Implementation of a Routine Genetic Evaluation for Longevity Based on Survival Analysis Techniques in Dairy Cattle Populations in Switzerland

Abstract

Genetic evaluation of sires for functional longevity of their daughters based on survival analysis has been implemented in the populations of Braunvieh, Simmental, and Holstein cattle in Switzerland. A Weibull mixed sire-maternal grandsire survival model was used to estimate breeding values of sires with data on cows that calved since April 1, 1980. Data on Braunvieh and Simmental cows included about 1.1 million records, data on Holstein cows comprised about 220,000 records. Data contained approximately 20 to 24% right-censored records and 6 to 9% left-truncated records. Besides the random sire and maternal grandsire effects, the model included effects of herd-year-season, age at first calving, parity, stage of lactation, alpine pasturing (Braunvieh and Simmental), and relative milk yield and relative fat and protein percentage within herd to account for culling for production. Heritability of functional longevity, estimated on a subset of data including approximately 150,000 animals, were 0.181, 0.198, and 0.184 for Braunvieh, Simmental, and Holstein, respectively. Breeding values were estimated for all sires with at least six daughters or three granddaughters in the data. Breeding values of sires are expressed in months of functional productive life and published in sire catalogs along with breeding values for production traits.

Comparison of piecewise Weibull baseline survival models for estimation of true and functional longevity in Brown cattle raised in small herds

“…Cows with an extremely low milk yield were mainly culled in the first lactation, which is in agreement with the studies by Vukasinovic et al (2001), Roxströ m and Strandberg (2002) and Ducrocq (2005). These similarities with other studies show that creating milk yield classes as a function of herd size group and at a population level is not detrimental and can be applied in practice for the estimation of functional longevity in small herds.…”

“…Many other studies, mainly in the Holstein breed (e.g. Dü rr et al, 1999) and some other breeds, for example, Pintzgau (Mèszá ros et al, 2008), Braunvieh and Simmental (Vukasinovic et al, 2001), found that the age at first calving had an impact on productive life. One explanation for these differences might be given by Bielfeldt et al (2006), who found out that the target age at first calving significantly differed between herd management systems.…”

Influence of age, body weight and body condition score before mating start date on the pubertal rate of maiden Holstein–Friesian heifers and implications for subsequent cow performance and profitability

“…Lin et al (1988), however, reported that a reduction in milk yield was confined to first lactation, with heifers mated at a younger age producing similar amounts of milk in subsequent lactations. Vukasinovic et al (2001) found that the risk of being culled increased linearly with increasing age at first calving. This was attributed to decreased fertility in older (later calving) heifers.…”

The association between age at first calving and survival of first lactation heifers within dairy herds

“…The impact of AFC on survival of animals has been debated in the literature with significant associations being found in some studies, but not in others (Ducrocq, 1994;Lin et al, 1988;Vukasinovic et al, 1997 and2001;Ojango et al, 2005). Studies that have shown an impact of AFC on survival have reported that the relative risk of culling heifers is higher in animals older at first calving (Pirlo et al, 2000;Berry and Cromie, 2009;Chirinos et al, 2015).…”