Analysis of longevity in Slovenian holstein cattle

Potočnik, Klemen; Gantner, Vesna; Krsnik, Jurij; Štepec, Miran; Logar, Betka

doi:10.2478/v10014-011-0025-5

Cited by 11 publications

(12 citation statements)

References 13 publications

(15 reference statements)

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“…Strapakova et al (2014) stated that the subsequent risk ratio increased moderately at the end of the first parity and that the trend of culling risk was similar across and along each parity. Potocnik et al (2011) reported that risk level at the end of parity can increase significantly 271 days after the start of milking and during dry periods, which is in agreement with our findings. Vukasinovic (2001) found that cows in the first parity were more vulnerable to culling than those at parity four and also increased gradually after that point, which indicated different selection criteria in the first parity; culling risk also increased after this parity.…”

Section: Interaction Between Parity × Stage Of Lactation and Proportisupporting

confidence: 83%

Genetic analysis of productive life length in Holstein dairy cows using Weibull proportional risk model

et al. 2016

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Abstract. In recent decades, there has been a downward trend in length of productive life (LPL) in Holstein cows across industrial dairy herds. This study examined the factors that might influence LPL and estimated the genetic parameters of LPL in Holstein dairy herds in Isfahan province, Iran. LPL is defined as the number of days between the first calving and the end of recording. Data consisted of 35 137 records of productive life from registered cows that started first calving between 1991 and 2012. Cows that remained alive at the end of the study were considered right-censored. The average lifetime for culled and censored cows was 938 and 1003 days, respectively. A survival analysis was applied using a proportional risk model with a Weibull distribution. Milk production was divided into five groups, where the culling risk of cows with a milk yield of less than 1.5 standard deviations (SD) of the mean was 3.5 times greater than the culling risk of high-producing cows producing more than 1.5 SD above the mean. Results showed that culling risk increased almost linearly beyond the milk production groups. Furthermore, somatic cell count and age at first calving significantly increased the culling risk across the herds. The results for the combined effect of parity × stage of lactation showed a decrease in culling risk during the first calving, and an increase during the further parities. Moreover, a higher age at first calving was observed, reflecting a lower risk of culling. Estimated heritability were 0.074 and 0.18 based on a logarithmic scale and original scale, respectively. According to the results, use of Weibull models showed that the proportional culling risk was higher in low-production cows, but a higher risk ratio was revealed in high-milk-production cows. However, there were some fluctuations in genetic trends, but an overall increase was observed in LPL which will lead to a longer LPL of Holstein cows in Isfahan province.

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Section: Interaction Between Parity × Stage Of Lactation and Proportisupporting

confidence: 83%

Genetic analysis of productive life length in Holstein dairy cows using Weibull proportional risk model

et al. 2016

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“…These results are similar to those observed by Zavadilová and Stípková (2012), who reported a genetic correlation between rump width and Long2 of -0.15, and less than that observed by Cruickshank et al (2002) and Zavadilová and Stípková (2012), who found correlations between rump width and Long5 of -0.27 and Long4 of -0.29, in Jersey and Holstein cows, respectively. Rump traits are associated with calving ease, this being important for the dairy industry, where cows with calving problems are less profitable due to the increase in veterinary costs and The average for Long2 (2.66) ( Table 3) was similar to that observed in dairy cows in the United States of America by Tsuruta et al (2005), with an average of 2.8 initiated lactations, slightly lower than those reported by Potočnik et al (2011) in Slovenia and Strapák et al (2011) in Slovakia, with averages of 3.0 and 3.4 lactations initiated, respectively, for Holsteins and Simmental dairy cows.…”

Section: Resultsmentioning

confidence: 71%

Genetic association between longevity and linear type traits of Holstein cows

Kern

Cobuci

Costa

et al. 2015

Sci. agric. (Piracicaba, Braz.)

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Longevity is a desirable trait in the dairy industry because of its relationship to profitability. The aim of this study was to estimate genetic parameters for longevity measurements related to productive life, or life in the herd, and linear type traits of Brazilian Holstein cows born between the years 1990 and 2008. The (co) variance components were estimated by the restricted maximum likelihood method. The heritability for measurements of longevity and linear type traits ranged from 0.05 to 0.07 and 0.08 to 0.39, respectively. The genetic correlations between measurements of longevity and linear type traits ranged from -0.39 to 0.31. Direct selection for longevity does not necessarily lead to long-lived cows, due to low heritability. Indirect genetic selection for udder depth, bone quality, udder height, rear teat placement and conformation traits showed the highest genetic correlations with measurements of time between birth and last milk record and time from first calving to last milk record.

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“…Longevity genetic evaluation for the Brown dairy cattle population in Slovenia was first implemented by Potočnik et al (2011). Breeding values were estimated using a unique baseline hazard for the whole period considered.…”

Section: Introductionmentioning

confidence: 99%

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

Jenko

Ducrocq

Kovač

2013

Animal

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Piecewise Weibull proportional hazard models were used to investigate the effect of genetic and nongenetic factors on functional and true longevity traits of the Slovenian Brown cattle breed. Records of 37 908 Brown cows from 2401 Slovenian herds were used. As these herds were characterised by a relatively small average herd size starting from 6.7 in 1999 and increasing to 8.7 Brown cows per herd in 2008, milk yield classification was made within different herd size groups. The hazard rate was the lowest in the first part of each lactation and was increasing for later stages. Culling risk was lower for cows from herds increasing in size, for cows with higher milk production and for cows from a region with smaller herd sizes and tougher conditions for cattle breeding. The latter result is surprising and may be related to better attention to maintain the animals, despite their lower milk production. The introduction of the milk quota system and drought was found to have an important effect on culling policy between the last seasons of the years 2001 and 2003. Seasonal effects were not related to the milk quota year (from April to March), but to the effect of shortage in fodder during the winter time. The effect of age at first calving and the interaction between year and milk yield class were not found to be significant. Heritability for functional and for true longevity were similar at around 10% each. Inclusion of a correction for class of milk yield to approximate functional longevity increased the herd-year random effect variance by 53%, whereas the sire variance increased by only 14%. The correlation coefficient between ranks of breeding values for functional and true longevity was high (0.91), whereas genetic trends were not found to be significant. To assess their predictive ability, models were compared looking at the survival rate of 4212 second-crop daughters not included in the initial models. The average correlation between estimated breeding values and survival at different stages was 0.39 for true longevity and 0.43 for functional longevity. Results showed that ranking milk yield at population level is appropriate to correct for voluntary culling on low production in small herds.

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Analysis of longevity in Slovenian holstein cattle

Cited by 11 publications

References 13 publications

Genetic analysis of productive life length in Holstein dairy cows using Weibull proportional risk model

Genetic analysis of productive life length in Holstein dairy cows using Weibull proportional risk model

Genetic association between longevity and linear type traits of Holstein cows

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

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