SciELO - Scientific Electronic Library Online

 
vol.30 número3Ferramentas ultrassonográficas para avaliação do baço em cães: Revisão da literatura índice de autoresíndice de assuntospesquisa de artigos
Home Pagelista alfabética de periódicos  

Serviços Personalizados

Journal

Artigo

Indicadores

Links relacionados

  • Em processo de indexaçãoCitado por Google
  • Não possue artigos similaresSimilares em SciELO
  • Em processo de indexaçãoSimilares em Google

Compartilhar


Revista Colombiana de Ciencias Pecuarias

versão impressa ISSN 0120-0690

Resumo

SANCHEZ-DUARTE*, Juan I.  e  GARCIA, Álvaro. Ammonia-N concentration in alfalfa silage and its effects on dairy cow performance: A meta-analysis. Rev Colom Cienc Pecua [online]. 2017, vol.30, n.3, pp.175-184. ISSN 0120-0690.  https://doi.org/10.17533/udea.rccp.v30n3a01.

Background:

Ammonia nitrogen (N) in alfalfa silage is used to evaluate silage quality, but its effect on dairy cows production is unknown.

Objective:

A meta-analysis was conducted to assess the effects of ammonia-N concentration in alfalfa silage on dairy cow performance.

Methods:

Thirty-four comparisons from 10 studies were analyzed with linear and quadratic models by the mixed-effect models of the R program using study as a random effect. The variance explained by the models was evaluated calculating marginal R2 (m) and conditional R2 (c) .

Results:

Dry matter intake declined (DMI; p = 0.007), and milk production and milk fat yield tended to decrease linearly in response to increasing ammonia-N concentration (p = 0.08). Milk fat and milk protein percentages were unaffected. Milk protein yield, however, showed a positive linear trend effect (p = 0.07) along with a significant quadratic effect (p = 0.01) in response to increasing ammonia-N concentration. Values of R2 (m) and R2 (c) indicated less variation for significant models.

Conclusion:

Increased ammonia-N in alfalfa silage reduced DMI, negatively impacting milk production and milk fat yield. The quadratic response in milk protein yield might be explained by the initial reduction in milk product

ion, and the subsequent utilization of ammonia-N to produce more rumen microbial protein, which results in more milk protein.

Palavras-chave : dairy cattle; Medicago sativa L.; milk fat; milk protein; milk yield; regression model.

        · resumo em Português | Espanhol     · texto em Inglês     · Inglês ( pdf )