scholarly journals Detection of QTL Underlying Milk Traits in Sheep: An Update

10.5772/50762 ◽  
2012 ◽  
Author(s):  
Juan Jose ◽  
Beatriz Gutierrez-Gil
Keyword(s):  
Milk Traits

scholarly journals Effects of melatonin treatment on milk traits, reproductive performance and immune response in Sarda dairy sheep

2021 ◽  
Vol 20 (1) ◽  
pp. 632-639
Author(s):  
Giovanni Cosso ◽  
Maria Consuelo Mura ◽  
Luisa Pulinas ◽  
Giulio Curone ◽  
Daniele Vigo ◽  
...  
Keyword(s):  
Immune Response ◽  
Reproductive Performance ◽  
Dairy Sheep ◽  
Melatonin Treatment ◽  
Milk Traits

scholarly journals Selection Response Due to Different Combination of Antagonistic Milk, Beef, and Morphological Traits in the Alpine Grey Cattle Breed

Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1340
Author(s):  
Enrico Mancin ◽  
Cristina Sartori ◽  
Nadia Guzzo ◽  
Beniamino Tuliozi ◽  
Roberto Mantovani
Keyword(s):  
Genetic Correlation ◽  
Functional Traits ◽  
Performance Test ◽  
Genetic Relationships ◽  
Selection Index ◽  
Milk Traits ◽  
Linear Type ◽  
Dual Purpose ◽  
Type Traits ◽  
Selection Indexes

Selection in local dual-purpose breeds requires great carefulness because of the need to preserve peculiar traits and also guarantee the positive genetic progress for milk and beef production to maintain economic competitiveness. A specific breeding plan accounting for milk, beef, and functional traits is required by breeders of the Alpine Grey cattle (AG), a local dual-purpose breed of the Italian Alps. Hereditability and genetic correlations among all traits have been analyzed for this purpose. After that, different selection indexes were proposed to identify the most suitable for this breed. Firstly, a genetic parameters analysis was carried out with different datasets. The milk dataset contained 406,918 test day records of milk, protein, and fat yields and somatic cells (expressed as SCS). The beef dataset included performance test data conducted on 749 young bulls. Average daily gain, in vivo estimated carcass yields, and carcass conformation (SEUROP) were the phenotypes obtained from the performance tests. The morphological dataset included 21 linear type evaluations of 11,320 first party cows. Linear type traits were aggregated through factor analysis and three factors were retained, while head typicality (HT) and rear muscularity (RM) were analyzed as single traits. Heritability estimates (h2) for milk traits ranged from 0.125 to 0.219. Analysis of beef traits showed h2 greater than milk traits, ranging from 0.282 to 0.501. Type traits showed a medium value of h2 ranging from 0.238 to 0.374. Regarding genetic correlation, SCS and milk traits were strongly positively correlated. Milk traits had a negative genetic correlation with the factor accounting for udder conformations (−0.40) and with all performance test traits and RM. These latter traits showed also a negative genetic correlation with udder volume (−0.28). The HT and the factor accounting for rear legs traits were not correlated with milk traits, but negatively correlated with beef traits (−0.32 with RM). We argue that the consequence of these results is that the use of the current selection index, which is mainly focused on milk attitude, will lead to a deterioration of all other traits. In this study, we propose more appropriate selection indexes that account for genetic relationships among traits, including functional traits.

scholarly journals Short communication: Importance of introgression for milk traits in the German Vorderwald and Hinterwald cattle

2015 ◽  
Vol 98 (3) ◽  
pp. 2033-2038 ◽  
Author(s):  
S. Hartwig ◽  
R. Wellmann ◽  
R. Emmerling ◽  
H. Hamann ◽  
J. Bennewitz
Keyword(s):  
Short Communication ◽  
Milk Traits

Combined haplotype blocks regression and multi-locus mixed model analysis reveals novel candidate genes associated with milk traits in dairy sheep

2019 ◽  
Vol 220 ◽  
pp. 8-16
Author(s):  
A. Saridaki ◽  
G. Antonakos ◽  
A.L. Hager-Theodorides ◽  
E. Zoidis ◽  
G. Tsiamis ◽  
...  
Keyword(s):  
Candidate Genes ◽  
Mixed Model ◽  
Model Analysis ◽  
Dairy Sheep ◽  
Milk Traits ◽  
Mixed Model Analysis ◽  
Haplotype Blocks

Association of prolactin polymorphism with milk fat content in Iranian Sarabi cows

2007 ◽  
Vol 2007 ◽  
pp. 160-160
Author(s):  
A. Heravi Moussavi ◽  
M.R. Nassiry ◽  
M. Tahmoores Pour ◽  
A. Javadmanesh ◽  
M.H. Sekhavati
Keyword(s):  
Dairy Cattle ◽  
Candidate Gene ◽  
Milk Fat ◽  
Anterior Pituitary ◽  
Fat Content ◽  
Genetic Differences ◽  
Biological Functions ◽  
Milk Traits ◽  
Polypeptide Hormones ◽  
Prl Gene

Prolactin (PRL) is a polypeptide hormones produced by cells of the anterior pituitary. The bovine PRL gene consists of 4 introns and 5 exons, located on chromosome 23. Different biological functions of PRL were subdivided into five broad categories: reproduction, osmoregulation, growth, integument, and synergism with steroids. Also, It has been shown to be important for control of mammary growth, lactogenesis and lactation (Skinkyteet al., 2005). Chung et al, (1996) showed that PRL-RsaI locus had a significant effect on milk fat percent in dairy cattle. Therefore the PRL gene was chosen as a candidate gene for milk traits in dairy cattle. The objective of this study was to evaluate the association of genetic differences in bovine PRL gene and milk fat content in Iranian Sarabi cows.

scholarly journals Estimation of variance components of milk, fat, and protein yields of Tunisian Holstein dairy cattle using Bayesian and REML methods

2016 ◽  
Vol 59 (2) ◽  
pp. 243-248 ◽  
Author(s):  
Hafedh Ben Zaabza ◽  
Abderrahmen Ben Gara ◽  
Hedi Hammami ◽  
Mohamed Amine Ferchichi ◽  
Boulbaba Rekik
Keyword(s):  
Dairy Cattle ◽  
Bayesian Methods ◽  
Milk Fat ◽  
Variance Components ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Bayesian Procedure ◽  
Milk Traits ◽  
Residual Variances ◽  
Estimation Of Variance

Abstract. A multi-trait repeatability animal model under restricted maximum likelihood (REML) and Bayesian methods was used to estimate genetic parameters of milk, fat, and protein yields in Tunisian Holstein cows. The estimates of heritability for milk, fat, and protein yields from the REML procedure were 0.21 ± 0.05, 0.159 ± 0.04, and 0.158 ± 0.04, respectively. The corresponding results from the Bayesian procedure were 0.273 ± 0.02, 0.198 ± 0.01, and 0.187 ± 0.01. Heritability estimates tended to be larger via the Bayesian than those obtained by the REML method. Genetic and permanent environmental variances estimated by REML were smaller than those obtained by the Bayesian analysis. Inversely, REML estimates of the residual variances were larger than Bayesian estimates. Genetic and permanent correlation estimates were on the other hand comparable by both REML and Bayesian methods with permanent environmental being larger than genetic correlations. Results from this study confirm previous reports on genetic parameters for milk traits in Tunisian Holsteins and suggest that a multi-trait approach can be an alternative for implementing a routine genetic evaluation of the Tunisian dairy cattle population.

scholarly journals The effect of the farm size on milk traits of cows

2011 ◽  
Vol 27 (3) ◽  
pp. 951-958 ◽  
Author(s):  
D. Kucevic ◽  
S. Trivunovic ◽  
M. Radinovic ◽  
M. Plavsic ◽  
Z. Skalicki ◽  
...  
Keyword(s):  
Milk Yield ◽  
Milk Fat ◽  
Dairy Farm ◽  
Farm Size ◽  
Small Farms ◽  
Milk Traits ◽  
Holstein Friesian ◽  
Milk Performance ◽  
Fat Yield ◽  
Large Farms

Objective of this study was to analyze the effect of the dairy farm on milk traits of cows in Vojvodina. The research was carried out on small farms with 10 to 20 cows, medium farms with 20 to 50 cows, and large farms with over 50 dairy cows. The study included registered animals of Simmental (SM) and Holstein-Friesian breed (HF; including Red Holstein) in the first lactation for traits of milk yield and yield and content of milk fat. Total of 1323 first lactations were analyzed. The average milk yield (both breeds) in the first lactation of 305 days was 6295 kg of milk with 234,3 kg of milk fat and average milk fat content of 3,74%. Milk performance of cows varied significantly (CV=22,9% and SD=1447,8), as well as milk fat yield (CV=21,6% and SD=50,8). Large farms produced in average 6534 kg of milk, medium farms 6347kg and small farms 4717kg. Size of the farm exhibited significantly high effect on all observed traits, and the tendency was that farms with higher number of animals realize also higher average of production. Farm management and various breeding-zootechnical conditions present on farms had significant effect on milk performance of cows.

scholarly journals The Effect of Pre-milking Stimulation on Teat Morphological Parameters and Milk Traits in the Italian Water Buffalo

2020 ◽  
Vol 7 ◽  
Author(s):  
Angela Costa ◽  
Massimo De Marchi ◽  
Giulio Visentin ◽  
Maria Concetta Campagna ◽  
Antonio Borghese ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Somatic Cell ◽  
Milk Yield ◽  
Large Scale ◽  
Chloride Concentration ◽  
Morphological Characteristics ◽  
Health Indicators ◽  
Milk Traits ◽  
Manual Stimulation ◽  
The Impact

Water buffaloes (Bubalus bubalis) are very sensitive to environmental stimulus before and during milking, and this explains why disrupted milk ejections due to blood oxytocin level instability are frequent in this species. According to the literature, the manual stimulation (MS) of teats before milking promotes oxytocin release and allows milk ejection to start within 2–3 min. However, the pre-milking stimulation of teats is not always part of the milking routine in Italian buffalo farms; moreover, buffaloes with unstable milk let-down are sometimes treated with exogenous oxytocin (OX). Different types of pre-milking stimulation can impact differently on the mammary gland epithelium and structures and, therefore, on milk yield. In this study, we observed the changes in teat morphological traits before and after the application of three types of stimuli, i.e., no manual stimulation (NS), MS, and OX, in buffaloes reared in an Italian dairy farm. In particular, measurements were available for 23 and 21 buffaloes for front and rear teats, respectively. Subsequently, the effect of the pre-milking stimulation type was estimated on teat morphological characteristics and on milk traits recorded after the application of stimuli. The results showed that the teat canal length was shorter (P < 0.05) after stimulation in the case of MS and OX compared to NS. Cistern diameter was overall greater for MS and lower for OX. On the contrary, teat wall thickness was greater and lower for OX and MS, respectively. Milk yield and quality (fat, protein, and somatic cell score) were similar across the three types of pre-milking stimulation. In perspective, the impact of these types of pre-milking stimulation should be evaluated on a large scale, and the focus might be put on mammary gland epithelium integrity, mastitis incidence, and other udder health indicators in milk, e.g., electrical conductivity, differential somatic cell count, lactose content, and sodium and chloride concentration.

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