J. I. Sánchez-Duarte, Alvaro García, K. Rodríguez-Hernández, David G. Reta-Sánchez, Homero Salinas-González, E. Ochoa-Martínez, Arturo Reyes-González
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引用次数: 6
Abstract
The objective was to evaluate the effects of two (2×) vs three (3×) times per day milking on milk production and milk composition in dairy cows. Fourteen scientific papers, containing production data from 16 trials, where dairy cows were milked 2× or 3×, were analysed using meta-analysis with fixed and random-effects with the R statistical program. The degree of heterogeneity and publication bias were measured with the I2 statistic and Begg’s test, respectively. In addition, the meta-regression analysis explored other sources of heterogeneity for the response. The estimated effect size of 2× and 3× milkings was calculated for dry matter intake (DMI), milk production, and milk composition. Dry matter intake, milk production, and milk fat and protein yields showed substantial heterogeneity (I2>50%). Whereas milk fat-percentage had moderate heterogeneity (I2 .05). Cows milked 2× produced less milk (2.23 kg/d), less milk fat (0.06kg/d), and less milk protein (0.05 kg/d). In contrast, the fat percentage was lower (0.07 units) in 3×, compared with 2× milking frequency. There was no effect of milking frequency on DMI and milk protein percentage. In conclusion, milk production and milk fat and protein yields improves as milking frequency increase from 2× to 3× daily, without affecting DMI. The implementation of 3× milking frequency must consider dairy cow management, labor, and milking parlour infrastructure, particular to each dairy farm.
期刊介绍:
Veterinaria México OA (ISSN 2448-6760) is an online scientific journal edited by Universidad Nacional Autónoma de México (UNAM). The journal is Open Access and follows UNAM''s initiative, to transmit knowledge free of charge to the readership and authors, with no Article Processing Charges.
This journal publishes advances in Veterinary Sciences and Animal Production, and to reach more lectures across the world the journal was updated since 2014 from its predecessor printed in paper Veterinaria México (ISSN 0301-5092) and its digital version (ISSN 2007-5472).