USE OF LATER RECORDS IN DAIRY SIRE EVALUATION

1978 ◽  
Vol 58 (4) ◽  
pp. 615-620 ◽  
Author(s):  
H. H. NICHOLSON ◽  
L. R. SCHAEFFER ◽  
E. B. BURNSIDE ◽  
M. G. FREEMAN
Keyword(s):  
Artificial Insemination ◽  
Selection Intensity ◽  
Evaluation Procedures ◽  
Sire Evaluation ◽  
Percentage Survival ◽  
Highly Correlated ◽  
Dairy Sire ◽  
Sire Selection

First, second, and third lactation Ontario Record of Performance (ROP) 305-day milk records were analyzed separately to evaluate 246 Holstein sires. Second and third lactation records were analyzed with and without adjustment for realized selection intensity of each bull’s daughters on the basis of first lactation yield. The magnitude of adjustments for selection was small, but adjusted records gave sire proofs for second and third lactations that had a variance similar to proofs based on first lactation records. Proofs using adjusted records were more highly correlated with first lactation proofs and with percentage survival figures. One bull out of six significantly reranked on the basis of second or third lactation proofs compared to first lactation proofs. There possibly exists a sire by age of daughter interaction, but the size of the interchange does not warrant an immediate change in sire evaluation procedures or artificial insemination organization sire selection programs.

scholarly journals Costs and Risks for Sire Selection Strategies in Artificial Insemination

1981 ◽  
Vol 64 (3) ◽  
pp. 491-496 ◽  
Author(s):  
M. Schneeberger ◽  
A.E. Freeman ◽  
P.J. Berger
Keyword(s):  
Artificial Insemination ◽  
Selection Strategies ◽  
Sire Selection

scholarly journals Effect of Heterogeneity of Variance on Dairy Sire Evaluation

1988 ◽  
Vol 71 (11) ◽  
pp. 3033-3039 ◽  
Author(s):  
A. Winkelman ◽  
L.R. Schaeffer
Keyword(s):  
Sire Evaluation ◽  
Heterogeneity Of Variance ◽  
Dairy Sire

INTERRELATIONS BETWEEN SOME REPRODUCTIVE TRAITS IN SWINE

1972 ◽  
Vol 52 (1) ◽  
pp. 39-45 ◽  
Author(s):  
M. H. FAHMY ◽  
C. S. BERNARD
Keyword(s):  
Litter Size ◽  
Survival Rates ◽  
Reproductive Traits ◽  
The Other ◽  
Gestation Length ◽  
Percentage Survival ◽  
Weaning Pig ◽  
Highly Correlated ◽  
Daily Gain ◽  
Size At Birth

The associations between 15 preweaning traits in pigs were studied to determine which had the most important effects on litter weights at birth and weaning. The traits were litter size at birth and weaning, number born alive, percentage survival to birth and weaning, pig and litter weights at birth and weaning, daily gain from birth to weaning, gestation length, number of teats, weights of dam at farrowing and at weaning, and the change in dam weight during lactation. Of the 105 correlations, 66 were statistically significant, though many were markedly low. Litter weights at birth and weaning were significantly and relatively highly correlated with most of the other traits, whereas number of teats was correlated only with survival rates at birth and weaning and pig birth weight. The results showed that the importance of litter size was almost twice that of pig weight in determining litter weights at birth and weaning. The results in general indicated that most of the economically important traits related to swine reproductivity are favorably associated.

A note on the properties of the cumulative difference method for sire evaluation

1976 ◽  
Vol 23 (1) ◽  
pp. 121-124 ◽  
Author(s):  
L. Dempfle
Keyword(s):  
Difference Method ◽  
Evaluation Methods ◽  
Sire Evaluation ◽  
Genetic Level ◽  
Cumulative Difference ◽  
Dairy Sire

SUMMARYSeveral of the various dairy sire evaluation methods now in use account for the genetic level of contemporary herdmates. In the cumulative difference method of Bar-Anan and Sacks the contemporary comparison estimate is first calculated and then adjusted by taking into account the genetic level of the contemporaries. These estimates depend on the genetic level of the herdmates. A modification of the procedure in which account is taken of the herdmates' genotype before regressing for small numbers would remedy this deficiency without increasing computing costs.

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