Milk Production Of Cows Research Articles

The Effect of Variation in Dietary Cation-Anion Difference on Calcium Status, Blood Metabolites and Rumen Activity during the Transition Period of Holstein Dairy Cows

A negative dietary cation-anion difference (DCAD) induces a compensated metabolic acidosis, stimulating calcium (Ca) absorption and mobilization before calving, thereby decreasing clinical and subclinical hypocalcemia postpartum. The study was designed to determine the effects of varying pre- and postpartum DCAD diets on serum total calcium, ionized calcium, blood and ruminal fluid metabolites, and milk production in prepartum and postpartum Holstein cows. Fifty-four multiparous dry Holstein cows n= 54, were enrolled in a completely randomized block experimental design at 29 days prior to expected parturition through 86 days in milk. A 3 x 2 factorial arrangement of treatments was utilized. Three DCAD levels were fed precalving (0, -120 and -200 mEq/kg DM), n=18 cows per treatment and two DCAD levels were fed post calving (+200 and +400 mEq/kg DM), n=27 cows per treatment. Prepartum urine pH was lower for cows fed -200 DCAD compared with those fed -120 or 0 DCAD. Postpartum urine pH was higher for cows fed +400 mEq/kg compared to cows fed +200 mEq/kg DCAD. Prepartum serum total calcium, ionized calcium, and hydroxyproline was highest for cows fed -200 DCAD compared to those fed -120 and 0 DCAD. Parathyroid hormone was highest for cows fed 0 DCAD compared to those fed -120 and -200 DCAD. Prepartum dry matter intake (DMI) was lower for -200 and -120 DCAD compared with 0 DCAD. Postpartum DMI was not different among treatments. Pre- and postpartum DCAD treatments did not affect total milk yield or milk fat, percentage of milk protein not affected by different pre-and postpartum DCAD levels. Prepartum anionic diets lowered urine pH and parathyroid hormone and raised serum hydroxyproline, resulting in improved Ca availability after parturition. Postpartum blood metabolites were unaffected in cows given positive DCAD (+200 and +400 mEq/kg DM). Calves born to cows fed low DCAD had no change in calf bieth weight. Colostrum amount and IgG concentrations were unaffected by treatments. No effects of pre-or postpartum DCAD treatments were observed for milk yield and fat-corrected milk. Feeding prepartum an acidogenic diet improved postpartum Ca status in multiparous Holstein cows.

Correlations of reproduction and productive traits in Holstein cows during dynamics on lactations

The task facing livestock breeders is to get a calf from each cow during the calendar year. Insemination of cows in the fi rst two months after calving is a necessary condition for increasing the rate of reproduction of livestock on the farm and increasing the economic effi ciency of the dairy industry. The purpose of the work was to evaluate the correlations between reproduction and productive traits in dairy cattle of Holstein breed, taking into account age in lactations. It was established as a result of the research that the herd has a large number of young cows in their fi rst and second lactations. The highest productivity indicators were found in cows in the third lactation, then there was a decrease in milk yield until the end of their use with slight fl uctuations in the direction of increase or decrease in milk yield, but in any case they turned out to be lower than in the third lactation. The mass fraction of fat in milk is a fairly stable indicator, as is the mass fraction of protein. The duration of the period of open days generally exceeded the optimal norms by 13–24 days or 14,4–26,7 %. This leads to the increase in the duration of lactation and the calving interval. The reproductive effi ciency coeffi cient ranged from 0,97 (9 and 10 lactations) to 0,91 (1, 5 and 11 lactations) and was mostly below 0,95, but tended towards this indicator. It can be concluded that the breeding stock in the dairy cattle herd of the breeding farm has satisfactory reproductive traits and there are certain problems with reproduction. The reliable influence of the duration of the period of open days on the milk productivity of cows has not been determined. Based on milk yield during early lactation we can predict about the further productivity of cows.

The effect of the gene of the main fibroblast growth factor (FGF2) on the dairy productivity of Holstein cattle

The effect of polymorphism of the gene of the basic fibroblast growth factor (SNP11646 A/G) on the milk production of Holstein cows in the conditions of the Republic of Tatarstan was studied. The DNA of 270 full–aged cows was genotyped by PCR - PDRF. As a result, two FGFA – 0,591 and FGFG – 0,409 alleles were identified; and three FGFAA genotypes – 19,6% (53 goals) and FGFAG – 42,6% (115 goals), FGFGG – 37,8% (102 goals). The highest milk yield for full lactation and for 305 days of lactation, a high coefficient of lactation was noted in individuals with the genotype FGF2AG. The best milk quality indicators (high protein content, fewer somatic cells) were found in animals homozygous for the A allele. All cows have a high stable and smoothly decreasing lactation curve, the coefficient of lactation stability is higher for the GG genotype.

Dairy productivity of Holstein cattle with different genotypes of the osteopontin gene (<i>OPN</i>)

The study was conducted in order to study the polymorphism of the osteopontin gene (OPN) and to evaluate the indicators of milk productivity of Holstein first-calf cows with different genotypes. The work was carried out in the agricultural complex "Plemzavod im. Lenin" of the Atninsky district of the Republic of Tatarstan and the laboratory of the Department of Physiology, Biochemistry, Genetics and Animal Nutrition of the TatNIISKh FIT KAZNTS RAS. Genotyping was carried out by PCR-PDRF at the locus of the OPN-Bse1 I gene. The analysis of the genetic structure showed that the studied population is polymorphic by the OPN gene. The distribution of alleles and genotypes was as follows: C-0.432 and T0.568; CC – 14.3% (37 goals), CT - 57.8% (149 goals) and TT - 27.9% (72 goals). The highest milk yield for 305 days of lactation and a high yield of milk protein was observed in individuals with the CC genotype. During DNA testing of 258 Holstein firstcalf cows by PCR-PDRF of osteopontin gene polymorphism (OPN), it was revealed that the studied cattle population is polymorphic and is represented by all alleles and genotypes. According to the content of the mass fraction of fat and the yield of milk fat, a statistically significant superiority is observed in animals with a heterozygous CT genotype. It has been established that the C allele has a positive effect on the signs of milk productivity and the qualitative composition of milk.

PRODUCTION POTENTIAL OF DAIRY CATTLE BREEDING IN THE KRASNOYARSK REGION: A NEW APPROACH TO ITS FORMATION AND EFFECTIVE USE IN CONDITIONS OF DIGITAL TRANSFORMATION OF THE ECONOMY

Recently, more and more attention has been paid to the development of the agrarian sector of the Russian economy, as well as the formation of conditions necessary for the dynamic evolution of its sectors at the regional level. The article systematises and presents various approaches to studying the definition of “production potential” set out in the scientific works of domestic and foreign economists. The research methodology was based on a theoretical analysis of approaches to the interpretation of the concept of “production potential”, a retrospective and statistical analysis of gross milk production, livestock and productivity of cows, and per capita milk consumption, taking into account the practical approach to the definition of “production potential”. The problem of degradation of dairy cattle breeding in the Krasnoyarsk Territory has been identified, which entails a decrease in the average per capita consumption of milk and dairy products and an imbalance in food security in the region. The task of studying the issues of forming and increasing the efficiency of using the production potential of the industry is outlined, taking into account the dynamically changing conditions for the development of the domestic economy. Based on the analysis of global trends in the development of the industry, as well as the experience of leading domestic farms, the composition of the tools for the digital transformation of dairy cattle breeding is presented. As a result of the study, a new approach to forming the industry’s production potential was formulated, which made it possible to revise the conceptual policy for developing dairy cattle breeding, considering modern digital tools.

Effect of Different Zinc Sources on Milk Production and Reproductive Performance of Friesian Cows

Effect of Different Zinc Sources on Milk Production and Reproductive Performance of Friesian Cows

Soy Formula as An Alternative for Infants with Cow’s Milk Allergy: Perspective from Pediatricians and Midwives in Indonesia

The prevalence of food allergy in children is increasing globally, with cow's milk allergy beingthe most common in infants and increasing from 2% to 3% in developed countries. However, data oncow's milk allergy in infants is limited in Indonesia. This study used a mixed methods approach using anonline survey and in-depth interviews. The survey was conducted from September 2021 to March 2022.Qualitative analysis, all interviews were recorded and transcribed. Data were analyzed using simplethematic analysis. The results showed that a total of 93 pediatricians and 104 midwives participated inthe survey. However, among the 93 pediatricians, only 56 (60.2%) completed the survey. Meanwhile, 11midwives (10.6%) were excluded because they had no experience in handling CMA cases. The majorityof CMA cases occurred in children under two years old, and most were treated by pediatricians. In termsof diagnostic tests, 51.8% of pediatricians recommended all specific IgE tests, prick tests, and provocationtests to diagnose allergies. More than 80% (46/56) of pediatricians chose to avoid all types of cow's milkproducts in the mother and child's diet as the main treatment. Meanwhile, only 22.1% of midwives didthe same. Milk choice will differ depending on the severity of CMA. Soy milk formula is preferred bymidwives for patients with low-level and moderate to severe allergies. Meanwhile, pediatriciansrecommend extensive hydrolysate formula for low severity patients and amino acid-based formula formoderate to severe.

Occurrence and antimicrobial susceptibility patterns of Escherichia coli and Escherichia coli O157 isolated from cow milk and milk products, Ethiopia

Escherichia coli is a major foodborne pathogen worldwide. This study was conducted to assess the prevalence, risk factors, and antimicrobial susceptibility of E. coli and E. coli O157 in milk and milk products and hygienic practices in West Shoa, Oromia, Ethiopia. Five hundred fifty-six milk samples comprising 421 udder milk, 57 bulk tank milk, and 78 milk products were investigated. Moreover, a questionnaire was administered to 145 participants to assess hygienic practices. A standard microbiological procedure was used to detect E. coli and E. coli O157. The Kirby Bauer disc diffusion method was used to test the antimicrobial susceptibility of the isolates. Petri film plates were used to enumerate the coliform in raw bulk tank milk. Farm and animal-level E coli prevalence were estimated and association with risk factors was assessed. Escherichia coli was detected in 33.8% (95% confidence interval (CI) 29.9–37.9%) of the samples, of which only one isolate (0.2%) was E. coli O157. Escherichia coli contamination was higher in bulk tank samples (47.4%; 95% CI 34.0–61.0%) than in udder milk (34.7%; CI 30.1–39.4%), cottage cheese (27.0%; 95% CI 14.6–43.9%), and yoghurt 10.5% (95% CI 2.9–24.8%). For the animal-level E. coli contamination, only the study area was identified as a risk factor. Risk factors such as types of milk containers, udder washing practices, hygiene, and management systems were associated with both farm-level and milk products E. coli contamination. Most (59.0%) of the farmers practice udder washing only before milking and the remaining did not practice udder washing at all. The mean coliform count in raw bulk tank milk was higher than the international standard (4.09 log10 CFU/ml). All the 42 E. coli isolates tested were multidrug resistant. The occurrence of E. coli is high, while that of E. coli O157 is too low. The milk-handling practices are poor in the study areas. The high prevalence of E. coli, as well as the high coliform count and higher multi-drug resistance may pose risk to public health and food safety. Therefore, proper hygienic practices throughout the milk chain as well as rational drug use are advised.

Effect of grain vinegar feeding on milk production and fatty acid profile of Holstein cows

Effect of grain vinegar feeding on milk production and fatty acid profile of Holstein cows

Polymorphism of the <i>Kappa Casein</i> gene and milk production in cows resulting from crossbreeding with holstein or montbeliarde in the peri-urban area of Bamako

The objective of this contribution is to study the polymorphism of the kappa casein gene in crossbred cows in the peri-urban area of Bamako. Fifty (50) cows, including 22 Montbeliarde crosses and 28 Holstein crosses, were subjected to descriptive analysis comparing average milk production and milk fat and protein percentages and genetic analysis of the kappa-casein gene and its interaction with the crossbred types or breed. The results showed 2 types of crosses for each breed, ½ and ¾ exotic blood. The average daily milk production was 8.2±0.46 kg/d for the Holstein crosses and 7.2±0.73 kg/d for the Montbeliarde crosses with a significant difference. No significant differences were observed for the fat and protein content between Holstein crosses (3.56 ± 0.14% and 3.68±0.02%) and Montbeliarde crosses (3.79 ± 0.10% and 3.74±0.02%). Genetic analysis revealed three genotypes of kappa casein (AA, AB and BB). The AA genotype (0.5) was the most frequent followed by AB (0.41) and BB (0.09). A close link was observed between milk production and the polymorphisms of the kappa casein gene. Individuals with the AB genotype had the highest daily milk production followed by individuals with the AA genotype and those with the BB genotype with respective mean values of 8.6±0.64 kg/d; 7.3±0.56 kg/d and 6.6±1.58 kg/d. Individuals of the BB genotype presented a higher fat content (4.0±0.08%) than that of the other genotypes. The mean milk protein content varied little among the genotypes. These results will contribute to the strengthening of knowledge on the genetic effects of kappa casein polymorphisms on milk production performance and milk composition of crossbred cows in Mali.

Sirtuin 3 mitigates oxidative-stress-induced apoptosis in bovine mammary epithelial cells

Ketosis is often accompanied by a reduction in milk production in dairy cows, but the molecular mechanism has not been fully elucidated. Ketotic cows possess systemic oxidative stress (OS), which may implicate apoptosis in mammary glands. Sirtuin 3 (SIRT3) is a vital regulator of cellular redox homeostasis and is under the control of AMP-activated protein kinase (AMPK) signaling in nonruminants. Thus, we aimed to investigate (1) the AMPK-SIRT3 and apoptosis status of mammary glands from ketotic cows, (2) the effect of SIRT3 on OS-induced apoptosis in bovine mammary epithelial cells (BMEC), and (3) the role of AMPK signaling on SIRT3-mediated effects on apoptosis. Mammary gland samples were reused from a previous study, which contained healthy and ketotic cows (both n = 15). BMEC were incubated with 0, 0.3, 0.6, or 0.9 mM H2O2 for 6 h with/without a 30 min incubation of an antioxidant MitoQ (1 μM). Then BMEC were incubated with SIRT3 overexpression adenovirus (Ad-SIRT3) for 6 h followed by a 6 h incubation with 0.6 mM H2O2. Finally, BMEC were treated with the AMPK inhibitor Compound C (Cd C,10 μM) for 30 min before the H2O2 challenge, or cells were initially treated with the AMPK agonist MK8722 (10 μM) for 30 min followed by a 30-h culture with/without si-SIRT3 and eventually the H2O2 exposure. Ketotic cows displayed higher levels of Bax, Caspase-3 and Bax/Bcl-2 but lower levels of Bcl-2 in mammary glands. H2O2 incubation displayed similar results, exhibiting a dose-dependent manner between the H2O2 concentration and the apoptosis degree. Mito Q pretreatment reduced cellular reactive oxygen species and rescued cells from apoptosis. Ketotic cows had a lower mammary protein abundance of SIRT3. Similarly, H2O2 incubation downregulated both mRNA and protein levels of SIRT3 in a dose- and time-dependent manner. Ad-SIRT3 infection lowered levels of cellular reactive oxygen species, Bax, Caspase-3 and Bax/Bcl-2 but increased levels of Bcl-2. TUNEL assays confirmed that Ad-SIRT3 infection mitigated H2O2-induced apoptosis. Both ketotic cows and H2O2-induced BMEC had lower levels of p-AMPK and p-AMPK/AMPK. Additionally, Cd C pretreatment decreased SIRT3 and Bcl-2 expression but increased levels of Bax and Caspase-3. Contrary to the inhibitor, MK8722 had opposite effects and reduced the percentage of apoptotic cells. However, these effects of MK8722 were reversed upon SIRT3 silencing. In conclusion, in vivo data confirmed that ketosis is associated with greater apoptosis and restricted AMPK-SIRT3 signaling in mammary glands; in vitro data indicated that SIRT3 mitigates OS-induced apoptosis via AMPK signaling. As such, there may be potential benefits for targeting the AMPK-SIRT3 axis to help counteract the negative effects of mammary glands during ketosis.

Analytical tools for managing sustainable development in dairy cattle breeding

The article is devoted to the formation of analytical tools for managing a sustainable sector of dairy cattle breeding of agricultural companies. Offers of results of researches of volumes of production of milk. A system of indicators for the analysis and assessment of the level of sustainable development of dairy cattle breeding of agricultural companies is proposed. A key factor in the sustainable development of dairy cattle breeding has been identified — the productivity of cows, the reduction of the carbon footprint. Proposed measure to increase the milk productivity of cows. The results obtained were used to manage sustainable dairy cattle breeding, develop a food security strategy for the subjects’ farms and substantiate management decisions.

Influence of the energy and carbohydrate additive “Tanrem” on milk productivity and milk composition of cows of Holstein breed

The highest sensitivity to deficiencies in feeding is shown by highly productive cows Holstein breed that has become widespread both in Russia as a whole and in the Urals region. Against the background of many advantages of the breed, there are problems with reproduction and negative energy balance after calving. An innovative approach in feeding is the enrichment of the ration of animals with the energy and carbohydrate additive “Tanrem”, nutrients of which being natural prebiotics and energy sources, are able to activate metabolic processes. The purpose of the research was to study the effect of the energy and carbohydrate additive “Tanrem” on milk productivity and milk composition of cows of Holstein breed. Scientifi c and economic experiment was carried out in LLC “Agro-Alliance” in the Chishminsky district of the Republic of Bashkortostan. For the experiment cows of Holstein breed for the third lactation were selected in the amount of 40 animals, which were provided with the same conditions of housing. In order to select the optimal dosages of the additive the animals were divided into 4 groups. Cows of the 1st control group received the main ration adopted on the farm. Cows of the experimental groups consumed a ration enriched with the energy and carbohydrate additive “Tanrem” in a daily dose, respectively: group 2 – 250, group 3 – 500 and group 4 – 750 g/head. For 305 days of lactation the superiority of cows of the 2nd, 3rd and 4th experimental groups on the control was as follows: 198,2 kg or 2,39 % (p < 0,05), 458,8 kg or 5,53 % (p < 0,001) and 408,9 kg or 4,93 % (p < 0,001), respectively. The data obtained indicate the expediency of enriching the ration of dairy cows with the energy and carbohydrate additive “Tanrem”. The economic analysis confirmed the established fact and indicated that the most effective rate of application of the tested additive is 500 g/head per day.

Effects of bovine leukemia virus seropositivity and proviral load on milk, fat, and protein production of dairy cows

The objective was to evaluate the effects of bovine leukemia virus (BLV) infection, as determined by BLV seropositivity and proviral load, on 305-d milk, fat, and protein production of dairy cows. A cross-sectional study was conducted among 1,712 cows from 9 dairy herds in Alberta, Canada. The BLV status was assessed using an antibody ELISA, whereas BLV proviral load in BLV-seropositive cattle was determined with quantitative PCR. Dairy Herd Improvement 305-d milk, fat, and protein production data were obtained for all enrolled cattle. Differences in these milk end points were assessed in 2 ways: first, by categorizing cows based on BLV serostatus (i.e., BLV positive or negative), and second, by categorizing based on BLV proviral load (i.e., BLV negative, low proviral load [LPL] BLV positive, and high proviral load [HPL] BLV positive). A mixed-effect multivariable linear regression model was used to assess differences in milk parameters. We found that BLV positivity, adjusted for parity and natural log-transformed somatic cell count (SCC), was not associated with reduction in 305-d milk, fat, or protein production. However, significant reductions in 305-d milk, fat, and protein yield occurred in HPL cows, but not in LPL cows, compared with BLV-negative cows, when adjusted for parity number and natural log-transformed SCC. In summary, BLV proviral load may predict effects of BLV infection on milk, fat, and protein production.

Dynamic lactation responses to dietary crude protein oscillation in diets adequate and deficient in metabolizable protein in Holstein cows

Limited research has examined the interaction between dietary crude protein (CP) level and CP feeding pattern. We tested CP level (low protein [LP], 13.8%; high protein [HP], 15.5% CP, dry matter [DM] basis) and CP feeding pattern (OF = oscillating, SF = static) using a 2 × 2 factorial in 16 mid- to late-lactation Holsteins (initially 128 ± 12 d in milk; mean ± SD). Cows ate total mixed rations formulated by exchanging soy hulls and ground corn with solvent soybean meal to keep constant ratios of neutral detergent fiber to starch (1.18:1), rumen-degradable protein to CP (0.61:1), and forage-to-concentrate (1.5:1) in DM. The OF treatments alternated diets every 48 h to vary CP above and below the mean CP level (OF-LP = 13.8% ± 1.8%; OF-HP = 15.5% ± 1.8% CP [DM basis]) whereas diets were constant in SF (SF-LP = 13.8%; SF-HP = 15.5% CP [DM basis]). In four 28-d periods, 8 rumen-cannulated and 8 noncannulated cows formed 2 Latin rectangles. On d 25 to 28 of each period, each cow's feed intake and milk production were recorded, and samples were taken of orts (1×/d) and milk (2×/d). We fit linear mixed models with fixed CP level, CP feeding pattern, and period effects, and a random intercept for cow, computing least squares means and standard errors. Neither CP level, CP feeding pattern, nor the interaction affected DM intake, feed efficiency, or production of milk, fat- and protein-corrected milk (FPCM), fat, true protein, or lactose. Milk urea-N (MUN) yield was lesser for LP. The LP and OF conditions decreased MUN concentration. The CP level tended to interact with CP feeding pattern so that milk protein concentration was greatest for OF-HP. The OF and LP conditions increased the ratio of true protein to MUN yield. Within OF, cosinor mixed models of selected variables showed that cows maintained production of FPCM across dietary changes, but MUN followed a wave-pattern at a 2-d delay relative to dietary changes. A tendency for lesser MUN with OF contradicted prior research and suggested potential differences in urea-N metabolism between OF and SF. Results showed that cows maintained production of economically-relevant components regardless of CP feeding pattern and CP level. Contrary to our hypothesis, the effects of 48-h oscillating CP were mostly consistent across CP levels, suggesting that productivity is resilient to patterned variation in dietary CP over time even when average CP supply is low (13.8% of DM) and despite 48 h restrictions at 12.2% CP.

Effects of dietary fat, nitrate, and 3-nitrooxypropanol and their combinations on methane emission, feed intake, and milk production in dairy cows

The objective of the present study was to investigate the effect of individual and combined use of dietary fat, nitrate, and 3-nitrooxypropanol (3-NOP) on dairy cows' enteric methane (CH4) emission and production performance. Twenty-four primiparous and 24 multiparous Danish Holstein cows (111 ± 44.6 d in milk; mean ± standard deviation) were included in an incomplete 8 × 8 Latin square design with six 21-d periods. Dietary treatments were organized in a 2 × 2 × 2 factorial arrangement aiming for 2 levels of FAT (30 or 63 g of crude fat/kg of dry matter [DM]; LF or HF, respectively), 2 levels of NITRATE (0 or 10 g of nitrate/kg of DM; UREA or NIT, respectively), and 2 levels of 3-NOP (0 or 80 mg/kg DM; BLANK or NOP, respectively). Treatments were included in ad libitum-fed partial mixed rations in bins that automatically measured feed intake and eating behavior. Additional concentrate was offered as bait in GreenFeed units used for measurement of gas emission. For total DM intake (DMI), a FAT × NITRATE interaction showed that DMI, across parities and levels of 3-NOP, was unaffected by separate fat supplementation, but reduced by nitrate with 4.6% and synergistically decreased (significant 2-way interaction) with 13.0% when fat and nitrate were combined. Additionally, 3-NOP decreased DMI by 13.4% and the combination of 3-NOP with fat and nitrate decreased DMI in an additive way (no significant 3-way interaction). The decreasing effects on DMI were more pronounced in multiparous cows than in primiparous cows. For treatments with largest reductions in DMI, eating behavior was altered toward more frequent, but smaller meals, a slower eating rate and increased attempts to visit unassigned feed bins. Energy-corrected milk (ECM) yield increased by 6.3% with fat supplementation, whereas ECM yield did not differ among diets including nitrate (FAT × NITRATE interaction). Cows supplemented with 3-NOP had 9.0% lower ECM yield than cows fed no 3-NOP. Based on three 2-way interactions including FAT, NITRATE, and 3-NOP, the combined use of the additives resulted in antagonistic effects on CH4 reduction. A 6% to 7% reduction in CH4 yield (CH4/kg of DMI) could be ascribed to the effect of fat, a 12% to 13% reduction could be ascribed to the effect of nitrate and an 18% to 23% reduction could be ascribed to the effect of 3-NOP. Hence, no combinations of additives resulted in CH4 yield-reductions that were greater than what was obtained by separate supplementation of the most potent additive within the combination. The CH4 yield reduction potential of additives was similar between parities. Increased apparent total-tract digestibility of organic matter (OM) in cows fed combinations including nitrate or 3-NOP was a result of a NITRATE × 3-NOP interaction. Apparent total-tract digestibility of OM was also increased by fat supplementation. These increases reflected observed decreases in DMI. In conclusion, combined use of fat, nitrate, and 3-NOP in all combinations did not result in CH4 reductions that were greater than separate supplementation of the most potent additive within the combination (3-NOP > nitrate > fat). Additionally, separate supplementation of some additives and combined use of all additives reduced DMI.

Phenotypic parameters of the mother stock of the Jersey breed

Recently, in connection with the transition to an industrial approach in animal husbandry and an increase in demand for planned breeds bred in Ukraine, high requirements have arisen for their productivity, feed cost, suitability for machine milking and other characteristics. Breeding of the Jersey breed can serve as an important reserve for the further development of dairy cattle breeding in Ukraine. The Jersey breed is characterized by high productivity and is the most fat-milk breed in the world, with high feed value and good technological properties of the udder. The purpose of the research was to evaluate the phenotypic parameters of the Jersey cattle herd and to study the influence of the duration of the service period on the efficiency of milk production. 1,331 head of breeding stock of the Jersey breed are kept in the APNVP “Vizit” of the Khmelnytskyi district of the Vinnytsia region, of which 68.4 % are cows. Youngsters are rated elite-record and elite – 99.3 %. Up to 3 lactations are kept in a herd of Jersey cows. Hope per cow is 5819 kg of milk, with a fat content of 6.05 % and a protein content of 4.2 %. The milk productivity of cows exceeds the minimum requirements for the Jersey breed by 83 % for the first lactation, by 82.1 % for the second, and by 73.1 % for the third. The hope for 305 days of lactation in cows with a service period of 90 days in the second lactation is 11.8 % less than the data of cows with a service period of 120 days, for the third lactation – by 11.4 %. The average daily survival of cows with a service period of 120 days was lower than that of control cows by 7.0 %. The efficiency of using cows when extending the service period beyond the 90-day limit recommended by experts reduces the milk productivity of cows. The ratio of fat to protein is higher in Jerseys by 0.3, fat to dry skimmed milk residue by 0.2, and protein to dry skimmed milk residue by 0.06.

The influence of the behavior of cows and the method of feeding a grain mix-ture on their milk productivity

At the “Pchany-Denkovych” farm of the Stryi district of the Lviv region, the influence of the behavior of Simmental cows and the method of feeding a grain mixture on their quantitative and qualitative composition of milk depending on the level of feeding was studied, as well as the possibility of using ethological assessment as one of the criteria when selecting animals for industrial use. It was established that there was a slight advantage in terms of expenditure on foraging behavior by classes in active and ultraactive individuals in both experimental groups of cows. Thus, animals from the first and second groups of the active class spent the most time on feed consumption, respectively – 21.4 and 22.0 min, which is 20.2 and 19.6 % more than the rate of infrapassive animals (17.8 and 18.4 min). A similar pattern was found in cows and in terms of time spent on water consumption. Thus, cows of the infrapassive classes spent the least amount of time on water consumption, respectively – In the first group – 9.6 minutes, and in the second group – 10.5 minutes. Cows of the active class with a high level of general activity of the first and second groups spent the most time on water consumption, respectively – by 16.3 and 16.6 minutes. The influence of the level of general activity of cows on their milk productivity was established - with an increase in the level of activity, an increase in milk productivity was observed. It was established that the cows belonging to the active class were characterized by the highest milk yield. At the same time, in order to increase the efficiency of the use and assimilation of feed, it is recommended to feed concentrated feed to dairy cows in portions – part of it as part of the feed mixture, and part of it during the milking of the cows. It was established that the cows of the first group with a low level of general activity, which received concentrated feed during milking, were characterized by the lowest milk productivity. Thus, the infrapassive animals of the first group had a 15.1 % (Р < 0.05) lower hope for lactation, compared to the peers of the active class, which were given the feed mixture in portions. In each class, there were also differences in milk productivity depending on feeding Thus, the cows of the second group exceeded their peers from the first group of different classes of ethological activity in terms of milk yield, respectively – by 2.4, 3.9, 2.1, and 2.9 %, given the grain mixture during milking. A little higher the milk productivity of the animals of the second group is associated with better eating of the feed mixture and the content of the percentage of concentrated feed in the recipe. Better consumption of feed mixture by animals contributed to greater consumption of nutrients in the diet, which was reflected in the milk productivity of cows. It was established that the density and acidity of milk of different classes of ethological activity were within normal limits. There are practically no differences in these indicators between groups, and small intergroup fluctuations are statistically improbable.

Manifestation of signs of milk productivity of firstborn cows depending on the productivity of their female ancestors

One of the most important breeding methods in cattle breeding is the determination of genetic similarity in productive traits of female ancestors and their descendants. In view of the above, the aim of the study was to determine the variability of cow milk production traits depending on the productivity of their mothers and fathers' mothers. The studies were conducted on farms located in different climatic zones of Ukraine, namely: SE DG “Oleksandrivske”, Vinnytsia region (Forest-Steppe zone, n = 714), LLC SHP “Imeni Volovikova”, Rivne region (Polissia zone, n = 1840) and SE “Experimental Farm “Askaniyske” (Steppe zone, n = 926) on firstborn and full-grown cows (III lactation) of the Ukrainian Black-and-White dairy breed. The sample included cows that had completed at least the third lactation at the time of the study. It was found that the most productive cows in the controlled herds were those whose mothers' milk yields for the highest lactation reached more than 8000 kg, and the mothers' milk yields of the fathers, depending on the breeding zone, ranged from 9000 to 15000 kg. A certain influence of mothers on the value of indicators of cows' milk production traits is evidenced by correlation analysis. Thus, a rather significant straightforward and reliable relationship was established between the milk yield of mothers and their daughters in the controlled farms, and between the milk yield of mothers and the fat content of daughters, this relationship was inverse, but reliable. The correlation between maternal fat and milk yield and fat and milk yield of daughters was multidirectional and insignificant. The coefficient of heritability, which was determined by doubling the mother-daughter correlation, ranged from 0.47 to 0.59 for milk yield, from 0.30 to 0.55 for milk fat yield, and from incorrect (negative) in animals from the Steppe zone (-0.27) to positive (0.18) in animals from the Polissya zone. The analysis of variance confirmed a certain predetermination of phenotypic variability of quantitative traits of milk production depending on the productivity of mothers and mothers of fathers established by the comparison of group means. Thus, their mothers had a somewhat greater, although not significant, influence on milk yield (depending on the farm and lactation – 3.8–6.9 %) and fat content in cows' milk (4.2–6.6 %), and their fathers' mothers had a somewhat lesser influence (2.1–4.2 and 2.0–4.5 %, respectively).

Partial replacement of a total mixed ration with annual ryegrass herbage: effects on dairy cow dry matter intake and milk production

ABSTRACT Studies with dairy cows receiving mixed ration and grazing annual pastures, which have low tiller density, are scarce. This study examined the effect of partial replacement of a total mixed ration (TMR) with annual temperate pasture. Treatments were ad libitum TMR (TMR100), 75% ad libitum TMR + ryegrass (Lolium multiflorum ‘Maximus’) (pTMR75), and 50% ad libitum TMR + ryegrass (pTMR50). Twelve multiparous Holstein and F1 Jersey × Holstein cows were divided into six groups (experimental units), taking account of milk production (26.6 ± 4.55 kg/day), days-in-milk (129 ± 50.8) and body weight (546 ± 30.6 kg). Treatments were compared using two 3 × 3 Latin square arangements, comprising three 21-day periods (measurements during final 5 days). Herbage DM intake increased from 4.8 kg/day with pTMR75 to 6.7 kg/day with pTMR50. Total DM intake decreased from 19.4 kg/day (TMR100), to 18.1 and 15.8 kg/day (pTMR75 and pTMR50, respectively). Milk production, energy corrected milk production (ECM), and milk fat content were similar between treatments, averaging 25.6, 28.4 kg/day and 44.6 g/kg, respectively. Ryegrass pastures were able to replace up to 50% of TMR offered to mid lactation dairy cows with no adverse effects on ECM production.