Effects of excess metabolizable protein on ovarian function and circulating amino acids of beef cows: 2. Excessive supply in varying concentrations from corn gluten meal

Evaluation of peripartum supplementation of methionine hydroxy analogue on beef cow-calf performance

The objective was to evaluate the effects of peripartum supplementation of a methionine hydroxy analogue (MHA) to primiparous, spring-calving beef females on dam and progeny performance. Angus heifers (n = 60) were blocked by expected parturition date, stratified by body weight (BW) and body condition score (BCS), and randomized to 1 of 15 pens. Pens were randomly assigned to 1 of 3 dietary treatments: a basal diet supplemented with 0 (M0), 15 (M15), or 30 (M30) g/animal/d of MHA (provided as MFP feed supplement, Novus International Inc., St. Charles, MO). Diets were fed from 45 ± 13 (SD) d pre-calving through 81 ± 13 d postpartum (DPP), after which all cow-calf pairs were managed as a single group on pasture until weaning (199 ± 13 DPP). Dam BW, BCS, and blood samples were taken at 6 predetermined timepoints. Progeny data were collected at birth, 2 intermediate timepoints, and at weaning. Milk samples were collected for composition analysis at 7 ± 2 DPP and at 55 ± 5 DPP. Serial progesterone samples were analyzed to establish resumption of cyclicity, and ultrasonography was performed at 55 ± 5 DPP to evaluate ovarian function. Cows were bred via artificial insemination at 82 ± 13 DPP and subsequently exposed to bulls for a 55-d breeding season. Pen was the experimental unit, and preplanned orthogonal contrasts were tested (linear effect and M0 vs. M15 + M30). Dam BW and BCS were not affected by treatment (P ≥ 0.29) throughout the study. Week 1 milk fat concentration increased linearly (P = 0.05) and total solids tended to increase linearly (P = 0.07) as MHA increased; however, no other milk components were affected (P ≥ 0.16). Treatment did not affect (P ≥ 0.16) dam reproductive parameters or progeny growth from birth until weaning. Post-calving, circulating methionine equivalents tended to linearly increase (P = 0.10) with increasing MHA supplementation. At breeding, plasma urea N linearly decreased (P = 0.03) with increased supplementation of MHA, and plasma non-esterified fatty acids were less (P = 0.04) in MHA-supplemented dams compared with dams receiving no MHA. Maternal circulating glucose, glutathione peroxidase, and thiobarbituric acid-reactive substances were not affected (P ≥ 0.15) by treatment at any point. These data indicate that peripartum supplementation of MHA may increase milk fat composition shortly after calving, but MHA supplementation did not improve progeny growth or dam reproductive performance in the current study.

Metabolites Secreted by Bovine Embryos In Vitro Predict Pregnancies That the Recipient Plasma Metabolome Cannot, and Vice Versa

This work describes the use of mass spectrometry-based metabolomics as a non-invasive approach to accurately predict birth prior to embryo transfer (ET) starting from embryo culture media and plasma recipient. Metabolomics was used here as a predictive platform. Day-6 in vitro produced embryos developed singly in modified synthetic oviduct fluid culture medium (CM) drops for 24 h were vitrified as Day-7 blastocysts and transferred to recipients. Day-0 and Day-7 recipient plasma (N = 36 × 2) and CM (N = 36) were analyzed by gas chromatography coupled to the quadrupole time of flight mass spectrometry (GC-qTOF). Metabolites quantified in CM and plasma were analyzed as a function to predict pregnancy at Day-40, Day-62, and birth (univariate and multivariate statistics). Subsequently, a Boolean matrix (F1 score) was constructed with metabolite pairs (one from the embryo, and one from the recipient) to combine the predictive power of embryos and recipients. Validation was performed in independent cohorts of ETs analyzed. Embryos that did not reach birth released more stearic acid, capric acid, palmitic acid, and glyceryl monostearate in CM (i.e., (p < 0.05, FDR < 0.05, Receiver Operator Characteristic—area under curve (ROC-AUC) > 0.669)). Within Holstein recipients, hydrocinnamic acid, alanine, and lysine predicted birth (ROC-AUC > 0.778). Asturiana de los Valles recipients that reached birth showed lower concentrations of 6-methyl-5-hepten-2-one, stearic acid, palmitic acid, and hippuric acid (ROC-AUC > 0.832). Embryonal capric acid and glyceryl-monostearate formed F1 scores generally >0.900, with metabolites found both to differ (e.g., hippuric acid, hydrocinnamic acid) or not (e.g., heptadecanoic acid, citric acid) with pregnancy in plasmas, as hypothesized. Efficient lipid metabolism in the embryo and the recipient can allow pregnancy to proceed. Changes in phenolics from plasma suggest that microbiota and liver metabolism influence the pregnancy establishment in cattle.

Metabonomics analysis of Zi goose follicular granulosa cells using ENO1 gene expression interference

The Zi goose is native to North-east China and is noted for its high egg production. Alpha enolase (ENO1) is a glycolytic enzyme which functions as a plasminogen receptor in follicular granulosa cells (FGCs), with several studies showing that FGCs can support follicular development. By transfecting the ENO1 interfering plasmid (shRNA) into FGCs, ENO1 expression in these cells was downregulated, suggesting the successful knock-down of ENO1 in these cells. In this knock-down model, we detected 13 metabolites from FGCs using LC/MS. When compared with the non-coding shRNA (NC) group, the lower level metabolites were (R)-(+)-citronellic acid, altretamine, 3-hydroxycaproic acid, heptadecanoic acid, cholecalciferol vitamin D3, indole, benzoic acid, capric acid, caffeic acid, azelaic acid, 3,4-dihydroxyhydrocinnamic acid and cholic acid, while oleic acid was detected at high levels. To further examine the results of metabolomics, six key metabolites were verified by gas chromatography-mass spectrometry (GC-MS). We found that vitamin D3, indole, benzoic acid, capric acid and cholic acid were significantly downregulated in the shRNA group, while oleic acid was significantly upregulated. This observation was consistent with the metabolomics data. Through these studies, we found that decreased ENO1 levels altered certain metabolite levels in FGCs.