• Asian-Australasian Journal of Animal Sciences
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• v.24 no.8
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• pp.1048-1052
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• 2011

The Chinese Holstein cattle breed, an introduced breed in China, has been crossbred with native cattle breeds. We hypothesised that the Chinese Holstein local population in Beijing share haplotypes with native Asian cattle breeds, the result of a sudden population expansion in the recent past. We also hypothesised that crossbreeding and population expansion left traces that shaped the genetic makeup of the breed. Evaluation of this was performed by mitochondrial DNA (mtDNA) sequence analysis of Chinese Holstein cattle from Beijing (n = 41) and a comparison of them with the published mtDNA sequences (n = 293) of 14 Asian breeds with an emphasis on Chinese native cattle breeds. Three shared common haplotypes between Chinese Holstein cattle and native Asian cattle were found. Moreover, a high level of haplotype diversity in Chinese Holstein cattle (h = 0.9557) and low nucleotide diversity (${\pi}$ = 0.0052) was found, indicating a past population bottleneck followed by rapid population growth. These findings are supported by the significantly negative deviation of Tajima's D (-1.82085), the star-like pattern of dominant haplotypes and the pairwise mismatch distribution analysis, which showed a unimodal pattern.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.4
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• pp.459-462
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• 2006

Prolactin (PRL) plays an important role in promoting mammalian mammary gland development, and milk production during lactation. Therefore the PRL gene was chosen as a candidate gene for milk traits in Holstein dairy cows. PCR-SSCP and PCR-RFLP were used to analyze genetic variations in the 5' regulation region of the PRL gene. In this part of the gene, two new polymorphic sites were detected in the Chinese Holstein dairy cows. One was a XbaI-RFLP locus, and the other was an SSCP locus. Statistical analysis showed that the XbaI-RFLP locus and the SSCP locus had a significant positive effect on milk traits.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.4
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• pp.425-429
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• 2010

To develop an efficient DNA typing system for Chinese Holstein cattle, 17 microsatellites, which were amplified in four fluorescent multiplex reactions and genotyped by two capillary electrophoresis injections, were evaluated for parentage verification and identity test. These markers were highly polymorphic with a mean of 8.35 alleles per locus and an average expected heterozygosity of 0.711 in 371 individuals. Parentage exclusion probability with only one sampled parent was approximately 0.999. Parentage exclusion probability when another parent' genotype was known was over 0.99999. Overall probability of identity, i.e. the probability that two animals share a common genotype by chance, was $1.52{\times}10^{-16}$. In a test case of parentage assignment, the 17 loci assigned 31 out of 33 cows to the pedigree sires with 95% confidence, while 2 cows were excluded from the paternity relationship with candidate sires. The results demonstrated the high efficacy of the 17 markers in parentage analysis and individual identification for Chinese Holstein cattle.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.2
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• pp.166-171
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• 2007

The objective of this study was to assess the association of polymorphisms in ${\kappa}$-cn, ${\beta}$-lg, ${\beta}$-lg 5′ flanking region, CSN1S2, and IGFBP-3 genes with milk production traits and mastitis-related traits in Chinese Holstein. Traits analyzed were 305 day standard milk yield, protein percentage, fat percentage, the ratio of fat percentage and protein percentage, pre-somatic cell count, somatic cell count, and somatic cell score, respectively. CSN1S2 locus was uninformative because only one genotype BB was found in Chinese Holstein. Allele frequencies of A and B in IGFBP-3 gene were 0.5738 and 0.4262 in Chinese Holstein population, which was different from reported Qinchuan cattle population. The genotypes of animals at IGFBP-3 locus significantly affected 305 day standard milk yield, protein percentage, and somatic cell score. The ${\beta}$-lg genotypes had a significant effect on protein percentage and the ratio of fat percentage and protein percentage. Polymorphism in ${\beta}$-lg 5′ flanking region was associated with 305 day standard milk yield, protein percentage, fat percentage, pre-somatic cell count, and somatic cell count. No significant associations of the polymorphism in ${\kappa}$-cn gene were observed for any trait.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.4
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• pp.495-502
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• 2014

The effect of Bacillus subtilis natto on hindgut fermentation and microbiota of early lactation Holstein dairy cows was investigated in this study. Thirty-six Holstein dairy cows in early lactation were randomly allocated to three groups: no B. subtilis natto as the control group, B. subtilis natto with $0.5{\times}10^{11}cfu$ as DMF1 group and B. subtilis natto with $1.0{\times}10^{11}cfu$ as DMF2 group. After 14 days of adaptation period, the formal experiment was started and lasted for 63 days. Fecal samples were collected directly from the rectum of each animal on the morning at the end of eighth week and placed into sterile plastic bags. The pH, $NH_3$-N and VFA concentration were determined and fecal bacteria DNA was extracted and analyzed by DGGE. The results showed that the addition of B. subtilus natto at either treatment level resulted in a decrease in fecal $NH_3$-N concentration but had no effect on fecal pH and VFA. The DGGE profile revealed that B. subtilis natto affected the population of fecal bacteria. The diversity index of Shannon-Wiener in DFM1 decreased significantly compared to the control. Fecal Alistipes sp., Clostridium sp., Roseospira sp., beta proteobacterium were decreased and Bifidobacterium was increased after supplementing with B. subtilis natto. This study demonstrated that B. subtilis natto had a tendency to change fecal microbiota balance.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.9
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• pp.1327-1333
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• 2007

Lactose synthase catalyses the formation of lactose which is the major osmole of bovine milk and regulates the milk volume. Alpha-lactalbumin (${\alpha}$-LA) is involved in the synthesis of lactose synthase in the mammary gland. Therefore ${\alpha}$-LA is regarded as a plausible candidate gene for the milk yield trait. To determine whether ${\alpha}$-LA is associated with milk performance traits, 1,028 Chinese Holstein cows were used to detect polymorphisms in the ${\alpha}$-LA by means of single-strand conformation polymorphism (SSCP). Two nucleotide transitions were identified in the 5'flanking region and intron 3 of ${\alpha}$-LA. Associations of such polymorphisms with five milk performance traits were analyzed using a general linear model procedure. No significant associations were observed between these polymorphisms and the five milk performance traits (p>0.05). RH mapping placed ${\alpha}$-LA on BTA5q21, linked most closely to markers U63110, CC537786 and L10347 (LOD>8.3), which is far distant from the region of the quantitative trait locus (QTL) on bovine chromosome 5 for variation in the milk yield trait. In summary, based on our findings, we eliminated these SNPs from having an effect on milk performance traits.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.3
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• pp.390-395
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• 2006

This work was conducted to study the effect of rumen-protected choline (RPC) addition on milk performance and blood metabolic parameters in transition dairy cows. In Experiment 1, fourteen Chinese Holstein dairy cows were supplemented with 0 or 20 g/d of RPC from 7 d before expected calving to 21 d post partum. Feeding of RPC tended to increase milk yield and milk protein percentage, while milk fat and lactose percentage were not changed. Plasma concentrations of glucose tended to increase as cows consumed RPC, while plasma concentrations of triglycerides, very low density lipoproteins, cholesterol and nonesterified fatty acids were not significantly different between the two groups. In Experiment 2, thirty-six Chinese Holstein dairy cows were supplemented with 0, 30, 60 or 90 g/d RPC from 15 d before expected calving to 15 d post partum. Feeding of RPC tended to increase yield of milk and 4% fat-corrected milk for all the lactating cows, and milk composition was similar among the four groups. Plasma concentrations of glucose were remained at a higher level in 30 or 60 g/d RPC-supplemented groups, and nonesterified fatty acids were decreased in the 30 g/d group. Concentrations of triglycerides tended to reduce in 30 and 90 g/d RPC-supplemented animals, and cholesterol was reduced in 0 or 30 g/d group. These results suggest that RPC addition tended to increase milk yield and improve blood metabolic parameters during transition dairy cows, and feeding 30 g/d of RPC may be the optimal.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.2
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• pp.173-180
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• 2011

Osteocalcin (OC), a marker of bone turnover, displays patterns in relation to physiological and genetic factors. Here, we present an association study in a population of Chinese Holstein cattle (n = 24) with OC serum concentration as a phenotypic trait. We hypothesised that OC status is associated with phylogeny, vitamin D serum level and single nucleotide polymorphisms (SNPs). Mitochondrial DNA (mtDNA) was used as an unlinked marker to examine phylogeny and linkage to measured phenotypic traits of vitamin D and OC status. Following an association study with OC serum variability as the trait, genotyping of SNPs (n = 27) in OC-related genes was performed. Candidate SNPs were chosen in genes with an emphasis on the vitamin D and vitamin K pathways. Multivariant factor analysis revealed a correlation between vitamin D serum concentration and a SNP in the gene GC (rs43338565), which encodes a vitamin D-binding protein, as well as between a SNP in NFATc1 (rs42038422) and OC concentration. However, univariate analysis revealed that population structure, vitamin D serum levels and SNPs were not significant determinants of OC status in the studied group.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.11
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• pp.1527-1530
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• 2002

Factor analysis was applied to the phenotypic correlation matrix of 15 linear type traits (scored linearly 1 to 50 points) for 2035 Holstein cows of 38 sires computed from data collected between 1988 and 1992 in Beijing Shuangqiao Farm and Beijing Xijiao Farm. The 15 linear type traits were stature, body strength, body depth, dairy form, rump angle, rump length, rump width, rear leg side view, foot angle, fore udder attachment, rear udder height, rear udder width, udder cleft, udder depth and teat placement rear view. The first four components accounted for 49.1% of the total variance in type scores. Factor 1 reflected strong cows, with deep bodies, with long and wide rumps, and tall in stature. Factor 2 reflected cows with well attached fore udders, wide rear udders and whose udders were supported by strong suspensory ligaments with close teat placement. Factor 3 reflected cows with good dairyness, sickled in the hocks, high rear udders and udder floors above the hocks. Factor 4 reflected cows with sloping rumps from hooks to pins and with steep foot angle. Principal component and factor analyses are useful to clarify the relationships among type traits.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.11
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• pp.1725-1731
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• 2020

Objective: An initial RNA-Sequencing study revealed that UDP-galactose-4-epimerase (GALE) was one of the most promising candidates for milk protein concentration in Chinese Holstein cattle. This enzyme catalyzes the interconversion of UDP-galactose and UDP-glucose, an important step in galactose catabolism. To further validate the genetic effect of GALE on milk protein traits, genetic variations were identified, and genotypes-phenotypes associations were performed. Methods: The entire coding region and the 5'-regulatory region (5'-UTR) of GALE were re-sequenced using pooled DNA of 17 unrelated sires. Association studies for five milk production traits were performed using a mixed linear animal model with a population encompassing 1,027 Chinese Holstein cows. Results: A total of three variants in GALE were identified, including two novel variants (g.2114 A>G and g.2037 G>A) in the 5'-UTR and one previously reported variant (g.3836 G>C) in an intron. All three single nucleotide polymorphisms (SNPs) were associated with milk yield (p<0.0001), fat yield (p = 0.0006 to <0.0001), protein yield (p = 0.0232 to <0.0001) and protein percentage (p<0.0001), while no significant associations were detected between the SNPs and fat percentage. A strong linkage disequilibrium (D' = 0.96 to 1.00) was observed among all three SNPs, and a 5 Kb haplotype block involving three main haplotypes with GAG, AGC, and AGG was formed. The results of haplotype association analyses were consistent with the results of single locus association analysis (p<0.0001). The phenotypic variance ratio above 3.00% was observed for milk protein yield that was explained by SNP-g.3836G >C. Conclusion: Overall, our findings provided new insights into the polymorphic variations in bovine GALE gene and their associations with milk protein concentration. The data indicate their potential uses for marker-assisted breeding or genetic selection schemes.