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The aim was to estimate the relative contribution of imprinting effects from both paternal and maternal sides to phenotypic variation in milk production traits including 305 days milk yield (MY), average daily milk production (ADM), fat percentage (F%), protein percentage (P%), 305 days fat yield (FY), 305 days protein yield (PY), ratio of fat percentage to protein percentage (F:P) and somatic cell score (SCS) in Iranian Holstein cows. To do this, each trait was analysed with a series of four animal models, which were identical for fixed and additive genetic effects but differed for combinations of paternal and maternal imprinting effects. The log‐likelihood ratio test (LRT) and Akaike's information criteria (AIC) were used to select the best model for each trait. Correlations between traits due to additive and imprinting effects were estimated by bivariate analyses. For all traits studied, fitting the imprinting effect led to a better data fit. Also, it resulted in a noticeable decrease in additive genetic variance from 8% (SCS) to 28% (F:P). A significant maternal imprinting effect was detected on all traits studied. Estimates of maternal imprinting heritability (hmi2) were 0.07 ± 0.02, 0.04 ± 0.01, 0.06 ± 0.01, 0.05 ± 0.01, 0.5 ± 0.01, 0.09 ± 0.02, 0.07 ± 0.02 and 0.06 ± 0.01 for MY, ADM, F%, P%, FY, PY, F:P and SCS, respectively. For F:P, in addition to the maternal imprinting effect, a significant paternal imprinting component was also detected with a 7% contribution to phenotypic variance of F:P. Estimates of direct heritability (ha2) were 0.29 ± 0.02, 0.17 ± 0.01, 0.22 ± 0.02, 0.11 ± 0.01, 0.18 ± 0.02, 0.22 ± 0.02, 0.15 ± 0.04 and 0.06 ± 0.01 for MY, ADM, F%, P%, FY, PY, F:P and SCS, respectively. Maternal imprinting correlations (rmi) were in a wide range between −0.75 ± 0.15 (P%‐SCS) and 0.95 ± 0.11 (MY‐ADM). Additive genetic correlations (ra) ranged between −0.54 ± 0.05 (MY‐P%) and 0.99 ± 0.01 (MY‐ADM) and phenotypic correlations (rp) ranged from −0.30 ± 0.01 (MY‐F%) to 0.93 ± 0.01 (MY‐ADM). The Spearman's correlation between additive breeding values including and excluding imprinting effects deviated from unity especially for top‐ranked animals implying re‐ranking of top animals following the inclusion of imprinting effects in the model. Since including imprinting effects in the model resulted in better data fit and re‐ranking of top animals, including these effects in the genetic evaluation models for milk production traits was recommended. [ABSTRACT FROM AUTHOR]

Extended Abstract Background: High-yielding cows, especially at the beginning of the lactation period, are mainly in a negative energy balance. This problem occurs due to energy consumption less than the requirements for high production, which causes the animal to use its body reserves. Therefore, it is necessary to enrich the diet in various ways, one of which is to use fat supplements. Increasing the level of dietary fat is important to provide energy during this period. Fat supplementation can reduce negative energy balance in high-yielding cows. The beneficial effects of fat supplementation depend on its type and amount. Fats should be relatively ineffective to reduce their harmful effects = in the rumen (such as reductions in the ratio of acetate to propionate, fiber digestion, and methane production). Fats reduce fat oxidation in the liver and dry matter consumption in livestock by influencing the hormones of the digestive system. A decrease in the passage rate of digestible substances from the rumen by adding fat to the diet can increase the expansion of the rumen and stimulate the stretch receptors in the rumen, resulting in probably a decrease in dry matter intake. However, the use of fat in feeding dairy cows also has limitations that must be overcome. Using emulsifier compounds can be very important during this period due to the property of emulsifying fats and increasing fat digestion. The emulsifier molecule can be dissolved in water with its hydrophilic part and in fat with its hydrophobic part and plays an important role in helping to form micelles. Therefore, emulsifiers can distribute fat droplets in the emulsion, which is necessary for fat digestion and absorption. Lysophospholipids are among the emulsifying compounds that increase fat digestion and absorption in the diet. Lysophospholipid is a strong feed additive to improve digestion and absorption and increase feed productivity, which increases production, feed efficiency, and absorption of dietary nutrients. In this research, the effects of using this emulsifier on blood and milk biochemical parameters, liver enzymes, and rumen microbial population are studied in the early lactation period of Holstein dairy cows. Methods: This experiment was carried out on 15 multi-calving Holstein dairy cows (three groups of five cows) with an average weight of 720 ± 50 kg and lactation days of 16 ± 5 days in a completely randomized design. The treatments were three levels of lysophospholipid in the feed (zero, 0.1, and 0.15%) for 35 days. The experimental diets were completely mixed and provided to the cows twice a day in the morning and afternoon. Cows had free access to water. At the end of the experimental period (35 days), blood was taken from the tail vein of randomly selected cows in three replications of each treatment to measure total protein, triglyceride, total cholesterol, blood nitrogen, unesterified fatty acids, and beta-hydroxybutyrate. To check the liver enzymes, blood samples were taken from cows before feed consumption on days 0 and 34 of the experimental period, by applying a 12-hour deprivation of feed consumption, to measure the activity of liver enzymes, viz. alkaline phosphatase (ALP), alanine aminotransferase (ALT), and aspartate aminotransferase (AST). At the end of the experimental period, rumen fluid was obtained from the rumens of all experimental cows to evaluate pH, ammonia nitrogen, volatile fatty acids (VFAs), enzymes, and bacterial and protozoan populations. Results: The diets containing lysophospholipid decreased blood urea nitrogen. The lowest blood urea nitrogen was observed in the treatment containing 0.15% lysophospholipid, which was significantly different from the treatments containing different levels of lysophospholipid (p < 0.05). However, no significant differences were observed between different treatments in total protein, triglyceride, total cholesterol, non-esterified fatty acids, and beta-hydroxybutyrate. Adding lysophospholipid caused a significant decrease in the level of liver AIT, but it did not significantly affect the other liver enzymes (AIP and AST). A significant increase was also observed in the activity level of ruminal carboxymethylcellulase (p < 0.05). However, there were no significant differences between the treatments in the activity of ruminal microcrystalline cellulase. An improvement in the production of ruminal VFAs (acetic acid and valeric) was observed in the treatments containing lysophospholipid (especially the 0.15% level) compared to the control treatment (p < 0.05), but it did not significantly influence other ruminal VFAs. In addition, the results of the experimental treatments on the rumen microbial population showed that the bacterial and protozoan population was not significantly affected by supplementing the diet with lysophospholipid. Conclusion: In general, the results show that the use of lysophospholipid supplement not only has no negative effects, but it has positive results, especially at the level of 0.15%, on blood and rumen parameters and the rumen bacterial population in the early lactation period of Holstein dairy cows.

Background and Objectives: Cow's milk is known as one of the primary food sources for humans, offering a broad spectrum of nutritional compounds. Fatty acids are considered as a key component of milk, recognized as essential constituents of the fat present in milk. These components contribute to the creation of a unique fatty acid profile in milk. Genome-wide association studies (GWAS), with high statistical accuracy, play a crucial role in identifying potential causative loci. Numerous GWAS in cattle, particularly in Holstein cows, provide favorable conditions for integrating multiple independent studies. Using advanced techniques such as meta-analysis, the possibility of more precise identification of loci associated with quantitative traits of milk fatty acids in Holstein cows has been facilitated. The main objective of this research is the precise identification of loci associated with quantitative traits of milk fatty acids in Holstein cows. To achieve this goal, techniques such as meta-analysis was employed. This study may improve the accuracy of genetic selections and optimizing fatty acids in Holstein cow milk, through identification of genetic structure of fatty acids. Materials and Methods: Searching for GWAS studies in Holstein cows, was conducted on Google Scholar using relevant keywords such as Holstein cows, GWAS and milk fatty acids. Single nucleotide polymorphisms (SNPs) derived from Holstein cows (Chinese, Danish, and Dutch) from various countries was available in four independent studies published during 2012 to 2019. A total of 1524 SNPs related to milk fatty acids was avialble from previous GWAS studies. Meta-analysis using a summary statistics approach (i.e., P-values, sample size, allelic effects, etc.) was performed among Holstein cows. In the present study, the METAL software was employed for meta-analysis, utilizing a weighted Z-score model. This method combined and assessed significant SNPs with a P-value less than 0.05. Results: The most significant SNPs associated with milk fatty acids were identified. For instance, the most meaningful SNPs for the C16:0 trait were rs109421300 and rs137372738, with P-values of 1.05e-102 and 6.62e-23, respectively. These SNPs play a crucial and key role in producing C16:0 fatty acid and may influence the quality of milk production. Conclusion: Overall, the results of this study demonstrated that based on SNPs with higher significant levels through meta-analysis compared to individual GWAS studies, it is possible to identify SNPs associated with quantitative traits with higher accuracy. Such studies contribute to a better understanding of genomic regions related to quantitative traits for milk fatty acids. Therefore, the identification of SNPs and key genes with high accuracy can play a significant role in genomic assessment and the design of breeding programs for improving fatty acids and the quality of milk production. [ABSTRACT FROM AUTHOR]

Background: High-yielding cows, especially at the beginning of the lactation period, are mainly in a negative energy balance. This problem occurs due to energy consumption less than the requirements for high production, which causes the animal to use its body reserves. Therefore, it is necessary to enrich the diet in various ways, one of which is to use fat supplements. Increasing the level of dietary fat is important to provide energy during this period. Fat supplementation can reduce negative energy balance in high-yielding cows. The beneficial effects of fat supplementation depend on its type and amount. Fats should be relatively ineffective to reduce their harmful effects = in the rumen (such as reductions in the ratio of acetate to propionate, fiber digestion, and methane production). Fats reduce fat oxidation in the liver and dry matter consumption in livestock by influencing the hormones of the digestive system. A decrease in the passage rate of digestible substances from the rumen by adding fat to the diet can increase the expansion of the rumen and stimulate the stretch receptors in the rumen, resulting in probably a decrease in dry matter intake. However, the use of fat in feeding dairy cows also has limitations that must be overcome. Using emulsifier compounds can be very important during this period due to the property of emulsifying fats and increasing fat digestion. The emulsifier molecule can be dissolved in water with its hydrophilic part and in fat with its hydrophobic part and plays an important role in helping to form micelles. Therefore, emulsifiers can distribute fat droplets in the emulsion, which is necessary for fat digestion and absorption. Lysophospholipids are among the emulsifying compounds that increase fat digestion and absorption in the diet. Lysophospholipid is a strong feed additive to improve digestion and absorption and increase feed productivity, which increases production, feed efficiency, and absorption of dietary nutrients. In this research, the effects of using this emulsifier on blood and milk biochemical parameters, liver enzymes, and rumen microbial population are studied in the early lactation period of Holstein dairy cows. Methods: This experiment was carried out on 15 multi-calving Holstein dairy cows (three groups of five cows) with an average weight of 720 ± 50 kg and lactation days of 16 ± 5 days in a completely randomized design. The treatments were three levels of lysophospholipid in the feed (zero, 0.1, and 0.15%) for 35 days. The experimental diets were completely mixed and provided to the cows twice a day in the morning and afternoon. Cows had free access to water. At the end of the experimental period (35 days), blood was taken from the tail vein of randomly selected cows in three replications of each treatment to measure total protein, triglyceride, total cholesterol, blood nitrogen, unesterified fatty acids, and beta-hydroxybutyrate. To check the liver enzymes, blood samples were taken from cows before feed consumption on days 0 and 34 of the experimental period, by applying a 12-hour deprivation of feed consumption, to measure the activity of liver enzymes, viz. alkaline phosphatase (ALP), alanine aminotransferase (ALT), and aspartate aminotransferase (AST). At the end of the experimental period, rumen fluid was obtained from the rumens of all experimental cows to evaluate pH, ammonia nitrogen, volatile fatty acids (VFAs), enzymes, and bacterial and protozoan populations. Results: The diets containing lysophospholipid decreased blood urea nitrogen. The lowest blood urea nitrogen was observed in the treatment containing 0.15% lysophospholipid, which was significantly different from the treatments containing different levels of lysophospholipid (p < 0.05). However, no significant differences were observed between different treatments in total protein, triglyceride, total cholesterol, non-esterified fatty acids, and beta-hydroxybutyrate. Adding lysophospholipid caused a significant decrease in the level of liver AIT, but it did not significantly affect the other liver enzymes (AIP and AST). A significant increase was also observed in the activity level of ruminal carboxymethylcellulase (p < 0.05). However, there were no significant differences between the treatments in the activity of ruminal microcrystalline cellulase. An improvement in the production of ruminal VFAs (acetic acid and valeric) was observed in the treatments containing lysophospholipid (especially the 0.15% level) compared to the control treatment (p < 0.05), but it did not significantly influence other ruminal VFAs. In addition, the results of the experimental treatments on the rumen microbial population showed that the bacterial and protozoan population was not significantly affected by supplementing the diet with lysophospholipid. Conclusion: In general, the results show that the use of lysophospholipid supplement not only has no negative effects, but it has positive results, especially at the level of 0.15%, on blood and rumen parameters and the rumen bacterial population in the early lactation period of Holstein dairy cows. [ABSTRACT FROM AUTHOR]

Selection as a factor increases the frequency of positive mutations in some subpopulations and creates selection signatures in the genome. Identifying the selection signatures in animals aimed at promoting economic traits and reducing diseases is one of the main and most challenging research areas in population genetics. This study aimed to conduct an extensive genome scan using single nucleotide polymorphisms (SNPs) to identify genomic regions under positive selection between diseased and healthy Holstein cattle populations. The data included 145 Holstein cows from Foka. These cows were genotyped using Illumina 30K chips. The cows were divided into diseased (45 cows) and healthy (100 cows) groups. FST and XP-EHH statistics were used in this study to identify genomic regions under selection. The genes identified by FST statistics in both diseased and healthy populations included RAB37, ZC3H10, ESR1, HSD17B6, KCNC4, and ERBB3. Genes identified by XP-EHH statistics in both diseased and healthy populations included AK1, ATP8A1, BTBD1, C1GALT1, CCDC6, CEP295, CLGN, CLSTN2, EHHADH, ERBB4, FRK, GRID2, GRIP1, and LRP6. Most of the genes identified in this study were related to immunity, diseases such as cancer, lactation, skeletal muscles, estrous cycle, feed consumption, sperm adhesion, and growth, which are among the important biological traits and characteristics of living organisms. Further research using an increased sample size in the population will provide a better understanding of candidate genes for ion disease in cattle. Moreover, the design of successful breeding programs will help reduce the costs associated with this disease. [ABSTRACT FROM AUTHOR]

Simple Summary: Peanut vines are abundant and cheap, and are a key forage source for ruminants; however, knowledge of the bacterial species that colonize peanut vines over time during rumen incubation remains limited. In this study, in situ nylon bag degradation, scanning electron microscopy, and 16S rRNA gene sequencing and metagenomics technology were used to study the attachment characteristics and function of microorganisms involved in peanut vine degradation, with the aim of providing basic knowledge regarding the utilization of peanut vine and other roughage. Our results demonstrate that the colonization of peanut vine by microorganisms is dynamic in the rumen. The dominant phyla and genera, as well as the structure and function, of the microbial communities varied over time. This experiment identified the key microorganisms and CAZymes were important for plant fiber degradation. Therefore, our data proved new insights into biomass conversion, reveal that numerous bacteria and enzymes are involved in forage degradation in the rumen, and lay the foundation for targeted improvement of crop residue utilization for ruminants. The aim of this study was to improve the utilization of peanut vines as forage material for ruminants by investigating the degradation pattern of peanut vines in the dairy cow rumen. Samples of peanut vine incubated in cow rumens were collected at various time points. Bacterial diversity was investigated by scanning electron microscopy (SEM) and 16S rRNA gene sequencing. Carbohydrate-active enzymes (CAZymes) were analyzed by metagenomics. The peanut vines degraded rapidly from 2 to 24 h, before slowing from 24 to 72 h. SEM images confirmed dynamic peanut vine colonization. Firmicutes and Bacteroidetes were the two most dominant bacterial phyla throughout. Principal coordinates analysis indicated significant microbial composition changes at 6 and 24 h. This may be because, in the early stage, soluble carbohydrates that are easily degradable were degraded, while in the later stage, fibrous substances that are difficult to degrade were mainly degraded. Glycoside hydrolases (GHs) were the most abundant CAZymes, with peak relative abundance at 6 h (56.7 trans per million, TPM), and reducing at 24 (55.9 TPM) and 72 h (55.3 TPM). Spearman correlation analysis showed that Alistipes_sp._CAG:435, Alistipes_sp._CAG:514, Bacteroides_sp._CAG:1060, Bacteroides_sp._CAG:545, Bacteroides_sp._CAG:709, Bacteroides_sp._CAG:770, bacterium_F082, bacterium_F083, GH29, GH78, and GH92 were important for plant fiber degradation. These findings provide fundamental knowledge about forage degradation in the cow rumen, and will be important for the targeted improvement of ruminant plant biomass utilization efficiency. [ABSTRACT FROM AUTHOR]

The dairy industry occupies an important position in the development of China's animal husbandry. It is a prominently developed industry in the animal husbandry industry and an important symbol of the country's agricultural development. The development of the dairy industry is of extremely important significance for promoting the transformation and upgrading of China's animal husbandry industry, increasing farmers' income, and enhancing the health quality of the entire nation. Therefore, the study aimed to explore the genetic effect of selective functional groups on milk production traits in Chinese Holstein cows to find the genes that caused mutations, and to study the identification strategies of the major genes that determined milk production traits. DNA was extracted from the frozen sperm genomes of 1,109 Holstein cows, and coagulated DNA from their blood was extracted. The mixed gene pool was sequenced, and different mutation sites were screened to classify genes. The collected data were statistically processed to analyze the correlation between genes. Haploid association analysis showed that all 35 Single Nucleotide Polymorphisms (SNP) and 3 indels were strongly associated with at least one trait, and 1, 1, 3, and 1 haplotype blocks were found in DDIT3, RPL23A, SESN2, and NR4A1 genes after continuous disequilibrium analysis. Correlation analysis showed that some haplotypes were correlated with lactation traits in dairy cows. The analysis of JASPAR software showed that 11 SNP sites and 3 binding sites had different degrees of changes, suggesting that this site would affect the transcriptional activity of transcription factor. The genetic effects of four candidate functional genes were further verified, and the four genes were identified as significantly associated with milk yield and milk composition traits in Chinese Holstein cow for the first time. [ABSTRACT FROM AUTHOR]

Background: DNA methylation has been documented to play vital roles in diseases and biological processes. In bovine, little is known about the regulatory roles of DNA methylation alterations on production and health traits, including mastitis. Results: Here, we employed whole-genome DNA methylation sequencing to profile the DNA methylation patterns of milk somatic cells from sixteen cows with naturally occurring Staphylococcus aureus (S. aureus) subclinical mastitis and ten healthy control cows. We observed abundant DNA methylation alterations, including 3,356,456 differentially methylated cytosines and 153,783 differential methylation haplotype blocks (dMHBs). The DNA methylation in regulatory regions, including promoters, first exons and first introns, showed global significant negative correlations with gene expression status. We identified 6435 dMHBs located in the regulatory regions of differentially expressed genes and significantly correlated with their corresponding genes, revealing their potential effects on transcriptional activities. Genes harboring DNA methylation alterations were significantly enriched in multiple immune- and disease-related pathways, suggesting the involvement of DNA methylation in regulating host responses to S. aureus subclinical mastitis. In addition, we found nine discriminant signatures (differentiates cows with S. aureus subclinical mastitis from healthy cows) representing the majority of the DNA methylation variations related to S. aureus subclinical mastitis. Validation of seven dMHBs in 200 cows indicated significant associations with mammary gland health (SCC and SCS) and milk production performance (milk yield). Conclusions: In conclusion, our findings revealed abundant DNA methylation alterations in milk somatic cells that may be involved in regulating mammary gland defense against S. aureus infection. Particularly noteworthy is the identification of seven dMHBs showing significant associations with mammary gland health, underscoring their potential as promising epigenetic biomarkers. Overall, our findings on DNA methylation alterations offer novel insights into the regulatory mechanisms of bovine subclinical mastitis, providing further avenues for the development of effective control measures. [ABSTRACT FROM AUTHOR]

ABSTRACT: Adoption of automated monitoring devices (AMD) affords the opportunity to tailor reproductive management according to the cow's needs. We hypothesized that a targeted reproductive management (TRM) would reduce the use of reproductive hormones while increasing the percentage of cows pregnant 305 d in milk (DIM). Holstein cows from 2 herds (n = 1,930) were fitted with an AMD at 251.0 ± 0.4 d of gestation. Early-postpartum estrus characteristics (EPEC; intense estrus = heat index ≥70; 0 = minimum, 100 = maximum) of multiparous cows were evaluated at 40 (herd 1) or 41 (herd 2) DIM and EPEC of primiparous cows were evaluated at 54 (herd 1) or 55 (herd 2) DIM. Control cows received the first artificial insemination at fixed time (TAI; primiparous, herd 1 = 82 and herd 2 = 83 DIM; multiparous, herd 1 = 68 and herd 2 = 69 DIM) following the Double-Ovsynch (DOV) protocol. Cows enrolled in the TRM treatment were managed as follows: (1) cows with at least one intense estrus were inseminated upon AMD detected estrus for 42 d and, if not inseminated, were enrolled in the DOV protocol; and (2) cows without an intense estrus were enrolled in the DOV protocol at the same time as cows in the control treatment. Control cows were re-inseminated based on visual or patch aided detection of estrus, whereas TRM cows were re-inseminated as described for control cows with the aid of the AMD. Cows received a GnRH injection 27 ± 3 d after insemination and, if diagnosed as nonpregnant, completed the 5-d Cosynch protocol and received TAI 35 ± 3 d after insemination. Among cows in the TRM treatment, 55.8 and 42.9% of primiparous and multiparous cows, respectively, received the first insemination in spontaneous estrus. The interaction between treatment and parity affected pregnancy 67 d after the first AI (primiparous: control = 37.6%, TRM = 27.4%; multiparous: control = 41.0%, TRM = 44.7%). The TRM treatment increased re-insemination in estrus (control = 48.3%, TRM = 70.5%). Pregnancy 67 d after re-inseminations tended to be affected by the interaction between treatment and EPEC (no intense estrus: control = 25.3%, TRM = 32.0%; intense estrus: control = 32.9%, TRM = 32.2%). The interaction between treatment and EPEC affected pregnancy by 305 DIM (no intense estrus: control = 80.8%, TRM = 88.2%; intense estrus: control = 87.1%, TRM = 86.1%). Treatment did not affect the number of reproductive hormone treatments among cows that had not had an intense estrus (control = 10.5 ± 0.3, TRM = 9.1 ± 0.2 treatments/cow), but cows in the TRM treatment that had an intense estrus received fewer reproductive hormone treatments than cows in the control treatment (2.0 ± 0.1 vs. 9.6 ± 0.2 treatments/cow). Selecting multiparous cows for first AI in estrus based on EPEC reduced the use of reproductive hormones without impairing the likelihood of pregnancy to first AI. The use of AMD for re-insemination expedited the establishment of pregnancy among cows that did not display an intense estrus early postpartum.

Abstract Background The tongue-rolling behaviour of cows is regarded as an outward sign of stressed animals in a low welfare status. The primary aim of this observational study was to evaluate the association between the frequency of tongue-rolling behaviour and its physiological function. The secondary aim was to explore the relationship between general activities and the frequency of tongue-rolling behaviour of cows. A total of 126 scan sampling behavioural observations were collected over 7 d on 348 Holstein cows with the same lactation stage in the same barn. The tongue-rolling frequency was defined as the number of tongue-rolling observations as a percentage to the total observations per individual cow. According to their tongue-rolling frequency, the cows were grouped into the CON (no tongue-rolling), LT (frequency 1%), MT (frequency 5%), and HT (frequency 10%) groups. Six cows from each group were randomly selected for sampling. Serum samples, rumen fluid, milk yield, and background information were collected. The general behaviour data during 72 continuous hours of dairy cows, including eating time, rumination time, food time (eating time + rumination time), and lying time, were recorded by the collar sensor. Results Cortisol (P = 0.012), γ-hydroxybutyric acid (P = 0.008), epinephrine (P = 0.030), and dopamine (P = 0.047) levels were significantly higher in tongue-rolling groups than in the CON group. Cortisol levels and tongue-rolling frequency had a moderate positive correlation (linearly r = 0.363). With the increase in tongue-rolling frequency, the rumen pH decreased first and then increased (P = 0.013), comparing to the CON group. HT cows had significantly less food time than CON cows (P = 0.035). The frequency of tongue-rolling had a moderate negative relationship with rumination time (r = −0.384) and food time (r = −0.492). Conclusions The tongue-rolling behaviour is considered as a passive coping mechanism, as the stress response in cows with high tongue-rolling frequency increased. Food intake and rumination activities were all closely related to the occurrence of tongue-rolling behaviour.

ABSTRACT: Although there is evidence that ketosis negatively affects fertility, the effect of late and early ketosis on the reproductive performance of lactating cows has not been systematically investigated. The aim of this study was to evaluate the association between time and amplitude of elevated milk BHB (EMB) occurring within 42 d in milk (DIM) and subsequent reproductive performance of lactating Holstein cows. The dairy herd information data of 30,413 cows with 2 test-day milk BHB recordings during early lactation periods 1 and 2 (5–14 and 15–42 DIM, respectively) assessed as negative (

Abstract This study aimed to understand the changes in the milk and gut microbiota of dairy cows with mastitis, and to further explore the relationship between mastitis and the microbiota. In this study, we extracted microbial DNA from healthy and mastitis cows and performed high-throughput sequencing using the Illumina NovaSeq sequencing platform. OTU clustering was performed to analyze complexity, multi-sample comparisons, differences in community structure between groups, and differential analysis of species composition and abundance. The results showed that there were differences in microbial diversity and community composition in the milk and feces of normal and mastitis cows, where the diversity of microbiota decreased and species abundance increased in the mastitis group. There was a significant difference in the flora composition of the two groups of samples (P

The structure of the fixed and random parts of the genetic evaluation model plays a significant role in fitting data and the estimation of genetic parameters for economic traits in livestock. The present study was conducted to investigate the effect of different fixed and random effects combinations in an animal model framework on the general properties of the model and estimates of the genetic parameters for milk production traits. Traits studied were 305-day milk production (305-MY, 15920 records), fat percentage (FP, 27954 records), protein percentage (PP, 26183 records), average daily milk production (ADM, 30954 records) and milk somatic cell score (SCS, 25408 records) in Isfahan Holstein cows. In general, 54 scenarios were studied which differed in fixed and random parts of the model. Variance components were estimated using the animal model fitting restricted maximum likelihood (REML) procedure. The best model for each trait was selected based on the Bayesian Information Criterion (BIC). Results showed that for all traits studied, models in which the effect of contemporary groups Herd-Year-Season (HYS) or Herd-Year-Month (HYM) were fitted as the random or fixed effect together with age at the first calving and inbreeding as a classified fixed effect or covariate lead to a significantly better data fit instead of fitting herd, year, season and month of calving separately. For each trait, a wide range of heritability was obtained by fitting 54 models. Based on the best models, the estimates of heritability for 305-MY, ADM, FP, PP and SCS were 0.33, 0.28, 0.21, 0.16 and 0.61, respectively. It was concluded that a single model should not be used for analyzing all milk production traits and that for each trait a series of models which differ in random and fixed parts should be tested to find the most suitable model which describes the data best. Fitting the effects of herd and year, season and month of calving as contemporary groups HYS or HYM was recommended for genetic evaluation of milk production traits as resulted in better data fit. Depending on the trait, inbreeding and age at first calving can be fitted as a classified fixed effect or as a covariate. [ABSTRACT FROM AUTHOR]

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Abstract Fibrosarcomas occur as a mesenchymal tumour of malignant fibroblasts in a collagen background and are usually found in the female genital organs and rarely involve the skin. A 5‐year‐old female Holstein cow with a raised mass at the base of right ear was referred. On gross examination, the mass was approximately 13.00 × 10.00 × 7.00 cm in size. Finally, complete surgical removal was selected. The mass was encapsulated and the dermis was expanded by spindle‐shaped to polygonal neoplastic cells. These cells were arranged in interwoven pattern. Mitotic figures were infrequent. Masson's trichrome demonstrated the positive and blue staining of collagen. Immunohistochemically, the sections were uniformly positive for Vimentin and negative for Desmin, SMA and GFAP. A well‐differentiated fibrosarcoma was diagnosed based on histopathological features. Surgical excision is the treatment of choice for this neoplasm. In the present case, surgery was also performed successfully and no new growth of the mass was observed 4 months following the surgical procedures. To our knowledge, this is the first report of well‐differentiated fibrosarcoma in a Holstein cow.

The experiment was to evaluate the effect of improved lactation performance of Tibetan improved cows (Holstein cow× Tibet cow♀, F3 generation). A total of 60 imported Holstein cows, 60 imported Tibetan cows and 60 Tibetan improved cows were selected to record the milk yield of F1~F3 generation of Tibetan improved cows, and determined the blood routine indexes, hemorheology indexes and cow performance (DHI) of F3 generation of Tibetan improved cows. The results showed that through hybridization, the milk yield of improved cows increased obviously from generation to generation, but other indexes still need to be further improved. The MCH, HGB and HCT of Tibetan improved cow were significantly higher than those of Tibetan cow ( P<0.05), and MCHC of Tibetan improved cow was significantly higher than that of imported Holstein cow and Tibetan cow ( P<0.05). RBC was significantly lower than that of imported Holstein cow ( P<0.05). The fibrinogen concentration, plasma viscosity and intracellular red blood cell viscosity of Tibetan improved cow were significantly higher than those of imported Holstein cow ( P<0.05), the red blood cell aggregation index and red blood cell aggregation coefficient were lower than those of imported Holstein cow and Tibetan cow ( P<0.05), and the casson viscosity and yield stress were significantly higher than those of Tibetan cow ( P<0.05). The study indicates that compare with Tibetan cow, the milk yield and milk fat ratio of Tibetan improved cow gradually with the increase of Holstein cow blood content. Compare with Hostein cow, the blood physiological indexes of Tibetan improved cow is improved. [ABSTRACT FROM AUTHOR]

Background: The tongue-rolling behaviour of cows is regarded as an outward sign of stressed animals in a low welfare status. The primary aim of this observational study was to evaluate the association between the frequency of tongue-rolling behaviour and its physiological function. The secondary aim was to explore the relationship between general activities and the frequency of tongue-rolling behaviour of cows. A total of 126 scan sampling behavioural observations were collected over 7 d on 348 Holstein cows with the same lactation stage in the same barn. The tongue-rolling frequency was defined as the number of tongue-rolling observations as a percentage to the total observations per individual cow. According to their tongue-rolling frequency, the cows were grouped into the CON (no tongue-rolling), LT (frequency 1%), MT (frequency 5%), and HT (frequency 10%) groups. Six cows from each group were randomly selected for sampling. Serum samples, rumen fluid, milk yield, and background information were collected. The general behaviour data during 72 continuous hours of dairy cows, including eating time, rumination time, food time (eating time + rumination time), and lying time, were recorded by the collar sensor. Results: Cortisol (P = 0.012), γ-hydroxybutyric acid (P = 0.008), epinephrine (P = 0.030), and dopamine (P = 0.047) levels were significantly higher in tongue-rolling groups than in the CON group. Cortisol levels and tongue-rolling frequency had a moderate positive correlation (linearly r = 0.363). With the increase in tongue-rolling frequency, the rumen pH decreased first and then increased (P = 0.013), comparing to the CON group. HT cows had significantly less food time than CON cows (P = 0.035). The frequency of tongue-rolling had a moderate negative relationship with rumination time (r = −0.384) and food time (r = −0.492). Conclusions: The tongue-rolling behaviour is considered as a passive coping mechanism, as the stress response in cows with high tongue-rolling frequency increased. Food intake and rumination activities were all closely related to the occurrence of tongue-rolling behaviour. [ABSTRACT FROM AUTHOR]

Microsatellite markers, also known as short tandem repeats (STRs), are important for marker-assisted selection to detect genetic polymorphism, and they are uniformly distributed in eukaryotic genomes. To analyze the relationship between microsatellite loci and lactation traits of Holstein cows in Xinjiang, 175 lactating cows with similar birth dates, the same parity, and similar calving dates were selected, and 10 STR loci closely linked to quantitative trait loci were used to analyze the correlation between each STR locus and four lactation traits (daily milk yield, milk fat percentage, milk protein percentage, and lactose percentage). All loci showed different degrees of genetic polymorphism. The average values of observed alleles, effective alleles, expected heterozygosity, observed heterozygosity, and polymorphic information content of the 10 STR loci were 10, 3.11, 0.62, 0.64, and 0.58, respectively. Chi-square and G-square tests showed that all populations of loci were in accordance with the Hardy–Weinberg equilibrium. Analysis of the correlation between STR locus genotype and lactation performance in the whole lactation period showed three loci (namely, BM143, BM415, and BP7) with no significant correlation with all lactation traits, two loci (BM302 and UWCA9) related to milk yield, three loci (BM103, BM302, and BM6425) related to milk fat percentage, two loci (BM302 and BM6425) related to milk protein percentage, and three loci (BM1443, BM302, and BMS1943) related to lactose percentage. The microsatellite loci selected in this study showed rich polymorphism in the experimental dairy cow population and were related to the lactation traits, which can be used for the evaluation of genetic resources and early breeding and improvement of Holstein dairy cows in Xinjiang. [ABSTRACT FROM AUTHOR]

This study aimed to understand the changes in the milk and gut microbiota of dairy cows with mastitis, and to further explore the relationship between mastitis and the microbiota. In this study, we extracted microbial DNA from healthy and mastitis cows and performed high-throughput sequencing using the Illumina NovaSeq sequencing platform. OTU clustering was performed to analyze complexity, multi-sample comparisons, differences in community structure between groups, and differential analysis of species composition and abundance. The results showed that there were differences in microbial diversity and community composition in the milk and feces of normal and mastitis cows, where the diversity of microbiota decreased and species abundance increased in the mastitis group. There was a significant difference in the flora composition of the two groups of samples (P < 0.05), especially at the genus level, the difference in the milk samples was Sphingomonas (P < 0.05) and Stenotrophomonas (P < 0.05), the differences in stool samples were Alistipes (P < 0.05), Flavonifractor (P < 0.05), Agathobacter (P < 0.05) and Pygmaiobacter (P < 0.05). In conclusion, the microbiota of the udder and intestinal tissues of dairy cows suffering from mastitis will change significantly. This suggests that the development of mastitis is related to the endogenous pathway of microbial intestinal mammary glands, but the mechanisms involved need further study. [ABSTRACT FROM AUTHOR]

A genome-wide association study (GWAS) of the daughter pregnancy rate (DPR), cow conception rate (CCR), and heifer conception rate (HCR) using 1,001,374–1,194,736 first-lactation Holstein cows and 75,140–75,295 SNPs identified 7567, 3798, and 726 additive effects, as well as 22, 27, and 25 dominance effects for DPR, CCR, and HCR, respectively, with log10(1/p) > 8. Most of these effects were new effects, and some new effects were in or near genes known to affect reproduction including GNRHR, SHBG, and ESR1, and a gene cluster of pregnancy-associated glycoproteins. The confirmed effects included those in or near the SLC4A4-GC-NPFFR2 and AFF1 regions of Chr06 and the KALRN region of Chr01. Eleven SNPs in the CEBPG-PEPD-CHST8 region of Chr18, the AFF1-KLHL8 region of Chr06, and the CCDC14-KALRN region of Chr01 with sharply negative allelic effects and dominance values for the recessive homozygous genotypes were recommended for heifer culling. Two SNPs in and near the AGMO region of Chr04 that were sharply negative for HCR and age at first calving, but slightly positive for the yield traits could also be considered for heifer culling. The results from this study provided new evidence and understanding about the genetic variants and genome regions affecting the three fertility traits in U.S. Holstein cows. [ABSTRACT FROM AUTHOR]

Abstract Background Abnormal or stereotyped behaviours in dairy cows are common in large-scale indoor farms and are usually accompanied by high physiological stress levels. Feed tossing is an abnormal behaviour commonly seen in cows while being fed, making farm management difficult. However, the reasons behind this behaviour have not been sufficiently reported. The objective of this study was to explore the changes in rumen fermentation, serum indicators, inflammatory conditions and the performance of cows with feed tossing behaviour. Holstein cows with similar lactation stages in the same barn were subjected to behaviour observations two times per day for 21 consecutive days. Ten cows with feed tossing behaviour (FT) and ten cows without abnormal behaviours (CON) were selected for further sampling. Plasma samples, rumen fluid, milk yield data of cows, and an indoor environment temperature-humidity index (THI) were collected. Results There was no significant difference in average daily milk yield during the observation period between feed-tossing cows (n = 68) and the other cows (n = 112). The number of cows showing FT behaviour had a moderately strong negative linear correlation with the THI of the environment. Compared to the CON cows, the FT cows had higher cortisol, norepinephrine and urea nitrogen levels in plasma, as well as higher plasma levels of inflammatory indicators, including total protein, lactate dehydrogenase, albumin, aspartate aminotransferase levels, and the ratio of aspartate aminotransferase to alanine aminotransferase. The FT cows had no significant variations from the CON cows regarding their rumen fermentation indicators, such as pH, ammonia nitrogen, and volatile fatty acids. In addition, 16S rRNA analysis revealed that there might be no clear association between the diversity and abundance of rumen bacteria and feed tossing behaviour. Conclusions Our findings suggested that cows might have suffered from high levels of physiological stress and immune state for a long period when they exhibited FT behaviour. The environmental THI could affect the FT behaviour of cows; as the THI increases, the willingness of cows to throw decreases. This work provided the first evidence that feed tossing might be a response associated with high levels of physiological stress and immune. It also explored our insights into a commonly observed behavioural response to cow welfare traits.

ABSTRACT: The dairy industry is moving toward selecting animals with better fertility to decrease the economic losses linked to reproductive issues. The reproductive tract size and position score (SPS) was recently developed in physiological studies as an indicator of pregnancy rate and the number of services to conception. Cows are scored as SPS 1, 2, or 3 based on the size of their reproductive tract and its position in the pelvis, as determined by transrectal palpation. The objective of this study was to estimate genetic parameters for SPS to assess its potential as a novel fertility trait. Phenotypes were collected at the University of British Columbia's research herd from 2017 to 2020, consisting of 3,247 within- and across-lactation SPS records from 490 Holstein cows. A univariate animal model was used to estimate the variance components for SPS. Both threshold and linear models were fit under a Bayesian approach and the results were compared using the Spearman rank correlation (r) between the estimated breeding values. The 2 models ranked the animals very similarly (r = 0.99), and the linear model was selected for further analysis. Genetic correlations with other currently evaluated traits were estimated using a bivariate animal model. The posterior means (± posterior standard deviation) for heritability and repeatability within- and across-lactation were 0.113 (± 0.013), 0.242 (± 0.012), and 0.134 (± 0.014), respectively. The SPS showed null correlations with production traits and favorable correlations with traditional fertility traits, varying from −0.730 (nonreturn rate) to 0.931 (number of services). Although preliminary, these results are encouraging because SPS seems to be more heritable than and strongly genetically correlated with number of services, nonreturn rate, and first service to conception, indicating potential for effective indirect selection response on these traits from SPS genetic selection. Therefore, further studies with larger data sets to validate these findings are warranted.

Although it is stated that there is an increase in calf loss rates at the global level and especially in modern dairy farms, this issue, which is an international animal welfare issue, has not been adequately defined at the national, large farm, or small farm level in most developing Countries. The rate of calf deaths before, during, and after birth is between 2–20% in heifers and cows. Previous studies showed that 75% of deaths occur during birth or within the first hour after birth, 10% before birth, and 15% within 48 hours after birth. This study aimed to determine the effect of Meloxicam administration on the quality of life and development of calves. An experimental method was used to achieve the aim of this research. A total of 60 Holstein calves, 30 in the experimental group and 30 in the control group, were included in the study for the study group. MELOXICAM (0.5 mg·kg-1) was administered to the mother cow and the calf immediately after birth, 2 days before the expected delivery. In this study, an 8 week process was passed to collect the data. It was concluded that Meloxicam did not affect the BHBA values of maternal cows. No calves died from pneumonia and diarrhea–related diseases after being treated with Meloxicam. From the total protein and total albumin values of the calves, it was concluded that Meloxicam did not affect the protein ratio, but did affect the albumin ratio. It was concluded that Meloxicam application increased the vital activity of calves.

Fibrosarcomas occur as a mesenchymal tumour of malignant fibroblasts in a collagen background and are usually found in the female genital organs and rarely involve the skin. A 5‐year‐old female Holstein cow with a raised mass at the base of right ear was referred. On gross examination, the mass was approximately 13.00 × 10.00 × 7.00 cm in size. Finally, complete surgical removal was selected. The mass was encapsulated and the dermis was expanded by spindle‐shaped to polygonal neoplastic cells. These cells were arranged in interwoven pattern. Mitotic figures were infrequent. Masson's trichrome demonstrated the positive and blue staining of collagen. Immunohistochemically, the sections were uniformly positive for Vimentin and negative for Desmin, SMA and GFAP. A well‐differentiated fibrosarcoma was diagnosed based on histopathological features. Surgical excision is the treatment of choice for this neoplasm. In the present case, surgery was also performed successfully and no new growth of the mass was observed 4 months following the surgical procedures. To our knowledge, this is the first report of well‐differentiated fibrosarcoma in a Holstein cow. [ABSTRACT FROM AUTHOR]

Copyright of Revista Cientifica de la Facultade de Veterinaria is the property of Universidad del Zulia, Facultad de Ciencias Veterinarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, 73 non-pregnant and clinically healthy and lactating Holstein cows without any clinical signs, and with a mean parity of 3.2 ± 1.4, days in milk at the beginning of study 110 ± 20 days, body condition scour (BCS) of about 3.2 ± 0.3, and milk production rate of 48± 10 kg were selected and randomly placed in two treatment and control groups. In the treatment group (n=36), arginine (155 µmol / kg body weight) was injected once every 8 hours a day for 6 days, and in the control group (n=37) saline solution (0.11 ml/kg body weight, once every 8 hours a day) was injected for 6 days. The results showed that there was no difference between the treatment and the controle group in terms of milk production (38.5 and 36 kg, P=0.3), fat (3.7 and 3.8%, P=0.8) and protein (3.1 and 3.1%, P=0.5) levels. It was concluded from this study that the use of arginine after the peak of milk production could not increase the fat, protein, and production levels of milk. [ABSTRACT FROM AUTHOR]

Background: Abnormal or stereotyped behaviours in dairy cows are common in large-scale indoor farms and are usually accompanied by high physiological stress levels. Feed tossing is an abnormal behaviour commonly seen in cows while being fed, making farm management difficult. However, the reasons behind this behaviour have not been sufficiently reported. The objective of this study was to explore the changes in rumen fermentation, serum indicators, inflammatory conditions and the performance of cows with feed tossing behaviour. Holstein cows with similar lactation stages in the same barn were subjected to behaviour observations two times per day for 21 consecutive days. Ten cows with feed tossing behaviour (FT) and ten cows without abnormal behaviours (CON) were selected for further sampling. Plasma samples, rumen fluid, milk yield data of cows, and an indoor environment temperature-humidity index (THI) were collected. Results: There was no significant difference in average daily milk yield during the observation period between feed-tossing cows (n = 68) and the other cows (n = 112). The number of cows showing FT behaviour had a moderately strong negative linear correlation with the THI of the environment. Compared to the CON cows, the FT cows had higher cortisol, norepinephrine and urea nitrogen levels in plasma, as well as higher plasma levels of inflammatory indicators, including total protein, lactate dehydrogenase, albumin, aspartate aminotransferase levels, and the ratio of aspartate aminotransferase to alanine aminotransferase. The FT cows had no significant variations from the CON cows regarding their rumen fermentation indicators, such as pH, ammonia nitrogen, and volatile fatty acids. In addition, 16S rRNA analysis revealed that there might be no clear association between the diversity and abundance of rumen bacteria and feed tossing behaviour. Conclusions: Our findings suggested that cows might have suffered from high levels of physiological stress and immune state for a long period when they exhibited FT behaviour. The environmental THI could affect the FT behaviour of cows; as the THI increases, the willingness of cows to throw decreases. This work provided the first evidence that feed tossing might be a response associated with high levels of physiological stress and immune. It also explored our insights into a commonly observed behavioural response to cow welfare traits. [ABSTRACT FROM AUTHOR]

Simple Summary: Lyophilized horse-platelet-derived growth factor (L-GFequina) is a brand-new, improved platelet-rich protein growth factor. It has been successfully used to treat a number of inflammatory and degenerative musculoskeletal diseases in several disciplines of regenerative medicine. Our study aimed to evaluate the possibility of using an intraovarian injection of L-GFequina in the assisted reproduction of Holstein cows. L-GFequina employs allogenic, pathogen-free platelets from horses that have been successfully used in other species to prevent changes in technical platelet specifications caused by the centrifugation process and time, as well as the integrity and quality of autologous platelets. The number of ovum pick-up (OPU) sessions per cycle, the growth of medium- and large-sized follicles, the number of COCs produced per cow per session, and the formation of blastocysts during OPU-IVEP in eCG stimulated Holstein cows were all boosted in this study by an intraovarian injection of L-GFequina. The purpose of this study was to determine the impact of intraovarian injections of a reconstituted lyophilized growth-promoting factor extracted from horse blood platelets (L-GFequina) on the number of ovarian follicles, the recovery of cumulus–oocyte complexes (COCs), and embryo development to the blastocyst stage in Holstein cows. Thus, 12 Holstein cows were assigned to three protocols. According to the number of punctured follicles in protocol 1, ovum pick-up (OPU) was conducted on days 6 and 14 of the cycle (day 0 = estrus). In protocol 2, every large follicle (more than 7 mm) was removed, and 1 mL of L-GFequina was intraovarian injected (day 0). Two days later, equine chorionic gonadotropin (eCG) was administered, and OPU sessions were conducted on days 6, 10, and 14. The same ovarian stimulation procedure as that in protocol 2 was performed in protocol 3, except that equine L-GFequina was not supplied. OPU was carried out on days 6 and 10 of the cycle. The results indicate that the intraovarian injection of L-GFequina significantly (p < 0.05) increased the number of OPU sessions per cycle, the recovery of cumulus–oocyte complexes (COCs), and the production of blastocysts. In conclusion, an intraovarian injection of L-GFequina can improves OPU-IVEP results in Holstein cows. [ABSTRACT FROM AUTHOR]

Aim of this study was estimation of two genetic parameters: heritability and repeatability, for five milk production traits. Data used in current paper consisted from phenotypic information from 998 cows with 1897 yield records. The traits which were considered for 305 days of lactation included milk, fat ant protein yields and percentages of milk fat and protein. Data were statistically analyzed through the S.A.V.C. (Statistical Analyze of Variance and Covariance) software. The estimated heritabilities for studied traits were 0.24 to 0.38 for milk yield (MY), 0.27 to 0.41 for fat yield (FY), 0.61 to 0.87 for percentage of fat (F%), 0.25 to 0.39 for protein yield (PY) and 0.59 to 0.78 for percentage of protein (P%). Repeatability estimates for studied traits ranged from 0.27 to 0.34 for MY, from 0.30 to 0.41 for FY, from 0.67 to 0.86 for F%, from 0.28 to 0.39 for PY and from 0.62 to 0.77 for P%. Results from this paper are in line with values reported from other authors. Also, Fisher results indicate significant differences between studied farms.

Copyright of Journal of Ruminant Research / Pizhūhish dar Nushkhvār/Kunandigān is the property of Gorgan University of Agricultural Sciences & Natural Resources and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study was conducted to investigate the metabolic mechanism underlying the disparity in the milk yield of Holstein cows. Eighteen lactating Holstein cows in their second parity and 56 (±14.81 SD) days in milking (DIM) were selected from 94 cows. Based on the milk yield of the cows, they were divided into two groups of nine cows each, the high milk yield group (HP) (44.57 ± 2.11 kg/day) and the low milk yield group (LP) (26.71 ± 0.70 kg/day). The experimental cows were fed the same diet and kept under the same management system for more than 60 days. Rumen metagenomics revealed that two Archaea genera, one Bacteria genus, eight Eukaryota genera, and two Virus genera differ between the HP and LP groups. The analysis of metabolites in the rumen fluid, milk, and serum showed that several metabolites differed between the HP and LP groups. Correlation analysis between the predominant microbiota and milk yield-associated metabolites (MP-metabolites) revealed that four Bacteria and two Eukaryota genera have a positive relationship with MP-metabolites. Pathway enrichment analysis of the differential metabolites revealed that five pathways were enriched in all the samples (two pathways in the milk, two pathways in the serum, and one pathway in the rumen fluid). Further investigation revealed that the low milk yield observed in the LP group might be due to an upregulation in dopamine levels in the rumen fluid and milk, which could inhibit the release of prolactin or suppress the action of oxytocin in the udder resulting in reduced milk yield. On the other hand, the high milk yield in the HP group is attributed to an upregulation in citrulline, and N -acetylornithine, which could be used as substrates for energy metabolism in the citric acid cycle and ultimately gluconeogenesis. [ABSTRACT FROM AUTHOR]

Aims: This study aims to investigate the effect of hydroxy‐selenomethionine supplementation on the in vitro rumen fermentation characteristics and microorganisms of Holstein cows. Methods and Results: Five fermentation substrates, including control (without selenium supplementation, CON), sodium selenite supplementation (0.3 mg kg−1 DM, SS03), and hydroxy‐selenomethionine supplementation (0.3, 0.6 and 0.9 mg kg−1 DM, SM03, SM06 and SM09, respectively) were incubated with rumen fluid in vitro. The results showed that in vitro dry matter disappearance and gas production at 48 h was significantly higher in SM06 than SM03, SS03 and CON; propionate and total volatile fatty acid (VFA) production was higher in SM06 than CON. Moreover, higher species richness of rumen fluid was found in SM06 than others. Higher relative abundance of Prevotella and Prevotellaceae‐UCG‐003 and lower relative abundance of Ruminococcus‐1 were detected in SM06 than CON. Besides, higher relative abundance of Ruminococcaceae_UCG‐005 was found in CON than other treatments. Conclusions: It is observed that 0.6 mg kg−1 DM hydroxy‐selenomethionine supplementation could increase cumulative gas production, propionate, and total VFAs production by altering the relative abundance of Prevotella, Prevotellaceae‐UCG‐003, Ruminococcaceae_UCG‐005 and Ruminococcus‐1, so that it can be used as a rumen fermentation regulator in Holstein cows. Significance and Impact of the Study: This study provides an optimal addition ratio of hydroxy‐selenomethionine on rumen fermentation and bacterial composition via an in vitro test. [ABSTRACT FROM AUTHOR]

This study was conducted to investigate the metabolic mechanism underlying the disparity in the milk yield of Holstein cows. Eighteen lactating Holstein cows in their second parity and 56 (±14.81 SD) days in milking (DIM) were selected from 94 cows. Based on the milk yield of the cows, they were divided into two groups of nine cows each, the high milk yield group (HP) (44.57 ± 2.11 kg/day) and the low milk yield group (LP) (26.71 ± 0.70 kg/day). The experimental cows were fed the same diet and kept under the same management system for more than 60 days. Rumen metagenomics revealed that two Archaea genera, one Bacteria genus, eight Eukaryota genera, and two Virus genera differ between the HP and LP groups. The analysis of metabolites in the rumen fluid, milk, and serum showed that several metabolites differed between the HP and LP groups. Correlation analysis between the predominant microbiota and milk yield-associated metabolites (MP-metabolites) revealed that four Bacteria and two Eukaryota genera have a positive relationship with MP-metabolites. Pathway enrichment analysis of the differential metabolites revealed that five pathways were enriched in all the samples (two pathways in the milk, two pathways in the serum, and one pathway in the rumen fluid). Further investigation revealed that the low milk yield observed in the LP group might be due to an upregulation in dopamine levels in the rumen fluid and milk, which could inhibit the release of prolactin or suppress the action of oxytocin in the udder resulting in reduced milk yield. On the other hand, the high milk yield in the HP group is attributed to an upregulation in citrulline, and N-acetylornithine, which could be used as substrates for energy metabolism in the citric acid cycle and ultimately gluconeogenesis.

Copyright of Anadolu Journal of Agricultural Sciences / Anadolu Tarım Bilimleri Dergisi is the property of Ondokuz Mayis Universitesi, Ziraat Fakultesi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: To determine effects of variations of heart girth, volume trait on embryo quality grade, and to explore the relationship between heart girth and circulating progesterone and correlations of circulating progesterone with embryo quality grade in superstimulated donor Holstein cows. Methods: Nineteen cows were subjected to a standard superstimulation protocol using follicle stimulating hormone. Blood samples were collected before superovulation, at insemination and at collection of embryos for progesterone analysis. Embryo quality grades were compared between high and low heart girth donors. Moreover, Pearson's correlations were determined between heart girth, progesterone and embryo quality. Results: Variation of heart girth was not associated with significant differences in embryo quality grade between high and low heart girth donor cows (P>0.05). However, we observed a significantly higher percentage of the third-grade embryo (24.09%) in low heart girth donors compared to 9.64% in high heart girth donors. Moreover, the percentage of the transferable embryo was numerically higher and that of the degenerated embryo was numerically lower in low heart girth cows. Donor cows with low response to superovulation (total structures ≤ 3) expressed numerically higher mean heart girth, compared to donors with high (total structures >15) and medium (total structures = 4-15) superovulation. Heart girth and body weight of donor cows were moderately correlated (r=0.45, P

The goal was to investigate the relationship among mRNA expressions of anti‐Mullérian hormone (AMH), follicle‐stimulating hormone receptor (FSHR) and responses to superovulation (SO) in embryo donor dairy cows. Holstein cows (n = 19) were submitted to a standard SO protocol, with twice daily FSH treatments, and artificially inseminated. Prior to SO (Day 0), relative mRNA expressions of AMH and FSHR in blood were determined for all cows. Day 7 embryos were collected and were graded to determine superovulatory response for each donor. Results showed that relative mRNA expressions of AMH and FSHR were positively correlated (R2 = 0.94). Relative mRNA expressions of both AMH and FSHR were positively correlated with total embryos (R2 = 0.68 and 0.69, respectively), total transferable embryos (R2 = 0.92 and 0.97, respectively) and total grade 1 embryos (R2 = 0.54 and 0.59, respectively). Further, transcript abundances of AMH and FSHR positively associated with milk production of donor cows, and meanwhile, they were negatively associated with days in milk (DIM) at submission of cows to SO (p <.05) protocol. The relative mRNA expression of AMH was higher (p <.05) in donor cows <5 years of age. However, age of donor at superovulation did not influence mRNA expression of FSHR. Collectively, we infer that the mRNA expressions of AMH and FSHR prior to superovulation can predict donor cows' positive response to superovulation. [ABSTRACT FROM AUTHOR]

The potential combined effects of oleic, linoleic and linolenic acids supplementation on lactation performance and the milk fatty acid (FA) profile in dairy cows have not been well investigated. Our objective was to examine the effects of supplementation with a combination of these FA as well as the effects of removing each from the combination on lactation performance and the milk FA profile in dairy cows. Eight Holstein cows (101±11 days in milk) received four intravenously infused treatments in a 4×4 Latin square design, and each period lasted for 12 days which consisted of 5 days of infusion and 7 days of recovery. The control treatment (CTL) contained 58.30, 58.17 and 39.96 g/day of C18: 1 cis-9; C18: 2 cis-9, cis-12; and C18: 3 cis-9, cis-12, cis-15, respectively. The other three treatments were designated −−C18: 1 (20.68, 61.17 and 41.72 g/day of C18: 1 cis-9; C18: 2 cis-9, cis-12; and C18: 3 cis-9, cis-12, cis-15, respectively), −C18: 2 (61.49, 19.55 and 42.13 g/day of C18: 1 cis-9; C18: 2 cis-9, cis-12; and C18: 3 cis-9, cis-12, cis-15, respectively) and −C18: 3 (60.89, 60.16 and 1.53 g/day of C18: 1 cis-9; C18: 2 cis-9, cis-12; and C18: 3 cis-9, cis-12, cis-15, respectively). Dry matter intake and lactose content were not affected by the treatments, but the milk protein content was lower in cows treated with −C18: 2 than that in CTL-treated cows. Milk yield as well as milk fat, protein and lactose yields were higher in cows treated with −C18: 3 than the yields in CTL-treated cows, and these yields increased linearly as the unsaturation degree of the supplemental FA decreased. Compared with the CTL treatment, the −C18: 2 treatment decreased milk C18: 2 cis-9 content (by 2.80%) and yield (by 22.12 g/day), and the −C18: 3 treatment decreased milk C18: 3 cis-9, cis-12, cis-15 content (by 2.72%) and yield (by 22.33 g/day). In contrast, removing C18: 1 cis-9 did not affect the milk content or yield of C18: 1 cis-9. The −C18: 2-treated cows had a higher C18: 1 cis-9 content and tended to have a higher C18: 1 cis-9 yield than CTL-treated cows. The yields of C8: 0, C14: 0 and C16: 0 as well as

Dairy cows often suffer metabolic disorders due to the challenges of the transition period. The aim of study was to determine the effects of feeding pomegranate byproduct silage (PBS) on feed intake and some blood parameters, such as non-esterified fatty acids (NEFA) and beta hydroxy butyric acid (BHBA), interleukin-1 (IL-1), serum amyloid-A (SAA), prostaglandin F2α metabolites (PGFM), and progesterone (P4) in fresh Holstein cows. The experimental groups were as follows: CON (0 g PBS of DM) and PBS (120 g PBS of DM). Results showed that replacing corn silage with PBS had no effect on dry matter intake (DMI) throughout the study. The CON group had highest (p < .05) NEFA at 14 d postpartum and serum BHBA was decreased by feeding PBS, especially on days 21 (p < .05) and 28 (p < .05) and the entire study (p < .01). Cows fed PBS had lower (p < .05) serum Malondialdehyde (MDA) than CON cows at different times. Feeding PBS decreased (p < .01) serum IL-1 compared to CON group (216.7 versus. 515.5 Pg/ml) at 28 d postpartum, and also cows fed 120 g PBS had higher (p < .01) serum P4. It was concluded that feeding PBS had no adverse effect on feed intake, milk production, and some reproductive parameters. Moreover, PBS positively affected serum metabolites in fresh dairy cows. [ABSTRACT FROM AUTHOR]

Light emitting diode (LED) is more energy efficient than incandescent or fluorescent light. This study was to evaluate effects of different colored LEDs on milk production, milk composition, and physiology of Holstein cow. According to milk production and parity, cows (n = 186) were allotted to four treatments: control (natural daylight), white, yellow, and blue LED groups. Of these, 40 cows that had passed 57 day-in-milk were used. Yellow and blue LED groups demonstrated greater rates of decline in milk production than control and white LED groups. At the finish point, milk fat, protein, and lactose contents were the lowest in the blue LED group, whereas milk-urea-nitrogen levels were the highest in the yellow and blue LED groups. Extended exposure to blue LED light lowered antioxidant enzyme activity and insulin-like growth factor-1 levels. Prolactin concentrations were higher in the white and blue LED groups than in the control. Cortisol level was the highest in the blue LED group among the groups. Nonesterified fatty acid levels in the yellow and blue LED groups decreased to the greatest extent compared to the start point. These results suggest that blue LED light can decrease milk production and generate more stress than white and yellow LED lights. [ABSTRACT FROM AUTHOR]

This study was conducted to investigate the effects of replacement of soybean meal with canola meal and corn processing on productive performance of Holstein dairy cows. Twelve Holstein cows (milk yield= 46±3 kg/d) were assigned to a replicated 4x4 Latin square design with a 2x2 factorial arrangement of treatments. Factor 1 was corn processing method, ground corn or steam flaked corn, and factor 2 was two ratio canola meal to soybean meal (50:50 or 100:0). No significant interactions of main treatment effects occurred for lactation performance data. Dry matter intake and milk production was not affected by replacement of soybean meal with canola meal. Milk compounds concentration was not affected by this replacement. Substitution of hundred percent of soybean meal with canola meal in the diet decreased the apparent digestibility of the dry matter. Feed intake was decrease when the cows received steam flaked corn compared with those receiving ground corn. Milk fat content decreased but milk protein content increased in cows fed steam flaked compared with those fed ground corn. Although these results showed no interaction effects of replacement of soybean meal with canola meal and corn processing method on performance, higher canola meal ratio and steam flaked corn improved feed efficiency and has a positive effect on the metabolism of nitrogen and energy, so recommended to fed in high-yielding cows under the conditions of this experiment. [ABSTRACT FROM AUTHOR]

In order to study the effects of replacing different proportions of silage maize with silage sweet sorghum treated by different fermentation methods on the production performance and blood biochemical indexes of dairy cows, 25 Chinese Holstein lactating cows were randomly divided into 5 groups, 5 in each group. The control check(CK) was fed the basal diet; for the experimental group 1 and the experimental group 2, 50% of the silage maize in the basal diet was replaced with the additive silage sweet sorghum and the conventional silage sweet sorghum, respectively; and as to the experimental group 3 and the experimental group 4, all the silage maize in the basal diet was replaced with additive silage sweet sorghum and conventional silage sweet sorghum, respectively. The preliminary trial period was 7 d, and the trial period was 35 d. The results showed that the experimental group 1 and the experimental group 3 had the dry matter intake significantly higher than that of the experimental group 2, the experimental group 4 and the CK(P<.05). The daily milk yields of the experimental group 1 and the experimental group 2 were significantly lower than that of the CK(P<.05), and the experimental group 3 and the experimental group 4 were significantly lower than the experimental group 1 and the experimental group 2(P<.05). The milk protein percentage of the experimental group 2 was extremely significantly higher than that of the experimental group 4(P<.01). The experimental group 1, the experimental group 2 and the experimental group 3 showed the blood glucose levels extremely significantly higher than that in the CK(P<.01). The blood urea nitrogen contents in the experimental group 2 and the experimental group 4 were significantly higher than those in the experimental group 1 and the CK(P<.01). There were no significant differences in other blood biochemical indexes between various groups(P<.05). It is feasible to use silage sweet sorghum to feed dairy cows, but the proportion should not be too large, and attention should be paid to the energy and nitrogen balance of the diet. [ABSTRACT FROM AUTHOR]

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This experiment was conducted to investigate the effects of different levels of dietary NDF in diets rich in plant oil (sunflower) on milk performance and feeding behavior of mid-lactating Holstein dairy cows. Four primiparous (BW: 525±30 kg; DIM: 103±6) and four multiparous (BW: 587±88 kg; DIM: 99±12) cows were used in a 4×4 replicated Latin square design with 21-d experimental periods. Cows were received 1 of 4 four treatments: 1) 31% fiber (NDF) and no supplement plant oil, LF, 2) 31% fiber with 2% supplement plant oil, LFO 3) 35% fiber with 2% plant oil, MFO 4) 39% fiber with 2% plant oil, HFO. Daily dry matter intake (DMI), milk yield and composition, blood metabolites, dry matter digestibility, rumen fluid characteristics and BW variations were determined. There was no significant different in milk production among diets. Milk fat (P<0.01) and protein (P<0.05) concentrations were significantly affected by treatments. Dry matter intake and DM digestibility were higher (P<0.01) in LFO diet. The cows fed HFO had higher NDF digestibility (P<0.01). Total VFA and acetate concentration were greater for HFO diet and propionate concentration was greater for LFO diet (P<0.01) than the others. Rumen fluid pH was increased by increasing dietary NDF concentration (P<0.01). Chewing activity was positively affected by increasing concentration of dietary NDF (P<0.01). This study showed that diets rich in plant oil and low concentration of NDF induce the milk fat depression in mid-lactating cows. [ABSTRACT FROM AUTHOR]

The use of abnormal milk mid-infrared (MIR) spectrum strongly affects prediction quality, even if the prediction equations used are accurate. So, this record must be detected after or before the prediction process to avoid erroneous spectral extrapolation or the use of poor-quality spectral data by dairy herd improvement (DHI) organizations. For financial or practical reasons, adapting the quality protocol currently used to improve the accuracy of fat and protein contents is unfeasible. This study proposed three different statistical methods that would be easy to implement by DHI organizations to solve this issue: the deletion of 1% of the extreme high and low predictive values (M1), the deletion of records based on the Global-H (GH) distance (M2), and the deletion of records based on the absolute fat residual value (M3). Additionally, the combinations of these three methods were investigated. A total of 346,818 milk samples were analyzed by MIR spectrometry to predict the contents of fat, protein, and fatty acids. Then, the same traits were also predicted externally using their corresponded standardized MIR spectra. The interest in cleaning procedures was assessed by estimating the root mean square differences (RMSDs) between those internal and external predicted phenotypes. All methods allowed for a decrease in the RMSD, with a gain ranging from 0.32% to 41.39%. Based on the obtained results, the “M1 and M2” combination should be preferred to be more parsimonious in the data loss, as it had the higher ratio of RMSD gain to data loss. This method deleted the records based on the 2% extreme predictions and a GH threshold set at 5. However, to ensure the lowest RMSD, the “M2 or M3” combination, considering a GH threshold of 5 and an absolute fat residual difference set at 0.30 g/dL of milk, was the most relevant. Both combinations involved M2 confirming the high interest of calculating the GH distance for all samples to predict. However, if it is impossible to estimate the GH distance due to a lack of relevant information to compute this statistical parameter, the obtained results recommended the use of M1 combined with M3. The limitation used in M3 must be adapted by the DHI, as this will depend on the spectral data and the equation used. The methodology proposed in this study can be generalized for other MIR-based phenotypes.

Heat stress has been reported to affect the immunity of dairy cows. However, the mechanisms through which this occurs are not fully understood. Two breeds of dairy cow, Holstein and Jersey, have distinct characteristics, including productivity, heat resistance, and disease in high-temperature environments. The objective of this study is to understand the dynamics of the immune response of two breeds of dairy cow to environmental change. Ribonucleic acid sequencing (RNA-seq) results were analyzed to characterize the gene expression change of peripheral blood mononuclear cells (PBMCs) in Holstein and Jersey cows between moderate temperature-humidity index (THI) and high THI environmental conditions. Many of the differentially expressed genes (DEGs) identified are associated with critical immunological functions, particularly phagocytosis, chemokines, and cytokine response. Among the DEGs, CXCL3 and IL1A were the top down-regulated genes in both breeds of dairy cow, and many DEGs were related to antimicrobial immunity. Functional analysis revealed that cytokine and chemokine response-associated pathways in both Holstein and Jersey PBMCs were the most important pathways affected by the THI environmental condition. However, there were also breed-specific genes and pathways that altered according to THI environmental condition. Collectively, there were both common and breed-specific altered genes and pathways in Holstein and Jersey cows. The findings of this study expand our understanding of the dynamics of immunity in different breeds of dairy cow between moderate THI and high THI environmental conditions.

Rumen microorganisms are the origin of many bioactive fatty acids (FA) found in ruminant-derived food products. Differences in plant leaf anatomy and chemical composition between cool- and warm-season pastures may alter rumen microorganisms, potentially enhancing the quantity/profile of bioactive FA available for incorporation into milk. The objective of this study was to identify rumen bacteria and protozoa and their cellular FA when cows grazed a warm-season annual, pearl millet (PM), in comparison to a diverse cool-season pasture (CSP). Individual rumen digesta samples were obtained from five Holstein cows in a repeated measures design with 28-day periods. The treatment sequence was PM, CSP, then PM. Microbial DNA was extracted from rumen digesta and sequence reads were produced with Illumina MiSeq. Fatty acids (FA) were identified in rumen bacteria and protozoa using gas-liquid chromatography/mass spectroscopy. Microbial communities shifted in response to grazing regime. Bacteria of the phylum Bacteroidetes were more abundant during PM than CSP (P < 0.05), while protozoa of the genus Eudiplodinium were more abundant during CSP than PM (P < 0.05). Microbial cellular FA profiles differed between treatments. Bacteria and protozoa from cows grazing CSP contained more n-3 FA (P < 0.001) and vaccenic acid (P < 0.01), but lower proportions of branched-chain FA (P < 0.05). Microbial FA correlated with microbial taxa and levels of vaccenic acid, rumenic acid, and α-linolenic acid in milk. In conclusion, grazing regime can potentially be used to alter microbial communities shifting the FA profile of microbial cells, and subsequently, alter the milk FA profile.