Hostname: page-component-cd9895bd7-7cvxr Total loading time: 0 Render date: 2024-12-25T14:52:13.986Z Has data issue: false hasContentIssue false
  • English
  • Français

Relationships among post-calving anoestrous interval, oestrous cycles, conception rates and calving date in Angus and Hereford × Friesian cows calving in six successive years

Published online by Cambridge University Press:  02 September 2010

A. B. Pleasants  and
D. G. McCall
A. B. Pleasants
Affiliation:
Whatawhata Research Centre, Private Bag 3089, Hamilton, New Zealand
D. G. McCall
Affiliation:
Whatawhata Research Centre, Private Bag 3089, Hamilton, New Zealand
Get access

Abstract

The records of 1397 cows calving in the spring were collected in the years 1979 to 1984. They were from 638 Angus and 759 Hereford × Friesian cows, and were used to examine the dependencies of post-partum anoestrous interval (ppai), length of oestrous cycle after calving, and conception rate to each oestrus after calving.

Two-year-old cows had longer ppai (P < 0·05) than older cows (76 v. 72 days), and Hereford × Friesian cows had shorter (P < 0·05) ppai than Angus cows (68 v. 72 days). Cows due to begin calving on 8 August (early calving) had longer (P < 0·01) ppai than cows due to begin calving on 19 September (71 v. 55 days).

The linear regression between ppai and calving date (−0·60) did not differ between years, nor between early and late calving. Non-parametric regressions showed that the dependence between ppai and calving date was linear between plus or minus 20 days of the mean ppai in both early- and late-calving herds. Outside these limits variability of ppai increased and there was no relationship with calving date.

The length of the first oestrous cycle after calving was 22 days in 2-year-old cows and 24 days in older cows. Second and third oestrous cycles after calving were 20 days for all breeds and age classes. There was a correlation of −0·41 between the ppai and the length of the first oestrous cycle after anoestrum. There was no significant deviation from normality of ppai or the succeeding post-partum oestrous cycle lengths.

The conception rate to the first oestrus after calving was significantly lower (P < 0·01) than for later oestrous periods. The conception rate to first post-partum oestrus showed dependence on the ppai, logit regressions showing a 0·005 to 0·01 proportional improvement in conception at first oestrus per day increase in ppai.

The significance of these results to the construction of mathematical models of reproduction in the beef cow is discussed.

Keywords

anoestrouscalving dateconceptioncowsoestrous cycle
Type
Research Article
Information
Animal Production , Volume 56 , Issue 2 , April 1993 , pp. 187 - 192
Copyright
Copyright © British Society of Animal Science 1993

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Bellows, R. A. and Short, R. E. 1978. Effects of precalving feed level on birth weight, calving difficulty and subsequent fertility. Journal of Animal Science 46: 1522–1528.CrossRefGoogle Scholar
Diciccio, T. J. and Romano, J. P. 1988. A review of bootstrap confidence intervals. Journal of the Royal Statistical Society B 50: 338–354.Google Scholar
Eubank, R. L. and Speckman, P. 1990. Curve fitting by polynomial-trigonometric regression. Biometrika 77: 1–9.Google Scholar
Knight, T. W. and Nicoll, B. G. 1978. Factors influencing the interval from calving to first estrus in beef cattle on North Island hill country. Proceedings of the New Zealand Society of Animal Production 38:175–180.Google Scholar
Hinkley, D. V. 1988. Bootstrap methods. Journal of the Royal Statistical Association 50: 321–337.Google Scholar
Macmillan, K. L. and Clayton, D. G. 1980. Factors influencing the interval to post-partum oestrus, conception date and empty rate in an intensively managed dairy herd. Proceedings of the New Zealand Society of Animal Production 40: 236–239.Google Scholar
Montgomery, G. W., Davis, G. H. and Hurrell, G. A. 1980. Interval from calving to first oestrus in autumn- and spring-calving herds in the same locality. Proceedings of the New Zealand Society of Animal Production 40:280–284.Google Scholar
Morris, S. T., Pleasants, A. B. and Barton, R. A. 1978. Post-partum oestrous interval of single suckled Angus beef cows. New Zealand Journal of Agricultural Research 21: 577–582.CrossRefGoogle Scholar
Morris, C. A. 1980. A review of the relationships between aspects of reproduction in beef heifers and their lifetime production. 2. Associations with relative calving date and with dystocia. Animal Breeding Abstracts 48: 753–767.Google Scholar
Morris, C. A. 1984. Calving dates and subsequent intercalving intervals in New Zealand beef herds. Animal Production 39: 51–57.Google Scholar
Pindyck, R. S. and Rubinfeld, D. L. 1981. Econometric models and economic forecasts. 2nd ed. McGraw-Hill, Auckland.Google Scholar
Pleasants, A. B. and Barton, R. A. 1985. Pre-calving nutrition of Angus beef breeding cows. New Zealand journal of Experimental Agriculture 13: 231–234.CrossRefGoogle Scholar
Pleasants, A. B. and Barton, R. A. 1992. Observations on the length of the post-partum oestrous cycles and their relationship to other reproductive parameters in mature Angus cows calving in the spring of two consecutive years. New Zealand journal of Agricultural Research 35: 59–62.Google Scholar
Press, W. H., Flannery, B. P., Teukolsky, S. A. and Vetterling, W. T. 1989. Numerical recipes in Pascal. Cambridge University Press.Google Scholar
Snedecor, G. W. and Cochran, W. G. 1967. Statistical methods. 6th ed. Iowa State University, Ames.Google Scholar
Sokal, R. R. and Rohlf, F. J. 1989. Biometry. 2nd ed. Freeman, San Francisco.Google Scholar
Wiltbank, J. N., Rowden, W. W., Ingalls, J. E., Gregory, K. E. and Koch, R. M. 1962. Effect of energy level on reproductive phenomena of mature Hereford cows. Journal of Animal Science 21: 219–225.CrossRefGoogle Scholar