Variance of daily milk yield as an indicator trait in Czech Holstein cows

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00027014%3A_____%2F24%3A10006035" target="_blank" >RIV/00027014:_____/24:10006035 - isvavai.cz</a>

Výsledek na webu

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DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Variance of daily milk yield as an indicator trait in Czech Holstein cows

Popis výsledku v původním jazyce

Fluctuations in daily milk yield (DMY) could be used as an indicator of the health and resilience of dairy cows. We evaluated the natural logarithm of DMY variance (LnVar) in 2,468 Holstein cows distributed on 9 farms. The data were collected between October 2022 and January 2024. Cows were required to have records for at least 20 successive days with the first day in milk (DIM) &lt;50 and the last day up to 150 DIM. DMY ranged between 3 and 76 kg with a mean of 41 kg of milk per cow and day. The estimation of heritability (h2=0.2) and genomic breeding values (GEBV) was based on a single trait linear animal model and performed with a single-step GBLUP method (BLUPF90 family of programs). The model included fixed effects of the farm*year of calving, the season of calving, the lactation order and the minimum and maximum observed DIM, the random effect of animals (1,878 animals were genotyped with Illumina BovineSNP50 BeadChip) and the random residual. Sires were divided according to their GEBV to lower quartile (Q1, low variance) and upper quartile (Q3, high variance). The data of all their daughters were added from the national database, and their performance in the first three lactations was compared. Q1 daughters had lower milk (-366 kg in first, -142 kg in second and -113 kg in third lactation), protein (-7/-3/-1 kg), fat (-6/0/0 kg) and lactose (-14/-8/-6 kg) production, lower somatic cells count (-10,000/-16,000/-24,000 cells in ml of milk), shorter interval from calving to the first insemination (-1/-1/-1 day) and from calving to conception (-2/-4/-4 days). The two groups did not differ significantly in the number of lactations completed or in the reasons for culling. The study was supported by the Ministry of Agriculture of the Czech Republic, project QK22020280 and institutional support MZE-RO0723-V02.

Název v anglickém jazyce

Variance of daily milk yield as an indicator trait in Czech Holstein cows

Popis výsledku anglicky

Fluctuations in daily milk yield (DMY) could be used as an indicator of the health and resilience of dairy cows. We evaluated the natural logarithm of DMY variance (LnVar) in 2,468 Holstein cows distributed on 9 farms. The data were collected between October 2022 and January 2024. Cows were required to have records for at least 20 successive days with the first day in milk (DIM) &lt;50 and the last day up to 150 DIM. DMY ranged between 3 and 76 kg with a mean of 41 kg of milk per cow and day. The estimation of heritability (h2=0.2) and genomic breeding values (GEBV) was based on a single trait linear animal model and performed with a single-step GBLUP method (BLUPF90 family of programs). The model included fixed effects of the farm*year of calving, the season of calving, the lactation order and the minimum and maximum observed DIM, the random effect of animals (1,878 animals were genotyped with Illumina BovineSNP50 BeadChip) and the random residual. Sires were divided according to their GEBV to lower quartile (Q1, low variance) and upper quartile (Q3, high variance). The data of all their daughters were added from the national database, and their performance in the first three lactations was compared. Q1 daughters had lower milk (-366 kg in first, -142 kg in second and -113 kg in third lactation), protein (-7/-3/-1 kg), fat (-6/0/0 kg) and lactose (-14/-8/-6 kg) production, lower somatic cells count (-10,000/-16,000/-24,000 cells in ml of milk), shorter interval from calving to the first insemination (-1/-1/-1 day) and from calving to conception (-2/-4/-4 days). The two groups did not differ significantly in the number of lactations completed or in the reasons for culling. The study was supported by the Ministry of Agriculture of the Czech Republic, project QK22020280 and institutional support MZE-RO0723-V02.

Druh

O - Ostatní výsledky

CEP obor

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OECD FORD obor

40203 - Husbandry

Projekt

<a href="/cs/project/QK22020280" target="_blank" >QK22020280: Využití genomické selekce pro optimalizaci resilience dojeného skotu</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2024

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů