yield and days: open and only significant (P< 0.01) effects on number of service per conception. While, non significant effect on age at first calving. The sire variance component (cr²s) were 3.62%,6.13%,2.43% and 1.30% fbrTMY, DO, NSPC and AFC. respectively. The estimates of heritability of total milk yield and reproductive traits of the cows at their first ",arity (llased on parental half-sibs methods) were 0.15. 0.25, 0.10 and 0.Q5 for TM'l, DO, NSPC and AFC, respectively. O. Gel1letic correlations- between reproductive traits studied were positive and significant (P< 0.0.1), except NSPC with AFC it was negative and significant (P< 0.01). Phenotypic correlations between some reproductive studied traits were showed positive and significant (P< 0.01) values. Environmental correlation between reproductive traits studied were positive and highly significant (P< 0.01).
Keywords
Friesian; cattle; total milk yield; reproductive traits; genetic parameters


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. GENET~C AND NON-GENETIC FACTORS AFFECTING TOTAL MilK YJELDJ DAYS OPEN, NUMBER OF SERVICE " . PER -CONCEPTION AND AGE At FIRST CALVING OF FRIESIAN COWS tN EGYPT.