Increased yearling weight as a proportion of 21-month weight was associated with increased milk production in dairy heifers.
N Z Vet J
; 68(5): 272-282, 2020 Sep.
Article
em En
| MEDLINE
| ID: mdl-32248756
ABSTRACT
Aims:
To examine the relationship between liveweight (LWT) at 12 months as a proportion of LWT at 21 months of age (LWT(12/21)%) and first lactation and cumulative 3-year milk production in dairy heifers in New Zealand.Methods:
Liveweight and milk production records were obtained for dairy heifers born from June to December (spring-calving season) between 2006-2007 and 2013-2014 dairy seasons; production records included first lactation (n = 140,113) and cumulative 3-year (n = 67,833) milksolids and energy-corrected milk (ECM) yields. Heifers were classified into five breed groups; Holstein-Friesian, Holstein-Friesian crossbred, Jersey, Jersey crossbred and Holstein-Friesian-Jersey crossbred. Within each breed group heifers were categorised into quintiles based on 21-month LWT. The LWT(12/21)% was calculated for each animal. Relationships between LWT(12/21)% and milk production within each breed group and LWT category were estimated using linear mixed effects models including the linear and quadratic effects of LWT(12/21)%.Results:
The relationship between LWT(12/21)% and milk production was predominantly curvilinear, with lower milk production at lesser LWT(12/21)% compared with greater LWT(12/21)%. For all breed groups and most LWT categories, heifers that were 55 or 65% LWT(12/21)% produced greater ECM and milksolids yields compared with heifers that were 45% LWT(12/21)%. Holstein-Friesian, Holstein-Friesian crossbred and Holstein-Friesian-Jersey crossbred heifers that were 65% LWT(12/21)% produced greater cumulative 3-year ECM and milksolids yields compared with heifers of the same breed group that were 45% LWT(12/21)% Conclusions and clinical relevance Heifers that were a greater proportion of their 21-month LWT at 12 months of age produced more first lactation and cumulative 3-year milk yields than heifers that were a lesser proportion of their 21-month LWT at 12 months of age. These results indicate that increased growth in early life of New Zealand dairy heifers is beneficial to future milk production.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Peso Corporal
/
Lactação
/
Aumento de Peso
/
Leite
Tipo de estudo:
Risk_factors_studies
Limite:
Animals
País/Região como assunto:
Oceania
Idioma:
En
Revista:
N Z Vet J
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Nova Zelândia