Supplementing rumen-protected methionine to lactating multiparous dairy cows did not improve reproductive performance.

David Süss,Karen Wagener,Erika Gusterer,Claudia Parys,Dawit Tesfaye,Ariane Helmbrecht,Karl Schellander,Michael Iwersen,Michael Hoelker,Stefanie Krieger,Harald Pothmann,Marc Drillich,Peter Kanz,Vanessa Schweinzer

doi:10.1111/rda.13509

Abstract

There is evidence that supplementing methionine has positive effects on uterine environment, oocyte quality and embryo development in cattle. Thus, the objective of this study was to evaluate reproductive traits of cows supplemented with rumen‐protected methionine (RPM) during early to mid‐lactation in comparison with an untreated control group (CON). An additional focus was on the effect of puerperal diseases on reproductive performance parameters in RPM‐supplemented group MET and in CON. A total of 1,709 multiparous Holstein‐Friesian cows were enrolled in this field trial conducted on a commercial dairy farm in Slovakia. Cows were allocated at approximately 12 days post‐partum (dpp) to either CON or MET, the latter supplemented with 25.0 g–27.2 g RPM per cow per day incorporated into the total mixed ration (TMR) until leaving the study pen at approximately 140 dpp. The amount of RPM was calculated based on individual feed ingredients analysis and adjusted during the study period when TMR changed. Cows were monitored during the post‐partum period by vaginal examination (day 5 pp), measuring of beta‐hydroxybutyrate in blood (3, 5, and 8 dpp) and by vaginal examination, uterine cytology and measuring of back fat thickness by ultrasound (all at 31 ± 3 dpp).Compared with CON, cows supplemented with RPM did not show better reproduction performance parameters (first service submission rate, days to first service, conception risk, days open 140). Results from binary logistic regression model for the risk of conception showed that metritis had a significant effect, but the supplementation of methionine had not. Results of Cox regression analysis for the odds of conception within 140 dpp revealed only metritis and clinical endometritis as significant factors. In conclusion, supplementation of RPM had no beneficial effect on reproductive performance in this study farm compared with an untreated control group.

Highlights

The intensive genetic selection for high milk yields in the last decades has reduced fertility, due to poor expression of oestrus, uterine infections, defective embryos and oocytes and other post‐partum clinical problems (Dobson, Smith, Royal, Knight, & Sheldon, 2007)
It has been demonstrated that supplementing rumen‐ protected methionine (RPM) leads to a greater lipid accumulation in the preimplantation embryo, which serves as an energy substrate and enhances the embryo's capacity for survival, when RPM was supplemented between 21 days before calving to 30 days post‐partum (Acosta et al, 2016)
first service con‐ ception risk (FSCR), second service conception risk (SSCR) and total conception risk (TCR) in our study showed no significant differences for control group (CON) and TA B L E 4 Results of cox regression analysis for odds of conception until day 140 of lactation endometritis Clinical endometritis Back fat thickness

Summary

Introduction

The intensive genetic selection for high milk yields in the last decades has reduced fertility, due to poor expression of oestrus, uterine infections, defective embryos and oocytes and other post‐partum clinical problems (Dobson, Smith, Royal, Knight, & Sheldon, 2007). Studies that tested effects of RPM on fertility on a herd level, are rare. Several authors (Acosta et al, 2016, 2017; Stella et al, 2018) postulated positive effects of RPM on fertility supplemented already at the beginning of the transition period, some publications (Peñagaricano et al, 2013; Toledo et al, 2017) stated positive effects of RPM fed only post‐partum. There is a need to investigate the effects of methionine supplementation on re‐ productive performance on herd level. The hypothesis of our study was that supplementation of 25.0 to 27.2 g RPM incorpo‐ rated into the total mixed ration during early to mid‐lactation im‐ proves reproductive performance in dairy cows at the herd level in comparison with an untreated control group. We analysed the effect of puerperal diseases on reproductive per‐ formance on both groups

Objectives

Findings

Discussion

Conclusion