Milk Production Traits In Cattle Research Articles

A systematic review of effect of calving season and parity as non-genetic factors on milk production traits of cattle

A systematic review of effect of calving season and parity as non-genetic factors on milk production traits of cattle

Analysis of the impact of DGAT1 p.M435L and p.K232A variants on pre-mRNA splicing in a full-length gene assay

DGAT1 is playing a major role in fat metabolism and triacylglyceride synthesis. Only two DGAT1 loss-of-function variants altering milk production traits in cattle have been reported to date, namely p.M435L and p.K232A. The p.M435L variant is a rare alteration and has been associated with skipping of exon 16 which results in a non-functional truncated protein, and the p.K232A-containing haplotype has been associated with modifications of the splicing rate of several DGAT1 introns. In particular, the direct causality of the p.K232A variant in decreasing the splicing rate of the intron 7 junction was validated using a minigene assay in MAC-T cells. As both these DGAT1 variants were shown to be spliceogenic, we developed a full-length gene assay (FLGA) to re-analyse p.M435L and p.K232A variants in HEK293T and MAC-T cells. Qualitative RT-PCR analysis of cells transfected with the full-length DGAT1 expression construct carrying the p.M435L variant highlighted complete skipping of exon 16. The same analysis performed using the construct carrying the p.K232A variant showed moderate differences compared to the wild-type construct, suggesting a possible effect of this variant on the splicing of intron 7. Finally, quantitative RT-PCR analyses of cells transfected with the p.K232A-carrying construct did not show any significant modification on the splicing rate of introns 1, 2 and 7. In conclusion, the DGAT1 FLGA confirmed the p.M435L impact previously observed in vivo, but invalidated the hypothesis whereby the p.K232A variant strongly decreased the splicing rate of intron 7.

Estimation of co-variance components and genetic parameters of fertility and production traits in crossbred cattle of Kerala

Estimation of co-variance components and genetic parameters of fertility and production traits will help to find out the relative importance of genetic and environmental components of each trait and to develop a genetic evaluation system for overall improvement in performances of crossbred cattle of Kerala. In the present study, major fertility trait considered was daughters pregnancy rate (DPR), measures the percentage of non-pregnant animals that become pregnant during each oestrous cycle. Data pertaining to 1180 crossbred cattle sired by 208 Frieswal bulls, spread over a period of 16 years from 2003 to 2019, maintained at different farms of Kerala Veterinary and Animal Sciences University and field centres of ICAR- Filed Progeny Testing Scheme were analysed in the study. Estimates of covariance components and genetic parameters were obtained using restricted maximum likelihood (REML) approach using average information (AI) algorithm. It was observed that DPR had low heritability (0.092 ± 0.03), compared to 305 days milk yield (MY) (0.170 ± 0.094) and fat percent (FP) (0.173 ± 0.072). Phenotypic (rp), genetic (rg) and residual (re) correlation indicated unfavourable association of fertility with production traits. The estimates of variance and (co)variance components were computed by multivariate animal model. The results indicated that DPR was having lower direct additive (σ2a) 0.046 and environmental variance (σ2c) 0.063 compared to other traits. Highest additive genetic variance (σ2a) 27035.8 was obtained for MY. The study estimates the magnitude of correlations and covariances of fertility and production traits. Since DPR had lower additive genetic variance and negative association with milk production traits in cattle, it would be included as an indirect measure in the evaluation and breeding programs of crossbred cattle of Kerala.

A Meta-Analysis of the Associations Between Prolactin (PRL) Gene Polymorphism and Milk Production Traits in Cattle

A Meta-Analysis of the Associations Between Prolactin (PRL) Gene Polymorphism and Milk Production Traits in Cattle

Single-Nucleotide Polymorphism Variations Associated With Specific Genes Putatively Identified Enhanced Genetic Predisposition for 305-Day Milk Yield in the Girolando Crossbreed.

Milk production phenotypes are the main focus of genetic selection in dairy herds, and although there are many genes identified as related to the biology of these traits in pure breeds, little is known about crossbreed animals. This study aimed to identify potential genes associated with the 305-day milk yield in 337 crossbreed Gir × Holstein (Girolando) animals. Milk production records were genotyped for 45,613 single-nucleotide polymorphisms (SNPs). This dataset was used for a genome-wide association study (GWAS) using the 305-day milk yield adjusted for the fixed effects of herd and year and linear and quadratic effects of age at calving (in days) and calving factor averaged per animal. Genes within the significant SNPs were retrieved from the Bos taurus ARS-UCD1.2 assembly (bosTau9) for gene ontology analysis. In summary, the GWAS identified 52 SNPs associated [p ≤ 10–4, false discovery rate (FDR) = 8.77%] with milk production, including NUB1 and SLC24A2, which were previously described as related to milk production traits in cattle. The results suggest that SNPs associated mainly with NUB1 and SLC24A2 could be useful to understand milk production in Girolando and used as predictive markers for selecting genetic predisposition for milk yield in Girolando.

GWAS-Based Identification of New Loci for Milk Yield, Fat, and Protein in Holstein Cattle.

Simple SummaryUnderstanding the genetic architecture underlying milk production traits in cattle is beneficial so that genetic variants can be targeted toward the genetic improvement. In this study, we performed a genome-wide association study for milk production and quality traits in Holstein cattle. In the total of ten significant single-nucleotide polymorphisms (SNPs) associated with milk fat and protein, six are located in previously reported quantitative traits locus (QTL) regions. The study not only identified the effect of DGAT1 gene on milk fat and protein but also found several novel candidate genes. In addition, some pleiotropic SNPs and QTLs were identified that associated with more than two traits, these results could provide some basis for molecular breeding in dairy cattle.High-yield and high-quality of milk are the primary goals of dairy production. Understanding the genetic architecture underlying these milk-related traits is beneficial so that genetic variants can be targeted toward the genetic improvement. In this study, we measured five milk production and quality traits in Holstein cattle population from China. These traits included milk yield, fat, and protein. We used the estimated breeding values as dependent variables to conduct the genome-wide association studies (GWAS). Breeding values were estimated through pedigree relationships by using a linear mixed model. Genotyping was carried out on the individuals with phenotypes by using the Illumina BovineSNP150 BeadChip. The association analyses were conducted by using the fixed and random model Circulating Probability Unification (FarmCPU) method. A total of ten single-nucleotide polymorphisms (SNPs) were detected above the genome-wide significant threshold (p < 4.0 × 10−7), including six located in previously reported quantitative traits locus (QTL) regions. We found eight candidate genes within distances of 120 kb upstream or downstream to the associated SNPs. The study not only identified the effect of DGAT1 gene on milk fat and protein, but also discovered novel genetic loci and candidate genes related to milk traits. These novel genetic loci would be an important basis for molecular breeding in dairy cattle.

Effect of polymorphism in the 5’ promoter region of the TG gene on the milk production traits of Polish Holstein-Friesian cattle

The aim of the study was to determine the relationship between the occurrence of three different point mutations (257C&gt;T, 335A&gt;G and 422 C&gt;T) in the promoter region of the gene encoding thyroglobulin (causing polymorphism) and the milk production traits of cattle. The research was conducted on a herd of Polish Holstein-Friesian cows. Genotypes were determined by PCR and its ACRS modification. The frequency of more common alleles for the point mutations was determined: C ‒ 0.830 (257C&gt;T), A ‒ 0.765 (335A&gt;G), and C ‒ 0.635 (422C&gt;T). The statistical analysis showed that all three point mutations in the promoter region of the TG gene significantly (P ≤ 0.05; P ≤ 0.01) affect the analysed milk production traits, i.e. daily milk yield, content of milk fat and protein, and somatic cell count.

Association of Different Genetic Variants of Alpha S2-Casein Gene (CSN1S2) with Milk Production Traits in Cattle

Association of Different Genetic Variants of Alpha S2-Casein Gene (CSN1S2) with Milk Production Traits in Cattle

Polymorphism in the SREBP-1 gene is associated with milk production traits of Jersey cattle

The sterol regulatory element-binding protein-1 (SREBP- 1) gene has been indicated to be linked to milk production traits in cattle, especially to milk fat yield and fatty acid composition. The transcription factor encoded by this gene is involved in the regulation of fat metabolism, so it is supposed that the variability of the SREBP-1 gene could influence these traits. The aim of this study was to analyze the association between the 84-bp insertion/deletion polymorphism of the SREBP-1 gene and milk production traits in Jersey cattle. The study found significant associations of the SREBP-1 gene polymorphism with fat content in the first lactation and protein content in the first three lactations analyzed both individually and together. In all cases, the LL genotype was linked to the higher value of the analyzed traits.

The study of the SNP in the corticotropin-releasing hormone gene (Exon 2) and milk production traits in cattle

The aim of this study was estimate the relations between CRH C22G and milk production traits (milk yield, yield of protein and fat, content of protein and fat in milk). The study was carried on 169 Polish Holstein-Friesian strain Red-and-White cows kept in the south-western region of Poland. The CRH C22G (exon 2) polymorphisms were detected using PCR-RFLP method. The genotype and allele frequencies were estimated and they were as follows: CC - 0.89, CG - 0.09, GG - 0.02; C - 0.93, G - 0.07. Statistically significant (P < or = 0.05) associations between CRH C22G genotypes and milk production traits like milk yield and protein yield in the second lactation were found. Moreover, the obtained results should be verified by conducting research on a larger group of animals and various cattle breeds.

Study on the STAT5A/AvaI polymorphism in Jersey cows and association with milk production traits

In mammals, the STAT proteins (signal transducers and activators of transcription) are a group of cytoplasmic transcription factors that mediate the actions of many peptide hormones and cytokines within target cells. In this study, the STAT5A/AvaI polymorphism was investigated with the PCR-RFLP technique in a sample of 191 Jersey cows reared in southern Italy. This polymorphism is localized in the coding region of the bovine STAT5A gene. It is a substitution C → T at position 6853 within the exon 7. All the possible genotypes for the C/T polymorphism were identified. The overall frequencies of alleles C and T were 0.75 and 0.25 respectively. In order to study the relationship between this SNP and milk production traits, data for 305-day milk production were used. Significant differences between CC and CT genotypes were found in milk yield (MY), fat yield (FY), solids not fat (SNF) yield, total solids (TS) yield (P < 0.01) and protein yield (PY) (P < 0.05). In particular the CC cows produced more milk than CT ones (6196.07 vs. 5744.66 kg) without differences in protein and fat content. As a consequence, CC cows yielded more fat, protein, solids not fat and total solids than CT. As far as concerns lactose and ash contents and the fat/protein ratio, no significant difference was found between the two genotypes. Even if further studies should be carry out to assess the role of this SNP on production traits, it is possible to conclude that STAT5A/AvaI polymorphism seems to be a promising indirect marker to improve milk production traits in cattle.

ANXA9, SLC27A3, FABP3 and FABP4 single nucleotide polymorphisms in relation to milk production traitsin Jersey cows

Milk components originating from blood plasma substrates are synthesized in epithelial cells of the mammary gland. Milk lipids are synthesized from fatty acids which bind to specific proteins &amp;ndash; FABPs (fatty acid binding proteins). FABPs are a family of small cytoplasmic proteins; nine members of the family have been identified so far (FABP1&amp;ndash;FABP9) (Chmurzyńska et al., 2006). Their main roles include fatty acid uptake, transport and metabolism. FABPs can modulate the fatty acid concentration in cells and therefore they affect different cellular processes, especially lipid metabolism. FABP3 and FABP4 are present in tissues with a high demand for fatty acids, such as heart muscle, skeletal muscles, lactating mammary gland, liver or adipose tissue (Roy et al., 2003). FABP3 gene was mapped to bovine chromosome 2 (Calvo et al., 2004), where QTLs affecting milk fat yield and content were described (Khatkar et al., 2004). FABP4 gene was mapped to BTA14 (Michal et al., 2006), which is very rich in QTLs for milk production traits (Khatkar et al., 2004). Fatty acid transport is assisted by the specific proteins called FATPs (fatty acid transport proteins). This protein group includes SLC27A3 (solute carrier family 27, member 3). It belongs to the family of proteins that facilitate long-chain fatty acid transport across the cytoplasmic membrane. Another protein with similar functions is ANXA9 (annexin A9), the member of Ca2+ and phospholipid-binding protein family (Calvo et al., 2006b). Genes encoding SLC27A3 and ANXA9 were mapped to chromosome 3, within the region where QTLs for milk fat content and the other milk traits have been mapped. Both of the above-mentioned genes are expressed in the mammary gland (Calvo et al., 2006b). The polymorphic sites (SNPs &amp;ndash; single nucleotide polymorphisms) within the bovine FABP3, FABP4, SLC27A3 and ANXA9 genes were identified (Wu et al., 2005; Calvo et al., 2006b; Michal et al., 2006; Cho et al., 2008). Associations between SNPs in these genes and milk production traits in cattle have not been reported so far. However, polymorphism in the FABP4 gene has been significantly associated with carcass traits in cattle (Michal et al., 2006; Cho et al., 2008). Due to their expression sites, physiological properties and chromosomal localisation, the described genes might be considered as candidate genes for milk production traits. The aim of this study was to determine allele and genotype frequencies and to establish possible associations between the ANXA9, SLC27A3, FABP3 and FABP4 SNPs, and selected milk traits in Jersey cows.

Effect of &amp;lt;i&amp;gt;SCD&amp;lt;/i&amp;gt; SNPs on milk production traits of Jersey cows (Brief Report)

Abstract. Studies concerning associations between candidate gene polymorphisms and milk production traits in cattle are carried out on a large scale (CITEK et al. 2007, KULIG 2005). Stearoyl-CoA desaturase (SCD) is the enzyme involved in conversion of saturated fatty acids into monounsaturated fatty acids. The gene encoding SCD was mapped to bovine chromosome 26 (CAMPBELL et al. 2001), where some QTLs for fat yield and other milk production traits as well as for somatic cells count (SCC) were also identified. Some of the SNPs identified within the SCD were significantly associated with fatty acid composition in milk and in carcass fat tissue (MOIOLI et al. 2007, TANIGUCHI et al. 2004). The effect of genotypes on milk production traits and SCC in cattle has not been reported so far. The aim of this study was therefore to establish possible associations between two SNPs in the SCD and milk production traits and SCC in Jersey cows.

ANXA9, SLC27A3, FABP3 and FABP4 single nucleotide polymorphisms in relation to milk production traits in Jersey cows

Milk components originating from blood plasma substrates are synthesized in epithelial cells of the mammary gland. Milk lipids are synthesized from fatty acids which bind to specific proteins &amp;ndash; FABPs (fatty acid binding proteins). FABPs are a family of small cytoplasmic proteins; nine members of the family have been identified so far (FABP1&amp;ndash;FABP9) (Chmurzyńska et al., 2006). Their main roles include fatty acid uptake, transport and metabolism. FABPs can modulate the fatty acid concentration in cells and therefore they affect different cellular processes, especially lipid metabolism. FABP3 and FABP4 are present in tissues with a high demand for fatty acids, such as heart muscle, skeletal muscles, lactating mammary gland, liver or adipose tissue (Roy et al., 2003). FABP3 gene was mapped to bovine chromosome 2 (Calvo et al., 2004), where QTLs affecting milk fat yield and content were described (Khatkar et al., 2004). FABP4 gene was mapped to BTA14 (Michal et al., 2006), which is very rich in QTLs for milk production traits (Khatkar et al., 2004). Fatty acid transport is assisted by the specific proteins called FATPs (fatty acid transport proteins). This protein group includes SLC27A3 (solute carrier family 27, member 3). It belongs to the family of proteins that facilitate long-chain fatty acid transport across the cytoplasmic membrane. Another protein with similar functions is ANXA9 (annexin A9), the member of Ca2+ and phospholipid-binding protein family (Calvo et al., 2006b). Genes encoding SLC27A3 and ANXA9 were mapped to chromosome 3, within the region where QTLs for milk fat content and the other milk traits have been mapped. Both of the above-mentioned genes are expressed in the mammary gland (Calvo et al., 2006b). The polymorphic sites (SNPs &amp;ndash; single nucleotide polymorphisms) within the bovine FABP3, FABP4, SLC27A3 and ANXA9 genes were identified (Wu et al., 2005; Calvo et al., 2006b; Michal et al., 2006; Cho et al., 2008). Associations between SNPs in these genes and milk production traits in cattle have not been reported so far. However, polymorphism in the FABP4 gene has been significantly associated with carcass traits in cattle (Michal et al., 2006; Cho et al., 2008). Due to their expression sites, physiological properties and chromosomal localisation, the described genes might be considered as candidate genes for milk production traits. The aim of this study was to determine allele and genotype frequencies and to establish possible associations between the ANXA9, SLC27A3, FABP3 and FABP4 SNPs, and selected milk traits in Jersey cows.

Genetic polymorphism of STAT5A protein: relationships with production traits and milk composition in Italian Brown cattle

STATs are a group of transcription factors that mediate actions of a variety of peptide hormones and cytokines within target cells (for example, prolactin and growth hormone). Therefore, STAT5A gene is a candidate marker for quantitative traits in farm animals with respect to milk production traits. In this study the STAT5A/AvaI polymorphism was investigated with PCR-RFLP in a sample of 233 Italian Brown cattle. This polymorphism is localized in the coding region of the bovine STAT5A gene. It is a substitution C-->T at position 6853 within exon 7. All three possible genotypes for the C/T polymorphism were identified. The overall frequencies of alleles C and T were 0.83 and 0.17 respectively; the Hardy-Weinberg equilibrium was verified. In order to study the relationship between STAT5A/AvaI polymorphism and milk performance traits, the data for a 305-d milk production that included milk yield, protein and fat yield, fat and protein percentage were used. Significant differences between the two genotypes were found in yields of milk, fat and protein and protein percentage (P<0.01). CC cows produced more milk than CT (5418.68 v. 5149.54 kg). Protein content was higher in milk from CC compared with CT genotypes (3.40 v. 3.21%). No significant difference was found in fat content. Owing to the low number of TT cows in the studied population, this genotype was not included in the statistical analysis; in fact the number of TT cows was not enough to provide an accurate statistical analysis. Although more studies are needed to better clarify the role of this SNP on production traits, STAT5A/AvaI polymorphism appears to be a promising indirect marker to improve milk production traits in cattle.

Analysis of chromosomal localization of loci controlling milk production traits in cattle

Analysis of the pattern of the chromosomal localization of quantitative trait loci (QTLs) is necessary for comprehensively understanding their functions. The chromosomal localization of QTLs controlling milk production traits has been studied in cattle chromosomes. The distribution of QTLs between chromosomes has proved to be binomial. Their distribution along each chromosome was, in general, uniform, except for the QTLs controlling the somatic cell score (SCS), which tended towards telomeric location. However, there are chromosomes either enriched with or particularly poor in QTLs. The QTL distribution patters are the most similar for the milk yield (M) and milk protein yield (P) and for milk fat yield (F) and milk fat content (%F). The pattern of the SCS QTLs stands out among those of other QTLs. The distance between the QTLs of contrasting traits is the shortest for M and P QTLs, longer for M and milk protein content (%P) QTLs, and still longer for M and %F QTLs, which may be explained by QTL pleiotropy, a common phenomenon in cattle.

Genetic polymorphisms of osteopontin (OPN), prolactin (PRL) and pituitary-specific transcript factor-1 (PIT-1) in South Anatolian and East Anatolian Red cattle

The objective of the present study was to determine the genotype and allele frequencies for osteopontin (OPN), prolactin (PRL) and pituitary-specific transcription factor-1 (PIT-1) that are claimed to be associated with milk production traits in cattle in South Anatolian Red (SAR) and East Anatolian Red (EAR) cattle. In this study, 40 cattle for each of SAR and EAR were used. OPN in intron 4, PRL in exon 3 and PIT-1 in exon 6 were amplified by polymerase chain reaction (PCR) and the resulting PCR products were subjected to digestion using BseNI, RsaI and HinfI enzymes, respectively, to determine the single nucleotide polymorphisms (SNPs). Results showed that frequencies of the OPN allele C, PRL allele B, and PIT-1 allele A which are associated with milk production tarits were found low in SAR and EAR. As a result, SAR and EAR cattle breeds have the lower allel frequencies that influence the milk production traits for three genes than high-yielding European dairy cattle breeds.

Serotonin receptor 1B ( HTR1B) genotype associated with milk production traits in cattle

Serotonin receptor 1B ( HTR1B) is one of the 14 different identified serotonin receptors which are involved in the regulation of behaviors such as sleep, fear, aggression, mood, and feeding. The aims of this study were to characterize polymorphisms in the 5′ coding and the 3′ flanking regions of the bovine HTR1B gene among Chinese Holsteins and to identify the association of HTR1B polymorphisms with milk production performance. SSCP was used to examine the polymorphisms at four loci and the fragments with different SSCP patterns were sequenced. A total of three single nucleotide polymorphisms (SNPs) were detected, among which the 205G > T mutation was found to cause a predicted amino acid change: from Ala to Ser at position 69. The polymorphism of G205T was identified to be associated with milk yield trait. Furthermore, the H1-C genotype was found to be associated with a significant increase in milk yield of 489 kg vs. the H1-A genotype ( P < 0.05).

A radiation hybrid map of river buffalo (Bubalus bubalis) chromosome 7 and comparative mapping to the cattle and human genomes

A preliminary radiation hybrid (RH) map containing 50 loci on chromosome 7 of the domestic river buffalo Bubalus bubalis (BBU; 2n = 50) was constructed based on a comparative mapping approach. The RH map of BBU7 includes thirty-seven gene markers and thirteen microsatellites. All loci have been previously assigned to Bos taurus (BTA) chromosome BTA6, which is known for its association with several economically important milk production traits in cattle. The map consists of two linkage groups spanning a total length of 627.9 cR_5,000. Comparative analysis of the BBU7 RH_5,000 map with BTA6 in cattle gave new evidence for strong similarity between the two chromosomes over their entire length and exposed minor differences in locus order. Comparison of the BBU7 RH_5,000 map with the Homo sapiens (HSA) genome revealed similarity with a large chromosome segment of HSA4. Comparative analysis of loci in both species revealed more variability than previously known in gene order and several chromosome rearrangements including centromere relocation. The data obtained in our study define the evolutionarily conserved segment on BBU7 and HSA4 to be between 3.5 megabases (Mb) and 115.8 Mb in the HSA4 (genome build 36) DNA sequence.

Combining mouse mammary gland gene expression and comparative mapping for the identification of candidate genes for QTL of milk production traits in cattle

BackgroundMany studies have found segregating quantitative trait loci (QTL) for milk production traits in different dairy cattle populations. However, even for relatively large effects with a saturated marker map the confidence interval for QTL location by linkage analysis spans tens of map units, or hundreds of genes. Combining mapping and arraying has been suggested as an approach to identify candidate genes. Thus, gene expression analysis in the mammary gland of genes positioned in the confidence interval of the QTL can bridge the gap between fine mapping and quantitative trait nucleotide (QTN) determination.ResultsWe hybridized Affymetrix microarray (MG-U74v2), containing 12,488 murine probes, with RNA derived from mammary gland of virgin, pregnant, lactating and involuting C57BL/6J mice in a total of nine biological replicates. We combined microarray data from two additional studies that used the same design in mice with a total of 75 biological replicates. The same filtering and normalization was applied to each microarray data using GeneSpring software. Analysis of variance identified 249 differentially expressed probe sets common to the three experiments along the four developmental stages of puberty, pregnancy, lactation and involution. 212 genes were assigned to their bovine map positions through comparative mapping, and thus form a list of candidate genes for previously identified QTLs for milk production traits. A total of 82 of the genes showed mammary gland-specific expression with at least 3-fold expression over the median representing all tissues tested in GeneAtlas.ConclusionThis work presents a web tool for candidate genes for QTL (cgQTL) that allows navigation between the map of bovine milk production QTL, potential candidate genes and their level of expression in mammary gland arrays and in GeneAtlas. Three out of four confirmed genes that affect QTL in livestock (ABCG2, DGAT1, GDF8, IGF2) were over expressed in the target organ. Thus, cgQTL can be used to determine priority of candidate genes for QTN analysis based on differential expression in the target organ.