The effect of age at calving on reproduction, milk production and disease incidence in the first lactation of dairy heifers
| Autor: | B.P. van Dam, Paul C. Bartlett, Edward C. Mather, J.H. Kirk |
|---|---|
| Rok vydání: | 1987 |
| Předmět: |
Equine
animal diseases media_common.quotation_subject Incidence (epidemiology) Day of life Ice calving Biology medicine.disease Herd health Milk production medicine.anatomical_structure Animal science Food Animals Lactation medicine Animal Science and Zoology Ketosis Reproduction Small Animals media_common |
| Zdroj: | Theriogenology. 30(3) |
| ISSN: | 0093-691X |
| Popis: | Herd health and production records of 1161 Holstein-Friesian heifers from 22 Michigan dairy herds were utilized to study the effect of age at first calving upon reproductive efficiency, milk production and the incidence of disease in the first lactation. Age at first calving was not significantly related to either milk production or reproductive efficiency. Heifers displaying dystocia were significantly older at calving than those that calved without problems. Additionally, the incidence of ketosis was associated with a significantly greater age at first calving. Heifers with diarrhea and those that aborted were significantly younger at calving than their herdmates. Incidence of 12 other common dairy diseases was not related to age at first calving. It would, therefore, appear that the dairy producers we studied could inseminate their heifers at an earlier age, and thereby increase production per day of life, without suffering serious detrimental effects in lactational milk production, reproductive efficiency or overall disease incidence. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|