Milk Composition In Dairy Cows Research Articles

Effects of seasonal factors on the milk composition of dairy cows in Tafawa Balewa L.G.A, Bauchi State

This study compared the nutrient composition of milk between cattle breeds of Bunaji, Rahaji, Sokoto gudali and Adamawa gudali for both rainy and dry season. One hundred questionnaires were administered to respondents and 5% had milk yield of 3litre/day. 55% recorded 2 litre/day of milk while 40% had the least yield of 1litre/day. That early lactation produces highest milk quantity. The result of laboratory analysis showed that season have effect on nutrient composition of cow milk. It was observed that the early dry season milk composition was better for Bunaji, Rahaji, Sokoto gudali except for Adamawa gudali. For rainy season comparison, early rainy season milk composition was better for Bunaji, Sokoto gudali, Adamawa gudali except for Rahaji. Moisture content in dry season (70.08%) was lower (P>0.05) than moisture content in rainy season (87.36%) for Bunaji breed, similar result was obtained for Rahaji, Sokoto gudali and Adamawa gudali. The energy content and carbohydrate were higher (P<0.05) in the dry season for Bunaji(132.15KCal and 14.06%), Rahaji (126.20KCal and 14.55%), Sokoto gudali (148.00KCal and 22.05%) and Adamawa gudali (135.18KCal and 20.99%). The crude protein of analysed milk was slightly higher (P<0.05) in rainy season for Bunaji (5.64%), but higher in dry season for Rahaji (5.48%), Sokoto gudali (7.47%) and Adamawa gudali (6.01%). ether extract were all higher in dry season for breeds except Sokoto gudali. crude fibre was higher (5.34% Bunaji, 5.28% Rahaji, 3.45% S. gudali, 4.04% A. gudali) in dry season for all breed. Milk in all the four breeds of cattle have more of the nutrient composition in dry season at a higher level. Seasonal variation and climatic factors like rain, humidity and wind affects milk composition and cattle production in terms of pasture availability and the quality. The herders need to be encouraged to engaged in modern way of herding by possessing land for farming, they can rent it in exchange of crop residues and they can cultivate their personal farm produce and faster yielding pasture can be cultivated.

Effects of Brown Seaweed (Ascophyllum nodosum) Supplementation on Enteric Methane Emissions, Metabolic Status and Milk Composition in Peak-Lactating Holstein Cows.

The dairy industry contributes significantly to anthropogenic methane emissions, which have an impact on global warming. This study aimed to investigate the effects of a dietary inclusion of brown seaweed Ascophyllum nodosum on enteric methane emissions (EMEs), hematological and blood biochemical profiles, and milk composition in dairy cows. Eighteen Holstein cows were divided into three groups: CON (non-supplemented cows), BS50 (50 mL of 10% A. nodosum), and BS100 (100 mL of 10% A. nodosum). In each cow, measurements of EME, dry matter intake (DMI), and milk yield (MY), as well as blood and milk sampling with respective analyzes, were performed before supplementation (P1), after 15 (P2) days, and after 30 (P3) days of supplementation. A. nodosum reduced (p < 0.05) methane production, methane yield, and methane intensity in both BS50 and BS100, and raised DMI (p < 0.05) only in BS50. Total bilirubin (p < 0.05) was higher in BS50 compared to CON cows in P2, and triacylglycerols were lower (p < 0.05) in BS50 than in CON cows in P3. Higher milk fat content was found in BS50 than in CON cows in P3. C16:0 proportions were higher (p < 0.05) in BS50 and BS100 than in CON cows, while C18:3n-3 was higher (p < 0.05) in BS100 than in BS50 and CON cows in P3. Dietary treatment with A. nodosum reduced EMEs and showed the potential to increase DMI and to improve energy status as well as milk composition in peak-lactating dairy cows.

Variations in milk, udder skin, and fecal microbiota and their relationships with blood metabolites and milk composition in dairy cows.

This study examined the milk, udder skin, feces, and bedding microbiota in a dairy farm. Blood metabolites concentration and milk composition were also determined to examine their relationship with variations in the microbiota. Samples were collected from 10 healthy cows during the summers of 2018 and 2020. Milk protein, fat, and solid-not-fat contents were higher, and blood urea nitrogen and nonesterified fatty acid levels were lower in the 2020 samples. Principal coordinate analysis demonstrated that milk, udder skin, and fecal microbiota were separate groups. Year-to-year differences were distinct for milk and udder skin microbiota; however, the fecal microbiota of the 2018 and 2020 samples were similar. The bedding microbiota grouped with the udder skin microbiota of the 2018 samples. Although nonpathogens found as prevalent taxa in udder skin microbiota were likely to be found as abundant taxa in milk microbiota, selection and elimination occurred during transmission. Network analysis suggested that bacterial taxa of milk, udder skin, and fecal microbiota were unrelated to blood metabolites and milk composition, regardless of pathogens or nonpathogens.

Effect of oil and tannin supplementation on intake, milk yield and milk composition of dairy cows

Supplementation of oils rich in polyunsaturated fatty acids and condensed tannin has been known as a feeding approach to improve healthy fatty acids in ruminant milk, but it can cause an adverse effect on feed intake and animal performance. This study aimed to investigate the effect of feeding oil alone or in combination with grape seed tannin extract (GSTE) on feed intake, milk yield and composition of dairy cows. Sixteen low production dairy cows in mid-lactation fed a basal diet based on agro-industrial by-products were arranged to a completely randomized design for a 6-week duration. Animals were fed basal diet without oil and GSTE inclusion (CON), 2.5% DM soybean oil (SBO), 2.5% DM blend of soybean oil and tuna fish oil at 3:2 w:w (SFO), or SFO plus 0.4% DM GSTE (OCT). The results showed that DM intake was reduced (P &lt; 0.05) by 14.4% in OCT relative to CON. Milk yield was not affected by oil and GSTE supplementation, but SFO and OCT strongly depressed milk fat, protein and total solids (P &lt; 0.001). In conclusion, in a low production cow diet based on agro-industrial by-products containing high lipid, supplementation of oil and GSTE should be considered in the aspects of feed intake and milk composition.

Effect of Brazilian spinach (Alternanthera sissoo) pellet supplementation and dietary ratios on rumen characteristics, microorganisms, methane production, milk yield, and milk composition in dairy cows.

The aim of the previous research was to evaluate the effects of Brazilian spinach pellet (BSP) supplementation and dietary ratios on rumen characteristics, methane estimation, and milk production in dairy cows. Four crossbred Thai dairy cattle, with Holstein Friesian (HF) cows with a body weight of 442 ± 50 kg were assessed in a 2 × 2 factorial in a 4 × 4 Latin square design to obtain diets; factor A was the roughage (R) to concentrate (C) ratio at 40:60 and 30:70, and factor B was level of BSP supplantation at 2% and 6% of dry matter (basis) intake (DMI). R:C ratio and supplementation of BSP had no interaction effect on DMI and nutrient digestibility. On DM, organic matter (OM), crude protein (CP), and acid detergent fiber (ADF) intake, the R:C ratio increased (p < 0.05). The digestibility of OM improved (p < 0.05) when cows were fed a R:C ratio of 30:70. On pH, ammonia-nitrogen, protozoal population, and blood urea-nitrogen, there were no interactions between the R:C ratio and BSP supplementation. Increasing the BSP supplementation to 6% (p < 0.01) decreased the protozoal population. The R:C ratio of 30:70 increased total volatile fatty acid (VFA) and propionate (C3) concentrations while decreasing the acetate (C2) to C3 ratio and methane (CH4 ) estimation (p < 0.01). The average concentration of total VFA has increased by 114.46 mmol/L for 6% of BSP supplementation. Increased BSP supplementation increased the C3 concentration while decreasing the C2:C3 ratio and CH4 emissions (p < 0.05). The R:C ratio and BSP supplementation had no interaction effect on milk yield, 3.5% fat-corrected milk (FCM), or milk composition. The R:C ratio of 30:70 increased milk yield (p < 0.05) to the highest level of 12.18 kg/day. In conclusion, the diet containing a R:C ratio of 30:70 increased feed intake, milk yield, BUN, total VFA, and C3 concentration, and decreased the C2:C3 ratio and CH4 emission. BSP supplementation at 6% could increase TVFA and C3 concentrations while decreasing the protozoal population and CH4 estimation.

A preliminary study on milk yield, composition and economic profitability of alfalfa pellets and long ryegrass fibre (Kit N°10) in a total mixed ratio in lactating dairy cows

This study was developed to improve the qualitative and quantitative performance of milk production of dairy cows. The aim of this work is to evaluate the impact of feeding Kit N°10 based on alfalfa pellets and long ryegrass fibre produced by “La Romana Farine srl” on the milk yield and milk composition in dairy cows. Kit N°10 was administered thrice daily to six multiparous Holstein–Friesian cows assigned to two treatments including control and staple feed Kit N°10. Feeding the Kit N°10 as basic ration improved animal performance by increasing significantly (p

Indicators of productivity and milk composition of dairy cows in different grazing seasons depending on the daily supply of grass: overview

Indicators of productivity and milk composition of dairy cows in different grazing seasons depending on the daily supply of grass: overview

Fermented Rubber Seed Kernel with Yeast in the Diets of Tropical Lactating Dairy Cows: Effects on Feed Intake, Hematology, Microbial Protein Synthesis, Milk Yield and Milk Composition.

Simple SummaryRubber seed kernels do not contain sufficient levels of crude protein to serve as a primary source of crude protein in ruminant diets. Yeast has been used to improve the nutritional value of feedstuffs, particularly their protein content, and to diminish their anti-nutritional components. Our earlier studies demonstrated that rubber seed kernels that had undergone yeast fermentation had enhanced levels of crude protein, decreased fiber content, and could be provided to dairy heifers as a source of protein. The current findings showed that the addition of yeast-fermented rubber seed kernels had no negative effects on the hematology, milk production, milk composition, or feed intake. Hence, yeast-fermented rubber seed kernels could be used as a source of protein in the diets of lactating dairy cows.The objective of the present study was to analyze the effects of yeast-fermented rubber seed kernels (YERSEK) on the feed intake, hematology, microbial protein synthesis, milk yield, and milk composition in dairy cows. Six crossbred Holstein Friesian (HF) × Thai lactating dairy cows with 110 ± 10 days in milk were randomly assigned to three different amounts of YERSEK at 0%, 10%, and 20% in a concentrate mixture using a 3 × 3 repeated Latin square design. Cows were fed with concentrate diets at a concentrate-to-milk yield ratio of 1:1.5, with rice straw fed ad libitum. The inclusion of YERSEK did not adversely affect feed intake, nutrient intake, or digestibility (p > 0.05), whereas ether extract intake and digestibility linearly increased in dairy cows receiving YERSEK (p < 0.01). Increasing YERSEK levels did not adversely affect blood urea nitrogen (BUN) levels, hematological parameters, or microbial protein synthesis (p > 0.05). Supplementation of YERSEK did not influence milk production, lactose, or protein levels (p > 0.05). However, milk fat and total solids decreased linearly (p < 0.05) with the addition of YERSEK. In conclusion, in a concentrate diet, YERSEK could be used as a protein source without negative effects on feed intake, digestibility, hematology, microbial protein synthesis, or milk yield. However, it reduced the milk fat and total solids of tropical lactating dairy cows.

Oilseed Supplementation Improves Milk Composition and Fatty Acid Profile of Cow Milk: A Meta-Analysis and Meta-Regression.

Simple SummaryMilk is the most consumed dairy product in the world and for humans is one of the major sources of beneficial biocomponents. Lipids from oilseeds can be transferred to milk from cows or converted to other biomolecules with nutraceutical effects, resulting in healthier milk. However, there is a great uncertainty with regard to the effect of some variables related to the animal, the seed, the level of inclusion and the characteristics of the diet. The objective of this review was to show the effect of the inclusion of oilseeds in the diet of dairy cows on milk yield, milk components and the fatty acid profile in milk. A systematized search was carried out of published articles with high scientific rigor where the feeding strategy in dairy cows was the inclusion of oilseeds in the diet. Milk from oilseed-fed cows contained a higher amount of unsaturated 18-carbon fatty acids, including omega-3 series, rumenic and vaccenic fatty acids. Overall, supplementation with oilseeds in the cow’s diets increases the concentration of biomolecules in milk with potential positive effects on human health.Oilseed supplementation is a strategy to improve milk production and milk composition in dairy cows; however, the response to this approach is inconsistent. Thus, the aim of this study was to evaluate the effect of oilseed supplementation on milk production and milk composition in dairy cows via a meta-analysis and meta-regression. A comprehensive and structured search was performed using the following electronic databases: Google Scholar, Primo-UAEH and PubMed. The response variables were: milk yield (MY), atherogenic index (AI), Σ omega-3 PUFA, Σ omega-6 PUFA, fat, protein, lactose, linoleic acid (LA), linolenic acid (LNA), oleic acid (OA), vaccenic acid (VA), conjugated linoleic acid (CLA), unsaturated fatty acid (UFA) and saturated fatty acid (SFA) contents. The explanatory variables were breed, lactation stage (first, second, and third), oilseed type (linseed, soybean, rapeseed, cottonseed, and sunflower), way (whole, extruded, ground, and roasted), dietary inclusion level, difference of the LA, LNA, OA, forage and NDF of supplemented and control rations, washout period and experimental design. A meta-analysis was performed with the “meta” package of the statistical program R. A meta-regression analysis was applied to explore the sources of heretogeneity. The inclusion of oilseeds in dairy cow rations had a positive effect on CLA (+0.27 g 100 g−1 fatty acids (FA); p < 0.0001), VA (+1.03 g 100 g−1 FA; p < 0.0001), OA (+3.44 g 100 g−1 FA; p < 0.0001), LNA (+0.28 g 100 g−1 FA; p < 0.0001) and UFA (+8.32 g 100 g−1 FA; p < 0.0001), and negative effects on AI (−1.01; p < 0.0001), SFA (−6.51; p < 0.0001), fat milk (−0.11%; p < 0.001) and protein milk (−0.04%; p < 0.007). Fat content was affected by animal breed, lactation stage, type and processing of oilseed and dietary NDF and LA contents. CLA, LA, OA and UFA, desirable FA milk components, were affected by type, processing, and the intake of oilseed; additionally, the concentrations of CLA and VA are affected by washout and design. Oilseed supplementation in dairy cow rations has a positive effect on desirable milk components for human consumption. However, animal response to oilseed supplementation depends on explanatory variables related to experimental design, animal characteristics and the type of oilseed.

Meta-Analysis of Rumen-Protected Methionine in Milk Production and Composition of Dairy Cows.

Simple SummaryIn terms of amino acid nutrition of dairy cows, many scholars have shown that adding rumen-protected methionine to dairy cow feed can improve milk yield and milk components such as milk protein, lactose and milk fat, but the research of some scholars is inconsistent. This paper aims to summarize and analyze all the research contents through meta-analysis and comprehensively understand the impact of rumen-protected methionine on the milk yield and milk composition of dairy cows. The results show that adding rumen-protected methionine to cow feed did not significantly improve milk yield nor the lactose concentration in milk but did improve the fat and protein concentrations in milk, and the effects were better in the high-protein feed than that in the low-protein feed.This study aims to evaluate the influence of rumen-protected methionine (RPM) on the milk yield and milk compositions of dairy cows by employing a meta-analysis method. The articles in the publication databases between January 2010 and January 2022 which reported on various concentrations of RPM supplements in dairy cow diets and then monitored the milk yield and milk compositions were searched. A total of 14 studies were included, covering 27 treatments with a total of 623 dairy cows. Comprehensive Meta-Analysis V3 was used for statistical analysis, the forest map was drawn by the standard mean difference (SMD) with a 95% confidence interval (95% CI), and the SMD was calculated by a random effect model. The dose effect curve was drawn by fitting the SMD and RPM dose of each study to explore the optimal dosage of RPM. Compared with the basal diet, the RPM supplement significantly increased the percentages of milk fat (SMD (95% CI): 1.017% [0.388, 1.646]) and milk protein (SMD (95% CI): 0.884 [0.392, 1.377]). However, the milk yield (SMD (95% CI): 0.227 kg/d [−0.193, 0.647]) and lactose concentration (SMD (95% CI): 0.240% [−0.540, 1.020]) were not affected. The subgroup analysis found that the effect of the RPM supplement on the milk fat and milk protein was greater in the high-protein feed than in the low-protein feed. Multiple regression analysis showed that feeding RPM significantly improved the milk yield and milk protein percentage of dairy cows. The results of the dose–effect analysis show that the optimal range for the RPM was 7.5–12.5 g/d. RPM supplements in a dairy diet can improve the milk protein percentages and milk fat percentages of dairy cows.

64. Association of teat hyperkeratosis on gross milk composition in dairy cows

64. Association of teat hyperkeratosis on gross milk composition in dairy cows

​Effect of Dietary Inclusion of Cumin Seed (Cuminum cyminum) on Voluntary Feed Intake, Milk Yield, Milk Quality and Udder Health of Dairy Cows

Background: Plants containing essential oils can be a cost-effective means of improving efficiency of milk production and optimizing milk composition of dairy cows. Cuminum cyminum (green cumin) belongs to the Apiaceae family and is a well-known herbal medicine in Iran. The medicinal properties of cumin may have beneficial effects on milk production. However, very few studies have been reported whereby cumin has been fed to ruminants. Therefore, the present study is design to investigate the effect of cumin supplementation on milk yield, milk quality and udder health of lactating dairy cows. Methods: Twelve multiparous lactating cows at early stage of lactation was selected and randomly allotted to two equal groups (n=6) on the basis of milk yield. In addition to normal routine feeds and fodders, cows in groups T1 was fed cumin seed @ 50 g/d/head for 90 days. Fortnightly body weight was determined on the basis of body measurement of animals. All feed samples was analysed for proximate composition, Ca and P. The daily milk yield (kg/d) of individual cows was recorded by weighing. Milk samples were collected after complete milking and thorough mixing for determination of milk composition. Udder health was monitored by MCMT (modified california mastitis test), measuring milk pH and SCC (somatic cell count) at fortnightly intervals. Result: The results indicated that overall mean body weight, average DMI was statistically (P greater than 0.05) similar in both the groups. The average milk yield (kg) of animals was statically non significant (P greater than 0.05) but numerically 20.64% higher milk yield was observed in cumin seed supplemented group than control group. There was no effect of cumin supplementation on chemical composition (Fat, TS, SNF, Lactose and Protein) of milk in dairy cows. Overall mean milk pH and somatic cell count (SCC) in both the groups was statically similar but numerically lower in treatment group. The overall mean (%) of MCMT positive animals was 14.29 and 9.52 in T0 (Control) and T1 (Treatment) groups, respectively. From the results it can be deduced that the cumin seed (Cuminum cyminum) supplementation improves milk yield by 20.64%. However, it has no effect on composition of milk in dairy cows. Supplementation improved the udder health and found no effect on dry matter intake (DMI) in dairy cows.

Effects of calcium propionate on milk performance and serum metabolome of dairy cows in early lactation

Calcium propionate is a source of energy and calcium for alleviating negative energy balance and hypocalcemia. The objective of this study was to investigate changes in milk composition and serum metabolites associated with calcium propionate fed to postpartum dairy cows for 5 weeks. Thirty-two multiparous Holstein cows after calving were randomly allocated to control (CON), low calcium propionate (LCaP), medium calcium propionate (MCaP) and high calcium propionate (HCaP) groups. The dairy cows in the four groups were given oral drench with 0, 200, 350, 500 g/d calcium propionate per cow, respectively, from calving to d 35 in early lactation. Milk yield increased quadratically with increasing amounts of calcium propionate; being the greatest in the MCaP group. Supplementation with calcium propionate did not affect milk composition of dairy cows in early lactation. Serum glucose, insulin, glucagon, β-hydroxybutyrate, calcium, magnesium, calcitonin and calcitriol were not affected by calcium propionate supplementation. Serum non-esterified fatty acid tended to decrease linearly and parathyroid hormone increased quadratically with treatment. Serum alanine aminotransferase concentration was the lowest in the MCaP group and aspartate aminotransferase was the highest in the HCaP group among the four groups. Compared with the CON group, serum alkaline phosphatase activity decreased linearly and quadratically with the increasing calcium propionate supplementation. Supplementation with increasing amounts of calcium propionate quadratically decreased the activity of serum total antioxidant capacity, glutathione peroxidase, superoxide dismutase and catalase, however, quadratically increased concentration of malondialdehyde. Calcium propionate affected serum metabolites were mainly involved in bile acid metabolism from the metabolomic results. The 350 g/d calcium propionate feeding level could significantly improve milk performance but decrease antioxidant capacity of dairy cows as well. The effects of calcium propionate on milk performance and serum metabolites in early lactation cows was related to the regulation of serum bile acids metabolism.

Genetic variation in the OPN gene affects milk composition in Chinese Holstein cows

The aim of this study was to investigate the association between genotypes and haplotypes of OPN, and milk composition in dairy cows. A total of 317 Chinese Holstein cows were genotyped via DNA sequencing in this study. Three single nucleotide polymorphisms (SNPs), g.2916G > A, g.58675C > T and g.58899C > A, and eight haplotypes were identified. Of the eight possible haplotypes, four haplotypes i.e., Hap2 (ACC; 55.30%), Hap6 (GCC, 15.6%), Hap1 (ACA, 13.6%) and Hap4 (ATC, 5.70%), were considered to be major with a cumulative estimated frequency of >90%. Single markers (g.2916G > A and g.58899C > A) and Haplotype Hap6/4 were found to be associated with an increase in butter-fat percentage (p < 0.05). Taken together, our results provided evidence that polymorphisms in OPN are associated with milk composition, and could potentially be used for marker-assisted selection in Chinese Holstein cows.

Relationship between Temperament and Stage of Lactation, Productivity and Milk Composition of Dairy Cows.

Simple SummaryCattle temperament can be described as a response to changes in the environment and is crucial for successful herd management using innovative technologies. Despite the economic aspects of animal productivity and welfare, there is still a lack of objective evidence for a wider use of temperament in dairy cattle breeding programmes. The aim of this study was to evaluate the relationship between cow temperament and milk indices describing cow productivity, metabolic status and mastitis resistance. The coefficient of heritability of temperament was determined. Only a small part of the phenotypic changes in this indicator in the analysed population was associated with genetic factors; however, the correlation of cow temperament with milk lactose and somatic cells suggests that temperament could be used in sustainable breeding programmes, giving priority to animal welfare and health. A statistically significant decrease in temperament scores with increasing lactation periods was only found in primiparous cows. It is also argued that changes in milk production, milk composition and quality associated with mastitis and a cow’s metabolic status should be taken into account when assessing the cow’s temperament, as these factors can affect the welfare and behaviour of an animal, and therefore the expression and intensity of their reaction to their environment.The aim of this study was to assess the relationship between temperament and milk performance in cows at different stages of lactation, describing their productivity, metabolic status and resistance to mastitis. This study showed that with increasing lactation, cows’ temperament indicators decreased (p < 0.001) and they became calmer. The highest temperament score on a five-point scale was found in cows between 45 and 100 days of lactation. In the group of pregnant cows, we found more cows (p = 0.005) with a temperament score of 1–2 compared with non-pregnant cows A normal temperament was usually detected in cows with lactose levels in milk of 4.60% or more and when the somatic cell count (SCC) values in cow milk were <100,000/mL and 100,000–200,000/mL, with a milk fat-to-protein ratio of 1.2. A larger number of more sensitive and highly aggressive cows was detected at a low milk urea level. In contrast to a positive phenotypic correlation (p < 0.05), this study showed a negative genetic correlation between the temperament of cows and milk yield (p < 0.001). Positive genetic correlations between temperament scores and milk somatic cells (p < 0.001) and milk fat-to-protein ratio (p < 0.05) were found to indicate a lower genetic predisposition in cows with a calmer temperament to subclinical mastitis and ketosis. On the other hand, the heritability of temperament (h2 = 0.044–0.100) showed that only a small part of the phenotypic changes in this indicator is associated with genetic factors.

Annatto seeds as Antioxidants Source with Linseed Oil for Dairy Cows.

Simple SummaryCurrently, functional foods are gaining widespread attention. Polyunsaturated fatty acids (PUFA) and antioxidant compounds have beneficial effects on health. It is possible to increase the concentration of these compounds in the milk obtained from dairy cows by manipulating their diets, thereby improving milk quality and consequently the health of animals and humans who consume this milk. Annatto seed (Bixa orellana L.) is a source of antioxidants, whereas linseed oil is rich in omega 3 fatty acid. We evaluated the inclusion of annatto seeds and linseed oil in the diets of dairy cows and their effects on dry matter intake (DMI), nutrient digestibility, milk yield, milk composition and antioxidant capacity in milk and blood. There was no effect of treatment on nutrient digestibility and antioxidant capacity, but the addition of annatto seeds decreased DMI and milk production and linseed oil supplementation reduced milk fat content. This study aimed to evaluate the effects of annatto seeds, linseed oil and their combination on DMI, apparent total tract digestibility, antioxidant capacity and milk composition of dairy cows. Four lactating Holstein cows (120 ± 43 days in milk; 15.98 ± 2.02 kg of milk/day, mean ± SD) were allocated in a 4 × 4 Latin square with a 2 × 2 factorial arrangement (with or without annatto seeds at 15 g/kg of dry matter (DM); with or without linseed oil at 30 g/kg of DM) and provided four different diets: control (no annatto seeds or linseed oil); annatto seeds (15 g/kg of DM); linseed oil (30 g/kg of DM); and a combination of both annatto seeds and linseed oil. Annatto seeds reduced DM intake, and milk yield, protein and lactose, but increased content of fat, total solids and short chain fatty acid, with no effect on total antioxidant capacity of milk. Linseed oil supplementation decreased medium chain fatty acid proportion and n-6/n-3 ratio, conversely it increased long chain fatty acids and n-3 fatty acid content of milk, ether extract intake and total-tract digestibility. Thus, linseed oil supplementation in dairy cow diets improved the milk FA profile but decreased milk fat concentration, whereas annatto seeds did not influence antioxidant capacity and depressed feed intake and milk yield.

MILK YIELD AND MILK COMPOSITION OF TECHNOLOGICAL GROUPS OF COWS IN THE DAIRY FARM LLP «KAMYSHENKA»

The article deals with the issues of milk productivity and milk composition of dairy cows divided into technological groups in order to increase milk productivity and improve the milk composition of cows of the dairy farm "Kamyshenka" LLP of the Akmola region. The authors present data on the structure of the herd, the specific weight of cows in which was insufficient for dairy farms.The issues of monitoring the milk productivity of cows of all technological groups, divided by the level of milk yield, physiological indicators and health status, which showed an increase in productivity in comparison with last year's indicators, were also considered. A study of the chemical composition for the fat content and protein content of milk from dairy cows was also conducted. At the same time, a study of the health of the udder of cows was conducted on the presence of somatic cells in milk on the analyzer "Somatos Mini". Somatic cell counts were within the normal range.

Effects of photoperiod and light intensity on milk production and milk composition of dairy cows in automatic milking system.

The purpose of this study was to determine the effects of photoperiod and light intensity on milk production, milk composition, hormones levels and blood metabolites indices of Korean Holstein dairy cows in automatic milking system (AMS). A total of 24 Holstein dairy cows were selected and used to four subsequent treatments for the experimental periods of 60 days. The light programs consisted of (1) Control: the natural photoperiod with 14.2 h of the light period and 9.4 h of the dark period (below 10 Lux); (2) T1: 16 h of the long day photoperiod (LDPP) with 50 Lux of light; (3) T2: 16 h of LDPP with 100 Lux of light; and (4) T3: 16 h of LDPP with 200 Lux of light, respectively. Importantly, there was a significant difference in the thurl activity of dairy cows between the different light intensity programs (p < 0.05). Milk yield was higher in T1 and T2 (40.80 ± 1.71 and 39.90 ± 2.02 kg/d, respectively) than those of Control and T3 (32.18 ± 1.51 and 35.76 ± 2.80 kg/d, respectively) (p < 0.05), but DMI was lower in T1, T2, and T3 compared to Control (p < 0.05). Also, milk fat percentage, the contents of milk fat and total solids were higher in T2 than those in the others (p < 0.05). The average daily melatonin level in milk was high to T3 (28.20 ± 0.43 pg/mL), T2 (24.62 ± 0.32 pg/mL), T1 (19.78 ± 0.35 pg/mL), and Control (19.36 ± 0.45 pg/mL) in order (p < 0.05). Also, the cortisol levels in milk and blood were lower in treatment groups than in Control (p < 0.05). The results of this study showed that it will be effective to improve the milk yield and milk composition, and to reduce the stress of dairy cows when the light conditions regulate to extend the photoperiod to 16 h at a light emitting diode (LED) intensity of 100 Lux under the AMS in dairy farm.

Effects of the circadian rhythm on milk composition in dairy cows: Does day milk differ from night milk?

Metabolism in most organisms can show variations between the day and night. These variations may also affect the composition of products derived from livestock. The aim of the present study was to investigate the difference in composition between the day milk and night milk of dairy cows. Ten multiparous Holstein cows (milk yield = 25.2 ± 5.00 kg/d) were randomly selected during mid lactation. Milk samples were collected at 0500 h ("night milk") and 1500 h ("day milk") and analyzed to determine their composition. Mid-infrared spectroscopy was used to analyze macronutrient content of milk. Metabolomics and lipidomics were used to detect and analyze small molecules and fatty acids, respectively. An automatic biochemical analyzer and ELISA kits were used to determine biochemical indicators, as well as antioxidant and immune parameters in the milk. Though milk fat, protein, lactose, and total milk solids were not different between day milk and night milk, small molecules, metabolites and lipids, and hormones and cytokines differed between day milk and night milk. Regarding biochemical and immune-related indicators, the concentrations of malondialdehyde, HSP70, and HSP90 in night milk were lower than that in day milk. However, interferon-γ levels were higher in night milk. Additionally, night milk was naturally rich in melatonin. Lipidomics analyses showed that the levels of some lipids in night milk were higher than those in day milk. Metabolomics analyses identified 36 different metabolites between day milk and night milk. Higher concentrations of N-acetyl-d-glucosamine, cis-aconitate, and d-sorbitol were observed in day milk. However, the other 33 metabolites analyzed, including carbohydrates, lipids, AA, and aromatic compounds, showed lower concentrations in day milk than in night milk. The present findings show that the composition of night milk differs considerably from that of day milk. Notable changes in the circadian rhythm also altered milk composition. These results provide evidence to support the strategic use and classification of day milk and night milk.

Comparative evaluation of the milk composition of dairy cows in the Volgograd region

The article presents the results of determining the indicators of milk productivity of dairy cows in the Volgograd region. The studies processed the data of monthly control milking of five large agricultural enterprises of the region (LLC JV “Donskoe” Kalachevsky district, PZK “Put Lenina” Surovikinsky district, “Vostok” Nikolaevsky district, “PZK named after Lenin” Surovikinsky district, FSUE “Irrigated” Sovetsky district ). A comparative characteristic of the milk yield of the presented breeds of cattle in different periods of the year is given. Physicochemical definitions of milk quality indicators were carried out according to generally accepted methods - fat content (GOST R ISO 2446-2011) and protein (GOST 23327-98). A comparative analysis of the fat and protein content in the milk of dairy cows by periods of the year is presented. To analyze the chemical composition of milk samples by inductively coupled plasma mass spectrometry (ICP-MS), a Nexion 300D quadrupole mass spectrometer (Perkin Elmer, USA) was used. The determination of the chemical composition of milk samples by inductively coupled plasma atomic emission spectrometry (ICP AES) was carried out using an Ortima 2000DV atomic emission spectrometer (Perkin Elmer, USA). The results obtained showed the content of chemical elements in the milk of cows in the summer period within the limits of permissible concentrations, including the content of heavy metals (cadmium, mercury, lead, arsenic). Studies carried out with milk samples obtained from animals from all experimental farms have shown that the controlled indicators of milk quality, the content of chemical elements correspond to regulatory documents and raw milk of all farms is recommended for use in the production of all types of fermented milk and dairy products.