Metabolite Comparison between Serum and Follicular Fluid of Dairy Cows with Inactive Ovaries Postpartum.

Zhijie Wang,Cheng Xia,Yuxi Song,Yunlong Bai,Shuhan Sun,Chang Zhao,Shixin Fu

doi:10.3390/ani12030285

Abstract

Simple SummaryAlthough the milk production of dairy cows has increased rapidly in recent decades, the reproductive performance of dairy cows has gradually declined. In modern intensive dairy farms, prevention and treatment of inactive ovaries has become an important challenge of reproduction disorders during early lactation. Our aim is to screen out metabolites and metabolic pathways related to inactive ovaries through serum and follicular fluid metabolomics. We found that the changes in serum and follicular fluid were mainly enriched in nine metabolic pathways. In serum, these included d-glutamine and d-glutamate metabolism, alanine, aspartic and glutamate metabolism, arginine and proline metabolism, pentose and glucuronate interconversions, and glycerophospholipid metabolism. In follicular fluid, they were valine, leucine, and isoleucine biosynthesis; arachidonic acid metabolism; glycerophospholipid metabolism; starch and sucrose metabolism; phenylalanine metabolism; and pentose and glucuronate interconversion. The common metabolic pathways of disease-related serum and follicular fluid were pentose and glucuronate interconversions and glycerophospholipid metabolism. This research will provide a theoretical basis for exploring the causes of inactive ovaries and provide new ideas for the prevention and treatment of inactive ovaries in the future.Inactive ovaries (IO) accounts for 50% of ovarian disease in postpartum dairy cows, which seriously affects their reproductive efficiency. To investigate the metabolic changes in the serum and follicular fluid of dairy cows with IO during lactation, six estrus (E) cows and six IO cows at 50 to 55 days in milk were selected based on B ultrasonic detection and clinical manifestations. The differential metabolites in serum and follicular fluid between the E cows and IO cows were identified by ultra-high-pressure liquid chromatography–quadrupole time-of-flight mass spectrometry, combined with multidimensional statistical methods. The results showed that dairy cows with IO were in a subclinical ketosis status where beta-hydroxybutyrate (BHB) exceeded 1.20 mmol/L, 14 differential metabolites in the serum of IO cows included 10 increased metabolites and 4 decreased metabolites, and 14 differential metabolites in the follicular fluid of IO cows included 8 increased metabolites and 6 decreased metabolites. These differential metabolites mainly involved nine metabolic pathways. The common enrichment pathway of different metabolites in serum and follicular fluid were glycerophospholipid metabolism and pentose and glucuronate interconversions. In conclusion, there were significant differences in the differential metabolites and enrichment pathways between serum and follicular fluid of IO cows, implying that there were complex changes in blood metabolism and local follicular metabolism of IO cows, whose interactions need further investigation.

Highlights

With the rapid increase of milk production in dairy cows, the reproductive performance has gradually declined in the past few decades [1]
It is known that inactive ovary (IO) is a postpartum ovarian disease in dairy cows, which sometimes accounts for 50% of ovarian disease [3]
This study found that the energy metabolism of IO cows was disturbed, and the urea cycle was affected, by affecting the formation of fumaric acid through amino acids such as arginine and participating in the tricarboxylic cycle [35], and by being involved in the synthesis of antioxidants and anti-inflammatory factors [36,37]

Summary

Introduction

With the rapid increase of milk production in dairy cows, the reproductive performance has gradually declined in the past few decades [1]. Cows with high milk production usually have low postpartum reproductive efficiency, which seriously impacts the economic development of the dairy industry [1]. It is known that inactive ovary (IO) is a postpartum ovarian disease in dairy cows, which sometimes accounts for 50% of ovarian disease [3]. Follicle waves appear on the surface of the ovaries, but the growth of the follicles stops before the follicles deviate, termed IO [4], so on modern intensive dairy farms, prevention and treatment of ovarian inactivity has become an important challenge of reproductive disorders during early lactation

Objectives

Methods

Results

Discussion

Conclusion