Evaluation of Canadian Holstein-Friesian Sires on Disposal Reasons of Their Daughters

Abstract

Data were lactations of 82,971 Canadian Holstein-Friesian cows by 4,778 sires recorded from 1975 to 1978 and included final disposal codes. Progeny were required to have first lactation records and were grouped according to whether they had the opportunity to complete one, two, or three lactations. Henderson's Method I technique was used to estimate sire, herd, and error variances within opportunity group for culling for low production, sickness, and all undesirable causes. Variances were low, and many were negative. Heritabilities ranged from 0 to .13. Best linear unbiased prediction techniques were used to estimate sire proofs for disposal reasons. Sire proofs were not distributed normally. Sire proofs were correlated between opportunity groups within disposal reason. All correlations were positive and ranged from .21 to .82. Correlations were greatest between contiguous opportunity groups and lowest between proofs on early opportunity groups and proofs on cows that were close to maturity, indicating that first opportunity group proofs for disposal are not accurate predictors of longevity. Routine evaluation of sires on disposal reasons is not recommended.

Heritability and economics of survival rate

“…RESULTS AND DISCUSSION Table 4 gives the estimates of the variance components for 2-year-aIds, 3-year -aIds, and all age groups in the binary scale. These estimates generally agree with those reported by Schaeffer et al (1974), Westall et al (1982), and Dong et al (1987). Table 5 gives the corresponding estimates of heritability on the binary and the underlying normal scale.…”

The Association Between Clinical Disease, Production and Culling of Holstein-Friesian Cows

“…In a recent study of reasons for culling using ROP data (Westell 1980) (Martin et al 1978) may be due to the combination of parturient and…”

“…A study of the association between disease occurrence, level of production and culling in 18 In an attempt to identify genetic factors as indirect reasons for culling, researchers have examined the association of sires and sire-proofs to culling but were able to explain only a small percentage of the variation in culling (Westell 1980 The association between production, disease and culling was investigated using discriminant analyses (Nie et al 1975 For personal use only. In a recent study of reasons for culling using ROP data (Westell 1980) (Martin et al 1978) may be due to the combination of parturient and…”

Economic analysis of alternative breeding programs

“…Deterioration of performance in fitness traits, with heavy emphasis on milk yield has been noticed by many producers (74), and researchers (2,7,8,19,33,58), and some as a cause to higher expenses (13,16,28,38,70,74). Although selection for high yield does not necessarily decrease total survival rates of the cow from birth through the early first lactation (41), high yield early in lactation was suggested to increase health disorders and increase involuntary culling (18,59).…”

“…Reduction in reproductive performance could affect culling rates and herd life, and reduce the genetic gain from primary traits (3,49). Currently, reproductive failures contribute a substantial proportion of total cow disposals, 16% in the US (13) and 25% in Canada (70). Fertility, often measured by age at first calving, days open, calving Interval, or number of services, is a major component of reproductive performance.…”