Relationships among Richards Growth Curve Parameters, Reproductive and Milk Production Traits in Brown Swiss Cattle

The study was carried out on 19 ewes of local Awassi sheep and 12ewes local Arabi sheep in the Al-kafeel sheep station Karbala, to determine the effect of breed and some non-genetic factors such as (sex of the lamb, type of birth, age and weight of ewes at birth) on daily and total milk production and lactation period and some of milk components (fat, protein and lactose). The results showed that a significant effect (P <0.05) of the breed on milk production traits where Awassi sheep recorded the highest mean (0.91 kg , 101.63 kg , 104.86 day) compared to the Arabi sheep she was means (0.77 kg , 88.15 kg , 99.15 day) respectively. As well as in proportions of milk components with mean( 5.1 , 4.90 , 5.51) % respectively compared to the Arabi sheep (4.70 . 4.20 . 4.89) ewes with male lambs also exceeded superior ewes with female lambs in daily and total milk production and the lactation period the sex of the lamb did not affect the proportions of milk components the weight of the ewes had a significant effect (P <0.05) in milk production attributes with superior weight of ewes on lower ewes and did not affect the proportions of milk ingredients except for lactose. The type of birth and the age of the ewes did not have a significant effect in all the studied traits except for the superiority (P<0.05) of young ewes on age ewes in the fat percentage of milk.

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An association analysis between PRL genotype and milk production traits in Italian Mediterranean river buffalo

Journal of Dairy Research ◽

10.1017/s0022029917000693 ◽

2017 ◽

Vol 84 (4) ◽

pp. 430-433 ◽

Cited By ~ 6

Author(s):

Jun Li ◽

Aixin Liang ◽

Zipeng Li ◽

Chao Du ◽

Guohua Hua ◽

...

Keyword(s):

Milk Production ◽

Milk Yield ◽

Milk Fat ◽

Fat Content ◽

Phenotypic Variance ◽

River Buffalo ◽

Production Traits ◽

Milk Production Traits ◽

Exon 2 ◽

Mediterranean River

This Research Communication describes the association between genetic variation within the prolactin (PRL) gene and the milk production traits of Italian Mediterranean river buffalo (Bufala mediterranea Italiana). High resolution melting (HRM) techniques were developed for genotyping 465 buffaloes. The association of genetic polymorphism with milk production traits was performed and subsequently the effects of parity and calving season were evaluated. Single nucleotide polymorphisms (SNPs) were identified at exons 2 and 5 and at introns 1 and 2. All the SNPs were in Hardy–Weinberg equilibrium, and statistical analysis showed that the polymorphism of intron1 was significantly (P < 0·05) associated with milk yield, milk protein content and peak milk yield. The average contribution of the intron1 genotype (r2intron1) to total phenotypic variance in milk production traits was 0·09, and the TT genotype showed lower values than CC and CT genotypes. A nonsynonymous SNP was identified in exon 2, which resulted in an amino acid change from arginine to cysteine. Moreover, the polymorphism of exon 2 was associated significantly with milk fat content (P < 0·05), and the buffaloes with TT genotype showed higher total fat content than the buffaloes with CT genotype. These findings provide evidence that polymorphisms of the buffalo PRL gene are associated with milk production traits and PRL can be used as a candidate gene for marker-assisted selection in Italian Mediterranean river buffalo breeding.

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Factors influencing milk osteopontin concentration based on measurements from Danish Holstein cows

Journal of Dairy Research ◽

10.1017/s0022029921000054 ◽

2021 ◽

pp. 1-6

Author(s):

Brian Christensen ◽

Elias D. Zachariae ◽

Nina A. Poulsen ◽

Albert J. Buitenhuis ◽

Lotte B. Larsen ◽

...

Keyword(s):

Milk Production ◽

Bovine Milk ◽

Farm Management ◽

Holstein Cows ◽

Enzyme Linked Immunosorbent Assay ◽

Production Traits ◽

Milk Production Traits ◽

Factors Influencing ◽

Significant Interest ◽

Variation Explained

Abstract Our objective was to determine the content of the bioactive protein osteopontin (OPN) in bovine milk and identify factors influencing its concentration. OPN is expressed in many tissues and body fluids, with by far the highest concentrations in milk. OPN plays a role in immunological and developmental processes and it has been associated with several milk production traits and lactation persistency in cows. In the present study, we report the development of an enzyme linked immunosorbent assay (ELISA) for measurement of OPN in bovine milk. The method was used to determine the concentration of OPN in milk from 661 individual Danish Holstein cows. The median OPN level was determined to 21.9 mg/l with a pronounced level of individual variation ranging from 0.4 mg/l to 67.8 mg/l. Breeding for increased OPN in cow's milk is of significant interest, however, the heritability of OPN in milk was found to be relatively low, with an estimated value of 0.19 in the current dataset. The variation explained by the herd was also found to be low suggesting that OPN levels are not affected by farm management or feeding. Interestingly, the concentration of OPN was found to increase with days in milk and to decrease with parity.

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Sequence Variations in the Bovine Growth Hormone Gene Characterized by Single-Strand Conformation Polymorphism (SSCP) Analysis and Their Association with Milk Production Traits in Holsteins

Genetics ◽

10.1093/genetics/144.4.1809 ◽

1996 ◽

Vol 144 (4) ◽

pp. 1809-1816 ◽

Cited By ~ 1

Author(s):

Jianbo Yao ◽

Samuel E Aggrey ◽

David Zadworny ◽

J Flan Hayes ◽

Urs Kühnlein

Keyword(s):

Growth Hormone ◽

Milk Production ◽

Milk Yield ◽

Single Strand Conformation Polymorphism ◽

Sscp Analysis ◽

Bovine Growth Hormone ◽

Production Traits ◽

Milk Production Traits ◽

Sequence Variations ◽

Conformation Polymorphism

Sequence variations in the bovine growth hormone (GH) gene were investigated by single strand conformation polymorphism (SSCP) analysis of seven amplified fragments covering almost the entire gene (2.7 kb). SSCPs were detected in four of these fragments and a total of six polymorphisms were found in a sample of 128 Holstein bulls. Two polymorphisms, a T→C transition in the third intron (designated GH4.1) and an A→C transversion in the fifth exon (designated GH6.2), were shown to be associated with milk production traits. GH4.1c/GH4.1c bulls had higher milk yield than GH4.1c/GH4.1t (P ≤ 0.005) and GH4.1t/GH4.1t (P ≤ 0.0022) bulls. GH4.1c/GH4.1c bulls had higher kg fat (P ≤ 0.0076) and protein (P ≤ 0.0018) than GH4.1c/GH4.1t bulls. Similar effects on milk production traits with the GH6.2 polymorphism were observed with the GH6.2a allele being the favorable allele. The average effects of the gene substitution for GH4.1 and GH6.2 are similar, with ±300 kg for milk yield, ±8 kg for fat content and ±7 kg for protein content per lactation. The positive association of GH4.1c and GH6.2a with milk production traits may be useful for improving milk performance in dairy cattle.

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Association of the Leu127 variant of the bovine growth hormone (bGH) gene with increased yield of milk, fat, and protein in Australian Holstein-Friesians

Australian Journal of Agricultural Research ◽

10.1071/ar99102 ◽

2000 ◽

Vol 51 (4) ◽

pp. 515 ◽

Cited By ~ 11

Author(s):

M. R. Shariflou ◽

C. Moran ◽

F. W. Nicholas

Keyword(s):

Growth Hormone ◽

Milk Production ◽

Milk Fat ◽

Bovine Growth Hormone ◽

Data Sets ◽

Production Traits ◽

Milk Production Traits ◽

Maximum Benefit ◽

Pcr Products ◽

Trait Locus

The occurrence of the Leu127/Val127 variants of the bovine growth hormone (bGH) gene and their effect on milk production traits was investigated in Australian Holstein-Friesian cattle. Animals were genotyped for the Leu127/Val127 variants, with RFLP methodology, using PCR and AluI digestion of PCR products (AluI-RFLP). Alleles Leu127 and Val127 occurred with frequencies of 82% and 18%, respectively. The quantitative effect of this polymorphic site on milk-production traits was estimated from lactation data and test-day data. Results from the 2 data sets consistently showed that the Leu127 allele is associated with higher production of milk, fat, and protein and is dominant to Val127. The average effects of the gene substitution are 95 L for milk yield, 7 kg for fat yield, and 3 kg for protein yield per lactation. This locus may be directly responsible for quantitative variation or it may be a marker for a closely linked quantitative trait locus (QTL) for milk-production traits in Australian dairy cattle. In either case, it will be useful as an aid to selection for improvement of milk production traits. As the Leu127 allele is dominant, selection of AI sires homozygous for the Leu127 allele (Leu127/Leu127) will result in maximum benefit without the need for genotyping cows.

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