Milk Production Traits In Goats Research Articles

Genetic improvement and conservation of goats in tropic

Goats indeed have a significant historical and contemporary importance in human civilization, particularly in the realm of agriculture and food production. Their adaptability and widespread distribution have made them crucial for various societies across the world. Goats have played a central role in the Neolithic agricultural revolution, aiding in the spread of human civilization globally. Their adaptability allowed them to thrive in diverse environments, contributing to the sustenance and expansion of human settlements. Goats are highly adaptable and are found in a wide range of geographical regions. Their presence spans across continents, from tropical to temperate climates, showcasing their ability to thrive in various environmental conditions. There is diversity in the production performance of goats based on the region of the world and the specific breeds. Genetic improvement programs aim to enhance economically important traits such as milk production, growth rates and fiber production, thereby increasing productivity and income for goat farmers. Understanding the genetic parameters such as heritabilities and repeatabilities for various traits is crucial for designing effective breeding programs. These parameters provide insights into the genetic potential of goats for traits like milk production, growth and fiber quality. Heritability estimates for reproductive traits, body weight, daily gain and direct and maternal heritability are important for implementing selective breeding strategies aimed at improving overall productivity and efficiency in goat farming. Genetic improvement programs have been implemented in tropical environments to enhance milk production traits in goats. Genetic improvements have also targeted fiber production in goats, with a focus on traits such as grease fleece weight and average fiber diameter. These efforts aim to enhance the quality and quantity of fiber produced by goats for various commercial purposes. Despite the importance of conserving goat breeds with unique characteristics, planned conservation programs in tropical regions are often neglected. It’s emphasized that preserving indigenous goat breeds in their native habitats is essential for maintaining genetic diversity and ensuring future resilience in goat farming.

Effect of breed, stage of lactation and nutrition on milk production traits in goats

This discussion is an attempt to explore the influence of breed, stage of lactation and nutrition on milk yield and major milk components in goats. Different breeds protray different lactation curves, this is possibly that their genomes from a genetically point of view are different. Crosses of pure breeds and local goat genetic resources will improve milk production in an extensive traditional system because they will be able to deal with low input that characterize the traditional extensive farming systems. However, nutrition is a vital component in an attempt to maximise milk synthesis in goats, as a result correct feed management is desirable through appropriate estimation of roughage to concentrate intake in order to optimize the utilization of feed supplements. It is suffice to suggest that feeding high producing dairy goat may be a major constraint in milk production, which implies greater attention to diet composition, feed quality, and the physical form of feedstuffs is required. The rate and extent to which a dairy goat is capable of drawing upon body reserves to meet the energy requirement at different stages of lactation is critical in determining her ability to produce and sustain a high level of milk production. In order to increase goat milk production and to ensure high feed efficiency, goat farmers need to pay close attention to the lactation curves of dams within their herds.

Polymorphisms of PRLR and FOLR1 genes and association with milk production traits in goats

We investigated the polymorphisms of PRLR and FOLR1 genes in Xinong Saanen, Guanzhong, and Boer goat breeds by DNA sequencing and PCR-RFLP. Two novel SNPs were identified: KC109741: g.62130C>T in the 3ꞌ-UTR of goat gene PRLR, and KC136296: g.7884A>C in exon 3 of goat gene FOLR1. In the three goat breeds, the polymorphism information content was 0.20-0.27 at the g.62130C>T locus. At the g.7884A>C locus, it was 0.36 in Boer goats. The three goat breeds were in Hardy-Weinberg disequilibrium at the g.62130C>T locus. The g.62130C>T SNP was found to be significantly associated with milk production traits in Xinong Saanen and Guanzhong breeds. These results are consistent with the regulatory function of PRLR in mammary gland development, milk secretion, and expression of milk protein genes; they extend the spectrum of genetic variation of the goat PRLR gene, which could be useful for breeding programs.

Growth hormone gene variability and its effects on milk traits in primiparous Sarda goats

The aim of this research was to investigate variability in each of the five exons of the caprine growth hormone (gGH) gene, in order to establish the possible relationships with milk traits in Sarda breed goat. The general linear model procedure was used to analyse the effects of the single strand conformation (SSCP) profiles on milk traits of 100 lactating goats. Analysis of conformational polymorphism at exons 1-5 revealed a total of 25 differing banding patterns. Sequencing revealed 21 nucleotide changes (compared with GenBank D00476): 14 were polymorphic and 7 monomorphic; 19 in exonic regions, 5 of which were nonsynonymous. A SNP upstream of the transcription initiation codon (c.-3A>G) and an indel (c.*29_30insC) in the 3'UTR, were detected. Alignment of 4 cloned sequences including the entire gGH gene led to the identification of 22 nucleotide variations within the intron regions, including two indels. Association analysis revealed that each exon, except exon-1, affected milk yield, exons 1 and 3 influenced milk fat percentage, and all exons, except exon-2, had an effect on protein percentage, supporting previous results in livestock. The variability detected at the caprine GH gene might provide useful information for the phylogeny of ruminants and, more importantly, have implications on the biological function of the growth hormone and on those traits resulting from its physiological action, including milk production and composition. The caprine GH gene may become a useful molecular marker for a more effective genetic selection for milk production traits in goats.

QTL detection for milk production traits in goats using a longitudinal model

Eight paternal half-sib families were used to identify chromosomal regions associated with variation in the lactation curves of dairy goats. DNA samples from 162 animals were amplified by PCR for 37 microsatellite markers, from Capra hircus autosomes CHI3, CHI6, CHI14 and CHI20. Milk samples were collected during 6 years, and there were 897 records for milk yield (MY) and 814 for fat (FP) and protein percentage (PP). The analysis was conducted in two stages. First, a random regression model with several fixed effects was fitted to describe the lactation function, using a scale (alpha) plus four shape parameters: beta and gamma, both associated with a decrease in the slope of the curve, and delta and phi that are related to the increase in slope. Predictions of alpha, beta, gamma, delta and phi were regressed using an interval mapping model, and F-tests were used to test for quantitative trait loci (QTL) effects. Significant (p < 0.05) QTLs were found for: (i) MY: CHI6 at 70-80 cM for all parameters; CHI14 at 14 cM for delta and phi; (ii) FP: CHI14, at 63 cM was associated with beta; CHI20, at 72 cM, showed association with alpha; (iii) PP: chromosomal regions associated with beta were found at 59 cM in CHI3 and at 55 cM in CHI20 with alpha and gamma. Analyses using more families and more animals will be useful to confirm or to reject these findings.