منابع مشابه
Relationship of sire expected progeny differences to milk yield in Brangus cows.
Milk yield from 160 Brangus cows sired by 65 Brangus bulls was measured over a 3-yr period with a single-cow milking machine to estimate the relationship of actual milk yield of daughters and their calves' BW with cow sire EPD for milk during the preweaning period. Milk yield was measured six times per year at an average 49, 78, 109, 138, 168, and 198 d postpartum. The regression of daughters' ...
متن کاملMATERNAL PERFORMANCE OF FIRST-CALF CROSSBRED BEEF COWS IN RELATION TO SIRE EXPECTED PROGENY DIFFERENCES (EPDs)
Cumulative milk production of crossbred daughters of sires of several breeds was estimated using weigh-suckle-weigh procedures. Pooled-across-breed analyses were conducted to determine, in retrospect, relationships of sire expected progeny difference (EPD) values for milk and total maternal value to daughter milk yield and daughter's offspring weaning weight. The pooled coefficient for regressi...
متن کاملOpposing effects of mortality factors on progeny operational sex ratio may thwart adaptive manipulation of primary sex ratio
Despite extensive research on mechanisms generating biases in sex ratios, the capacity of natural enemies to shift or further skew operational sex ratios following sex allocation and parental care remains largely unstudied in natural populations. Male cocoons of the sawfly Neodiprion abietis (Hymenoptera: Diprionidae) are consistently smaller than those of females, with very little overlap, and...
متن کاملSex effects on breed of sire differences for birth, weaning, and yearling weights.
Weights of males and females can be considered to be correlated traits with different averages and variances. This study attempted to determine whether defining traits as expressed in males or in females would change estimates of breed of sire differences needed to calculate across-breed factors for adjustment of within-breed EPD to across-breed EPD. Records from the US Meat Animal Research Cen...
متن کاملComparison of sire breed solutions for growth traits adjusted by mean expected progeny differences to a 1993 base.
Records on growth traits were obtained from five Midwestern agricultural experiment stations as part of a beef cattle crossbreeding project (NC-196). Records on birth weight (BWT, n =3,490), weaning weight (WWT, n = 3,237), and yearling weight (YWT, n = 1,372) were analyzed within locations and pooled across locations to obtain estimates of breed of sire differences. Solutions for breed of sire...
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ژورنال
عنوان ژورنال: Journal of Dairy Science
سال: 1975
ISSN: 0022-0302
DOI: 10.3168/jds.s0022-0302(75)84775-8