Regeneration of Teat Canal Keratin in Lactating Dairy Cows

Abstract

This study was designed to determine the regeneration rate of teat canal keratin in two groups of 10 lactating Holstein cows. The weight of keratin obtained upon successive collections of keratin was determined. Intervals between successive collections were varied between 8 and 72 h. Following initial collection, the quantity of keratin removed was regenerated within 1 to 2.5 d. The rate of keratin regeneration per teat was approximately 1.5 mg of wet weight or .6 mg of dry weight per 24 h. The concentration (microgram lipid/mg keratin, wet weight) of lipid in keratin samples collected during regeneration was almost twice that present initially or after regeneration was complete. With the exception of free cholesterol, composition (%) of lipid components of keratin did not differ between samples collected initially, those collected early in the process of regeneration, and those collected after the mass of keratin removed had been replaced. Although data suggest that keratin matures during the process of regeneration, maturation appears complete by the time mass of keratin is fully regenerated. Additionally, the quantity of keratin recovered at initial sampling was inversely correlated with milk production. We hypothesize that as milk production increases, more keratin is lost during milking.

Review: Milking machine settings, teat condition and milking efficiency in dairy cows

“…Physically, keratin entraps bacteria, preventing their entry into the mammary gland. Furthermore, keratin contains cationic proteins, xanthine oxidase, long-chain fatty acids which are reported to be bactericidal or bacteriostatic (Capuco et al, 1990). Impaired teat end condition due to excessive keratin growth and thickening of the keratin layer impairs the complete closure of the teat canal and hence increases the risk of bacterial invasion.…”

Reproductive Performances of Indigenous Ewes in Bangladesh

“…Under nutrition results in the loss of body weight and body condition, delays the onset of puberty, increases the post-partum onset of estrus, interferes with normal ovarian cyclicity by decreasing gonadotropin secretion and increases infertility [6], [7], [8]. Nutrition during gestation not only affects maternal body weight gain, body condition, and reproductive performance [9]; [10], but also affects prenatal and postnatal offspring growth and development [11], [12].…”

Reproductive Disorders and its Relationship with Hormones and Mineral Status in Bovines of Organized Dairy Farms

“…Further, zinc plays a critical role in the reproductive hormones and immune status of animals (Capuco et al, 1990). Zinc is also an essential component of various enzyme systems involved in metabolism of carbohydrate, protein and nucleic acid metabolism, epithelial tissue integrity, cell repair and division, vitamin A and E transport and their utilization.…”