Increased parity is negatively associated with survival and reproduction in different production systems

ABSTRACT: We conducted a retrospective meta-analysis based on individual cow data to assess the associations of parity, level of production, and pasture-based or intensively fed systems with fertility. Our goal was to provide understandings of the role of parity in risks for removal and reproductive...

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Main Authors: I.J. Lean, H.M. Golder, S.J. LeBlanc, T. Duffield, J.E.P. Santos
Format: Article
Language:English
Published: Elsevier 2023-01-01
Series:Journal of Dairy Science
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S0022030222006841
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author I.J. Lean
H.M. Golder
S.J. LeBlanc
T. Duffield
J.E.P. Santos
author_facet I.J. Lean
H.M. Golder
S.J. LeBlanc
T. Duffield
J.E.P. Santos
author_sort I.J. Lean
collection DOAJ
description ABSTRACT: We conducted a retrospective meta-analysis based on individual cow data to assess the associations of parity, level of production, and pasture-based or intensively fed systems with fertility. Our goal was to provide understandings of the role of parity in risks for removal and reproductive failure. Multilevel models were used to evaluate the fixed effects of parity, milk, milk solids, milk fat and protein percentage and yield, and production system [intensively fed (n = 28,675) or predominantly pasture fed (n = 4,108)] on reproductive outcomes. The outcomes were the hazard of not being bred (HNBRED), hazard of pregnancy (HPREG), pregnancy to first breeding (PREG1), and odds of becoming pregnant in a lactation (OPAL). The 32,783 cows were in 13 studies conducted in Australia (14.6% of cows), Canada (2.4% of cows), and the United States (83.0% of cows). There were 38.5% of cows in the sample in parity 1, 27.3% in parity 2, 16.7% in parity 3, 9.0% in parity 4, and 8.6% in parity ≥5. Compared with cows of parity 1, parity ≥5 cows had a greater HNBRED [hazard ratio (HR) = 2.45], lesser HPREG (HR = 0.73), and reduced OPAL (odds ratio = 0.36). However, the parity ≥5 cows had similar PREG1 to other parities except for parity 1. This suggests the possibility of a higher proportion of subfertile parity ≥5 cows than for other parities. Associations between parity and reproductive measures were influenced by the different milk production measures, indicating that milk yield and milk component percentages and yields modified the odds or hazards of successful reproduction. All milk production measures had quadratic associations with OPAL, indicating that either low or high production or concentration of solids within a cohort reduced OPAL. This reduced OPAL reflected a greater HNBRED for lower milk yield and milk protein and fat yielding cows. Both milk yield and milk protein percentage had quadratic associations with HPREG. When centered milk yield was categorized into quartiles, small differences in HPREG existed. A more marked association of milk protein percentage occurred with HPREG, with optimal HPREG at approximately 0.5% above group mean milk protein percentage. Milk fat percentage (HR = 0.901), fat yield (kg/d; HR = 0.78), protein yield (kg/d; HR = 0.71), and milk solids yield (kg/d; HR = 0.84) were all linearly associated with reduced HPREG. Difference in production systems did not have substantive effects on PREG1 but did for HNBRED, HPREG, and OPAL. Estimates of associations of parity with reproductive outcomes HNBRED, HPREG, and OPAL were influenced by milk and milk solids yield; older cows had markedly lower reproductive outcomes. Interestingly, for PREG1, there were few differences among parities and differences were less influenced by milk yield and constituent measures. The marked associations of parity with removal for all reasons, deaths and culling, and reductions in HNBRED, HPREG, and OPAL indicate a need to focus on the physiological changes with parity to produce better strategies to support optimal longevity of cows.
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spelling doaj.art-83a3115891ed4f1ebd1c5371733aea732022-12-22T03:53:02ZengElsevierJournal of Dairy Science0022-03022023-01-011061476499Increased parity is negatively associated with survival and reproduction in different production systemsI.J. Lean0H.M. Golder1S.J. LeBlanc2T. Duffield3J.E.P. Santos4Scibus, Camden, NSW, Australia 2570; Dairy UP, University of Sydney, Camden, New South Wales, Australia 2570; Corresponding authorScibus, Camden, NSW, Australia 2570; Dairy UP, University of Sydney, Camden, New South Wales, Australia 2570Department of Population Medicine, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada N1G 2W1Department of Population Medicine, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada N1G 2W1Department of Animal Sciences, University of Florida, Gainesville 32611ABSTRACT: We conducted a retrospective meta-analysis based on individual cow data to assess the associations of parity, level of production, and pasture-based or intensively fed systems with fertility. Our goal was to provide understandings of the role of parity in risks for removal and reproductive failure. Multilevel models were used to evaluate the fixed effects of parity, milk, milk solids, milk fat and protein percentage and yield, and production system [intensively fed (n = 28,675) or predominantly pasture fed (n = 4,108)] on reproductive outcomes. The outcomes were the hazard of not being bred (HNBRED), hazard of pregnancy (HPREG), pregnancy to first breeding (PREG1), and odds of becoming pregnant in a lactation (OPAL). The 32,783 cows were in 13 studies conducted in Australia (14.6% of cows), Canada (2.4% of cows), and the United States (83.0% of cows). There were 38.5% of cows in the sample in parity 1, 27.3% in parity 2, 16.7% in parity 3, 9.0% in parity 4, and 8.6% in parity ≥5. Compared with cows of parity 1, parity ≥5 cows had a greater HNBRED [hazard ratio (HR) = 2.45], lesser HPREG (HR = 0.73), and reduced OPAL (odds ratio = 0.36). However, the parity ≥5 cows had similar PREG1 to other parities except for parity 1. This suggests the possibility of a higher proportion of subfertile parity ≥5 cows than for other parities. Associations between parity and reproductive measures were influenced by the different milk production measures, indicating that milk yield and milk component percentages and yields modified the odds or hazards of successful reproduction. All milk production measures had quadratic associations with OPAL, indicating that either low or high production or concentration of solids within a cohort reduced OPAL. This reduced OPAL reflected a greater HNBRED for lower milk yield and milk protein and fat yielding cows. Both milk yield and milk protein percentage had quadratic associations with HPREG. When centered milk yield was categorized into quartiles, small differences in HPREG existed. A more marked association of milk protein percentage occurred with HPREG, with optimal HPREG at approximately 0.5% above group mean milk protein percentage. Milk fat percentage (HR = 0.901), fat yield (kg/d; HR = 0.78), protein yield (kg/d; HR = 0.71), and milk solids yield (kg/d; HR = 0.84) were all linearly associated with reduced HPREG. Difference in production systems did not have substantive effects on PREG1 but did for HNBRED, HPREG, and OPAL. Estimates of associations of parity with reproductive outcomes HNBRED, HPREG, and OPAL were influenced by milk and milk solids yield; older cows had markedly lower reproductive outcomes. Interestingly, for PREG1, there were few differences among parities and differences were less influenced by milk yield and constituent measures. The marked associations of parity with removal for all reasons, deaths and culling, and reductions in HNBRED, HPREG, and OPAL indicate a need to focus on the physiological changes with parity to produce better strategies to support optimal longevity of cows.http://www.sciencedirect.com/science/article/pii/S0022030222006841productionmilk-proteinparitypregnancylongevity
spellingShingle I.J. Lean
H.M. Golder
S.J. LeBlanc
T. Duffield
J.E.P. Santos
Increased parity is negatively associated with survival and reproduction in different production systems
Journal of Dairy Science
production
milk-protein
parity
pregnancy
longevity
title Increased parity is negatively associated with survival and reproduction in different production systems
title_full Increased parity is negatively associated with survival and reproduction in different production systems
title_fullStr Increased parity is negatively associated with survival and reproduction in different production systems
title_full_unstemmed Increased parity is negatively associated with survival and reproduction in different production systems
title_short Increased parity is negatively associated with survival and reproduction in different production systems
title_sort increased parity is negatively associated with survival and reproduction in different production systems
topic production
milk-protein
parity
pregnancy
longevity
url http://www.sciencedirect.com/science/article/pii/S0022030222006841
work_keys_str_mv AT ijlean increasedparityisnegativelyassociatedwithsurvivalandreproductionindifferentproductionsystems
AT hmgolder increasedparityisnegativelyassociatedwithsurvivalandreproductionindifferentproductionsystems
AT sjleblanc increasedparityisnegativelyassociatedwithsurvivalandreproductionindifferentproductionsystems
AT tduffield increasedparityisnegativelyassociatedwithsurvivalandreproductionindifferentproductionsystems
AT jepsantos increasedparityisnegativelyassociatedwithsurvivalandreproductionindifferentproductionsystems