Effect of melatonin administration to lactating cashmere goats on milk production of dams and on hair follicle development in their offspring

Abstract

Melatonin treatment in adult cashmere goats can increase cashmere yield and improve cashmere fibre quality by inducing cashmere growth during cashmere non-growth period, of which time cashmere goats are in the mid and late stages of lactation. However, whether melatonin treatment in adult cashmere goats affects their offspring’s growth performance remains unknown. Therefore, the objectives of the current study were to determine the effects of melatonin treatment in adult cashmere goats on cashmere and milk production performance in dams and on hair follicle development and subsequent cashmere production in their offspring. Twenty-four lactating Inner Mongolian Cashmere goat dams (50 ± 2 days in milk, mean ± SD) and their single-born female offspring (50 ± 2 days old, mean ± SD) were randomly assigned to one of two groups supplemented with melatonin implants (MEL; n = 12) or without (CON; n = 12). The melatonin implants were subcutaneously implanted behind the ear at a dose of 2 mg/kg live weight on two occasions – 30 April and 30 June 2016. The results demonstrated that melatonin treatment in adult cashmere goats increased cashmere production and improved cashmere fibre quality as indicated by greater cashmere yield, longer cashmere fibre staple length, finer cashmere fibre diameter and thicker cashmere fibre density. The milk fat content was higher in MEL compared with CON cashmere goats. The daily yields of milk production, milk protein and milk lactose were lower in MEL compared with CON cashmere goats. Serum melatonin concentrations were greater, serum prolactin concentrations were lower and milk melatonin concentrations and yields were greater in MEL compared with CON cashmere goats. With regard to offspring, there were no differences in cashmere yield, fibre staple length, fibre diameter and fibre density at yearling combing, and the primary and secondary hair follicles population and maturation between treatments. In conclusion, melatonin treatment in adult cashmere goats during cashmere non-growth period is a practical and an effective way in cashmere industry as indicated by not only increasing cashmere yield and improving cashmere fibre quality in adult cashmere goat dams but also having no impairment in hair follicle development and the subsequent cashmere production in their single-born offspring.

Genetic Signatures of Selection for Cashmere Traits in Chinese Goats

“…Moreover, the role of melatonin in promoting Cashmere yield has been demonstrated for decades [ 71 ], and melatonin also participates in stem cell differentiation pathways. Melatonin induces Cashmere growth through melatonin receptors [ 72 ] and is a critical intermediary between photoperiod and Cashmere growth [ 73 ]. Cashmere goats breed seasonally, and usually give birth between March and April, which conforms to a spring kidding system [ 72 ].…”

“…Melatonin induces Cashmere growth through melatonin receptors [ 72 ] and is a critical intermediary between photoperiod and Cashmere growth [ 73 ]. Cashmere goats breed seasonally, and usually give birth between March and April, which conforms to a spring kidding system [ 72 ]. Melatonin is administered to Cashmere goats in April, because melatonin treatment in adult Cashmere goats during the Cashmere non-growth period has been found to induce Cashmere growth, increase Cashmere yield, improve Cashmere quality and decrease the fiber diameter [ 74 ], which also present similar results from other countries of the world [ 75 ].…”

Melatonin and the Programming of Stem Cells

“…Effects of melatonin on the hair follicle have been repeatedly described, e.g., in cashmere goats [77] and rabbits [78], but the interest was mostly focused on hair growth and not so much on differentiation. In the Cashmere goat, a seasonal breeder that produces a valuable fur, the influence of melatonin on hair growth is likely, from a fundamental point of view, as it is related to the formation of winter fur.…”

Melatonin Regulates the Periodic Growth of Cashmere by Upregulating the Expression of Wnt10b and β-catenin in Inner Mongolia Cashmere Goats

“…It was reported that MT can accelerate the hair follicle reconstruction process and induce secondary hair follicle development, which results in early entry into the next cashmere growth cycle and increases cashmere yields (Duan et al, 2017;Ge and Wang, 2018;Yang X. Z., 2020;Yang C. H., 2020). According to previous studies, two MT implants during the non-fleece period can improve the cashmere yields of Inner Mongolia cashmere goats to different degrees (Yang et al, 2020).…”