Effects of bamboo leaf extract on the production performance, rumen fermentation parameters, and rumen bacterial communities of heat-stressed dairy cows.

Objective: An experiment was conducted to evaluate the effects of bamboo leaf extract (BLE) on the production performance, rumen fermentation parameters, and rumen bacterial communities of heat-stressed dairy cows.

Methods: The experiment comprised a 14-day adaptation period and a 21-day experimental period and was conducted in a high-temperature and humidity environment (daily mean ambient temperature = 33.5°C±1.

A post-GWAS confirming the genetic effects and functional polymorphisms of AGPAT3 gene on milk fatty acids in dairy cattle.

Background: People are paying more attention to the healthy and balanced diet with the improvement of their living standards. Milk fatty acids (FAs) have been reported that they were related to some atherosclerosis and coronary heart diseases in human. In our previous genome-wide association study (GWAS) on milk FAs in dairy cattle, 83 genome-wide significant single nucleotide polymorphisms (SNPs) were detected.

Selection and implementation of single nucleotide polymorphism markers for parentage analysis in crossbred cattle population.

Crossbreeding is an essential way of improving herd performance. However, frequent parentage record errors appear, which results in the lower accuracy of genetic parameter estimation and genetic evaluation. This study aims to build a single nucleotide polymorphism (SNP) panel with sufficient power for parentage testing in the crossbred population of Simmental and Holstein cattle.

Identification of genetic effects and potential causal polymorphisms of CPM gene impacting milk fatty acid traits in Chinese Holstein.

Our previous GWAS revealed 83 significant SNPs and 20 promising candidate genes associated with milk fatty acid traits in dairy cattle. Out of them, the carboxypeptidase M (CPM) gene contains a genome-wide significant SNP, Hapmap49848-BTA-106779, which is strongly associated with myristic acid (C14:0; P = 0.0064).

Identification of single nucleotide polymorphisms of and genes and their genetic associations with milk production traits in dairy cows.

Background: Previously, phosphoinositide-3-kinase regulatory subunit 1 () and dual specificity phosphatase 1 () were identified as promising candidate genes for milk production traits due to their being differentially expressed between the dry period and the peak of lactation in livers of dairy cows. Hence, in this study, the single nucleotide polymorphisms (SNPs) of and genes were identified and their genetic associations with milk yield, fat yield, fat percentage, protein yield, and protein percentage, were investigated using 1067 Chinese Holstein cows from 40 sire families.

Results: By re-sequencing the entire coding region and 2000 bp of the 5' and 3' flanking regions of the two genes, one SNP in the 5' untranslated region (UTR), three in the 3' UTR, and two in the 3' flanking region of were identified, and one in the 5' flanking region, one in the 3' UTR, and two in the 3' flanking region of were found.

Technical note: Development and application of KASP assays for rapid screening of 8 genetic defects in Holstein cattle.

Specific DNA mutations underlying several genetic defects associated with embryo loss or reduced calf survivability have been identified in dairy cattle, and a convenient and cost-effective platform is required for their routine screening. We developed Kompetitive allele-specific PCR (KASP) assays for discrimination of the wild-type alleles from the associated defective alleles at each of 8 common genetic defects in Holstein cattle, involving 5 SNP [HH1, HH3, HH4, bovine leukocyte adhesion deficiency (BLAD), and complex vertebral malformation (CVM)] and 3 insertion or deletion mutations [HH5, haplotype for cholesterol deficiency (HCD), and brachyspina (BS)]. A total of 390 cows from a Chinese Holstein herd were genotyped and the carriers identified at 7 of these 8 loci (except HH4), with the highest carrier frequencies found for CVM (10.

Mortality-Culling Rates of Dairy Calves and Replacement Heifers and Its Risk Factors in Holstein Cattle.

The rates of mortality and involuntary culling of dairy calves and replacement heifers have great economic implications on the dairy cattle industry around the world. The main objectives of this study were: (1) to obtain population parameters of mortality and involuntary culling rates of dairy calves and replacement heifers; and, (2) to investigate the factors affecting mortality and involuntary culling rates in Chinese Holstein cattle. Two datasets containing records of birth, calving, and culling events from 142,833 Holstein cattle born between 1991 and 2018 were used in this study.

Divergence Analyses of Sperm DNA Methylomes between Monozygotic Twin AI Bulls.

Semen quality is critical for fertility. However, it is easily influenced by environmental factors and can induce subfertility in the next generations. Here, we aimed to assess the impacts of differentially methylated regions and genes on semen quality and offspring fertility.

Polymorphisms and genetic effects of PRLR, MOGAT1, MINPP1 and CHUK genes on milk fatty acid traits in Chinese Holstein.

Background: Our initial genome-wide association study (GWAS) identified 20 promising candidate genes for milk fatty acid (FA) traits in a Chinese Holstein population, including PRLR, MOGAT1, MINPP1 and CHUK genes. In this study, we performed whether they had significant genetic effects on milk FA traits in Chinese Holstein.

Results: We re-sequenced the entire exons and 3000 bp of the 5' and 3' flanking regions, and identified 11 single nucleotide polymorphisms (SNPs), containing four in PRLR, two in MOGAT1, two in MINPP1, and three in CHUK.

Identification of genetic associations of ECHS1 gene with milk fatty acid traits in dairy cattle.

Our previous genome-wide association study identified 83 genome-wide significant SNPs and 20 novel promising candidate genes for milk fatty acids in Chinese Holstein. Among them, the enoyl-CoA hydratase, short chain 1 (ECHS1) and enoyl-CoA hydratase and 3-hydroxyacyl CoA dehydrogenase (EHHADH) genes were located near two SNPs and one SNP respectively, and they play important roles in fatty acid metabolism pathways. We herein validated whether the two genes have genetic effects on milk fatty acid traits in dairy cattle.

SNV discovery and functional candidate gene identification for milk composition based on whole genome resequencing of Holstein bulls with extremely high and low breeding values.

We have sequenced the whole genomes of eight proven Holstein bulls from the four half-sib or full-sib families with extremely high and low estimated breeding values (EBV) for milk protein percentage (PP) and fat percentage (FP) using Illumina re-sequencing technology. Consequently, 2.3 billion raw reads were obtained with an average effective depth of 8.

A post-GWAS confirming effects of PRKG1 gene on milk fatty acids in a Chinese Holstein dairy population.

Background: We previously conducted a genome-wide association study (GWAS) strategy for milk fatty acids in Chinese Holstein, and identified 83 genome-wide significant single nucleotide polymorphisms (SNPs) and 314 suggestive significant SNPs. Among them, two SNPs, BTB-01077939 and BTA-11275-no-rs associated with C10:0, C12:0, and C14 index (P = 0.000014 ~ 0.

Single Nucleotide Polymorphisms of and their Genetic Associations with Milk Production Traits in Dairy Cows.

We previously used the RNA sequencing technique to detect the hepatic transcriptome of Chinese Holstein cows among the dry period, early lactation, and peak of lactation, and implied that the nucleobindin 2 () gene might be associated with milk production traits due to its expression being significantly increased in early lactation or peak of lactation as compared to dry period ( value < 0.05). Hence, in this study, we detected the single nucleotide polymorphisms (SNPs) of and analyzed their genetic associations with milk yield, fat yield, fat percentage, protein yield, and protein percentage.

Determination of genetic associations between indels in 11 candidate genes and milk composition traits in Chinese Holstein population.

Background: We have previously identified 11 promising candidate genes for milk composition traits by resequencing the whole genomes of 8 Holstein bulls with extremely high and low estimated breeding values for milk protein and fat percentages (high and low groups), including FCGR2B, CENPE, RETSAT, ACSBG2, NFKB2, TBC1D1, NLK, MAP3K1, SLC30A2, ANGPT1 and UGDH those contained 25 indels between high and low groups. In this study, the purpose was to further examine whether these candidates have significant genetic effects on milk protein and fat traits.

Results: With PCR product sequencing, 13 indels identified by whole genome resequencing were successfully genotyped.

Genetic Effects of Polymorphisms on Milk Production Traits in Dairy Cattle.

Our initial RNA sequencing work identified that lipin 1 () was differentially expressed during dry period, early lactation, and peak of lactation in dairy cows, and it was enriched into the fat metabolic Gene Ontology (GO) terms and pathways, thus we considered as the candidate gene for milk production traits. In this study, we detected the polymorphisms of and verified their genetic effects on milk yield and composition in a Chinese Holstein cow population. We found seven SNPs by re-sequencing the entire coding region and partial flanking region of , including one in 5' flanking region, four in exons, and two in 3' flanking region.

Analysis of Liver Proteome and Identification of Critical Proteins Affecting Milk Fat, Protein, and Lactose Metabolism in Dariy Cattle with iTRAQ.

In this study, the proteomes of liver tissues are investigated in three periods of the lactation cycle of Holstein cows by using isobaric tag for relative and absolute quantification (iTRAQ) technique to obtain liver proteome and identify functional proteins/genes involved in milk synthesis in dairy cattle. Based on iTRAQ analysis, 3252 proteins are detected in the liver tissues (false discovery rate ≤0.01).

Genetic association of DDIT3, RPL23A, SESN2 and NR4A1 genes with milk yield and composition in dairy cattle.

Previously, we identified by RNA sequencing that DDIT3, RPL23A, SESN2 and NR4A1 genes were significantly differentially expressed between the mammary glands of lactating Holstein cows with extremely high and low milk protein and fat percentages; thus, these four genes are considered as promising candidates potentially affecting milk yield and composition traits in dairy cattle. In the present study, we further verified whether these genes have genetic effects on milk traits in a Chinese Holstein population. By re-sequencing part of the non-coding and the entire coding regions of the DDIT3, RPL23A, SESN2 and NR4A1 genes, a total of 35 SNPs and three insertions/deletions were identified, of which three were found in DDIT3, 12 in RPL23A, 16 in SESN2 and seven in NR4A1.

Determination of Genetic Effects of LIPK and LIPJ Genes on Milk Fatty Acids in Dairy Cattle.

In our previous genome-wide association study (GWAS) on milk fatty acids (FAs) in Chinese Holstein, we discovered 83 genome-wide significant single nucleotide polymorphisms (SNPs) associated with milk FAs. Two of them were close to lipase family member K () and lipase family member J (), respectively. Hence, this study is a follow-up to verify whether the and have significant genetic effects on milk FAs in dairy cattle.

Shifts of Hydrogen Metabolism From Methanogenesis to Propionate Production in Response to Replacement of Forage Fiber With Non-forage Fiber Sources in Diets .

The rumen microbial complex adaptive mechanism invalidates various methane (CH) mitigation strategies. Shifting the hydrogen flow toward alternative electron acceptors, such as propionate, was considered to be a meaningful mitigation strategy. A completely randomized design was applied in incubation to investigate the effects of replacing forage fiber with non-forage fiber sources (NFFS) in diets on methanogenesis, hydrogen metabolism, propionate production and the methanogenic and bacterial community.

Genetic association of the ACACB gene with milk yield and composition traits in dairy cattle.

Previously, we re-sequenced the whole genomes of eight Holstein bulls with high or low milk protein and fat percentage, and we detected two indels in the ACACB (acetyl-CoA carboxylase beta) gene that were polymorphic between the two groups. Thus, we considered ACACB as a promising candidate gene potentially affecting milk composition traits. Herein, we verified the genetic effects of ACACB on five milk traits in a Chinese Holstein population.

Murine pluripotent stem cells that escape differentiation inside teratomas maintain pluripotency.

Background: Pluripotent stem cells (PSCs) offer immense potential as a source for regenerative therapies. The teratoma assay is widely used in the field of stem cells and regenerative medicine, but the cell composition of teratoma is still elusive.

Methods: We utilized PSCs expressing enhanced green fluorescent protein (EGFP) under the control of the promoter to study the persistence of potential pluripotent cells during teratoma formation .

Genome-wide Association Studies for Female Fertility Traits in Chinese and Nordic Holsteins.

Reduced female fertility could cause considerable economic loss and has become a worldwide problem in the modern dairy industry. The objective of this study was to detect quantitative trait loci (QTL) for female fertility traits in Chinese and Nordic Holsteins using various strategies. First, single-trait association analyses were performed for female fertility traits in Chinese and Nordic Holsteins.

Substituting oat hay or maize silage for portion of alfalfa hay affects growth performance, ruminal fermentation, and nutrient digestibility of weaned calves.

Objective: The impact of forage feeding strategy on growth performance, ruminal fermentation and nutrient digestibility in post-weaning calves was investigated.

Methods: Forty-five female Holstein calves (body weight [BW] = 79.79±0.

Effects of feeding untreated, pasteurized and acidified waste milk and bunk tank milk on the performance, serum metabolic profiles, immunity, and intestinal development in Holstein calves.

Background: The present experiment was performed to assess the effects of different sources of milk on the growth performance, serum metabolism, immunity, and intestinal development of calves. Eighty-four Holstein male neonatal calves were assigned to one of the following four treatment groups: those that received bunk tank milk (BTM), untreated waste milk (UWM), pasteurized waste milk (PWM), and acidified waste milk (AWM) for 21 d.

Results: Calves in the BTM and AWM groups consumed more starter ( < 0.

Determination of genetic effects of ATF3 and CDKN1A genes on milk yield and compositions in Chinese Holstein population.

Background: Our previous RNA-sequencing study revealed that the ATF3 and CDKN1A genes were remarkably differentially expressed between the mammary glands of lactating Holstein cows with extremely high and low milk protein and fat percentage so that both of them were considered as candidates for milk composition. Herein, we further verified whether these genes have genetic effects on milk production traits in a Chinese Holstein cow population.

Results: By re-sequencing the entire coding and regulatory regions, we identified four SNPs in 5'promoter region, two in exons, seven in 3' un-translated region (UTR), and six in 3'flanking region of ATF3 gene, and one SNP in exon 5, two in 3'UTR, and two in 3'flanking region of CDKN1A gene.