Economic consequences of selecting for milk fat and protein

Revista Brasileira de Zootecnia

Madalena, Fernando Enrique¹ 

[1] UFMG

关键词: dairy cattle;    economic values;    milk fat;    milk protein;    selection index     IntroduçãoOs preços pagos ao produtor pela gordura e pela proteína são menores no Brasil em relação aos principais países produtores de leite;    ao passo que o "veículo" (leite sem proteína nem gordura;    "carrier" (PEARSON e MILLER;    1981);    que;    em muitos países tem preços muito baixos ou negativos;    é remunerado aqui a preços mais altos (VERCESI FILHO et al;   

DOI  :  10.1590/S1516-35982000000300007

学科分类：兽医学

来源: Universidade Federal de Vicosa

【 摘 要 】

- The objective of this work was to exam the convenience of paying for the genetic value of protein and fat in imported semen using the technique of discounted gene flow, based on economic values derived in a parallel paper and literature biological parameters. In the State Parana, semen of Holstein sires positive for protein and fat could be economic, depending on its cost, while in Minas Gerais such sires would be unprofitable. Genetic trends for protein and fat in Brazilian Holsteins, estimated from literature results, were, respectively, 0.181 and 0.237 kg/lactation, corresponding to an economic gain of R$0.357/lactation using the Parana economic values and a loss of R$ 0.112 /lactation using the values of Minas Gerais. Individual selection on an index of milk components based on Minas Gerais values would result, upon a gain of one standard deviation of the index, in a gain of R$31.27 per lactation if prices were to remain unchanged, but only in R$10.27 if prices were those of New Zealand, taken as an example of competitor country. On the other hand, selecting on an appropriated index for New Zealand would result in a gain of R$37.06 per lactation if Brazilian prices changed and R$9.66 if prices remained the same. The index based on the Parana values behaved intermediary between those two and similarly to selecting on milk yield only. Progeny test selection indexes had similar results, although the differences between the various indexes were smaller.

【 授权许可】

CC BY-NC