Efficiency Of Milk Production Research Articles

A newly developed strain of Enterococcus faecium isolated from fresh dairy products to be used as a probiotic in lactating Holstein cows.

The objective of this study was to determine the ability of an isolated strain (EGY_NRC1) or commercial (NCIMB 11181) Enterococcus faecium as a probiotic for lactating cows. Two experiments were conducted: In Experiment 1, the effects of three levels (1, 2, and 3 g/kg diet, DM basis) of isolated and commercial E. faecium on in vitro ruminal fermentation kinetics, gas, methane (CH4) and nutrient degradability were determined. In Experiment 2, thirty multiparous Holstein cows (633 ± 25.4 kg body weight) with 7 days in milk, were randomly assigned to 3 treatments in a completely randomized design in a 60-day experiment. Cows were fed without any additives (control treatment) or supplemented with 2 g/kg feed daily of E. faecium EGY_NRC1 (contain 1.1 × 109 CFU/g) or commercial E. faecium NCIMB 11181 (contain 2 × 1012 CFU/g). Diets were prepared to meet cow's nutrient requirements according to NRC recommendations. Probiotic doses were based on the in vitro Experiment 1. Feed intake, digestibility, blood parameters and lactation performance were evaluated. In Experiment 1, the isolated E. faecium linearly and quadratically increased (P < 0.001) in vitro total gas production (TGP), the degradability of dry matter (dDM) and organic matter (dOM) while decreased (P < 0.05) methane (CH4) percent of TGP, NH3CH4 production, and pH. The commercial E. faecium increased TGP and decreased (P < 0.01) CH4 production, pH and increased the dDM and dOM, short chain fatty acids and ruminal NH3-N concentration. In Experiment 2, the isolated E. faecium increased (P < 0.01) total tract digestibility of DM, neutral and acid detergent fiber, daily milk production and feed efficiency compared to the control treatment without affecting feed intake and milk composition. Moreover, the isolated E. faecium increased (P < 0.05) the proportion of C18:1 trans-9, C18:2 cis-9-12 and C18:2 trans-10 cis-12. Both isolated and commercial E. faecium improved (P < 0.01) organic matter, crude protein and nonstructural carbohydrates digestibility, increased serum glucose (P = 0.002) and decreased serum cholesterol (P = 0.002). Additionally, both E. faecium strains decreased C23:0 (P = 0.005) in milk. In conclusion, the use of E. faecium (isolated and commercial) at 2 g/kg DM of feed improved feed efficiency and production performance, with superior effects on animal performance from isolated E. faecium compared to the commercial one.

INFLUENCE OF THE DURATION OF THE SERVICE PERIOD ON THE MILK PRODUCTIVITY OF COWS

The aim of the work was to determine the prospects for increasing the economic efficiency of milk production with different duration of the service period. Based on research carried out in the conditions of 4 agricultural organizations in the Vitebsk and Mogilev regions, it has been found that cows with a service period of 61 to 90 days are characterized by higher milk productivity. Economic efficiency of milk production from cows with different duration of service period shows that with the duration of service period not less than 61-90 days the level of profitability of milk production increases by 7.3-9.4 percentage points.

Effects of dietary concentrate to forage ratio on milk performance, milk amino acid composition and milk protein synthesis of lactating donkeys

The purpose of this experiment was to compare the effects of the dietary concentrate-to-forage ratio on lactating donkey milk production performance, milk protein synthesis and milk amino acid composition by replacing part of low-quality roughage with alfalfa. The second objective was to investigate the possible mechanism by which the dietary concentrate-to-forage ratio affects donkey milk protein synthesis. These results will provide a theoretical basis for the rational preparation of feed and optimization of the amino acid composition of donkey milk. This experiment adopted a single-factor randomized trial design. Sixteen Dezhou donkeys with similar ages (6.73 ± 1.16 years), weights (250.84 ± 27.21 kg), parities (3.25 ± 1.12 foals) and lactation days (40 ± 4 days) were selected and evenly (n = 8 per group) divided into a low forage feed group (LF) and a high forage feed group (HF). The LF group was fed a diet with a concentrate to forage feed ratio of 40:60, and the HF group was fed a diet with a concentrate to forage feed ratio of 30:70. The energy and protein levels of the two diets were the same, and the test period lasted 8 weeks. Compared with the LF group, the concentrations of total protein, prolactin and hydrocortisone in the serum of donkeys in the HF group were increased (P < 0.05); the apparent digestibility of dry matter, neutral detergent fiber and energy digestibility and energy metabolic of the donkeys in the HF group were improved (P < 0.05); the concentrations of albumin, epidermal growth factor and urea phosphate tended to decrease (0.05 < P < 0.10); the concentrations of threonine (Thr), lysine (Lys), methionine, histidine, proline and limiting amino acids (LAAs) in the plasma and nitrogen metabolism of the donkeys in the HF group were increased (P < 0.05); milk yield, production and synthesis efficiency of milk protein and most amino acid (AA) production in milk (except serine and valine) were increased (P < 0.05); the proportions of Thr, Lys phenylalanine and LAA in donkey milk were increased (P < 0.05); the final body weight and the body weight gain of donkey foals in the HF group was improved. Under the condition of feeding the same energy and nitrogen levels, increasing the proportion of forage from 60% to 70% by replacing part of low-quality forage with alfalfa promoted the protein and energy metabolism, increased milk protein synthesis efficiency, milk production efficiency and milk production performance, improved the proportion of LAAs and optimized the AA composition of donkey milk.

Palm Kernel Cake in Diets for Lactating Goats: Intake, Digestibility, Feeding Behavior, Milk Production, and Nitrogen Metabolism.

Simple SummaryPalm kernel cake (PKC) is a by-product used in the diet of ruminants (sheep, dairy cows, beef cattle) with the aim of reducing production costs. The inclusion of PKC showed promising results mainly in feedlot animals. However, among domestic ruminant species, goats are the most selective feed animals, which may result in different feeding behavior and performance when PKC is included in the diet. We tested the dietary inclusion of PKC, a by-product of the biofuel industry, at the levels of 0, 80, 160 and 240 g kg−1, to evaluate its impact on the performance, feeding behavior and the metabolic profile of lactating goats. The inclusion of up to 80 g kg−1 PKC is recommended for the diet of goats without affecting the performance.This study was carried out to determine the optimal inclusion rate of palm kernel cake (PKC) in diets for lactating goats based on intake, digestibility, feeding behavior, milk production and nitrogen metabolism. Twelve goats were used, eight Saanen and four Anglo Nubian, with a body weight of 46.0 ± 9.4 kg and 105 ± 5 days of lactation, distributed in a 4 × 4 Latin square design in triplicate. The diets were composed of increasing levels of PKC; 0, 80, 160 and 240 g kg−1 of dry matter (DM). The DM, crude protein, neutral detergent fiber and non-fibrous carbohydrates intakes decreased (p < 0.01) with the PKC inclusion. Milk production and milk protein decreased (p = 0.001), and milk production efficiency was not affected (p > 0.05) by the PKC inclusion. The ether extract intake varied quadratically (p < 0.01). Feeding and rumination efficiencies of dry matter and NDF were reduced (p < 0.001). The fat and total solids contents of the milk were influenced quadratically (p < 0.05). Nitrogen excretion (feces and milk), and retained nitrogen decreased (p < 0.001). Moderate use of up to 80 g kg−1 DM of PKC in the diet of lactating goats is recommended since at these levels milk production or body weight are significantly affected.

Effects of rumen-native microbial feed supplementation on milk yield, composition, and feed efficiency in lactating dairy cows.

The objective of this study was to evaluate the effects of two rumen-native microbial feed supplements (MFS) on milk production, milk composition, and feed efficiency. A total of 90 multiparous cows between 40 and 60 d in milk were enrolled in a randomized block design study. Within each block (baseline milk yield), cows were randomly assigned to: control (no microbial feed supplementation), MFS1 (0.33 g/kg total mixed ration [TMR] of an MFS containing a minimum of Clostridium beijerinckii at 2 × 106 CFU/g and Pichia kudriavzevii at 2 × 107 CFU/g), or MFS2 (0.33 g/kg TMR of a MFS containing a minimum of C. beijerinckii at 2 × 106 CFU/g, P. kudriavzevii at 2 × 107 CFU/g, Ruminococcus bovis at 2 × 107 CFU/g, and Butyrivibrio fibrisolvens at 2 × 107 CFU/g). Cows were housed in a single group and fed the study diets ad libitum for 270 d. Individual milk yield was recorded using electronic milk meters, and milk fat and protein were measured using optical in-line analyzers at each of two daily milkings. Treatment and treatment by time effects were assessed through multiple linear regression analyses. Treatment effects were observed for milk and energy-corrected milk (ECM) yields, milk fat and protein yields and concentrations, dry matter intake (DMI), and feed efficiency; those effects were conditional to time for milk yield, DMI, and feed efficiency. Overall, milk, ECM, fat, and protein yields were higher for MFS2 compared with control cows (+3.0, 3.7, 0.12, and 0.12 kg/d, respectively). Compared with MFS1, milk yield was higher and protein yield tended to be higher for MFS2 cows (+2.9 and 0.09 kg/d, respectively). In contrast, MFS1 cows produced 0.17 and 0.08 units of percentage per day more fat and protein than MFS2 cows, and 0.07 units of percentage per day more protein than control cows. Dry matter intake and feed efficiency were higher for MFS2 cows compared with MFS1 cows (+1.3 kg/d and 0.06, respectively), and feed efficiency was higher for MFS2 cows compared with control cows (+0.04). Where observed, treatment by time effects suggest that the effects of MFS2 were more evident as time progressed after supplementation was initiated. No effects of microbial supplementation were observed on body weight, body condition score, somatic cell count, or clinical mastitis case incidence. In conclusion, the supplementation of MFS2 effectively improved economically important outcomes such as milk yield, solids, and feed efficiency.

The use of an energy feed additive in the rations of highly productive cows of Ayrshire breed

Under the conditions in the Vologda region the organization of complete feeding of cows in highly productive herds is especially difficult, since the range of harvested feed is reduced and their quality issues remain problematic. In the region many of the normalized nutrients in the rations of dairy cattle are limiting, which reduces the effi ciency of production of its products. The purpose of the work was to increase the effi ciency of milk production when using the energy additive Tirzana BSK in the rations of highly productive cows of Ayrshire breed. Studies on the eff ectiveness of the use of the energy additive Tirzana BSK were carried out in the winter-stall period of housing cows on the basis of the agricultural complex “Maysky Breeding Farm” in the Vologda region. A comprehensive research of the technology of milk production with the use of an energy additive in the rations of cows was carried out It was found that as a result of feeding the energy additive Tirzana BSK, there is an improvement in the digestibility of nutrients in rations, especially organic matter and fi ber. Higher digestibility coeffi cients in animals of experimental groups are obviously achieved due to the optimization of microbiological processes in the gastrointestinal tract due to the components of the additive, which includes propylene glycol, glycerin, polysaccharides and a complex of biologically active substances. Feeding Tirzana BSK additive has a positive eff ect on increasing milk productivity without reducing product quality. New data on the animal husbandry and economic feasibility of using the energy additive in feeding cows with a milk yield of over 8500 kg of milk per lactation have been obtained, which make it possible to identify additional reserves for increasing milk yields with rational expenditure of feed. The use of the energy additive Tirzana BSK in feeding highly productive cows of Ayrshire is economically justified, especially during periods of late dry period and the first 100 days of lactation.

Coupling genetic and mechanistic models to benchmark selection strategies for feed efficiency in dairy cows: sensitivity analysis validating this novel approach

Coupling genetic and mechanistic models is appealing to explore the impact of energy trade-offs on the expression of feed efficiency traits in dairy cattle and predict selection response. The objective of this study was to evaluate the sensitivity of genetic (co)variances among milk production and feed efficiency (FE) traits simulated with a mechanistic dairy cow model depending on the genetic variability assumed for input parameters. The cow model was calibrated for a grass-based production and included a genetic module. Four genetically driven input parameters described the energy acquisition and allocation to different biological functions of cows. In each simulation, a population of 20 000 cows from 200 unrelated sires was simulated. The nutritional environment was an input of the model and was tailored by modulating feed offer and quality. A non-limiting nutritional environment was simulated to mimic a situation of ad libitum feeding and was used as a reference. Two other scenarios were simulated by imposing a moderate and a high DM intake restriction on simulated cows. Five phenotypes related to milk production and FE were considered: milk production, BW at calving, DM intake, lactation efficiency and body reserves during early lactation. These traits were estimated both in first and third lactations. A baseline scenario was defined considering a heritability of 0.35 and a phenotypic CV of 10% for acquisition and allocation parameters (AAPs). Different scenarios were explored by reducing the heritability to 0.15 or increasing CV to 20 and 30% or both. Heritabilities and genetic correlations between simulated traits were estimated using animal linear mixed models. Each scenario was replicated 20 times. Simulated performance and genetic parameters for these traits were compared across scenarios using an ANOVA. The heritability of AAPs only influenced the heritability of simulated traits. The phenotypic CV of AAPs mainly influenced the variability of simulated traits. However, increasing the CV also affected the number of cows reaching first and third lactation, due to the early culling of females with extreme AAPs profiles. Compared to other input parameters, the nutritional environment had the largest effect on both performance and genetic correlations between traits. Using a heritability value of 0.35 and a CV of 10% for all four AAPs enabled the simulation of milk production and FE performance with a realistic mean, variance and genetic correlations among traits in the three considered environments.

Economics of Milk Production and Resource Use Efficiency of Milk Across Different Herd Size Categories in Chittoor District of Andhra Pradesh

Background: In India dairy farming is a significant part of the rural population, providing not only supplementary income and nutritional standards but also organic manures and draught power. Andhra Pradesh ranks 5th in total milk production in India with an output of 15.04 million metric tonnes and Chittoor district is one of the leading districts for dairy farming in the state. There is an increasing trend in milk production; however, the main drawback faced by the milk producers in dairy farming is the low productivity of milch animals. Assessing the economics of milk production would be extremely beneficial in planning for the improvement of productivity of dairy animals and framing policies to increase the profitability of dairy farms. Methods: Chittoor district of Andhra Pradesh was purposively selected for the present investigation. The primary data was collected from 80 respondents of which 40 each from two villages in the year 2021. The economics of milk production and the resource use efficiency of milk were computed based on collected data. Result: The per-day gross cost for maintaining local cow, crossbred cow and buffalo was found to be ₹ 161.09, ₹ 246.16 and ₹ 196.07, respectively. The overall cost per litre of milk was found to be slightly high in the case of buffalo (₹ 31.45), followed by the local cow (₹ 31.33) and crossbred cow (₹ 19.69), respectively. The net returns per litre of milk were found to be highest in the case of the crossbred cow (₹ 7.45), followed by buffalo (₹ 3.66) and local cow (₹ 0.12). It was observed that the net return per litre of milk for local cows was very less due to high feed cost, labour cost and low productivity of milk. Green fodder, dry fodder and concentrate were observed underutilized whereas labour was found to be over-utilized.

Evaluation and Forecasting of Increasing Competitiveness and Efficiency of Milk Production

The analysis of the state of milk production in the Russian Federation was carried out. The ways of increasing the volume of dairy production and the trends of its development in comparison with the countries that are the leading exporters of milk are determined. The contribution of productivity and livestock size to the volume of milk production has been established. The optimal milk yield was found depending on the cost of the cow's daily ration, which can be calculated for any farm.

The effectiveness of the probiotic additive from the microbiome of rumen of reindeer

The purpose of the work was to study the microfl ora of the reindeer rumen, to isolate highly active strains with cellulolytic and antagonistic properties for the making of a new probiotic additive and its testing when used in the rations of lactating cows. The paper compares the chemical analysis of feed from various northern regions and determines the level of toxicity of the feed ration of reindeer of Nenets breed in the winter-spring and summer-autumn periods. The microbiome of the Nenets reindeer rumen was studied using NGS sequencing and T-RFLP analysis, the results were compared depending on seasonal variability, age and sex of animals. Bacteria from the rumen of reindeer with antagonistic properties against pathogens, as well as used as a source of cellulases and biodestructors of mycotoxins were isolated. As a result, a probiotic feed additive Rumit was developed based on these strains and the eff ect of feeding probiotic on the productivity and quality of milk of lactating cows was studied. It has been established that the probiotic additive Rumit is not inferior in its eff ectiveness to the previously tested probiotic Cellobacterin+. Its use in the rations of highly productive cows led to the increase in milk yield, the increase in the fat content of milk and the protein content in it compared with the control group. The obtained research materials indicate the expediency of introducing the probiotic additive into the rations of cattle in a dose of 40 g/head/day, which contributes to the increase in dairy productivity of cows, reducing feed expenditures per unit of production and increasing the economic effi ciency of milk production.

Influence of Functional Feed Supplements on the Milk Production Efficiency, Feed Utilization, Blood Metabolites, and Health of Holstein Cows during Mid-Lactation

A 70-day feeding trial was performed to assess the effect of feeding a mixture of functional feed supplements (FFS; contains encapsulated cinnamaldehyde, condensed tannins, capsaicin, piperine, and curcumin) during mid-lactation on the milk production and composition, feed intake, and blood profile of multiparous dairy cows. Sixty Holstein dairy cows (116.1 ± 17.1 days in milk, 606 ± 9.3 kg BW, and 45.73 ± 6.7 kg/d milk production) were distributed into two trial groups: control (CON: n = 30), which received a basal diet; and FFS (n = 30) treatment, which received a basal diet fortified with the FFS at a rate of 35 g/day/head. The results revealed that daily milk production (p = 0.01) and solids-not-fat yield (p = 0.05) were significantly higher in dairy cows that had received FFS compared with the control group. In addition, the 3.5% fat-corrected milk, energy-corrected milk, lactose and protein yields, and milk energy output tended to be higher (p ≤ 0.10) in dairy cattle that consumed FFS during the experimental period. Significant treatment x period interactions were identified (p ≤ 0.02) with respect to feed efficiency and somatic cell count. Dry matter intake tended to be greater (p = 0.064) in dairy cattle that consumed FFS during weeks 0–2 and 2–4 of the trial period. Most serum biochemical parameters were not changed (p ≥ 0.114) between FFS and control cows. However, a greater concentration of serum albumin (p = 0.007) was observed in cows fed diets supplemented with FFS. In summary, supplementing FFS to lactating Holstein cows during mid-lactation was associated with enhanced lactation performance, feed efficiency, and a tendency to increase feed intake, with no obvious adverse effects.

Milk Composition and Production Efficiency within Feed-To-Yield Systems on Commercial Dairy Farms in Northern Ireland.

Simple SummaryFeed-to-yield concentrate allocation systems seek to improve precision by targeting more nutrients to dairy cows with the greatest nutrient requirements. This study investigated the effect of offering concentrates on a feed-to-yield basis to housed cows on the relationships between milk yield, intake, milk composition and production efficiency during the first five months of lactation. Performance data for individual cows were collected from 26 farms in Northern Ireland, and intakes were subsequently calculated. Total dry matter intake increased with increasing milk yield. Cows with higher milk yields produced milk with a lower fat and protein concentration, likely due to a combination of cow genetics, diet, and a ‘dilution’ effect associated with yield. The reduction in milk fat and milk protein concentration with increasing milk yield is particularly important for farmers supplying milk for processing, as milk pricing mechanisms within these supply contracts normally include bonuses or deductions determined by milk composition. Cows with greater milk yields had improved nitrogen and energy use efficiency but were offered more concentrates per kilogram of energy-corrected milk produced.This study examined the relationships between milk yield and diet composition, nutrient intakes, milk composition, and feed use efficiency when concentrates were offered using a feed-to-yield (FTY) approach. The study was conducted on 26 dairy farms in Northern Ireland. Cows (n = 3471) were fully housed and were offered concentrates on an FTY basis. Individual cow genetic information was obtained for 18 herds. Concentrate intakes of individual cows were either obtained from the farms or calculated, while milk yield and milk composition data were obtained from test-day milk recording. Mean test-day milk yields during months 2 to 5 post-calving were calculated for each cow, and cows within each lactation were placed into one of six equal-sized milk yield (kg/cow/day) groups. Diet effects and performance responses to milk yield groups were tested for linear and quadratic effects. Total dry matter intakes increased with increasing milk yield. Milk fat and milk protein concentration declined as milk yield increased, which could be attributed in part to genetics and diet. As milk yield increased, nitrogen and energy use efficiency was improved. However, concentrates offered per kg of energy-corrected milk also increased at higher milk yields, indicating an increased reliance on concentrates for these cows.

Efisiensi Produksi Susu Sapi Perah Di Kelompok Peternak Mandiri Sejahtera Desa Tajurhalang Kabupaten Bogor

This research aims to know efficiency of milk production at Mandiri Sejahtera Dairy Farmers Group and also to know how the factors of milk productions influence the amount of milk production at that group. Research methode which is used is with using giving quiz containing questions about factors relating to milk production. Factors of milk production which are researched are ownership of dairy cow for every farmer (SL), forage (H) and concentrate (K) which is used for every month/dairy cow, and working time per month/dairy cow. Data analysis used is using Cobb Douglass Equation, so, We could get milk production equation and know factors which significant (P &lt; 0,01 atau P &lt; 0,05) influence to milk production. Cobb Douglas Function of that milk production is LnPS = 0,38 + 0,432 LnH - 0,263 LnK + 0,590 LnJ* + 0,941 LnSL**. Factors most significant (P &lt; 0,01) influence the milk production are the ownership of dairy cow. The ownership of dairy cow which is efficient is about 3,32 LU/month/farmer which could produce milk about 250 liter/month/farmer. Keywords: Milk Production, Cobb Douglass, Ownership Of Dairy Cow, Dairy Farmer

Efficiency of feed conversion and milk yield in Murrah buffaloes fed with linseed and linseed oil

The present experiment was carried out to study the influence of feeding linseed and linseed oil on feed conversion and milk production efficiency (gross efficiency of milk production and gross protein efficiency) in lactating Murrah buffaloes. For this purpose, 18 lactating Murrah buffaloes were grouped in control (T0), T1 and T2 (06 animals in each) on basis of average live weight (516.55±9.53 kg), milk yield (7.50±0.3 kg), fat percentage in milk (6.70±0.29%) and lactation stage (2 weeks after parturition). Murrah buffaloes in all three groups were fed a same ration, consist of available green fodder, wheat straw and concentrate (69.03:30.97; roughage: concentrate ratio) to fulfill their nutrient requirement for maintenance and milk production of experimental Murrah buffaloes. In the treatment group (T1) 250 g/d linseed oil and 570 g/d whole linseed (T2) was supplemented with basal ration. The experimental feeding to the Murrah buffaloes was started 15 days after parturition and continues for 60 days. However, the experimental data were taken for the period of 6 months (i.e. 180 days). A 7 days digestion trial was conducted at the last of feeding experiment to know the digestibility of nutrient. The milk production, 4% FCM yield, SCM yield, ECM yield, change in body weight, dry matter intake and roughage to concentrate ration didn’t differ significantly between groups. No significant difference was observed in nutrient intake (TDN and CP) between groups. The digestibility of organic nutrient also didn’t differ significantly among experimental groups. The average gross efficiency of milk production was 26.51% and average gross protein efficiency of milk production was 36.49% and didn’t differ significantly. The average feed conversion efficiency as milk yield (kg) / DMI (kg) was 0.61, FCM yield(kg) / DMI (kg) was 0.86, average ECM yield (kg) / DMI (kg) was 0.89 and average SCM yield (kg) / DMI (kg) was 0.85 in lactating Murrah buffaloes. It was concluded that feeding linseed and linseed oil in lactating Murrah buffaloes didn’t affect the milk production efficiency (gross efficiency of milk production and gross protein efficiency) and feed conversion efficiency.

Reasons for culling cows from a productive herd

The article provides data on the causes and premature culling of cows. Extraordinary activities are a matter of productivity of cows, which significantly affect the efficiency of milk production in livestock farms. First of all, the number and intensity of manifestations of other pathological processes in the body to enhance the quality of milk (grade, bacterial contamination, etc.). The next factor in the economic condition of both an individual economy and the industry as a whole is the length of the productive period. Premature culling of cows entails damage from inefficient use of feed, costs for the unproductive period (from birth to 1 calving), losses from undersupply of calves and often loss of breeding value of the livestock. The aim of the work was to establish the reasons for the culling of cows, which affects the efficiency of the enterprise, especially at the age of 4-6 years (3-5 lactations). At the same time, we used the data of the Uniform-Agri accounting program of the Astarta-Kiev agricultural holding, statistical research methods, and the processing of the data obtained was carried out using a Microsoft Excel 2016 spreadsheet processor. It was found that during 2017-2019. out of 47,282 16538 head retired, which amounted to about 35.0% of the total breeding stock, the largest number of retired cows was observed in the first lactation - 4602, which is 27.8%. In 37.1% of cases, obstetric and gynecological diseases and pathological conditions of the mammary gland were diagnosed. At the same time, 24.5% of culled cows were diagnosed with surgical pathology. In addition, 20.8% of cows dropped out due to metabolic disorders, due to violations of the parameters of keeping and feeding. The next step was to determine the proportion of cow culling due to obstetric (23.9%), gynecological (49.0%), surgical (59.1%) pathology and breast diseases (27.7%). It was also important that 30% of the culled cows had a diagnosis of maceration and mummification of the fetus or ordinary abortion. It should be noted that the vast majority of animals had obstetric, gynecological and surgical pathology at the same time. The culling of animals by age was: after the 1st lactation 31.9%, the 2nd lactation decreased by 12.6 %, and the 3rd, 4th and 5th and more lactations, respectively, by 3.0%. 2.9 and 4.3% Key words: cow, culling, obstetric, gynecological, surgical pathology.

Effects of dietary crude protein concentration on animal performance and nitrogen utilisation efficiency at different stages of lactation in Holstein-Friesian dairy cows

Nitrogen (N) excretion from livestock production systems is of significant environmental concern; however, few studies have investigated the effect of dietary CP concentration on N utilisation efficiency at different stages of lactation, and the interaction between dietary CP levels and stages of lactation on N utilisation. Holstein-Friesian dairy cows (12 primiparous and 12 multiparous) used in the present study were selected from a larger group of cows involved in a whole-lactation study designed to examine the effect of dietary CP concentration on milk production and N excretion rates at different stages of lactation. The total diet CP concentrations evaluated were 114 (low CP), 144 (medium CP) and 173 (high CP) g/kg DM, with diets containing (g/kg DM) 550 concentrates, 270 grass silage and 180 maize silage. During early (70–80 days), mid- (150–160 days) and late (230–240 days) lactation, the same 24 animals were transferred from the main cow house to metabolism units for measurements of feed intake, milk production and faeces and urine outputs. Diet had no effect on BW, body condition score, or milk fat, protein or lactose concentration, but DM intake, milk yield and digestibilities of DM, energy and N increased with increasing diet CP concentration. The effect of diet on milk yield was largely due to differences between the low and medium CP diets. Increasing dietary CP concentration significantly increased urine N/N intake and urine N/manure N, and decreased faecal N/N intake, milk N/N intake and manure N/N intake. Although increasing dietary CP level significantly increased urine N/milk yield and manure N/milk yield, differences in these two variables between low and medium CP diets were not significant. There was no significant interaction between CP level and stage of lactation on any N utilisation variable, indicating that the effects of CP concentration on these variables were similar between stages of lactation. These results demonstrated that a decrease in dietary CP concentration from high (173 g/kg DM) to medium level (144 g/kg DM) may be appropriate for Holstein-Friesian dairy cow to maintain milk production efficiency, whilst reducing both urine N and manure N as a proportion of N intake or milk production.

Feeding native rumen microbial supplements increases energy-corrected milk production and feed efficiency by Holstein cows

The objective of this study was to investigate the effects of 2 novel native microbial feed supplements (MFS) on milk yield, milk composition, dry matter intake (DMI), body weight (BW), body condition score (BCS), and efficiency. A total of 73 lactating Holstein cows were enrolled over 4 mo. During a 2-wk covariate period, baseline data were collected. Using a randomized complete block design, cows were blocked in groups of 3 by days in milk (DIM), production, and parity. Within blocks cows were randomly assigned to a basal diet with a 150 g/d ground corn topdress and no MFS (control), the basal diet supplemented with a 5 g/d dose of Clostridium beijerinckii ASCUSDY20 and Pichia kudriavzevii ASCUSDY21 in a carrier mixed with a 150 g/d ground corn topdress (MFS1), or the basal diet with a 5 g/d dose of Ruminococcus bovis ASCUSDY10, Butyrivibrio fibrisolvens ASCUSDY19, Clostridium beijerinckii ASCUSDY20, and Pichia kudriavzevii ASCUSDY21 in a carrier mixed in a 150 g/d ground corn topdress (MFS2) for 140 d. Cows were fed the diets as a total mixed ration (TMR) for ad libitum DMI once daily. Analysis showed numerical increases in performance variables such as milk yield and fat and protein contents in both MFS1 and MFS2, although the differences were not significant over time. For energy-corrected milk (ECM), other solids percentage, and BW there were significant treatment by time interactions. Cows fed MFS1 and MFS2 produced 1.4 kg/d and 1.6 kg/d more ECM than control cows, respectively (time-dependent treatment significance). Up to wk 13 of treatment, both MFS groups had higher ECM production than the control group but after this point MFS1 rapidly decreased to the same level as control. All cows displayed a gradual decrease in ECM after wk 13 but the MFS2 group remained greater than both control and MFS1. A similar trend in the content of other milk solids was observed. Cow BW was affected over time; both control and MFS2 cows gained weight at a similar rate throughout the study, whereas the weight gain of MFS1 cows decreased briefly from wk 13 to 17 before increasing again. Feed efficiency tended to be improved by MFS, with greater improvement by MFS2 than by MFS1. The DIM when the supplementation began had a significant impact on MFS2 efficacy, where the supplementation of native rumen microbes at an earlier DIM resulted in a greater gain in ECM over the 140-d trial. A similar trend was observed for MFS1, although the effect was not significant. Our results suggest that dairy cow lactation stage and energy requirements also play an important role in product efficacy.

Effects of concentrate supplementation and genotype on milk production and nitrogen utilisation efficiency in late-lactation, spring-calving grazing dairy cows

The study objectives were to evaluate the effects of (1) concentrate supplementation (CS), (2) cow genotype, and (3) a potential interaction between CS and cow genotype on milk production, dry matter (DM) intake (DMI) and cow nitrogen (N) utilisation efficiency (NUE) in late lactation (+208 ± 14.1 days in milk), spring-calving grazing dairy cows. The experiment was a complete randomised block design with a 2 × 2 factorial arrangement of treatments and was conducted over a 52-day period. There were two feeding strategies (pasture-only (PO) and pasture + 2.7 kg DM CS) and two genotype groups [lower milk genotype (LM; milk kg PTA = -48 ± 59.9, fat kg PTA = +7 ± 4.7 and protein kg PTA = +3 ± 3.2) and higher milk genotype (HM; milk kg PTA = +190 ± 109.7, fat kg PTA = +12 ± 5.7 and protein kg PTA = +9 ± 3.6)]. Cows in their respective genotype group were randomly assigned to one of two feeding strategies, resulting in four treatment groups (n = 12). Cows grazed full time and were allocated 17 kg DM pasture/cow per d. No interactions were observed for any parameters measured. Cows offered CS had increased daily yields of fat + protein (+0.18 kg), lactose (+0.13 kg) and ECM (+2.46 kg) compared to cows offered PO. The HM cows had increased yields of daily fat + protein (+0.13 kg) and lactose (+0.1 kg) compared to the LM cows. Cows offered CS had decreased daily protein (-0.14%) but increased lactose (+0.08%) concentration compared to cows offered PO. The HM cows had decreased daily fat (-0.2%), protein (-0.16%) and casein (-0.07%) concentration compared to the LM cows. Cows offered CS had a reduced daily pasture DMI (-1.41 kg) but an increased daily total DMI (+1.29 kg) and feed N intake (+0.085 kg) compared to cows offered PO. Cows offered CS had decreased NUE (-0.1%) compared to cows offered PO. In conclusion, offering cows 2.7 kg DM CS per day improved milk production in late lactation but resulted in a poorer NUE. The poorer NUE was due to no difference in milk N output and an increase in the partitioning of feed N to urine. The HM cows had an increased milk response to CS with respect to milk fat + protein kg compared to the MR obtained from LM cows.

The economic efficiency of the use of mixed ligand complexes of Zinc, Man-ganese and Cobalt in the rations of highlyproductive cows of the Ukrainian Black-Spotted Dairy breed

The research results on the cost-effectiveness of using different doses of Zinc, Manganese, and Cobalt due to their mixed ligand complexes in the feeding rations of highly productive cows of the Ukrainian Black-Spotted Dairy breed in the first 100 days of lactation are presented. Experimental studies were conducted on five (one control and four experimental) groups of analogous cows in the conditions of the Kyiv region's ALC “Terezyne” Bila Tserkva district. The optimal dose of mixed-ligand complexes of Zinc, Manganese, and Cobalt was established in previous studies, with a concentration of 1 kg of dry matter (DM) of the feed mixture (FM), mg: Zinc – 60.8; Manganese – 60.8, and Cobalt – 0.78. For the second experimental group, the concentration of these trace elements increased by 10 %, and in the 3rd, fourth, and fifth experimental groups – on the contrary, it decreased by 10 %, 20, and 30 %, respectively, compared with the control. The highest hopes of essential fat milk were in experimental cows of the 4th group and were 4791.7 kg, where due to mixed ligand complexes, the doses of Zinc and Manganese were 48.6 mg, and Cobalt – 0.62 mg per 1 kg of DM. The hopes of essential fat milk, compared with the control, in cows of the second experimental group, was higher by 155.2 kg, the 3rd – by 211.3 kg, the 4th – by 427.0 kg, and the fifth experimental group – by 234.6 kg. The lowest hopes of essential fat milk were in cows of the first control group. Using additives of mixed ligand complexes of Zinc, Manganese, and Cobalt in complete feed mixtures allowed profit, UAH: in the first control group – 7581.5; second experimental group – 7963.1; third – 8004.1; fourth – 8437.6 and 5th – 8119.0. The most significant profit, by UAH 856.1, or 11.29 % more than control, was obtained in the fourth experimental group of cows of the Ukrainian Black-Spotted Dairy breed. The positive effect of feeding different levels of Zinc, Manganese, and Cobalt due to their mixed ligand complexes to cows of the Ukrainian Black-Spotted Dairy breed in the first 100 days of lactation on the indicators of economic efficiency of milk production. The best results were obtained in the fourth experimental group, whose cows were fed a feed mixture containing 1 kg of DM, mg: Zinc – 48.6; Manganese – 48.6; Cobalt – 0.62; Selenium – 0.3; Copper – 12 and Iodine – 1.1.

The influence of using plant‐mineral bolus in early fresh period on the efficiency of the first inseminations of dairy cows

The early fresh period has a big value in the productive life of animals. The level of management on this time in the farm and the animals’ body state have a correlation with milk production and reproductive efficiency. The purpose of the study was to research the influence of vegeto‐mineral bolus using in early fresh period on the efficiency of the first inseminations of dairy cows. The studies were carried out in one of the breeding farms of the Leningrad region. It was Holstein cows aged from 2 to 7 years. The milk production of cows was 9000 kg. It was two groups (n=80 by each). The cows of the experimental group in the early fresh period received plant‐mineral boluses Metrabol (Techna France Nutrition S.A.S., France). The compound of these boluses includes vitamin E, Mg, Zn, Cu, Se and herbal components (calendula, cinnamun, suisque). It was 2 boluses per animal during the first 12 hours after calving. The protocol of early fresh period of cows (control group) was used the injection of antibacterial, myotonic and multivitamin preparations in the first day of calving. The using of plant‐mineral boluses in the early fresh period had a positive influence on the efficiency of the first inseminations. The high result of first inseminations had cows of experimental group. The difference of values between two groups was 12,8% (first lactation); 1,3% (second lactation); 17,5% (third or more lactation). However, the higher percentage of efficiency after second insemination had cows of control group. The difference of values was 19 % (first lactation); 14,5 % (second lactation) and 15,8% (third or more lactation). More successful third and other inseminations were seen in cows of the experimental group. Thus, the percentage of first lactation’ cows was 6,2%, second lactation – 13,3%, the third and more lactations ‐1,8%. It can be concluded that the using of plant‐mineral boluses during the first 12 hours after calving contributes to a faster recovery of the reproductive system of cows in the postpartum period, which is expressed by a higher efficiency of the first inseminations.