Resumo

JARAMILLO-JAIMES, M. Teresa et al. Productive response and metabolic profiles and their effect on open days during early lactation in holstein cows. Agrociencia [online]. 2008, vol.42, n.3, pp.267-275. ISSN 2521-9766.

The relationship between productive variables and the serum levels of metabolites that can affect the number of open days (OD) during early lactation, was studied in 35 multiparous Holstein cows. The cows were classified in four groups according to the OD (I: 80 OD; II: 80 to 110 OD; III: 111 to 150 OD and IV: > 150 OD). The changes in weight, body condition (BC) and milk production were evaluated weekly, along with the serum levels of protein (PT), ureic nitrogen (N-UREA), low density lipoproteins (LDL) and cholesterol (CT). The experimental design was completely randomized and the data were analyzed as repeated measurements; in addition, a test of regression homogeneity was made along with an analysis of correlation. Milk production and weight gain were not statistically different. The BC was different (p<0.01), for a contrast between group I against groups II, III and IV, and different (p<0.05) for a second contrast between groups II and III. In the metabolites there were only differences (p<0.01) for proteins among the groups with the highest number of OD. There was a high correlation between CT and milk production (R = 0.53), the week of post-partum (R = 0.72) and the LDL (R=0.61). It is concluded that the productive variables and metabolites in this study do not influence the reproductive function reflected in the OD of Holstein cows in early lactation.

Palavras-chave : Open days; serum metabolites; early lactation; Holstein cows; productive variables.

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