Services on Demand
Journal
Article
Indicators
Cited by SciELO
Access statistics
Related links
Similars in SciELO
Share
Agronomía Mesoamericana
On-line version ISSN 2215-3608Print version ISSN 1659-1321
Abstract
CASTILLO-BADILLA, Gloriana; SALAZAR-CARRANZA, Mauren; MURILLO-HERRERA, Jaime and ROMERO-ZUNIGA, Juan José. Effect of age at first calving on productive parameters in Costa Rican Jersey cows. Agron. Mesoam [online]. 2013, vol.24, n.1, pp.177-187. ISSN 2215-3608.
The objective of this work was to quantify the effect of age at first calving (AFC) on milk production in the first and second lactation of specialized diary Jersey cows. Records of 28 367 cows belonging to 545 specialized dairy herds, registered in the software VAMPP Bovino 3.0 between January 2000 and December 2010, were used. Descriptive statistics and linear mixed models were performed. The AFC average was 29.35 months (SD: 6.77), with a trend to increase during the study period. A significant effect of the AFC was observed on milk production (kg/305d) in the first two lactations (P<0.0001); in the first lactation, cows with AFC < 25.8 months or between 25.8 and 41.0 months produced -275.81 and -167.70 kg/305d (P<0.0001) than those with AFC >41 months. Cows without retained placenta (RMF) produced +450 kg/305 d (P= 0.0022) than those with RMF. On the other hand, the inbreeding coefficient and type of birth had no effect on milk production. In the second lactation, the independent variables affected the milk production similarly to first lactation; however, the age at second calving did not affect the subsequent production. This study demonstrates the linear effect of AFC on first and second lactation milk production; thus, AFC seems to have an effect not only on first lactation, but also in the productive performance of second lactation.
Keywords : milk production; first lactation; age at first calving; Jersey.