Matches in SemOpenAlex for { <https://semopenalex.org/work/W1591764022> ?p ?o ?g. }
- W1591764022 endingPage "71" @default.
- W1591764022 startingPage "37" @default.
- W1591764022 abstract "Summary The 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." @default.
- W1591764022 created "2016-06-24" @default.
- W1591764022 creator A5055530759 @default.
- W1591764022 creator A5085725824 @default.
- W1591764022 creator A5089699934 @default.
- W1591764022 date "2004-01-01" @default.
- W1591764022 modified "2023-10-18" @default.
- W1591764022 title "Physiological Adaptations to Milk Production that Affect the Fertility of High Yielding Dairy Cows" @default.
- W1591764022 cites W1559985260 @default.
- W1591764022 cites W1577393409 @default.
- W1591764022 cites W1901547630 @default.
- W1591764022 cites W1935861295 @default.
- W1591764022 cites W1963482245 @default.
- W1591764022 cites W1965470725 @default.
- W1591764022 cites W1965727379 @default.
- W1591764022 cites W1968667188 @default.
- W1591764022 cites W1969372621 @default.
- W1591764022 cites W1971975995 @default.
- W1591764022 cites W1975915048 @default.
- W1591764022 cites W1977919947 @default.
- W1591764022 cites W1979359246 @default.
- W1591764022 cites W1980292497 @default.
- W1591764022 cites W1983258153 @default.
- W1591764022 cites W1984058894 @default.
- W1591764022 cites W1984594282 @default.
- W1591764022 cites W1988249861 @default.
- W1591764022 cites W1989312291 @default.
- W1591764022 cites W1990597467 @default.
- W1591764022 cites W1997783813 @default.
- W1591764022 cites W2001412472 @default.
- W1591764022 cites W2001680814 @default.
- W1591764022 cites W2003725370 @default.
- W1591764022 cites W2003946092 @default.
- W1591764022 cites W2004571614 @default.
- W1591764022 cites W2006023511 @default.
- W1591764022 cites W2006466321 @default.
- W1591764022 cites W2014116250 @default.
- W1591764022 cites W2024707038 @default.
- W1591764022 cites W2028817866 @default.
- W1591764022 cites W2029330969 @default.
- W1591764022 cites W2029532105 @default.
- W1591764022 cites W2029911489 @default.
- W1591764022 cites W2030112934 @default.
- W1591764022 cites W2032404645 @default.
- W1591764022 cites W2032472474 @default.
- W1591764022 cites W2032799461 @default.
- W1591764022 cites W2033859557 @default.
- W1591764022 cites W2034197399 @default.
- W1591764022 cites W2036276941 @default.
- W1591764022 cites W2036820372 @default.
- W1591764022 cites W2042127308 @default.
- W1591764022 cites W2046505570 @default.
- W1591764022 cites W2051007965 @default.
- W1591764022 cites W2057482820 @default.
- W1591764022 cites W2058634372 @default.
- W1591764022 cites W2059173919 @default.
- W1591764022 cites W2060904896 @default.
- W1591764022 cites W2062030782 @default.
- W1591764022 cites W2063688192 @default.
- W1591764022 cites W2064198515 @default.
- W1591764022 cites W2064903015 @default.
- W1591764022 cites W2066299488 @default.
- W1591764022 cites W2066535527 @default.
- W1591764022 cites W2068714846 @default.
- W1591764022 cites W2071731913 @default.
- W1591764022 cites W2073955701 @default.
- W1591764022 cites W2074585597 @default.
- W1591764022 cites W2084229885 @default.
- W1591764022 cites W2086247606 @default.
- W1591764022 cites W2088869129 @default.
- W1591764022 cites W2090228217 @default.
- W1591764022 cites W2092289307 @default.
- W1591764022 cites W2094975055 @default.
- W1591764022 cites W2094976181 @default.
- W1591764022 cites W2099004021 @default.
- W1591764022 cites W2103162366 @default.
- W1591764022 cites W2104980041 @default.
- W1591764022 cites W2108713386 @default.
- W1591764022 cites W2111031228 @default.
- W1591764022 cites W2121996121 @default.
- W1591764022 cites W2122451869 @default.
- W1591764022 cites W2125487311 @default.
- W1591764022 cites W2125909277 @default.
- W1591764022 cites W2128578870 @default.
- W1591764022 cites W2131263920 @default.
- W1591764022 cites W2132193315 @default.
- W1591764022 cites W2134606727 @default.
- W1591764022 cites W2146407048 @default.
- W1591764022 cites W2154688395 @default.
- W1591764022 cites W2157664561 @default.
- W1591764022 cites W2158853815 @default.
- W1591764022 cites W2160903592 @default.
- W1591764022 cites W2164432858 @default.
- W1591764022 cites W2168509890 @default.
- W1591764022 cites W2171179405 @default.
- W1591764022 cites W2172129660 @default.
- W1591764022 cites W2188232396 @default.
- W1591764022 cites W2278210606 @default.