PRELIMINARY MODEL TO INVESTIGATE CULLING AND REPLACEMENT POLICY IN DAIRY HERDS

被引：17

作者：

GARTNER, JA ^{[1
]}

HERBERT, WA ^{[1
]}

机构：

[1] MILK MARKETING BOARD,READING,ENGLAND

来源：

AGRICULTURAL SYSTEMS | 1979年 / 4卷 / 03期

关键词：

D O I：

10.1016/0308-521X(79)90030-1

中图分类号：

S [农业科学];

学科分类号：

09 ;

摘要：

Replacement policy in dairy herds is not easy to determine when heifers are both home-reared and compete for land with the cows. The difficulty lies in evaluating quantitatively the advantages and disadvantages of low and high replacement rates. A computer simulation model was developed to examine the effects of different replacement rates on genetic improvement in yield per cow, milk output and farm profit at two levels of culling for reasons other than insufficient yield. The working hypothesis suggested by the results is that profitability falls as replacement rate increases because the number of cows able to be milked and the maturity of the herd over-ride the gains in milk yield per cow due to genetic improvement by yield culling and the greater use of a sire of high genetic merit. © 1979.

引用

页码：189 / 215

页数：27

共 16 条

[1]

BEYNON VH, 1974, 192 U EX AGR EC UN R

[2]

LUXTON HWB, 1976, 196 U EX AGR EC UN R

[3]

MCARTHUR A T G, 1973, Proceedings of the New Zealand Society of Animal Production, V33, P141

[4]

MORRIS DW, 1976, PRACTICAL MILK PRODU, V2, P95