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New Zealand Veterinary Journal Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/tnzv20
Letter to the editor D.A. Barr B.V.SC M.SC PH.D
a
a
I.C.I. N.Z. Ltd , P.O. Box 16-150, Hornby, Christchurch Published online: 23 Feb 2011.
To cite this article: D.A. Barr B.V.SC M.SC PH.D (1976) Letter to the editor, New Zealand Veterinary Journal, 24:9, 211-211, DOI: 10.1080/00480169.1976.34318 To link to this article: http://dx.doi.org/10.1080/00480169.1976.34318
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http://www.tandfonline.com/page/termsand-conditions
1976
211
NEW ZEALAND VETERINARY JOURNAL
LETTER TO THE EDITOR
Downloaded by [Tufts University] at 14:00 31 October 2014
THE RELATIONSHIP BETWEEN OVARIAN STATUS AND OESTROUS BEHAVIOUR IN BEEF COWS Sir, - During field trials with leI 80996 ("Estrumate") for synchronizing oestrus in beef animals, the following observations were made which provided data on the relationship between ovarian status and subsequent oestrous behaviour in a mob of 21!2-year-old Aberdeen Angus cows. Twenty-eight first calvers, which had been run on hill country in Southland, had aU calved more than 50 days when their ovaries were first palpated on November 12, 1975. Their average liveweight was 314 kg with a range of 285 to 375 kg. They had been running with two teaser bulls from the end of October but none had been marked. They were run together with a group of heifers and from November 12 there was a total of 60 cows and heifers running with the two teasers. Ovarian palpation on November 12 revealed that 23/28 of the cows had inactive ovaries while the remaining 5 had a small follicle present in one ovary. Half these anim~ils, which included 3 of those whose ovaries contained small follicles, were palpated again 11 days later, when it was found that only one of these follicles had matured into a corpus luteum; a further 6 cows had small follicles present in one (5 cows) or both ovaries (1 cow). From this time (November 24) the cows and some experimental heifers were run together with the two teasers until January 4, 1976. Both teasers were keen and active but none of the 28 cows was marked until December 8 after which an average of one cow was marked daily. The heats were recorded and correlated with the previous ovarian status of these animals. While it is possible that a few heats may have been missed by the teasers, it is interesting that there was a period of a month between the appearance of the
first follicles and the first detection of oestrus by the teasers. The mean number of days to oestrus from the first follicular presence or anoestrum for the various groups of cows is shown in Table 1. From Table 1 it is clear" that it took more than one cycle length (~24 days) from the appearance of the first follicles until the first detected display o~ oestrous behaviour. Also, there was no apparent difference between those that had follicles in their ovaries, or were anoestrus, at a given time with respect to the mean time taken for oestrus to be detected (compare Group I with III and Group II with IV). Thus a group of animals with a similar history behaved, as might be expected in a similar manner. In fact, all but 5 were marked by t?e .teasers within a 24-day period. It is probably sIgmficant that these 5 non-detected animals had an average liveweight of only 294 kg in mid-November which is below the group average. One of these cows, which had a follicle on November 24 and was not detected in oestrus before January 4, had (he lowest liveweight of the whole group. It appears from the data that it can take from 27 to 42 days for beef animals to progress from (he appearance of the first follicles until oestrus is displayed. It should be noted that the onset of cyclicity generally was delayed by at least a month in this district during the 1975 breeding season. I should be interested to hear if any of your readers have any specific data on this subject, especially in beef animals. D. A.
BARR, B.V.SC., M.SC., PH.D.
I.C./. N.Z. Ltd,
P.O. Box 16-150, Hornby,
Christchurch
June 21, 1976.
TABLE 1: OVARIAN STATUS AND TIME TO OESTRUS Group
Ovarian Status
No. of Cows
I
Follicles present (Nov. 12)
5
II
Follicles present (Nov. 24)
6
III
Anoestrus (Nov. 12)
IV
Anoestrus (Nov. 12 & 24)
12 5
Mean Day to Oestrus (Teaser) 43 (35-50) ~27
(14-~
41)
(1 undetected by Jan. 4) ~ 41 (28-~ 53) (4 undetected by Jan. 4)
27 (24-30)
New Zealand Veterinary Journal Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/tnzv20
Letter to the editor D.A. Barr B.V.SC M.SC PH.D
a
a
I.C.I. N.Z. Ltd , P.O. Box 16-150, Hornby, Christchurch Published online: 23 Feb 2011.
To cite this article: D.A. Barr B.V.SC M.SC PH.D (1976) Letter to the editor, New Zealand Veterinary Journal, 24:9, 211-211, DOI: 10.1080/00480169.1976.34318 To link to this article: http://dx.doi.org/10.1080/00480169.1976.34318
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http://www.tandfonline.com/page/termsand-conditions
1976
211
NEW ZEALAND VETERINARY JOURNAL
LETTER TO THE EDITOR
Downloaded by [Tufts University] at 14:00 31 October 2014
THE RELATIONSHIP BETWEEN OVARIAN STATUS AND OESTROUS BEHAVIOUR IN BEEF COWS Sir, - During field trials with leI 80996 ("Estrumate") for synchronizing oestrus in beef animals, the following observations were made which provided data on the relationship between ovarian status and subsequent oestrous behaviour in a mob of 21!2-year-old Aberdeen Angus cows. Twenty-eight first calvers, which had been run on hill country in Southland, had aU calved more than 50 days when their ovaries were first palpated on November 12, 1975. Their average liveweight was 314 kg with a range of 285 to 375 kg. They had been running with two teaser bulls from the end of October but none had been marked. They were run together with a group of heifers and from November 12 there was a total of 60 cows and heifers running with the two teasers. Ovarian palpation on November 12 revealed that 23/28 of the cows had inactive ovaries while the remaining 5 had a small follicle present in one ovary. Half these anim~ils, which included 3 of those whose ovaries contained small follicles, were palpated again 11 days later, when it was found that only one of these follicles had matured into a corpus luteum; a further 6 cows had small follicles present in one (5 cows) or both ovaries (1 cow). From this time (November 24) the cows and some experimental heifers were run together with the two teasers until January 4, 1976. Both teasers were keen and active but none of the 28 cows was marked until December 8 after which an average of one cow was marked daily. The heats were recorded and correlated with the previous ovarian status of these animals. While it is possible that a few heats may have been missed by the teasers, it is interesting that there was a period of a month between the appearance of the
first follicles and the first detection of oestrus by the teasers. The mean number of days to oestrus from the first follicular presence or anoestrum for the various groups of cows is shown in Table 1. From Table 1 it is clear" that it took more than one cycle length (~24 days) from the appearance of the first follicles until the first detected display o~ oestrous behaviour. Also, there was no apparent difference between those that had follicles in their ovaries, or were anoestrus, at a given time with respect to the mean time taken for oestrus to be detected (compare Group I with III and Group II with IV). Thus a group of animals with a similar history behaved, as might be expected in a similar manner. In fact, all but 5 were marked by t?e .teasers within a 24-day period. It is probably sIgmficant that these 5 non-detected animals had an average liveweight of only 294 kg in mid-November which is below the group average. One of these cows, which had a follicle on November 24 and was not detected in oestrus before January 4, had (he lowest liveweight of the whole group. It appears from the data that it can take from 27 to 42 days for beef animals to progress from (he appearance of the first follicles until oestrus is displayed. It should be noted that the onset of cyclicity generally was delayed by at least a month in this district during the 1975 breeding season. I should be interested to hear if any of your readers have any specific data on this subject, especially in beef animals. D. A.
BARR, B.V.SC., M.SC., PH.D.
I.C./. N.Z. Ltd,
P.O. Box 16-150, Hornby,
Christchurch
June 21, 1976.
TABLE 1: OVARIAN STATUS AND TIME TO OESTRUS Group
Ovarian Status
No. of Cows
I
Follicles present (Nov. 12)
5
II
Follicles present (Nov. 24)
6
III
Anoestrus (Nov. 12)
IV
Anoestrus (Nov. 12 & 24)
12 5
Mean Day to Oestrus (Teaser) 43 (35-50) ~27
(14-~
41)
(1 undetected by Jan. 4) ~ 41 (28-~ 53) (4 undetected by Jan. 4)
27 (24-30)
