Effects of GnRH or PGF2α in week 5 postpartum on the incidence of cystic ovarian follicles and persistent corpora lutea and on fertility parameters in dairy cows

AbstractThe resumption of reproductive activity in the early post partum period and the subsequent fertility of dairy cows are of considerable practical and economic importance to the producer. Regular milk progesterone analysis was used in this study to monitor the re-establishment of reproductive cyclicity in animals of average (AGM, n=20) and high genetic merit (HGM, n=28) kept under standard management conditions. The profiles obtained were then characterised into normal and four different types of abnormal activity. Resumption of cycles occurred significantly later in the higher yielding cows than in those of average genetic merit (23 ±2.3 days in HGM cows and 15 ± 1.6 days in AGM cows; P=0.0089). There was a significant increase in the amount of abnormal cycles encountered in the high genetic merit animals compared with average yielding animals (61% and 30% respectively; χ2 test, P=0.045); in particular, the delayed occurrence of ovulation post partum (11% vs 0%) and an increased incidence of persistent corpora lutea (32% vs 20%). For high genetic merit animals, the incidence of abnormal cycles was associated with increased peak milkyields (abnormal cycles: peak milk yield 54.7 ± 1.11 kg/day; normal cycles: peak milk yield 46.4 ± 1.35 kg/day, P=0.002). This relationship was not apparent in average genetic merit animals. First service conception rates were 50% (9/18) for AGM cows and 38% (10/26) for HGM cows (χ2 test, n.s.). The calving to conception interval was 98 ± 9.7 days for AGM animals (n=l7) and 105 ± 9.1 days for HGMs (n=24) (t-test, n.s.). In conclusion, this study confirms that high genetic merit dairy cows have compromised reproductive function in terms of a delayed resumption of cyclicity and an increased incidence of abnormal progesterone cycles, which was associated with higher peak milk yields. There was also a reduced first service conception rate in high yielders although the difference was not significant with this group size.

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Steroidogenic, Metabolic, and Immunological Markers in Dairy Cows Diagnosed With Cystic Ovarian Follicles at Early and Mid-Late Lactation

Frontiers in Veterinary Science ◽

10.3389/fvets.2019.00324 ◽

2019 ◽

Vol 6 ◽

Cited By ~ 1

Author(s):

Fabio S. Lima ◽

Diego A. V. Acosta ◽

Tonja R. Egan ◽

Cassandra Skenandore ◽

Saige Sulzberger ◽

...

Keyword(s):

Dairy Cows ◽

Ovarian Follicles ◽

Immunological Markers

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Expression of estrogen receptor α (ERα) and estrogen receptor β (ERβ) in the ovarian follicles and corpora lutea of pregnant swine

Domestic Animal Endocrinology ◽

10.1016/j.domaniend.2008.05.001 ◽

2008 ◽

Vol 35 (2) ◽

pp. 170-179 ◽

Cited By ~ 23

Author(s):

Katarzyna Knapczyk ◽

Malgorzata Duda ◽

Malgorzata Durlej ◽

Jerzy Galas ◽

Marek Koziorowski ◽

...

Keyword(s):

Estrogen Receptor ◽

Estrogen Receptor Α ◽

Ovarian Follicles ◽

Estrogen Receptor Β ◽

Corpora Lutea

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Physiological Adaptations to Milk Production that Affect the Fertility of High Yielding Dairy Cows

BSAP Occasional Publication ◽

10.1017/s0263967x00040040 ◽

2004 ◽

Vol 29 ◽

pp. 37-71 ◽

Cited By ~ 4

Author(s):

V. J. Taylor ◽

D. E. Beever ◽

D. C. Wathes

Keyword(s):

Dairy Cows ◽

Milk Production ◽

Ovarian Function ◽

Post Partum ◽

Reproductive Function ◽

Influential Factors ◽

Corpora Lutea ◽

Expected Time ◽

Physiological Adaptations ◽

Igf I

SummaryThe high yielding dairy cow is expected to produce a substantial milk output every year and at the same time to conceive and maintain a pregnancy to term. To fulfil lifetime production potential a balance between yield, fertility and other influential factors has to be achieved. Any inability on the part of the management system to identify and rectify problems or on the part of the cow to cope with metabolic demands invariably results in economic or welfare issues. Our studies of high yielding dairy cows have revealed that some animals are capable of normal reproductive function whilst others are classic repeat breeders (requiring 3+ services per conception) or simply fail to rebreed. It is well established that the somatotrophic axis (growth hormone and insulin-like growth factors) drives lactation in ruminants but it is also intimately involved in reproductive processes. An awareness of metabolic adaptations to lactation that impact on reproduction in dairy cows is needed for appropriate management.The objective of our studies was to explore the metabolic profiles of high yielding dairy cows to identify factors influencing their ovarian function and fertility, hence to characterise the physiological adaptations involved. Our studies revealed different relationships between progesterone profile categories and metabolic status post partum. Delayed ovulation (DOV) or persistent corpora lutea (PCL) may be an appropriate response to a nutritional state or physiological situation and it may therefore be inaccurate to refer to these as ‘abnormal’. Whilst associated with high milk yields, not all profile categories detrimentally affected fertility parameters. Delayed ovulation postcalving (DOV1) was identified as the most prevalent abnormal profile encountered in first lactation high yielding cows. This may have occurred because the cows were not yet physically mature and unable to sustain both milk production and growth. The condition lasted long enough (71 ± 8.3 days from calving) to have a detrimental impact on their overall fertility parameters and was associated with significant physiological changes, representative of tissue mobilisation. Although the incidence of persistent luteal phases (PCL1 and PCL2) in dairy cows is increasing, this condition was not found to have any substantial detrimental effects on fertility or production parameters of the primiparous or multiparous cows in these studies. The main reproductive problems in our high yielding primiparous and multiparous cows appeared to be a failure to ovulate and conceive at the expected time or to maintain a pregnancy. These situations were associated predominantly with high milk yields and low concentrations of plasma IGF-I. A failure to ovulate appears to occur when body reserves are mobilised to maintain milk yield at the expense of reproduction and seems most likely to occur in primiparous high yielding cows or those experiencing GH-resistance (low IGF-I) due to excessive body condition loss, reduced feed intakes and factors such as stress and disease. More detailed investigations of dietary means of increasing IGF-I and optimising insulin concentrations, targeted at important reproductive times, are required in high yielding dairy cows, to aid in their management.

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IDENTIFICATION OF OVARIAN FOLLICLES AT ESTRUS AND DEVELOPMENT OF THEIR ENSUING CORPORA LUTEA IN SINGLE AND MULTIPLE OVULATING EWES ON TWO FEEDING REGIMES

Canadian Journal of Animal Science ◽

10.4141/cjas77-083 ◽

1977 ◽

Vol 57 (4) ◽

pp. 647-652 ◽

Cited By ~ 5

Author(s):

J. J. DUFOUR ◽

P. MATTON

Keyword(s):

High Energy ◽

Ovarian Follicles ◽

Low Energy ◽

Ovulation Rate ◽

Corpora Lutea ◽

The Third ◽

India Ink ◽

Feeding Regimes

Twelve hours after standing estrus was first detected, 30 ewes had their four largest follicles identified and marked with India ink. Seven days later, ovulation rates and origin of the corpora lutea (CL) from previously marked follicles were determined. Feeding a high energy ration from day 10 to estrus did not change the ovulation rate as compared to feeding a low energy ration. Its only effect was to increase the diameter of the third and fourth largest follicles. The diameter of the largest follicle was identical in single and multiple ovulators. However, in multiple ovulators, the diameter of the second largest follicle was larger than in single ovulators. The largest follicle identified at estrus developed into a CL that was 15% heavier in single than in multiple ovulators. In multiple ovulators, the second largest follicle developed into a CL of weight similar to that from the largest follicle.

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