Reproductive outcomes of prepubertal Bos indicus beef heifers raised in a pasture-based feeding system submitted to ovulation induction strategies prior to a timed-artificial insemination protocol

IF 2.4 2区 农林科学 Q3 REPRODUCTIVE BIOLOGY Theriogenology Pub Date : 2024-09-11 DOI:10.1016/j.theriogenology.2024.09.011
{"title":"Reproductive outcomes of prepubertal Bos indicus beef heifers raised in a pasture-based feeding system submitted to ovulation induction strategies prior to a timed-artificial insemination protocol","authors":"","doi":"10.1016/j.theriogenology.2024.09.011","DOIUrl":null,"url":null,"abstract":"<div><p>Reproductive outcomes were evaluated in Nelore (<em>Bos indicus</em>) heifers submitted to one, two or no ovulation induction protocols based on progesterone (P4) and estradiol (E2) prior to a timed-artificial insemination (TAI) protocol. A total of 1,437 heifers (13.0 ± 0.8 mo old; 3.1 ± 0.1 of body condition score [BCS] and 279.9 ± 25.8 kg of body weight [BW]) were randomly assigned to 1 of 3 treatments: <strong>0IND</strong> (n = 486): no ovulation induction protocol; <strong>1IND</strong> (n = 481): one ovulation induction protocol; or <strong>2IND</strong> (n = 470): two ovulation induction protocols. On Day −47, heifers from 2IND received a disinfected intravaginal P4 device (2 g, previously used for 21 d), kept until Day −40, when 0.5 mg of E2 cypionate (EC) was given. On Day −19, heifers from 2IND and 1IND underwent the same protocol. On Day 0, all heifers were submitted to the same TAI protocol, starting with a P4 device (0.5 g), 0.5 mg of cloprostenol sodium (PGF), and 1.5 mg of E2 benzoate. On Day 7, P4 device was removed, 0.5 mg of PGF, 0.5 mg of EC, and 200 IU of equine chorionic gonadotropin (eCG) were administered. The TAI was performed 2 d later (Day 9). Blood samples were collected on Days −47 and 0, to determine the presence of CL (circulating P4 concentrations ≥ 1.0 ng/mL). Ultrasound was performed on Days 40, 75 and between Day 150 and parturition to assess pregnancy per AI (P/AI) and pregnancy loss (PL). Statistical analyses were performed using SAS 9.4 (<sup>a-c</sup>P ≤ 0.05; <sup>A,B</sup>0.05 &lt; P ≤ 0.10). The proportion of heifers with CL on Day −47 was similar among groups (3.4%). A greater proportion of heifers from 1IND had CL on Day 0, followed by 2IND, then 0IND (87.9<sup>a</sup>; 80.4<sup>b</sup>; 28.8<sup>c</sup>%). There was an effect of treatment on expression of estrus (2IND: 66.6<sup>a</sup>; 1IND: 67.2<sup>a</sup>; 0IND: 57.4<sup>b</sup>%), P/AI on Day 40 (2IND: 53.4<sup>a</sup>; 1IND: 43.9<sup>b</sup>; 0IND: 46.5<sup>b</sup>%), P/AI on Day 75 (2IND: 49.8<sup>a</sup>; 1IND: 40.5<sup>b</sup>; 0IND: 44.4<sup>ab</sup>%) and final P/AI (2IND: 45.5<sup>a</sup>; 1IND: 35.8<sup>b</sup>; 0IND: 40.5<sup>ab</sup>%). No differences were observed in PL (40–75 = 6.3%; 75-final = 9.6%; Total = 15.3%). Particularly within lighter heifers, there was an effect of treatment on P/AI on Day 40 (0IND: 39.2<sup>b</sup>; 1IND: 43.3<sup>ab</sup>; 2IND: 53.9<sup>a</sup>%) and on Day 75 (0IND: 36.6<sup>B</sup>; 1IND: 39.0<sup>AB</sup>; 2IND: 48.5<sup>A</sup>%). At the first pregnancy diagnosis, more nonpregnant heifers from 2IND had CL on Day 40 than 0IND, but 1IND did not differ from the other groups (85.4<sup>a</sup>; 74.8<sup>b</sup>; 80.8<sup>ab</sup>%). In conclusion, ovulation induction protocols performed prior to the TAI protocol increased the proportion of heifers with CL on Day 0. The use of two induction protocols resulted in greater fertility, particularly in lighter heifers, and increased cyclicity among nonpregnant heifers. These results indicate that this strategy may be an optimized method for inducing cyclicity and enhancing fertility of prepubertal Nelore heifers raised in pasture-based feeding systems.</p></div>","PeriodicalId":23131,"journal":{"name":"Theriogenology","volume":null,"pages":null},"PeriodicalIF":2.4000,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Theriogenology","FirstCategoryId":"97","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0093691X24003807","RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"REPRODUCTIVE BIOLOGY","Score":null,"Total":0}
引用次数: 0

Abstract

Reproductive outcomes were evaluated in Nelore (Bos indicus) heifers submitted to one, two or no ovulation induction protocols based on progesterone (P4) and estradiol (E2) prior to a timed-artificial insemination (TAI) protocol. A total of 1,437 heifers (13.0 ± 0.8 mo old; 3.1 ± 0.1 of body condition score [BCS] and 279.9 ± 25.8 kg of body weight [BW]) were randomly assigned to 1 of 3 treatments: 0IND (n = 486): no ovulation induction protocol; 1IND (n = 481): one ovulation induction protocol; or 2IND (n = 470): two ovulation induction protocols. On Day −47, heifers from 2IND received a disinfected intravaginal P4 device (2 g, previously used for 21 d), kept until Day −40, when 0.5 mg of E2 cypionate (EC) was given. On Day −19, heifers from 2IND and 1IND underwent the same protocol. On Day 0, all heifers were submitted to the same TAI protocol, starting with a P4 device (0.5 g), 0.5 mg of cloprostenol sodium (PGF), and 1.5 mg of E2 benzoate. On Day 7, P4 device was removed, 0.5 mg of PGF, 0.5 mg of EC, and 200 IU of equine chorionic gonadotropin (eCG) were administered. The TAI was performed 2 d later (Day 9). Blood samples were collected on Days −47 and 0, to determine the presence of CL (circulating P4 concentrations ≥ 1.0 ng/mL). Ultrasound was performed on Days 40, 75 and between Day 150 and parturition to assess pregnancy per AI (P/AI) and pregnancy loss (PL). Statistical analyses were performed using SAS 9.4 (a-cP ≤ 0.05; A,B0.05 < P ≤ 0.10). The proportion of heifers with CL on Day −47 was similar among groups (3.4%). A greater proportion of heifers from 1IND had CL on Day 0, followed by 2IND, then 0IND (87.9a; 80.4b; 28.8c%). There was an effect of treatment on expression of estrus (2IND: 66.6a; 1IND: 67.2a; 0IND: 57.4b%), P/AI on Day 40 (2IND: 53.4a; 1IND: 43.9b; 0IND: 46.5b%), P/AI on Day 75 (2IND: 49.8a; 1IND: 40.5b; 0IND: 44.4ab%) and final P/AI (2IND: 45.5a; 1IND: 35.8b; 0IND: 40.5ab%). No differences were observed in PL (40–75 = 6.3%; 75-final = 9.6%; Total = 15.3%). Particularly within lighter heifers, there was an effect of treatment on P/AI on Day 40 (0IND: 39.2b; 1IND: 43.3ab; 2IND: 53.9a%) and on Day 75 (0IND: 36.6B; 1IND: 39.0AB; 2IND: 48.5A%). At the first pregnancy diagnosis, more nonpregnant heifers from 2IND had CL on Day 40 than 0IND, but 1IND did not differ from the other groups (85.4a; 74.8b; 80.8ab%). In conclusion, ovulation induction protocols performed prior to the TAI protocol increased the proportion of heifers with CL on Day 0. The use of two induction protocols resulted in greater fertility, particularly in lighter heifers, and increased cyclicity among nonpregnant heifers. These results indicate that this strategy may be an optimized method for inducing cyclicity and enhancing fertility of prepubertal Nelore heifers raised in pasture-based feeding systems.

查看原文
分享 分享
微信好友 朋友圈 QQ好友 复制链接
本刊更多论文
在定时人工授精方案之前,采用排卵诱导策略饲养以牧草为基础的饲养系统的青春期前肉用小母牛的生殖结果
在进行定时人工授精(TAI)之前,对采用一种、两种或不采用基于孕酮(P4)和雌二醇(E2)的排卵诱导方案的内洛尔(Bos indicus)小母牛的生殖结果进行了评估。共有 1,437 头母牛(13.0 ± 0.8 月龄;3.1 ± 0.1 体况评分 [BCS],279.9 ± 25.8 千克体重 [BW])被随机分配到三种处理中的一种:0IND(n = 486):无排卵诱导方案;1IND(n = 481):一个排卵诱导方案;或 2IND(n = 470):两个排卵诱导方案。第 -47 天,2IND 的母牛接受消毒过的阴道内 P4 装置(2 克,之前使用过 21 天),保留至第 -40 天,然后给予 0.5 毫克环戊丙酸酯(EC)。在第 -19 天,来自 2IND 和 1IND 的母牛接受了相同的方案。第0天,所有母牛接受相同的TAI方案,首先使用P4装置(0.5克)、0.5毫克氯前列醇钠(PGF)和1.5毫克苯甲酸E2。第 7 天,移除 P4 装置,注射 0.5 毫克 PGF、0.5 毫克 EC 和 200 IU 马绒毛膜促性腺激素(eCG)。2 天后(第 9 天)进行 TAI。在第 47 天和第 0 天采集血样,以确定是否存在 CL(循环 P4 浓度≥ 1.0 纳克/毫升)。在第 40 天、第 75 天和第 150 天至分娩期间进行超声波检查,以评估每次人工授精的妊娠率(P/AI)和妊娠损失率(PL)。使用 SAS 9.4 进行统计分析(a-CP ≤ 0.05; A,B0.05 < P ≤ 0.10)。第 47 天出现 CL 的母牛比例在各组之间相似(3.4%)。1IND组母牛在第0天出现CL的比例更高,其次是2IND组,然后是0IND组(87.9a; 80.4b; 28.8c%)。处理对发情表现(2IND:66.6a;1IND:67.2a;0IND:57.4b%)、第 40 天的 P/AI (2IND:53.4a;1IND:43.9b;0IND:46.5b%)、第 75 天的 P/AI(2IND:49.8a;1IND:40.5b;0IND:44.4ab%)和最终 P/AI(2IND:45.5a;1IND:35.8b;0IND:40.5ab%)。PL(40-75 = 6.3%;75-最终 = 9.6%;总计 = 15.3%)方面未观察到差异。特别是在体重较轻的母牛中,治疗对第 40 天(0IND:39.2b;1IND:43.3ab;2IND:53.9a%)和第 75 天(0IND:36.6B;1IND:39.0AB;2IND:48.5A%)的 P/AI 有影响。在首次妊娠诊断时,2IND组在第40天有CL的未孕母牛多于0IND组,但1IND组与其他组没有差异(85.4a;74.8b;80.8ab%)。总之,在TAI方案之前进行的排卵诱导方案增加了第0天有CL的母牛比例。使用两种诱导方案可提高母牛的繁殖力,尤其是体重较轻的母牛,并增加未孕母牛的周期性。这些结果表明,这种策略可能是诱导在牧草饲养系统中饲养的青春期前内洛尔母牛周期性和提高其繁殖力的最佳方法。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
求助全文
约1分钟内获得全文 去求助
来源期刊
Theriogenology
Theriogenology 农林科学-生殖生物学
CiteScore
5.50
自引率
14.30%
发文量
387
审稿时长
72 days
期刊介绍: Theriogenology provides an international forum for researchers, clinicians, and industry professionals in animal reproductive biology. This acclaimed journal publishes articles on a wide range of topics in reproductive and developmental biology, of domestic mammal, avian, and aquatic species as well as wild species which are the object of veterinary care in research or conservation programs.
期刊最新文献
Dexamethasone and azithromycin enhance goat sperm preservation quality by regulating lipid metabolism Increased in vitro production of bovine embryos resulting from oocyte maturation in the presence of triciribine, a specific inhibitor of AKT NAGK regulates the onset of puberty in female mice Clinical trials of intratesticular administration of nanostructured lipid carriers encapsulated alpha-mangostin: Safety and efficacy on feline reproductive health Taste receptor T1R3 regulates testosterone synthesis via the cAMP-PKA-SP1 pathway in testicular Leydig cells
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
0
微信
客服QQ
Book学术公众号 扫码关注我们
反馈
×
意见反馈
请填写您的意见或建议
请填写您的手机或邮箱
已复制链接
已复制链接
快去分享给好友吧!
我知道了
×
扫码分享
扫码分享
Book学术官方微信
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术
文献互助 智能选刊 最新文献 互助须知 联系我们:info@booksci.cn
Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。
Copyright © 2023 Book学术 All rights reserved.
ghs 京公网安备 11010802042870号 京ICP备2023020795号-1