Denatured collagen in keratin layers and smooth muscles of teats with low or high teat apex scores in Holstein dairy cows.

We hypothesized that teats with a teat apex score (TAS) of 4 on a 4-point scale would exhibit elevated levels of denatured collagen compared with teats with lower TAS. We procured keratin layer and smooth muscle samples from Holsteins with TAS ranging from 1 to 4, as well as from crossbred heifers (Japanese Black male and Holstein female) with TAS of 1. Teats with a TAS of 4 demonstrated increased total collagen content, higher amounts of type I collagen (the harder, thicker variant), and reduced amounts of type III collagen (the softer, thinner variant) compared with teats with lower TAS.

Exercise-induced muscle hormone "irisin" controls luteinizing hormone and follicle-stimulating hormone secretion by bovine gonadotrophs.

Irisin is a hormone secreted by muscle in response to exercise. The irisin receptor (IrisinR) is a heterodimer of integrin alpha V (ITGAV) and integrin beta 5 (ITGB5) subunits. Since irisin may mediate some beneficial effects of exercise on animal reproduction, we tested the hypothesis that bovine gonadotrophs express IrisinR and irisin stimulates luteinizing hormone (LH) and follicle stimulating hormone (FSH) secretion by gonadotrophs.

Alpha-synuclein expression in oxytocin neurons of young and old bovine brains.

Understanding of central nervous system mechanisms underlying age-related infertility remains limited. Fibril α-synuclein, distinct from its monomeric form, is implicated in age-related diseases. Notably, fibril α-synuclein spreads among neurons, similar to prions, from damaged old neurons in cortex and hippocampus to healthy neurons.

The effect of high temperature and humidity on milk yield in Ankole and crossbred cows.

Tropical regions are characterized by high temperature and humidity across the year. At high values of temperature humidity index (THI), there is a risk of heat stress leading to lower milk yield. The objective of this study was to describe the effect of season and the effect of maximum daily THI on milk yield of that day in purebred Ankole and Ankole-Friesian, Ankole-Jersey and Ankole-Sahiwal crosses in a tropical climate.