Lucas Gomes Da Silva , Luana Gomes Da Silva , Luiz Carlos Louzada Ferreira , Julia Mascarello , Joao Gabriel Nascimento Moraes , Matthew C. Lucy , Ériklis Nogueira
{"title":"影响巴西Nelore雌鼠每次人工授精受孕率和胚胎死亡率的因素","authors":"Lucas Gomes Da Silva , Luana Gomes Da Silva , Luiz Carlos Louzada Ferreira , Julia Mascarello , Joao Gabriel Nascimento Moraes , Matthew C. Lucy , Ériklis Nogueira","doi":"10.1016/j.anireprosci.2024.107475","DOIUrl":null,"url":null,"abstract":"<div><p>A greater understanding of factors influencing fertility is essential to improve pregnancy rates and reduce the occurrence of embryonic mortality in beef herds. The objective of the current study was to evaluate retrospective data of pregnancy per artificial insemination (P/AI) and pregnancy loss in Nelore females subjected to timed-AI (TAI) in Brazil. Data from 40,104 TAI collected from six breeding seasons (2016–2022) were analyzed, and the effects of animal category (e.g., classification based on age and parity), farm, month of parturition, sire, sire breed (Nelore vs Angus), estrus expression at TAI, animal temperament, and body condition scores (BCS) were evaluated. P/AI and pregnancy loss were affected (<em>P</em> < 0.001) by animal category. There was also an effect of farm (<em>P</em> = 0.0013) on P/AI and pregnancy loss (<em>P =</em> 0.001), as P/AI ranged from 49.28% and 55.58% and pregnancy loss from 3.37% to 6.89% across the herds evaluated. Month of parturition also affected (<em>P</em> < 0.001) <em>P/</em>AI and was higher for cows that became pregnant at the beginning of the previous breeding season. Calmer animals, presenting lower velocity scores while exiting the chute following TAI, achieved higher P/AI (<em>P</em> < 0.001). Lower BCS at TAI was associated (<em>P</em> < 0.001) with increased pregnancy loss, and BCS gain following AI was associated (<em>P</em> < 0.001) with reduced rates of embryonic mortality. There was a major effect (<em>P <</em> 0.001) of sire on P/AI and pregnancy loss, as P/AI ranged from 11% to 79%, and embryonic mortality from 0% to 40% for the bulls used in the study, highlighting the importance of the sire fertility on overall pregnancy success. Results from the current study reinforce the idea that animal age and parity at the beginning of the breeding season, BCS at the onset of estrous synchronization, BCS gain following AI, estrus expression at TAI, sire, and month of parturition are important factors influencing P/AI and rates of embryonic mortality in beef herds.</p></div>","PeriodicalId":7880,"journal":{"name":"Animal Reproduction Science","volume":null,"pages":null},"PeriodicalIF":2.2000,"publicationDate":"2024-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Factors influencing pregnancy per artificial insemination (AI) and embryonic mortality in Nelore females subjected to timed-AI in Brazil\",\"authors\":\"Lucas Gomes Da Silva , Luana Gomes Da Silva , Luiz Carlos Louzada Ferreira , Julia Mascarello , Joao Gabriel Nascimento Moraes , Matthew C. Lucy , Ériklis Nogueira\",\"doi\":\"10.1016/j.anireprosci.2024.107475\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>A greater understanding of factors influencing fertility is essential to improve pregnancy rates and reduce the occurrence of embryonic mortality in beef herds. The objective of the current study was to evaluate retrospective data of pregnancy per artificial insemination (P/AI) and pregnancy loss in Nelore females subjected to timed-AI (TAI) in Brazil. Data from 40,104 TAI collected from six breeding seasons (2016–2022) were analyzed, and the effects of animal category (e.g., classification based on age and parity), farm, month of parturition, sire, sire breed (Nelore vs Angus), estrus expression at TAI, animal temperament, and body condition scores (BCS) were evaluated. P/AI and pregnancy loss were affected (<em>P</em> < 0.001) by animal category. There was also an effect of farm (<em>P</em> = 0.0013) on P/AI and pregnancy loss (<em>P =</em> 0.001), as P/AI ranged from 49.28% and 55.58% and pregnancy loss from 3.37% to 6.89% across the herds evaluated. Month of parturition also affected (<em>P</em> < 0.001) <em>P/</em>AI and was higher for cows that became pregnant at the beginning of the previous breeding season. Calmer animals, presenting lower velocity scores while exiting the chute following TAI, achieved higher P/AI (<em>P</em> < 0.001). Lower BCS at TAI was associated (<em>P</em> < 0.001) with increased pregnancy loss, and BCS gain following AI was associated (<em>P</em> < 0.001) with reduced rates of embryonic mortality. There was a major effect (<em>P <</em> 0.001) of sire on P/AI and pregnancy loss, as P/AI ranged from 11% to 79%, and embryonic mortality from 0% to 40% for the bulls used in the study, highlighting the importance of the sire fertility on overall pregnancy success. Results from the current study reinforce the idea that animal age and parity at the beginning of the breeding season, BCS at the onset of estrous synchronization, BCS gain following AI, estrus expression at TAI, sire, and month of parturition are important factors influencing P/AI and rates of embryonic mortality in beef herds.</p></div>\",\"PeriodicalId\":7880,\"journal\":{\"name\":\"Animal Reproduction Science\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.2000,\"publicationDate\":\"2024-04-15\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Animal Reproduction Science\",\"FirstCategoryId\":\"97\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0378432024000666\",\"RegionNum\":2,\"RegionCategory\":\"农林科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"AGRICULTURE, DAIRY & ANIMAL SCIENCE\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Animal Reproduction Science","FirstCategoryId":"97","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0378432024000666","RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"AGRICULTURE, DAIRY & ANIMAL SCIENCE","Score":null,"Total":0}
Factors influencing pregnancy per artificial insemination (AI) and embryonic mortality in Nelore females subjected to timed-AI in Brazil
A greater understanding of factors influencing fertility is essential to improve pregnancy rates and reduce the occurrence of embryonic mortality in beef herds. The objective of the current study was to evaluate retrospective data of pregnancy per artificial insemination (P/AI) and pregnancy loss in Nelore females subjected to timed-AI (TAI) in Brazil. Data from 40,104 TAI collected from six breeding seasons (2016–2022) were analyzed, and the effects of animal category (e.g., classification based on age and parity), farm, month of parturition, sire, sire breed (Nelore vs Angus), estrus expression at TAI, animal temperament, and body condition scores (BCS) were evaluated. P/AI and pregnancy loss were affected (P < 0.001) by animal category. There was also an effect of farm (P = 0.0013) on P/AI and pregnancy loss (P = 0.001), as P/AI ranged from 49.28% and 55.58% and pregnancy loss from 3.37% to 6.89% across the herds evaluated. Month of parturition also affected (P < 0.001) P/AI and was higher for cows that became pregnant at the beginning of the previous breeding season. Calmer animals, presenting lower velocity scores while exiting the chute following TAI, achieved higher P/AI (P < 0.001). Lower BCS at TAI was associated (P < 0.001) with increased pregnancy loss, and BCS gain following AI was associated (P < 0.001) with reduced rates of embryonic mortality. There was a major effect (P < 0.001) of sire on P/AI and pregnancy loss, as P/AI ranged from 11% to 79%, and embryonic mortality from 0% to 40% for the bulls used in the study, highlighting the importance of the sire fertility on overall pregnancy success. Results from the current study reinforce the idea that animal age and parity at the beginning of the breeding season, BCS at the onset of estrous synchronization, BCS gain following AI, estrus expression at TAI, sire, and month of parturition are important factors influencing P/AI and rates of embryonic mortality in beef herds.
期刊介绍：
Animal Reproduction Science publishes results from studies relating to reproduction and fertility in animals. This includes both fundamental research and applied studies, including management practices that increase our understanding of the biology and manipulation of reproduction. Manuscripts should go into depth in the mechanisms involved in the research reported, rather than a give a mere description of findings. The focus is on animals that are useful to humans including food- and fibre-producing; companion/recreational; captive; and endangered species including zoo animals, but excluding laboratory animals unless the results of the study provide new information that impacts the basic understanding of the biology or manipulation of reproduction.
The journal''s scope includes the study of reproductive physiology and endocrinology, reproductive cycles, natural and artificial control of reproduction, preservation and use of gametes and embryos, pregnancy and parturition, infertility and sterility, diagnostic and therapeutic techniques.
The Editorial Board of Animal Reproduction Science has decided not to publish papers in which there is an exclusive examination of the in vitro development of oocytes and embryos; however, there will be consideration of papers that include in vitro studies where the source of the oocytes and/or development of the embryos beyond the blastocyst stage is part of the experimental design.
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