| Autor: |
R.D. Mascarenhas, A.V. Portugal, M.I.A.M. Rios Vasques, A.E.M. Horta, J. Robalo Silva |
| Rok vydání: |
1986 |
| Předmět: |
|
| Zdroj: |
Animal Reproduction Science. 10:251-259 |
| ISSN: |
0378-4320 |
| DOI: |
10.1016/0378-4320(86)90001-1 |
| Popis: |
Ovarian activity was assessed for over a year in 16 beef cows, 10 of the Alentejano and 6 of the Mirandes breed, by measuring plasma progesterone twice weekly. It was observed that there were acyclic cows from January to the end of May and from the end of August to the end of September. The greatest number of acyclic cows (3 out of 16) was observed in April. Progesterone determinations showed that after the period of acyclia there was a small short-lasting increase in progesterone, then a cycle with a short dioestrus followed by cycles of normal duration. Oestrous cycles were on average 23.16 ± 0.16 days long; the difference between breeds was not significant. The duration of cycles throughout the year was statistically different (P < 0.01) between months. Minimum and maximum values were observed in March (21.5 ± 0.6 days) and December (25.05 = 0.58 days) respectively. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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