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| Author(s): |
Mariana Pallú Viziack
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Medicina Veterinária e Zootecnia (FMVZ/SBD) |
| Defense date: | 2020-11-27 |
| Examining board members: |
Pietro Sampaio Baruselli;
Luiz Gustavo Bruno Siqueira;
Lais Mendes Vieira
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| Advisor: | Pietro Sampaio Baruselli |
| Abstract | |
Reproductive biotechnologies as AI, ET-in vivo and ET-in vitro have been applied as manegement strategies to acomplish productivity, genetic gain and reproductive efficiency on Brazilian and worldwide livestock. However, there are differences on the efficiency of this biotechnologies that may compromises the reproductive and productive development of the farms. The objective of this study was to evaluate the effect of different reproductive technologies (AI, ET-in vivo and ET-in vitro) on reproductive development of lactating Holstein cows, and evaluate the reproductive and productive development of their progeny. The study was conducted at Santa Rita/Agrindus S.A. Farm, located in Descalvado, SP, Brazil. The following variables of the lactating Holstein cows that received the three biotechnologies contemporaneously from 2013 to 2018 were analyzed: gestation rate at 30 (GR30) and 60 (GR60) days, gestation lost between 30 and 60 days (GLO) and abortion rate (AR). Additionally, other variables were analyzed: gestation length (GLE), labor facility (LF) and retention of fetal attachments (RFA). The following variables were analyzed on the progeny: genomic information (GI), weight at birth (WB) and at weaning (WW), mortality from calve to weaning (MCW) and age at first conception (ACON) of calves born from 2013 to 2018. Also, were analyzed age at first calve (ACA) and milk production from the first lactation (MP1) of calves born from 2013 to 2017, and milk production from the second lactation (MP2) of calves born from 2013 to 2015. The data were analyzed by procedures of SAS. There was interaction biotechnology year to GR30 (P<0,0001), GR60 (P<0,0001) and GLO (P=0,03), however, there was effect of biotechnology (P=0,01) and effect of year (P=0,03) to AR. There was interaction biotechnology year to GLE (P<0,0001). There was effect of biotechnology to LF (P<0,0001), without effect of biotechnology to RFA (P=0,14). There was interaction biotechnology year to GI (P<0,0001). There was no interaction biotechnology year (P=0,30), effect of biotechnology (P=0,62) and effect of year (P=0,82) to MCW. There was interaction biotechnology year to WB (P=0,01) and WW (P<0,0001). However, there was only effect of year to ACON (P<0,0001), ACA (P=0,0002) and MP1 (P<0,0001). There was no interaction biotechnology year (P=0,41), effect of biotechnology (P=0,97) and effect of year (P=0,92) to MP2. On lactating cows ET presented better reproductive efficiency, with similar gestation lost than AI. Additionally, ET-in vivo presented similar reproductive efficiency and lower gestation lost than ET-in vitro. On progeny, there were no differences between productivity of females born from AI, ET-in vivo or ET-in vitro. (AU) | |
| FAPESP's process: | 18/05780-8 - Effect of different reproductive biotechnologies (AI, ET-in vivo and ET-in vitro) on reproductive performance of Holstein females |
| Grantee: | Mariana Pallú Viziack |
| Support Opportunities: | Scholarships in Brazil - Master |