Application of vitamins B1 and B12 injection on milk yield and composition and some blood biochemical traits in Holstein dairy cows

Genetic relationship between heifers and cows fertility and milk yield traits in first-parity Iranian Holstein dairy cows

Simple SummaryThe aim of this study was to describe the basic status of milk production traits of Chinese Holstein cows in Jiangsu, and locate the QTLs and functional genes that affect the five milk production traits (milk yield, milk fat percentage, milk fat yield, milk protein percentage, and milk protein yield) of first-born cows. The five milk production traits showed significant phenotypic positive correlation and high genetic positive correlation among the three parities, and we identified 1731 CNVs and 236 CNVRs in the 29 autosomes of 4173 Holstein dairy cows, and 19 CNVRS were significantly associated with milk production traits. The study introduced the basic status of the milk production traits of Chinese Holstein cows in Jiangsu province, and 19 CNVRs were identified to be significantly related to milk production traits of Chinese Holstein cows in the first fetus. This study will provide a theoretical basis for molecular marker-assisted selection of dairy cows, help to analyze the genetic structure of milk production traits of dairy cows, and contribute to the genetic improvement of Chinese Holstein cattle in Jiangsu.Milk production traits are the most important quantitative economic traits in dairy cow production; improving the yield and quality of milk is an important way to ensure the production efficiency of the dairy industry. This study carried out a series of in-depth statistical genetics studies and molecular analyses on the Chinese Holstein cows in the Jiangsu Province, such as descriptive statistics and copy number variation analysis. A genetic correlation, phenotypic correlation, and descriptive statistical analysis of five milk production traits (milk yield, milk fat percentage, milk fat yield, milk protein percentage, and milk protein yield) of the dairy cows were analyzed using the SPSS and DMU software. Through quality control, 4173 cows and their genomes were used for genomic study. Then, SNPs were detected using DNA chips, and a copy number variation (CNV) analysis was carried out to locate the quantitative trait loci (QTL) of the milk production traits by Perl program software Penn CNV and hidden Markov model (HMM). The phenotypic means of the milk yield, milk fat percentage, milk fat mass, milk protein percentage, and milk protein mass at the first trimester were lower than those at the other trimesters by 8.821%, 1.031%, 0.930%, 0.003%, and 0.826%, respectively. The five milk production traits showed a significant phenotypic positive correlation (p < 0.01) and a high genetic positive correlation among the three parities. Based on the GGPBovine 100 K SNP data, QTL-detecting research on the fist-parity milk performance of dairy cows was carried out via the CNV. We identified 1731 CNVs and 236 CNVRs in the 29 autosomes of 984 Holstein dairy cows, and 19 CNVRs were significantly associated with the milk production traits (p < 0.05). These CNVRs were analyzed via a bioinformatics analysis; a total of 13 gene ontology (GO) terms and 20 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were significantly enriched (p < 0.05), and these terms and pathways are mainly related to lipid metabolism, amino acid metabolism, and cellular catabolic processes. This study provided a theoretical basis for the molecular-marker-assisted selection of dairy cows by developing descriptive statistics on the milk production traits of dairy cows and by locating the QTL and functional genes that affect the milk production traits of first-born dairy cows. The results describe the basic status of the milk production traits of the Chinese Holstein cows in Jiangsu and locate the QTL and functional genes that affect the milk production traits of the first-born cows, providing a theoretical basis for the molecular-marker-assisted selection of dairy cows.

SUMMARY This study aimed to investigate the relationship among somatic cell scores (SCS) and currently selected traits (milk yield, and fat, protein, lactose, total solids and no-fat-solids contents) in Holstein dairy cows in a semi-arid climate. The data were collected from available records of 272 Holstein cows from January 2007 to December 2016. Farms were located in Agreste region of Pernambuco whose climatic characteristics according to Instituto Nacional de Meteorologia-INMET were: average annual temperature of 25.21 °C; average annual precipitation 562.07 mm, and average annual relative humidity 75.61%.. A total of 4,586 records of somatic cell counts (SCC) in the milk, milk yield and milk components was analyzed. The SCC was transformed logarithmically into SCS SCS = log 2 ( SCC / 100 , 000 ) + 3 ) before statistical investigation. Ten SCS were obtained for determining their effects on milk yield and composition. Data were processed using PROC GLM and PROC CORR procedures in SAS. Results showed positive correlations among SCS and fat, protein, total solids and solids-non-fat contents, while the SCS and lactose content and milk yield were negatively correlated. The highest milk yield (34.43 kg/cow/day) was obtained for the lowest SCS (0; 0 to 24 cells x 1000/mL). The milk yield and lactose decreased while protein and fat contents increased when SCS increased mostly above score five (400 to 799 cells x 1000/mL). It was observed that the increase in SCS influenced negatively milk yield and composition in Holstein cows created in the semi-arid climate in Brazil.

This study was conducted to investigate the effects of supplementing additional sucrose, in the form of black sugar (BS), into the diet of Holstein dairy cows on dry matter intake (DMI), milk yield, and milk composition. Eight Holstein dairy cows (741 ±65.8 kg body weight) were divided into two groups, including the control and BS groups. Animals in the control group were offered a total mixed ration (TMR) ad libitum , and the BS group was offered TMR with 300 g of BS/head/d. After two weeks of adaptation period, the animal performance, including DMI, milk yield and milk composition, was measured. Cows supplemented with BS appeared to consume more feed than that by the controls (i.e., 17.08 and 18.28 kg/d for the control and BS groups, respectively). However, there were no significant differences between treatments. Milk yield or milk composition, such as milk fat, milk protein, lactose, solids-non-fat, total solids and pH, did not differ between treatments. However, there was a significant difference (p<0.05) in the concentration of milk urea nitrogen (MUN). The MUN concentration of the BS group was approximately 15% lower than that of the control group (i.e., 18.75 vs. 16.05 mg/dL for the control and BS groups, respectively), which suggests improved nitrogen metabolism in the animals. The somatic cell count was numerically lower in the cows of the BS group compared to those in the control group. However, a significant difference was not noted due to the substantial amount of variation among cows. In terms of the trace mineral composition for milk, the concentration of Cu from BS animals was higher (p<0.05) than that of the control animals. In summary, supplementing the diets of dairy cows with BS marginally affected animal performance and improved nitrogen metabolism. The level of supplementation and other factors, such as animal variation were discussed. (

A SNP in the 3′-untranslated region of AMPKγ1 may associate with serum ketone body and milk production of Holstein dairy cows

Yeast culture (YC) is widely used in dairy production to enhance milk yield and quality, yet effects vary due to differences in products, doses, and trial conditions. This meta-analysis evaluated the impact of YC supplementation on milk yield and composition in lactating Holstein cows, aiming to identify effective yeast culture types, dosages, and duration of use. A systematic search of PubMed, Web of Science, and CNKI for randomized controlled trials (RCTs) from 2000 to 2024 was conducted. Following PICOS criteria, 23 RCTs comprising 32 comparisons and over 3200 cows were included. Data were analyzed using RevMan 5.3 and Stata/MP 15.0 to compute standardized mean differences (SMD) and 95% confidence intervals with random-effects models. Subgroup and sensitivity analyses were performed. Results showed that YC supplementation significantly improved milk yield (SMD = 2.14), fat (SMD = 0.57), protein (SMD = 1.34), and lactose content (SMD = 0.61). Subgroup analysis revealed that supplementation with saccharomyces cerevisiae at a dosage of 10-50 g/d effectively increased milk yield during lactation 42-56 d. In contrast, during the lactation 21-30 d, different dosages of saccharomyces cerevisiae exerted differential effects on milk composition: supplementation at 60-120 g/d contributed to an increase in milk fat content, while supplementation at 10-50 g/d significantly enhanced milk protein level. Furthermore, lactose content was not significantly associated with the feeding period of saccharomyces cerevisiae; however, high-dose (>120 g/d) could significantly increase lactose content. Significant heterogeneity (I2 = 70.7-89.6%) was observed, largely due to strain and dose variations. In conclusion, YC effectively enhances milk production and composition, with optimal outcomes depending on yeast type, dose, and duration, providing evidence-based recommendations for targeted supplementation strategies.

Yield Response of Lactating Holstein Dairy Cows to Dietary Fish Meal or Meat and Bone Meal

Context Sugarcane is widely used as a forage source for dairy production in tropical areas worldwide. However, due to its low fibre degradability, large amounts of concentrates are needed to meet the energy requirements of high-producing cows, increasing production costs. Aims To evaluate how partially replacing sugarcane with cactus (Opuntia stricta [Haw.] Haw) cladodes affects nutrient intake and digestibility, feeding behaviour, protein efficiency, milk yield, and milk composition of Holstein dairy cows. Methods Ten lactating Holstein cows producing 22.04 kg/day (s.d. ± 1.94) were assigned to one of five diets in a duplicated 5 × 5 Latin square design. The diets were a control diet of sorghum silage and concentrates and four dietary treatments containing different proportions of cactus cladodes as a substitute for sugarcane (replacement levels of 0%, 17%, 34%, 52% on a DM basis). Diets were formulated to be isonitrogenous, and the roughage:concentrate ratio was 64:36 on a DM basis. Key results Milk yield and energy-corrected milk yield increased quadratically with an increasing amount of cactus cladodes in the diet. Maximum yields of 23.7 kg milk/day and 26.1 kg energy-corrected milk/day were achieved when 34.6% and 37.6% of sugarcane was replaced with cactus cladodes respectively. Milk protein and solids contents increased linearly, and there was no impact on fat and lactose content. Feed intake changed in a quadratic manner in response to an increased cactus cladode content, with maximum intakes being observed when cactus cladodes replaced 30% of sugarcane in the diet. Nutrient digestibility was unaffected by dietary treatments. Time spent on feeding was reduced and idling time was increased as the concentration of cactus cladodes increased in the diet. Conclusion Partial replacement of sugarcane with cactus cladodes can increase dairy cows’ milk yield without causing any detrimental effects on milk composition or other production-related variables. Implications Cactus cladodes can be an important forage source for dairy cows and other ruminants in the semiarid region of Brazil and other drylands across the globe.

This study was conducted to identify gene polymorphisms and to investigate the relationships of polymorphisms with yield and composition of milk from Holstein cows. Significant relationships of growth hormone (GH), leptin (LEP) and myogenic factor 5 (MYF5) gene polymorphisms with 305‐day milk yield were observed (P &lt; 0.01). Signal transducers and activators of transcription 5A (STAT5A) gene polymorphism did not show any significant relationships with investigated traits (P &gt; 0.05). With regard to the 305‐day milk yield, GH‐LV, LEP‐AA and AB and MYF5‐GG genotypes were found to be superior over the other genotypes. It was concluded based on present findings that GH, LEP and MYF5 genes could be used as candidate genes for milk yield of Holstein cows.

Simple SummaryNatural and processed fat supplements directly affect milk yield and composition in cows. Oilseed extrusion is a heat-treatment process used for seeds fed to ruminants to prevent rumen biohydrogenation of unsaturated fatty acids. This process increases postruminal fat absorption when compared with the effects of feeding whole oilseeds. Hence, we investigated the effects of feeding a mixture of extruded linseed and soybean on lactation performance, first service conception rate, and mastitis incidence in Holstein dairy cows. We found that supplementing dairy cow feed with a mixture of extruded linseed and soybean at a rate of 100 g/kg feed increased milk yield and both monounsaturated and polyunsaturated fatty acid content. However, incidences of clinical mastitis and first-service conception rates were not affected by extruded linseed and soybean supplementation.This study quantifies the effects of extruded linseed and soybean (ELS) dietary supplementation on milk yield, composition, and fatty acid profiles, as well as first-service conception rate in Holstein dairy cows. Seventy-eight open Holstein dairy cows were divided into two groups: (1) a control, which received a basal diet; and (2) a test group, which received a basal diet supplemented with the ELS (650 g/kg of extruded linseed and 150 g/kg of extruded soybean) at a rate of 100 g/kg. In the ELS group, milk yield per day and solid not fat (SNF) yield increased by 3.26% and 0.88%, respectively, in relation to the control. Percentage milk fat decreased significantly by 1.4% in the ELS group when compared with the control. The ELS supplement resulted in a decrease in saturated fatty acids (SFAs) and an increase in monounsaturated (MUFAs) and polyunsaturated fatty acids (PUFAs) in milk. In conclusion, the supplementation of dairy cow feed with 100 g/kg of ELS increases milk yield and milk unsaturated fatty acids (especially MUFAs and PUFAs). ELS supplementation also causes a decrease in percentage fat and SFA levels but does not affect the first-service conception rate or the incidence rate of mastitis.

Effects of dietary deoiled soy lecithin supplementation on milk production and fatty acid digestibility in Holstein dairy cows

The genes encoding the diacylglycerol O-acyltransferase (DGAT1) and leptin (LEP) became a functional candidate genes for lactation traits in cows. Several studies associated single nucleotide polymorphisms (SNP) in these genes with fat and protein content in milk, fat and protein yield, milk yield and some reproductive traits. Three reported SNPs in these genes were investigated in our study (DGAT1-K232A, LEP-R25C, LEP-A80V). One hundred and sixty-three primiparous dairy cows from one farm were genotyped. The milk yield, fat and protein yield, fat and protein content and the age at first calving were recorded. The frequencies of alleles and genotypes were assessed. The effect of genotypes on milk traits and age at first calving were studied using linear models. The assumption of the different allele frequencies resulting from selection aimed at milk yield was proved in DGAT1 and LEP-A80V. The significant effect (P&lt;0.01) of DGAT1 polymorphism was estimated only for the fat content. No significant effect of individual LEP polymorphism on milk trait or age at first calving was estimated. No significant effect of combination of LEP polymorphisms was estimated for those traits. The effect of DGAT1 on the age at first calving was indicated.

The aim was to estimate genetic parameters for milk urea (MU) concentration and its relationship with milk yield and compositions in Holstein dairy Cows. Edited data were 90,594 test-day records of milk yield and composition collected during 2015 to 2018 on 13,737 lactations obtained from 7,850 Holstein cows in 50 herds. Random regression test-day model was used to estimate genetic parameters. (Co)variance components were estimated with the Bayesian Gibbs sampling method using a single chain of 400,000 iterates. The first 50,000 iterates of each chain were regarded as a burn-in period. Mean (SD) of MU was 23.03 (5.99) and 22.41 (5.74) mg/dl in primiparous and multiparous cows, respectively. Average heritability estimates for daily MU was 0.33 (SD = 0.02) ranged 0.29 to 0.36 and 0.32 (SD = 0.03) ranged 0.27 to 0.34, respectively, for primiparous and multiparous cows. The mean (SD) genetic correlation between MU and milk yield, fat yield, protein yield, lactose yield, fat percentage, protein percentage, lactose percentage, and somatic cell score was, respectively, -0.02 (0.03), -0.02 (0.01), 0.01 (0.04), 0.01 (0.03), 0.00 (0.07), -0.03 (0.04), 0.00 (0.01), -0.11 (0.06) in primiparous cows. The corresponding values in multiparous cows were -0.01 (0.02), -0.01 (0.03), -0.04 (0.04), -0.04 (0.04), 0.04 (0.04), 0.04 (0.07), -0.03 (0.09), 0.06 (0.11), respectively. The results indicate that selection on MU is possible with no effect on milk yield or compositions, however, relationships between MU and other important traits such as longevity, metabolic diseases, and fertility are needed.

Effect of dietary supplements of biotin, intramuscular injections of vitamin B12, or both on postpartum lactation performance in multiparous dairy cows

Influence of corn silage hybrid type on lactation performance by Holstein dairy cows