The Interactions of Change in Nutrition on Uterine Environment and Cholesterol Concentrations in Beef Cattle

The objective of this study was to evaluate the impact of nutritional changes prior to and after artificial insemination (AI) on uterine environment and plasma cholesterol concentrations

Use of Sperm In Vitro Capacitation and Flow Cytometry to Estimate Bull Fertility

Study Description: Frozen-thawed semen from five bulls previously identified as high (48.1% and 47.7%, bulls A and B, respectively), intermediary (45.5%, bull C) or low (43.1% and 40.7%, bulls D and E, respectively) fertility, based on pregnancy per AI, were evaluated with several laboratory measures. Measures included total motility, sperm plasma membrane integrity (viability), acrosome integrity, reactive oxygen species (ROS), mitochondrial membrane energy potential (mito-potential), zinc signatures (signatures 1 to 4), and CD9 protein populations at pre-wash, post-wash, h 0 (diluted with non-capacitation media), and at 0, 3, 6, and 24 h after dilution with capacitation media and incubation at 37 ºC. Data were analyzed using the GLIMMIX procedure of SAS for repeated measures with bull, time, and the interaction as fixed effects. Bull by time interaction was significant (P ≤ 0.01) for total motility and viability. There tended (P = 0.06) to be a bull by time interaction for zinc signatures 1 + 2 combined. There was a significant effect of bull (P ≤ 0.03) for viability, viable sperm with disrupted acrosome, zinc signatures 1, 2, and 1 + 2, viable CD9- (CD9 negative), and dead CD9+ (CD9 positive). High and intermediary field fertility bulls had greater (P ≤ 0.04) percentages of viable sperm, zinc signature 2, and zinc signature 1 + 2 compared to low fertility bulls. High and intermediary fertility bulls had decreased (P ≤ 0.05) percentage of dead CD9+ compared to low fertility bulls. There was or tended to be a positive correlation between pregnancy per AI and viability (P = 0.10; r = 0.81), zinc signature 2 (P = 0.04; r = 0.89), and zinc signature 1 + 2 (P = 0.10; r = 0.80)

Interactions of Change in Nutrition After AI on Plasma Metabolites, Steroid Hormone Production, and Uterine Environment

Objective The objective was to evaluate the impact of nutritional changes post artificial insemination (AI) on plasma metabolites, steroid hormones, and uterine environment. Study Description Beef heifers (n = 43) were randomly assigned to two dietary treatment groups (High = 161.5% or Low = 77.5% of maintenance energy) for 14 d after AI (post-AI). Post-AI dietary treatments continued until uteri were flushed for embryo recovery (d 14 post-AI). Blood samples were collected on d -3, 0 (day of AI), 3, 6, 9, 12, and 14 for analysis of plasma glucose, proteins, non-esterified fatty acids (NEFAs), and cholesterol using colorimetric assays. Plasma collected on d 0, 3, 6, 9, 12, and 14 was analyzed for progesterone concentrations by radioimmunoassay. Uterine flushes were analyzed for mineral concentrations of Mg, P, S, K, Ca, Cu, Zn, Se, Mn, Co, B, Cr, and Fe by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Plasma progesterone, NEFAs, protein, glucose and cholesterol (repeated measures) and uterine mineral concentrations were analyzed using the MIXED procedures in SAS. Plasma NEFA concentrations differed between treatments (P = 0.03) with heifers on the low diet treatment having elevated NEFA concentrations. Plasma NEFA concentrations weren’t affected by embryo recovery (P \u3e 0.10), treatment by embryo recovery (P \u3e 0.10), and treatment by embryo recovery by day (P \u3e 0.10). Plasma progesterone, glucose, protein, and cholesterol concentrations were not influenced by treatment (P \u3e 0.10), embryo recovery (P \u3e 0.10), treatment by embryo recovery (P \u3e 0.10), and treatment by embryo recovery by day (P \u3e 0.10). Uterine mineral concentrations were affected by embryo presence for Mg (P = 0.02) and S (P = 0.01) a tendency for Ca (P = 0.08) with decreased concentrations in uterine flushes when an embryo was recovered. A tendency for increased concentration of Mn (P = 0.06) was observed in uterine flushes when an embryo was recovered. Additionally, treatment tended to impact Fe concentrations (P = 0.09), with heifers on the restricted diet having reduced uterine Fe concentrations. In conclusion, changing plane of nutrition post-AI had an effect on NEFA plasma concentrations, but no effect on plasma progesterone, protein, glucose, and cholesterol concentrations. The presence of an embryo however affected uterine mineral concentrations