<abstract xmlns="http://www.w3.org/1999/xhtml">

<p>Repeat breeding is a serious reproductive disorder in dairy cattle. The causes of repeat breeding are multifactorial and there are two main mechanisms: failure of fertilisation or early embryo death, mainly due to poor quality of oocytes and an inadequate uterine environment. Many methods have been used to increase the pregnancy rate for repeat breeder cows, such as intrauterine infusion of antibacterial agents or antibiotics, hormonal treatments for oestrus synchronisation and induction of ovulation, and progesterone supplementation or induction of accessory corpus luteum; however, the results were inconsistent between studies. Embryo transfer (ET) has the capability to minimalise the effects of poor oocyte quality and unfavourable uterine environments on early embryo development during the first seven days after ovulation in repeat breeder cows, and several studies showed that ET significantly improved the pregnancy rate in this group of animals. Thus, ET can be considered an option to increase the conception rate in repeat breeder dairy cows.</p>
</abstract>

Repeat breeding is a serious reproductive disorder in dairy cattle. The causes of repeat breeding are multifactorial and there are two main mechanisms: failure of fertilisation or early embryo death, mainly due to poor quality of oocytes and an inadequate uterine environment. Many methods have been used to increase the pregnancy rate for repeat breeder cows, such as intrauterine infusion of antibacterial agents or antibiotics, hormonal treatments for oestrus synchronisation and induction of ovulation, and progesterone supplementation or induction of accessory corpus luteum; however, the results were inconsistent between studies. Embryo transfer (ET) has the capability to minimalise the effects of poor oocyte quality and unfavourable uterine environments on early embryo development during the first seven days after ovulation in repeat breeder cows, and several studies showed that ET significantly improved the pregnancy rate in this group of animals. Thus, ET can be considered an option to increase the conception rate in repeat breeder dairy cows.

Embryo transfer as an option to improve fertility in repeat breeder dairy cows

Journal of Veterinary Research

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

{"article-title":"Embryo transfer as an option to improve fertility in repeat breeder dairy cows"}

Repeat breeding is a serious reproductive disorder in dairy cattle. The causes of repeat breeding are multifactorial and there are two main mechanisms: failure...

Author	Conception rate		Comments
Author	AI	ET	Comments
Tanabe et al. 1985 (65)	-	70%	fresh embryos transferred surgically
Rodrigues et al. 2007 (52)	17.9%	41.7%	frozen-thawed embryos
Son et al. 2007 (61)	heat 7.7% vs TAI 18.5%	53.8%	frozen-thawed embryos; TET with CIDR and EB
Dochi et al. 2008 (16)	20.4%	41.5%	frozen-thawed IVF embryos following AI
Block et al. 2010 (7)	TAI 31.3%	50.5% vs 27.7%	fresh embryos vs vitrified embryos (in vitro); TET
Rodrigues et al. 2010 (53)	-	42.9% vs 38.2%	frozen-thawed embryos; TET with norgestomet implant and eCG (cows with or without CL on day 0 of the protocol)
Canu et al. 2010 (11)	30.0%	52.6%	frozen-thawed embryos (92%) and fresh embryos (8%) following AI after natural heat
Yaginuma et al. 2019 (71)	-	46.9%	frozen-thawed IVF embryos following AI

Embryo transfer as an option to improve fertility in repeat breeder dairy cows

Article Category: Review article

Pubblicato online: 23 apr 2021

Pagine: 231 - 237

Ricevuto: 30 ago 2020

Accettato: 08 mar 2021

DOI: https://doi.org/10.2478/jvetres-2021-0018

Parole chiave
cows, repeat breeders, embryo transfer, dairy cattle

© 2021 A. Nowicki., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Fig. 1

Conception rate in repeat breeder cows after AI or ET

Embryo transfer as an option to improve fertility in repeat breeder dairy cows

Article Category: Review article

Pubblicato online: 23 apr 2021

Pagine: 231 - 237

Ricevuto: 30 ago 2020

Accettato: 08 mar 2021

DOI: https://doi.org/10.2478/jvetres-2021-0018

Parole chiavecows, repeat breeders, embryo transfer, dairy cattle

© 2021 A. Nowicki., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Fig. 1

Conception rate in repeat breeder cows after AI or ET

Parole chiave
cows, repeat breeders, embryo transfer, dairy cattle