Level Of Milk Production Research Articles

Short communication: Dairy Victory™ Platform: A Novel Benchmarking Platform to Empower Economic Decisions on Dairy Farms.

In the face of diminishing economic margins, dairy farmers globally are compelled to maintain economic competitiveness. Benchmarking emerges as a strategic tool to establish new, achievable improvement objectives that balance ambition with practicality. This typically requires integrating diverse data sources such as feed, milk production, diet, and market prices. However, many farms lack essential, cow-level data like daily milk output and milk income over feed cost (IOFC), which hampers economic performance visibility and informed decision-making. To address this challenge, we introduce “Dairy Victory™ platform (DVP)” a novel cloud-based benchmarking platform designed to simplify complex analyses. The DVP uniquely calculates zootechnical and economic key performance indicators (KPIs) at the cow and herd levels and benchmarks these against a dynamically selected cohort of farms, facilitating comparisons across various farm sizes, and milk production levels. The primary objective of this paper is to demonstrate the utility of DVP as a decision-making tool in supporting farmers and consultants with both operational and strategic decisions. It emphasizes leveraging benchmarking information to enhance decision-making processes, thereby highlighting the significant value that DVP brings to farmers, consultants, and dairy farm stakeholders. Our study analyzed data from 712 farms from December 2023, focusing on several KPIs, such as milk production, milk quality, feed efficiency, and IOFC using Dairy Herd Improvement (DHI) records. This approach showcases DV's ability to utilize minimal data inputs for detailed analysis, leveraging peer performance to set desirable and/or achievable goals. We present a case study demonstrating how the DVP platform can guide dairy farms using anonymized peer data. This approach enables users to potentially improve their IOFC by up to 35%. Our findings highlight DVP's potential as a powerful tool for generating insightful analyses, simulations, and recommendations, primarily from test-day data, but also integrated with market and estimated data. This supports more strategic decision-making in dairy management, including automatic goal-setting based on peer performance.

PSXI-30 Economic impact of pre-training on dairy cattle automatic milking system acclimation

Abstract Pre-training in automatic milking systems (AMS) has the potential to increase milk production and milk quality. In a recent study, cows that experienced pre-training (TRT; i.e. intentional training access with an AMS prior to first AMS milking) had greater milk yield and fat percentages compared with no pre-training (38.4 vs. 37.6 ± 0.2 kg/d; 4.75 vs. 4.38 ± 0.06%; P < 0.01, and < 0.01 respectively). Similarly, cows without pre-training had greater somatic cell count (SCC; 298,860 vs. 188,220 ± 10,700 cells/mL; P < 0.001). The time required for pre-training could be a limiting factor (40 ± 10 h/wk), and the economic implications of labor versus long-term benefits must be examined. To that end, a stochastic simulation tool was developed to consider the increased costs of labor and the potential benefits of improved milk yield, milk fat percentage, and decreased somatic cell count. The GRKS distribution with minimum, mean, and maximum values was used to model increases in milk yield (0, 1.4, 1.8 kg), fat percentage (0, 3.5%, 4.5%), and labor cost ($0.0011, $0.0016, $0.0020 per h) and decreases in SCC (0, 120, 130 x 103 cells/mL) per hundredweight of milk produced. Baseline values for milk production ranged from 14.7 to 59.2 kg/cow/d in 4.4 kg increments with fat percentage of 3.5% and SCC of 312,000 cells/mL. The model assumed a minimum increase across milk yield, fat, and SCC of 0 (no change). The Simetar add-on in Microsoft Excel simulated 500 iterations across three herd size scenarios (60, 120, and 480 cows) and calculated the marginal return on investment across a 90-d period for all milk production ranges. Regardless of starting milk production level, pre-training had a positive economic impact across all levels (30 to 50 h) and herd sizes (Table 1). Financial impact per cow per d with input of 30, 40, and 50 h ranged from $0.58 to $0.73, $0.56 to $0.71, and $0.54 to $0.70. The majority of simulations returned a positive marginal impact for pre-training. If pre-training resulted in a loss, it ranged from $242 to $1,937, $323 to $2,585, $405 to $3,246, across 30, 40, and 50 hours, respectively. Based on these results, the investment in pre-training time was consistently beneficial for simulated herds.

Profitability of dairy goat farms in Bulgaria

Abstract. The purpose of the present study was to establish the economic performance of dairy goat farms in Bulgaria by using the indicator profitability and the related indicators – total production, total revenues, total costs and profit per doe (before and after subsidy). Data for 2022 were provided by the owners of 8 farms within the survey and processed using a mathematical-statistical model and Excel program. The adopted production system was semi-intensive with indoor winter period and grazing (supplemented with cereals and hay) during most of the year. Profit before subsidies was found positive only for farm 5, and all other holdings were unprofitable based on the results of their own production. When subsidies were added, some of them reported a positive financial result, while others remained loss-making. Based on the results found within the study, it could be summarized that in the dairy sector the level of milk production is the leading factor for farm income. Оf great importance are also the sale of value-added dairy products, own feed production and optimization of labour costs. In most farms, subsidies (incl. for pastures) are extremely important for the viability of the farms. In addition, when analyzing the economic efficiency of dairy goats, an individual approach to farms is necessary. All elements of the production system, both biological and economic, should be taken into account in order to improve production and profits.

Liver Biopsy Technique for Analysis of Hepatic Content during Pregnancy and Early Lactation in Dairy Goats.

Biopsy techniques in dairy goats are currently limited. This study aimed to describe a liver biopsy technique in dairy goats and to evaluate liver triglyceride levels and glycogen content. Sixty-nine dairy goats in the final stage of pregnancy and early lactation period were selected. Fifty goats were selected randomly for hepatic biopsy (HB) according to gestational period and were characterized according to fetus number (single: n = 16, multiple: n = 34), supplementation with propylene glycol (diet: n = 23, diet+PG: n = 27), and milk production levels (high: 3.0 ± 0.4 L/day, n = 15; low: 1.4 ± 0.4 L/day, n = 26). Liver tissue samples were obtained through biopsy on days -30, -20, -15, -10, -5, and 15 days after calving. Hepatic triglyceride and glycogen were quantified. The results were analyzed using the F-test at a 5% significance level and a comparison of means using the Tukey test. The liver biopsies did not influence dry matter intake, body weight, or milk yield. Hepatic glycogen concentration was lower 15 days after calving than it was prior to calving, except on day -20. Goats that generated high levels of milk production had lower triglyceride levels than goats that generated low levels of milk production. The biopsy technique is a safe method for obtaining tissue and evaluating liver content in dairy goats. The milk production level and days relative to parturition influence the hepatic triglyceride and glycogen content in dairy goats.

Developmental programming of production and reproduction in dairy cows: V. Association of the main and interactive effects of maternal level of milk production and milk fat to protein ratio with offspring's birth weight, survival, and productive and reproductive performance from birth to the first lactation period

Level of dam milk production (DMP) and dam milk fat to protein ratio (DFPR), as an indicator of metabolic status in dairy cows, have been identified to be associated with productive and reproductive performance of the offspring. Yet whether the interaction of DMP by DFPR can be associated with performance of the offspring have not been studied to our knowledge. Therefore, the present study was conducted to investigate the association of the main and interactive effects of DMP and DFPR with offspring's birth weight, survival, milk yield and fertility. To this end, data of birth weight, culling rate, milk yield and reproductive variables of offspring born to lactating dams (n = 14,582) and data associated with DMP and DFPR during 305-day lactation were retrieved. Afterwards, offspring were classified in three categories of DMP, including DMP1 (dams with <10.00 × 103 kg of 305-day milk production), DMP2 (dams with ≥10.00 × 103 kg and <14.00 × 103 kg of 305-day milk production), DMP3 (dams with ≥14.00 × 103 kg of 305-day milk production), and three categories of DFPR, including DFPR1 (offspring born to dams with <1.00 FPR), DFPR2 (offspring born to dams with ≥1.00 and < 1.40 FPR) and DFPR3 (offspring born to dams with ≥1.40 FPR). Statistical analysis revealed no association of the interaction effect of DMP by DFPR with investigated variables in the offspring (P > 0.05). However, the main effect of DMP was positively associated with milk yield, but negatively associated with survival, age at first insemination and conception during nulliparity, and transgenerational improvement in milk yield in the offspring (P < 0.05). Moreover, the main effect of DFPR was positively associated with birth weight, survival and first service conception rate during nulliparity, but negatively associated with metabolic status and reproductive performance during primiparity in the offspring (P < 0.05). In conclusion, the present study did not find any interaction effect of DMP by DFPR on productive and reproductive variables in the offspring. This finding implicates the association of DMP with milk production in the offspring was regardless of DFPR. Moreover, this finding implies the association of DFPR with postpartum metabolic status and reproductive performance in the offspring was regardless of DMP.

Probiotic Lactobacillus rhamnosus GG improves insulin sensitivity and offspring survival via modulation of gut microbiota and serum metabolite in a sow model

BackgroundSows commonly experience insulin resistance in late gestation and lactation, causing lower feed intake and milk production, which can lead to higher mortality rates in newborn piglets. The probiotic Lactobacillus rhamnosus GG (LGG) is known to improve insulin resistance. However, whether supplementing LGG can improve insulin sensitivity in sows and enhance lactation performance, particularly the early survival of offspring remains unclear. Hence, we explored the effects and mechanisms of supplementing LGG during late gestation and lactation on sow insulin sensitivity, lactation performance, and offspring survival. In total, 20 sows were randomly allocated to an LGG (n = 10) and control group (n = 10).ResultsIn sows, LGG supplementation significantly improved insulin sensitivity during late gestation and lactation, increased feed intake, milk production and colostrum lactose levels in early lactation, and enhanced newborn piglet survival. Moreover, LGG treatment significantly reshaped the gut microbiota in sows, notably increasing microbiota diversity and enriching the relative abundance of insulin sensitivity-associated probiotics such as Lactobacillus, Bifidobacterium, and Bacteroides. Serum metabolite and amino acid profiling in late-gestation sows also revealed decreased branched-chain amino acid and kynurenine serum levels following LGG supplementation. Further analyses highlighted a correlation between mitigated insulin resistance in late pregnancy and lactation by LGG and gut microbiota reshaping and changes in serum amino acid metabolism. Furthermore, maternal LGG enhanced immunity in newborn piglets, reduced inflammation, and facilitated the establishment of a gut microbiota.ConclusionsWe provide the first evidence that LGG mitigates insulin resistance in sows and enhances offspring survival by modulating the gut microbiota and amino acid metabolism.

Assessing the Biodetoxification Potential of Enterococcus faecium on Aflatoxin M1 in Fresh Raw Cow Milk

Study’s Novelty/Excerpt This study contributes to the field of food safety by exploring the bio-detoxification potential of E. faecium isolates from locally fermented cow milk for reducing Aflatoxin M1 (AFM1) contamination. By employing both biochemical and molecular methods to identify and utilize these isolates, the research provides innovative insights into an environmentally friendly and health-beneficial approach to mitigating aflatoxin contamination. The findings demonstrate a significant AFM1 binding capacity of E. faecium, highlighting its potential as a practical and safe biocontrol agent, which is critical for improving milk safety standards and public health protection. Full Abstract The adverse effects of aflatoxins on the economy and public health have prompted research into strategies to prevent their contamination in food and feed. Biological methods have become popular because they are environmentally friendly and beneficial for health. This research aims to determine the bio-detoxification potential of E. faecium, on Aflatoxin M1 (AFM1) in raw cow milk. Biochemical and molecular methods were used to identify the E. faecium isolates obtained from locally fermented cow milk (Nono). Three (3) distinct sampling locations in the Zaria metropolis, Dan-Magaji, Kufena, and Gabari, were used to gather nine (9) fresh milk samples. A quick test kit was used to screen the samples for AFM1 contamination. To determine the level of contamination, AFM1-contaminated samples were analyzed using High-Performance Liquid Chromatography (HPLC) analysis. The isolates were injected into the tainted milk samples at a cell density of 1.5 x 108cfu/mL and 3.0x108cfu/mL for 30 and 60 minutes at 4 and 37 degrees Celsius. The amount of unbound AFM1 in the samples was measured using HPLC analysis and surface binding assay. "ANOVA" single factor and two ways were used to analyze the data. All collected raw milk samples were contaminated with aflatoxin M1 at concentrations exceeding the EU/NAFDAC limit of ≤0.05 µg/L. The isolates bound AFM1 at 35-45% rates at a cell concentration of 3.0x108 cfu/mL at 37°C for 60 minutes. This research suggests that E. faecium could be an effective option for reducing AFM1 contamination in milk samples due to its harmless nature and recognition as generally safe. Additionally, regulatory agencies should implement thorough monitoring to ensure AFM1 levels in milk and milk products remain below acceptable limits.

Milk productivity and the concentration of ketones in the blood of Kostroma cows of different LEP genotypes

Relevance. Currently, scientists are searching for genes associated not only with an increased level of dairy productivity, but also with the preservation of functional longevity and health of cows, with a high level of realization of their genetic potential, as well as with the distinctive quality of dairy products. The available data allow us to consider the leptin gene (LEP) as one of the candidate genes of milk productivity.Methods. The research was conducted in 2022–2023 on cows of the Kostroma breed (n = 107) bred in the Kostroma region. In cows in the postpartum period, the content of ketone bodies in the blood and genotypes were determined by the R25C locus of the LEP gene. The animals were divided into groups depending on the concentration of ketone bodies in the blood: 1st – 0–1.2 mmol/l, 2nd – above 1.2 mmol/l.Results. The presence of a predisposition of highly productive cows to ketosis (р &lt; 0.05) was established. The largest number of ketone bodies in the blood was determined in animals of the 2nd group with the LEPCT genotype. However, despite such a small difference, the difference in the frequency distribution of LEP alleles in groups 1 and 2 turned out to be statistically significant (χ2 = 63.48, р &lt; 0.001). When testing the hypothesis of a significant dependence of the level of milk productivity on the concentration of ketone bodies in the blood of carriers of the CC genotype, a statistically significant rho value was obtained among cows with the CC genotype, at the level of 0.37 (р = 0.038). The rank correlation between milk yield and ketone body content in carriers of LEPCT and LEPTT genotypes was low and unreliable (р &gt; 0.05). The tendency towards a close relationship between the level of ketone bodies and the fat content in the milk of cows of the TT genotype due to its low concentration in the sample requires further confirmation in a larger sample of cows with this genotype of the leptin gene.

Tradeoffs between herd turnover rate and milk production for marginal cash flow and enteric methane intensity

Longevity, productive lifespan, and culling are discussion top­ics among veterinarians, farmers, milk buyers and third par­ties such as NGOs. Further, the number of heifers to be raised as replacements is also of industry interest. It is sometimes proposed that having less replacement heifers and thus a lower herd turnover rate can lead to higher cash flow and lower enteric methane intensity associated with dairy production. Recently, some investigators have reported that cow culling de­cisions are made for farm investment decisions as opposed to poor health status (Owusu-Sekyere et al., 2023). Some European workers (Grandl et al., 2019) have investigated the association of length of productive life with greenhouse gas emissions and profit but included milk yields below what is observed on many U.S. dairy farms. There are likely trade-offs between replacing less productive cows with younger cows that possess greater potential for herd cash flow and enteric methane production at commonly ob­served or advocated turnover rates and milk production levels. Therefore, the objective of this work was to produce a math­ematical model using typical market prices, milk production levels, and turnover rates observed currently in the U.S. that examines these trade-offs.

Effect of commercial fibrolytic enzymes application to normal- and slightly lower energy diets on lactational performance, digestibility and plasma nutrients in high-producing dairy cows.

The inclusion of fibrolytic enzymes in the diet is believed to have positive effects on animal production. Hence, the objective of this study was to investigate the impact of supplementing diets with a commercial fibrolytic enzyme preparation (Vistamax; mixture of xylanase and cellulase) derived from Trichoderma reesei on lactational performance, digestibility, and plasma nutrient levels in high-producing dairy cows. Two dietary energy levels were considered: a normal energy diet (metabolizable energy = 2.68 Mcal/kg) and a slightly lower energy diet (metabolizable energy = 2.55 Mcal/kg). A total of 120 lactating Holstein cows (parity = 2; Days in Milk = 113 ± 23) were randomly assigned to four treatment groups using a 2 * 2 factorial arrangement. The dietary treatments consisted of: (1) normal energy diet without enzyme supplementation (NL); (2) normal energy diet with enzyme supplementation (NLE); (3) slightly lower energy diet without enzyme supplementation (SL); and (4) slightly lower energy diet with enzyme supplementation (SLE). The amount of enzyme added to the diets was determined based on previous in vitro studies and supplier recommendations. The enzyme and premix were mixed prior to the preparation of the total mixed ration, and the trial lasted for a duration of 42 days. The results indicated that the application of the fibrolytic enzyme did not have a significant effect on dry matter intake (DMI), but it did enhance the digestibility of dry matter (DM), neutral detergent fiber (NDF), potentially digestible NDF (pdNDF), organic matter (OM), milk production, milk urea nitrogen (MUN), and blood urea nitrogen (BUN). On the other hand, the slightly lower energy diet resulted in a decrease in DMI, milk production, milk protein yield, plasma free amino acids (FAA), and an increase in plasma B-hydroxybutyrate (BHBA). In conclusion, the inclusion of the fibrolytic enzyme in the diets of dairy cows led to improvements in the digestibility of DM, NDF, pdNDF, OM, milk production, and feed efficiency. Furthermore, the application of the enzyme to the slightly lower energy diet resulted in milk production levels comparable to those observed in cows fed the untreated normal energy diet.

Factors Affecting the Milk Production Traits and Lactation Curve of the Indigenous River Buffalo Populations in Bangladesh.

Household buffalo dairy farming is gaining popularity nowadays in Bangladesh because of the outstanding food value of buffalo milk as well as the lower production cost of buffalo compared to cattle. An initiative has recently been taken for the genetic improvement of indigenous dairy buffaloes. The present study was carried out to determine the influence of some environmental factors like age, parity, season of calving, calving interval, dry period on the lactation yield, and lactation curve of indigenous dairy buffaloes of Bangladesh. A total of 384 indigenous dairy buffaloes from the 3rd and 4th parity of seven herds under two different agroecological zones covering four seasons were selected and ear tagged for individual buffalo milk recording. A milk yield of 300 days (MY300d) was calculated following the International Committee for Animal Recording (ICAR) and the data were evaluated using the generalized linear model (GLM). In production traits, the mean of calculated lactation period (CLP), calculated lactation yield (CLY), and milk yield of 300 days (MY300d) of the overall population were 267.28 days, 749.36 kg, and 766.92 kg, respectively, whereas calving interval (CI) and dry period (DP) as reproductive traits were 453.06 days and 185.78 days, respectively. The season of calving, age of buffalo cows, population or herd, agroecological zone, calving interval, and dry period had significant effects on production traits (p < 0.05 to p < 0.001). The season of calving, level of milk production of 300 days, population, and agroecological zone significantly affected the reproduction traits (p < 0.01 to p < 0.001). Parity was found to be non-significant for both types of traits. The average peak yield of test day (TD) milk production was highest at TD4 (4.47 kg, 98th day of lactation). The average MY300d of milk production was the highest in the Lalpur buffalo population (1076.13 kg) and the lowest in the buffalo population of Bhola (592.44 kg). The correlations between milk production traits (CLP, CLY, and MY-300d) and reproduction traits (CI and DP) were highly significant (p < 0.01 to p < 0.001). Positive and high correlation was found within milk traits and reproduction traits, but correlation was negative between milk traits and reproduction traits. Therefore, these non-genetic factors should be considered in the future for any genetic improvement program for indigenous dairy buffaloes in Bangladesh.

Feeding Balanced Ration for Improving Dairy Cattle Productivity: A Review

In India and similar subtropical regions, dairy livestock primarily consume various by-products derived from locally cultivated crops, fodder, and oilseeds. Approximately 65-70 per cent of the total milk production cost is attributed to feed expenses. Ensuring a balanced diet is pivotal for the success of dairy development initiatives across India. The optimal productivity of dairy animals is achieved when they are provided with a nutritionally balanced diet that matches their genetic potential. To enhance the productivity of livestock owned by small-scale farmers, a balanced ration program was introduced. Under this program, animals are categorized based on their milk production levels: low (&lt;8 kg/day), medium (8–12 kg/day), and high (&gt;12 kg/day) yielders. The program assessed milk yield, milk fat content, and the net daily income of milk producers before and after implementing a balanced diet regimen. The nutritional assessment revealed that 71 per cent of the animals consumed excessive amounts of crude protein and metabolizable energy, while 65 per cent exhibited lower intake levels of calcium and phosphorus than required. Implementing a balanced ration resulted in an improvement in milk production ranging from 2 to 14 per cent, along with a 0.2 to 0.15 per cent increase in milk fat content.

Consumer Behavioural Patterns Towards Milk and Dairy Products: An Analytical Investigation of an Indian Dairy Supply Chain

Background: India has the most significant milk production and consumption level in the world. Fluid milk consumption will rise to 90 million metric tons in FY 2024 (Annual Report 202-23, United States Department of Agriculture). Milk is an essential component of daily diet in every age segment in India. Consumers’ behaviour and consumption patterns are based on their choices and preferences about product quality, price and preferences. This article critically investigates the consumer perception towards indigenous dairy markets and their consumption and behavioural pattern. Methods: Quantitative approach and Multiple Logistic Linear Regression Analysis (MLLRA) technique was used to test the hypothesis to establish a direct and indirect relationship among endogenous and exogenous variables. The sample was drawn from rural and urban regions of India’s top ten milk-producing states. Result: The research findings suggested a significant relationship between the direct and indirect role of consumers buying behaviour characteristics towards milk and dairy products and their satisfaction level. This research is limited to milk processors, dairy companies and dairy scientists in the field of marketing and dairy research. Dairy Farmers, Processors and Producers are vigilant about the quality of food products, especially milk delivered to their end users and their value-addition in the Milk Supply Chain (MSC) and logistics. In the past three years, during the unprecedented COVID-19, consumers’ consciousness level about health and well-being has been argued.

Developmental programming of reproduction in the female animal

Successful reproduction is a cornerstone in food animal industry in order to sustain food production for human. Therefore, various methods focusing on genetics and postnatal environment have been identified and applied to improve fertility in livestock. Yet there is evidence indicating that environmental factors during prenatal and/or neonatal life can also impact the function of reproductive system and fertility in the animals during adulthood, which is called the developmental programming of reproduction. The current review summarizes data associated with the developmental origins of reproduction in the female animals. In this regard, this review focuses on the effect of plane of nutrition, maternal body condition, hypoxia, litter size, maternal age, parity, level of milk production and milk components, lactocrine signaling, stress, thermal stress, exposure to androgens, endocrine disrupting chemicals, mycotoxins and pollutants, affliction with infection and inflammation, and maternal gut microbiota during prenatal and neonatal periods on the neuroendocrine system, puberty, health of reproductive organs and fertility in the female offspring. It is noteworthy that these prenatal and neonatal factors do not always exert their effects on the reproductive performance of the female by compromising the development of organs directly related to reproductive function such as hypothalamus, pituitary, ovary, oviduct and uterus. Since they can impair the development of non-reproductive organs and systems modulating reproductive function as well (e.g., metabolic system and level of milk yield in dairy animals). Furthermore, when these factors affect the epigenetics of the offspring, their adverse effects will not be limited to one generation and can transfer transgenerationally. Hence, pinpointing the factors influencing developmental programming of reproduction and considering them in management of livestock operations could be a potential strategy to help improve fertility in food animals.

ВЛИЯНИЕ ЖИВОЙ МАССЫ МОЛОДНЯКА НА ПОСЛЕДУЮЩУЮ МОЛОЧНУЮ ПРОДУКТИВНОСТЬ ПЕРВОТЕЛОК В РАЗНЫХ КЛИМАТИЧЕСКИХ ПОЯСАХ РОССИЙСКОЙ ФЕДЕРАЦИИ

The purpose of research is to study the effect of live weight of heifers at the age of 6 months on their subsequent milk production. Objectives: to study the growth rate of heifers with different live weights at 6 months; to assess the level of milk productivity (milk yield, mass fraction of fat and protein, amount of milk fat and protein) in first-calf heifers with different live weights at 6 months. The study included more than 25 thousand first-time Holstein heifers of the same genotypes (lines), bred in four climatic zones co-vering the territory of the Russian Federation. These zones include subtropical, temperate continental, extreme continental and arctic climates. The regions of the Far North with the most severe and cold climate, unsuitable for breeding Holstein dairy cattle, were not taken into account. Data from the Selex information system were used for the analysis. Statistical processing of the obtained data was carried out on the basis of generally accepted methods of variation statistics (using MS Excel). The reliability of the difference bet¬ween the compared values was determined using the significance criterion according to the Student's table. It was found that the live weight of calves at 6 months has a certain influence on the subsequent milk productivity of first-calf heifers. However, the optimal live weight varies depending on the climatic zone. Thus, in a subtropical climate, the optimal live weight is more than 175 kg; in a temperate continental climate – more than 185; in a sharp continental climate – less than 166; in a harsh arctic climate – over 200 kg. These results make it possible to optimize the breeding process and ensure maximum milk production in different climatic conditions.

Использование геномной оценки в совершенствовании продуктивных качеств коров голштинской породы

Abstract. Purpose of the study is analysis of productive and reproductive qualities of the Holstein cattle of the Tyumen region in comparison with the leading American enterprises using genomic selection. Materials and methods. Zootechnical, statistical and economic methods were used. As part of the work, the tasks were solved to consider the growth and development of replacement young animals; the main indicators of reproduction of heifers and cows of the main herd were analyzed; the milk productivity of cows and first-calf heifers was estimated according to the primary accounting data; a zootechnical assessment of sires used in the economy was carried out; the results of the genomic assessment were compared with the actual milk production. The scientific novelty of the work lies in the fact that genotyping was carried out in the conditions of a large industrial complex, because the use of genomic evaluation was not widely used in farms in the Russian Federation. Research results. The indicators of the intensity of growth of replacement young animals grown in the conditions of the Evika-Agro enterprise correspond to the world standards of the breed, and in some cases exceed them. The intensity of growing heifers allows for earlier insemination, which also contributes to early calving - 98% of animals calve up to 25 months of age. Estimates of milk production are largely consistent with those of advanced farms in the United States. “Evika-Agro” LLC uses outstanding sires from the world’s gene pool to improve economically useful traits, thereby accelerating the rate of selection. Analysis of the genomic assessment showed a significant discrepancy between the genetic basis of milk production and the actual level of milk production. This is most noticeable in the lifetime earnings index ($ 682) and the average increase in milk per lactation (916.2 kg) between the worst and best heifers in the sample.

Identification of genetic variants of bGH, GHR and IGF1 gene and their association with lactation persistency in Tharparkar cattle

Persistency can be explained as number of days during which the high level of milk production is maintained after the peak milk yield. The aim of this study was to identify genetic variants of bovine-Growth Hormone (bGH), Growth Hormone Receptor (GHR) and Insulin like Growth Factor1 (IGF1) gene and their association with lactation persistency in Tharparkar cattle. Study was carried out using data of daily milk yield, monthly test days, total milk yield and peak yield of 372 lactation records of 190 Tharparkar cattle maintained at Livestock Research Centre of ICAR-National Dairy Research Institute from 1996-2019. Lactation persistency was estimated using Woods and Wilminks method and its least squares means were 2.37±0.08 and -5.4±0.56, respectively. Investigations on polymorphism were performed using seven reported primers for amplifying targeted regions of bGH, GHR and IGF1 gene. In PCR-RFLP, bGH-MspI RFLP had shown polymorphism in intron 3 and its genotypic frequencies were TT 0.49, CT 0.39 and CC 0.12. The allelic frequency of C and T were 0.31 and 0.69, respectively. The bGH-AluI RFLP had shown monomorphism in exon 5. GHR-AluI had shown polymorphism in exon 10 with only two genotypes AA and AG with frequency of 0.92 and 0.08, respectively. The frequency of A and G allele was 0.96 and 0.04, respectively. In GHR-StuI and IGF1-TasI in promoter region, RsaI in exon 3 and SnaB I in exon 1 had shown monomorphism. No significant association was found between genetic variants of bGH and GHR with lactation persistency in Tharparkar cattle.

Determination of cypermethrin and hexachlorobenzene levels in milk and dairy products using high-performance liquid chromatography in Isfahan, Iran

ABSTRACT This study aimed to determine the levels of cypermethrin and hexachlorobenzene in milk and dairy products in Isfahan, Iran. In this study, 50 samples including raw milk, pasteurised milk, ultra-high temperature milk, traditional butter, pasteurised butter, traditional cheese, and pasteurised cheese were randomly collected from distribution centres in Isfahan city from June to September 2022. The pesticide levels in the samples were determined using high-performance liquid chromatography. The results indicated that the highest levels of cypermethrin, with 81.02 ± 23.77 µg/kg, were found in traditional butter, pasteurised butter, pasteurised cheese, and traditional cheese, which did not significantly differ. Regarding hexachlorobenzene, traditional butter with 66.68 ± 19.87 µg/kg and pasteurised butter with 47.16 ± 14.45 µg/kg had the highest contamination levels, which were not significantly different. The results indicated contamination of milk and dairy products supplied in Isfahan with pesticide residues.

Продуктивность коров при разной комбинации линий

The purpose of the study was to study the milk productivity of cows with different combinations of lines. The object of the study were first-calf cows of the black-and-white breed of the line Vis Back Aidiala 101341, Reflection Soveringa 198998, Montvik Chiefteina 95679. Cows obtained by intraline selection of the Aidial line have a high level of milk productivity, with milk yield of 5571 kg of milk, milk fat yield of 226 kg and protein yield of 171 kg, while significantly (P&lt;0.05-0.01) superior to first-calf heifers, belonging to the Sovering line for 102 kg, 4 kg of fat and 4 kg of protein, and to the Chieftain line - for 259 kg of milk, 16 kg of fat and 11 kg of protein, respectively. When crossing the Ideal-Sovering lines, the highest milk yield is observed (5667 kg), with good milk fat content (4.01 %), high yield of milk fat (227 kg) and milk protein (172 kg). With the reverse cross Sovering-Idial, slightly lower milk productivity rates were obtained. When using bulls of the Aidial line on cows of the Governer line, high milk fat content (4.07 %) and milk fat yield (228 kg) were obtained, with average values of milk yield (5596 kg), protein mass fraction (3.01 %) and its yield (168 kg). Unsuccessful combinations of lines in both forward and reverse directions are crosses of the Idial and Chieftain lines. The descendants of such combinations have the lowest milk productivity. Thus, the use of line manufacturers R. Sovering and V.B. Idiala, both with intraline selection and interline combination, gives the best milk productivity indicators. Consequently, it is necessary to evaluate bulls according to the compatibility of lines; this has a great influence on the productivity of the offspring, since sires of the same line, when inseminating cows of the same lines, produce offspring of different productivity.

Developmental programming of production and reproduction in dairy cows: III. Association of level of maternal milk production with offspring's birth weight, survival, productive and reproductive performance and AMH concentration from birth to the first lactation period

Although some studies investigated the relationship of dam milk production (DMP) with offspring birth weight and productive performance, limited information is available on the association of level of DMP with reproductive performance in dairy cows. Therefore, the present study was conducted to understand whether dams with various levels of milk production produce offspring with different fertility. In study I, offspring were classified based on the level of DMP into five categories, including DMP1 (dams with <10.00 × 103 kg of 305-day milk production), DMP2 (dams with ≥10.00 × 103 kg and <12.00 × 103 kg of 305-day milk production), DMP3 (dams with ≥12.00 × 103 kg and <14.00 × 103 kg of 305-day milk production), DMP4 (dams with ≥14.00 × 103 kg and <16.00 × 103 kg of 305-day milk production) and DMP5 (dams with ≥16.00 × 103 kg of 305-day milk production). In study I, data of birth weight, milk yield and reproductive variables of 14,536 offspring born to lactating dams and corresponding data of DMP were retrieved. In study II, blood samples (n = 339) were collected from offspring in various categories of DMP for measurement of serum AMH. Offspring were heavier at birth in DMP4 and DMP5 categories than DMP1 and DMP2 categories (P < 0.05). Milk yield of offspring increased as DMP elevated (P < 0.05); however, offspring in DMP1 and DMP2 categories produced higher milk as compared with their dams during primiparity (P < 0.05) whereas offspring in DMP3, DMP4 and DMP5 categories produced less milk as compared with their dams during primiparity (P < 0.05). Milk fat to protein ratio during the first month of lactation was greater in DMP4 and DMP5 categories than DMP1 category (P < 0.05). Offspring of DMP4 and DMP5 categories were inseminated and conceived at younger ages than offspring of DMP1 category during nulliparity (P < 0.05). Calving to conception interval was longer in DMP5 than DMP1 category in primiparous offspring (P < 0.05), but concentration of AMH did not differ among various categories of DMP (P > 0.05). In conclusion, dams with greater level of milk production produced heavier offspring with higher milk yield but worse transgenerational improvement in milk production and diminished reproductive performance, which were seemingly under higher pressure of negative energy balance during the first month of lactation.