Understanding the physiological strategies underlying high milk productivity requires a detailed analysis not only of group averages but also of the variability within genetically homogeneous animals. It is especially important to study the relationship between the amount of synthesized milk components and the level of productivity depending on the genotype of key milk protein genes. The purpose of this work was to identify the genotype-specific features of the relationship between milk fat yield and the synthesis of other milk components in Holstein first-calf heifers with different kappa-casein ( CSN3 ) genotypes using the percentile stratification method. The scientific and production trial was conducted from 2023 to 2025 at the agricultural enterprise in the Voronezh region. The study subjects were Holstein first-calf heifers (n=166) genotyped for the CSN3 locus. Within each genotype ( AA, AB, BB ), three strata (low, medium, high) were formed using the percentile stratification method based on the indicator "milk fat yield per 305-day lactation". Integral indicators for the complete lactation were analyzed: milk yield, yield and mass fraction of fat and protein, and lactation length. The obtained data are important for a differentiated approach to selection and feeding management depending on the genetic potential of animals. Genotype-specific features of the implementation of high milk productivity have been established. It has been shown that an increase in milk fat yield is mainly ensured by an increase in milk yield and is accompanied by a decrease in the mass fraction of protein, which indicates the presence of a metabolic compromise between the quantitative and qualitative characteristics of milk. The obtained results have practical significance for the development of differentiated selection and technological approaches to managing the productivity of cows with different genetic potential.

Introduction Subclinical ketosis (SCK) is a common condition in dairy cows, primarily caused by the excessive accumulation of β -hydroxybutyrate (BHBA). Research has shown that succinyl-CoA is negatively correlated with the production of hepatic BHBA, while it is positively correlated with the utilization of BHBA in peripheral tissues. This correlation is significantly modulated by thiamine levels. Therefore, the purpose of this study is to investigate whether thiamine serves as a critical rate-limiting cofactor in succinyl-CoA metabolism, potentially enhancing BHBA utilization and reducing the incidence of SCK. Methods To verify the purpose of the study, 60 SCK dairy cows with comparable body weight, milk yield, and lactation days were selected from a total of 1,126 dairy cows reared in the same environment. The selection was based on the criterion of blood beta-hydroxybutyrate concentration being greater than 1.2 mmol/L. Another 12 healthy dairy cows with similar productive performances were enrolled in the control treatment. Milk yield, milk quality, rumen fermentable parameters, rumen and blood metabolomics were measured to investigate the alleviative effects of thiamine on SCK. Results and discussion The results showed that thiamine significantly decreased plasma BHBA concentrations, milk colony-forming units (CFU), and somatic cell counts, while significantly increasing milk yield, milk fat content, acetate levels, and the acetate-to-propionate (A/P) ratio compared to SCK cows ( p < 0.05). Metabolomic analysis revealed that the upregulated metabolites in both the rumen and blood after thiamine supplementation were significantly enriched in the pathways of pyruvate metabolism, glycolysis or gluconeogenesis, tyrosine metabolism, and glycerophospholipid metabolism, while the downregulated metabolites were mainly enriched in ascorbate and aldarate metabolism, glycerophospholipid metabolism, pentose and glucuronate interconversions, and riboflavin metabolism. Collectively, thiamine supplementation effectively alleviated subclinical ketosis by promoting the mediated catabolism of succinyl-CoA for BHBA utilization, improving ruminal fermentability, and thereby enhancing the milk yield and quality.

Transcriptomic and metabolomic profiles reveal the functions of IGF-1 c.258 A > G synonymous mutation in milk fat content.

Neospora caninum, Sarcocystis spp. and Toxoplasma gondii infections and their relationship with milk production in goats from Argentina.

Currently, it is important in dairy farming to increase the milk yield of cows and improve the quality of milk. An important reserve for increasing milk production is the long-term use of highly productive cows of different genealogical lines. The purpose of the research was to identify the influence of different genealogical lines of cows of Holstein breed on their milk productivity under conditions of industrial technology. Milk productivity of cows and milk quality were studied during experiment. Some functions of the udder of cows were studied such as the shape of the udder and teats, udder measurements, milk excretion rate, and the milk index. The chemical composition and physic and chemical properties of milk were determined. The biological efficiency of cows was studied and the coefficient of biological usefulness of cow’s milk was calculated. Almost all the studied indicators were higher in cows of the line Reflection Sovereign 198998. For 305 days of lactation, 14308 kg of milk was produced from them, which was higher than from herdmates of the line Montvic Chieftain 95679 by 1142 kg and by 1578 kg than from cows of the line Wes Back Ideal 1013415. The best indicators of chemical composition were revealed such as milk contains more dry matter, protein, and casein. The energy value of 100 g of milk was in the range of 68.49–71.12 kcal. The cows of the line Reflection Sovereign 198998 were the leaders in terms of biological efficiency. They had this indicator higher than the herdmates of the line Montvic Chieftain 95679 by 3.8 % and the cows of the line Wes Back Ideal 1013415 by 10.5 %. In terms of the coefficient of biological usefulness of milk, the cows of the line Reflection Sovereign 198998 were the best. They had this indicator higher than other genealogical lines of cows by 6.3 and 10.8 %. The experimental results obtained allow us to recommend the use of breeding of cattle of Holstein breed, taking into account their genealogical lines. The breeding of animals of the line Reflection Sovereign 198998 is important.

Measurement of haptoglobin after the time of dry-off and effects of a non-steroidal anti-inflammatory drug administered on the day of dry-off to Holstein dairy cows.

Gilts have a lower capacity for voluntary feed intake and body reserves than multiparous sows, which limits their ability to cope with the needs of gestation and lactation. In this study, a nutritional supplement was formulated to support gilts during the peripartum period. Both control (C, n = 64) and treatment (T, n = 63) groups received standard commercial diets. Group T received 300gr of supplement per gilt and day for the last 35 days of gestation until the fifth day of lactation. This supplement contained calcium (Ca; 4.1%), sodium (Na; 4.0%), lysine (Lys; 1.96%), methionine (Met; 1.32%), vitamin B12 (0.3 mg/kg), choline chloride (600 mg/kg), betaine (475 mg/kg), and L-carnitine (500 mg/kg). Supplementation significantly reduced (p < 0.050) stillbirth rate, neonatal diarrhea, postpartum hypophagia, and both β-hydroxybutyrate (BHBA) and creatinine (CREA) concentrations (effect sizes: 0.240-0.993). Also, supplementation significantly increased (p < 0.050) piglet weight at birth and at 15 days of lactation and maternal backfat thickness at 26 days of lactation (effect sizes: 0.491-0.719). The concentrations of BHBA and CREA showed significant and negative associations with several productive parameters (p < 0.05); the strength of the associations was low-medium. Targeted peripartum supplementation represents a feasible nutritional strategy for commercial herds characterized by large litter sizes and limited voluntary feed intake capacity.

Genetic testing of animals is currently an essential part of the development of the agro-industrial complex. The unique characteristics of indigenous cow breeds are an important genetic resource in the dairy farming, essential for improving commercially valuable traits and meeting growing consumer demand for high-quality, ecofriendly dairy products. This article presents our own developments for cattle genotyping using TaqMan technology. As the result of genetic association studies, it was found that, in order to increase milk yield on average over 305 days of lactation for the Tagil breed, negative selection for the G* allele is recommended for rs110347054, while positive selection for the T* allele is recommended for rs41567027. For the Istobenskaya breed, positive selection for the C* allele is recommended for rs109529386. It is noted that the limitations of this study for association tests are unique for selection of native breeds and their sample size because of their endangered status. The aim of this work is to study the features of the milk productivity phenotype and genetic associations of 13 SNPs for the main parameters of milk productivity for five cattle breeds.

The paper monitors the concentration of glucose (Glc) and ketone bodies (β-HB) in cows with different milk production, and evaluates the effect of these metabolites on the reproductive function and milk production of animals. It was found that the lowest concentration of β-HB was present in cows with a milk yield in the range of 2000...2999 kg per 100 days of lactation, which is 23.5% (P&lt;0.05) lower than in animals with a milk yield of less than 2000 kg and 33.8% (P&lt;0.001) lower than in animals with a milk yield of more than 4000 kg. The maximum milk productivity was shown by cows with a Glc level of 2.2...3.9 mmol/l and β-HB of more than 0.9 mmol/l – 3248.9 for 100 days of milking. The shortest period of infertility was in cows with a β-HB level of less than 0.5 mmol/l and a Glc concentration of more than 3.9 mmol/l – 134.8 days, which is 58.6 days less than in animals with a β-HB concentration of less than 0.5 mmol/l and a Glc level in the range from 2.2 to 3.9 mmol/l (P&lt;0.05) and on day 57.1 in relation to cows with elevated blood levels of β-HB and Glc (P&lt;0.01). The correlation between the levels of β-HB and Glc in various samples had no significant values, with the exception of animals with ketonemia and hyperglycemia, where there was a moderate positive association (+0.450) of the metabolites under consideration. An increase in the concentration of β-HB with elevated blood glucose indicates the presence of an alternative mechanism for the development of ketosis in cows and requires further research.

BackgroundNicotinamide riboside (NR) supplementation has been demonstrated efficacy in enhancing female reproductive outcomes, but its regulatory role in sow performance and gut microbiome remains undefined. This study systematically evaluated the impacts of dietary NR supplementation during late gestation and lactation on sow performance and gut microbiome remodeling. A total of 280 sows were randomized assigned to one of four groups: a control group fed basal diet or one of three groups receiving NR-supplemented diets (2, 4, or 8 g/d; n = 70/group). Sow reproductive performance, blood metabolic parameters, milk metabolome, and fecal 16S rRNA sequencing were measured.ResultsMaternal NR supplementation linearly shortened farrowing duration (P < 0.01) and tended to decrease the incidence of intrauterine growth restriction and the number of late gestation mummies (P < 0.1), while concurrently increasing the within-litter uniformity (P = 0.1). Litter weaning weight and average daily gain increased quadratically with NR dosage (P < 0.05). NR supplementation orchestrated plasma metabolite regulation (triglycerides and total cholesterol; P < 0.05), enhanced antioxidant biomarkers (T-AOC, GSH-Px, T-SOD; P < 0.05), and reduced inflammatory cytokines (TNF-α; P < 0.05) across gestation and lactation. Milk yield, colostrum/milk dry matter, crude protein, and crude fat were increased (P < 0.05), together with higher levels of NAD+ metabolites (NAD⁺, NR, nicotinamide) and beneficial bioactive factors (milk polar lipids, 3-aminosalicylic acid, fenugreekine; P < 0.05). Gut microbiota analyses at lactation day 14 revealed NR-enriched beneficial taxa (Bifidobacterium, Ruminococcus, Lachnospiraceae, Subdoligranulum, Clostridium butyricum, Succiniclasticum) across sow-offspring dyads, which was associated with the activation of microbial NAD⁺ enzymes (NadR/NAMPT; P < 0.05) and enhancement of systemic short-chain fatty acid flux, notably an increase in plasma butyrate acid (P < 0.05).ConclusionMaternal supplementation of NR during late gestation and lactation increases sow performance and promotes gut NAD+ metabolic-associated microbiome remodeling. These findings propose maternal NR intervention as a novel strategy to enhance mammary lactogenesis and lactation metabolism in swine production, with potential applications for therapeutic strategies for lactation insufficiency.Graphical

Bioactive metabolites in neonates of mothers supplemented with Bifidobacterium animalis are linked to microbiota-related compounds in milk and maternal plasma in mice.

Long-term offspring loss in lactating rats: Neurobiological and emotional consequences in a novel animal model.

Relevance. An analysis of the structure of the breeding stock, including the selection method for breeding Holstein cattle, revealed a large number of cows obtained as a result of inbreeding, the degree of which will increase over time. Methods. The object of the study is repair heifers and cows born in 2018, divided into groups according to the type of selection – heterogeneous selection (outbreeding) and homogeneous selection (moderate and long–term inbreeding). The material and data for comparison were the database of the IAC “SELEX-Dairy Cattle”, the results of our own research. Milk yield for 305 days of lactation was taken into account according to control milks, MJ and MDB in milk. Results. The majority of cows were obtained as a result of the use of remote inbreeding — more than 65.0%. Cows obtained by heterogeneous (unrelated) selection turned out to be only 12.4%. Cows with the highest productivity rates were found in the second lactation — 10484±135.86 kg (13.8%), which was 1450 kg more than in the first heifers and 169 kg (1.6%) in the third lactation. Further, there was a slight decrease in milk yield by 16 kg and 301 kg, respectively, or by 0.15% and 2.9%. Cows obtained as a result of a moderate degree of inbred had the best indicators. They outperformed animals from other groups by 559 kg, or 5.46% (outbred) and by 268 kg, or 2.62% (distant inbreeding). In animals obtained as a result of outbred selection and moderate inbreeding, there is a gradual decrease in the ratio from the maximum for the first to the minimum for the last (fourth) lactation. In cows with distant inbreeding, the ratio of fat and protein in milk decreased sharply after the second lactation.

In populations with limited genotyping, single-step genomic best linear unbiased predictions (ssGBLUP) can produce biased or less accurate genomic predictions due to incompatibilities between genomic and pedigree relationship matrices. The study evaluated the impact of five alternative ssGBLUP models for genomic predictions of milk, fat, and protein yield production traits in South African Holstein cattle. The dataset included 696,413 milk production records and pedigrees of 541,325 animals. Production traits were 305-day lactation yields for milk, protein, and fat. Genotype data were based on the Illumina 50K chip v3, with 53,218 SNPs. A total of 1221 animals with genotypes and 41,407 SNP markers were in the final dataset. The five models used to estimate genomic estimated breeding values (GEBVs) were the single-step method (ssGBLUP), ssGBLUP accounting for inbreeding (ssGBLUP_Fx), ssGBLUP with unknown parent groups (ssGBLUP_upg), and two ssGBLUP models with blending, tuning, and scaling parameters set to optimum values in constructing the inverse of the unified relationship matrix (ssGBLUP_adjusted). Realized prediction accuracies were highest for ssGBLUP_adjusted models (6-7% improvements compared to ssGBLUP). Accuracy of GEBVs for milk, protein, and fat yields ranged from 0.23, 0.29, and 0.30 for both ssGBLUP and ssGBLUP_Fx, 0.26, 0.32, and 0.34 for ssGBLUP_upg, and 0.29, 0.35, and 0.37 for ssGBLUP_adjusted models, respectively. Corresponding bias, expressed as regression coefficients, ranged from 0.30, 0.31, and 0.36 for ssGBLUP; 0.31, 0.32, and 0.37 for ssGBLUP_Fx; 0.41, 0.44, and 0.49 for ssGBLUP_upg; and 0.44, 0.47, and 0.53 for ssGBLUP_adjusted models, respectively. The improved accuracy and reduced bias observed with the ssGBLUP_adjusted underscores the importance of optimizing the blending of pedigree- and genome-based relationships to achieve more reliable GEBVs, thereby improving selection decisions in Holstein dairy cattle.

Lactoferrin (LF) is an iron-binding immunoprotein of the mammary gland whose levels increase during mastitis and may be influenced by the metabolic status of the cow. During early lactation, dairy cows are exposed to a negative energy balance (NEB) and the associated increase in susceptibility to mastitis. However, the extent to which the metabolic profile influences LF secretion in milk during the postpartum period remains unclear. The objective of this study was to assess the associations between metabolic status and milk LF contents in Holstein cows (n = 122) in the first twenty days of lactation. Based on the milk LF contents, the cows were categorized into two groups: LF-LOW (≤123 mg/L; n = 81) and LF-HIGH (&gt;123 mg/L; n = 41). Serum indicators of energy and nitrogen metabolism, hepatic function, and selected macro-/microelements were measured; urine electrolytes and net acid–base excretion (U-ABB) were assessed; and milk composition, including somatic cell count (SCC), was determined. LF-HIGH cows showed higher SCC (p = 0.0516) and serum glucose (p &lt; 0.001), together with lower serum triglycerides (p = 0.0101) versus LF-LOW cows. Milk beta-hydroxybutyric acid (BHB) content was lower in the LF-HIGH group (trend, p ≈ 0.062). LF-HIGH also exhibited significantly greater natriuresis (p = 0.0078) and a more negative U-ABB (p &lt; 0.001), indicating higher acid–base load. In conclusion, elevated LF contents during the postpartum period were associated with the activation of local mammary gland immune defence and concurrent compensatory metabolic processes related to NEB, rather than with pronounced alterations in basic milk composition. Milk LF content may therefore be considered as a specific indicator of immunometabolic compensation during the early postpartum period, rather than as a general marker of overall cow health.

This study aimed to characterize changes in small metabolites in sow milk over the course of lactation. The impact of Moringa oleifera leaf powder addition to diet and electronic cooling pads (ECP) on milk metabolites of sow under moderate heat stress was also evaluated. A 2 × 2 factorial experiment was conducted with Yorkshire x Landrace sows (n = 48) from gestation day 100 to lactation day 21. Treatments included heat stress + control diet (HS + CS), heat stress + Moringa (HS + M), ECP + CS, and ECP + M beginning with 12 sows per treatment. Milk was collected on lactation days 0 (D0, colostrum), 3 (D3, transitional milk), and 14 (D14, mature milk). Metabolites were extracted using the Bligh and Dyer method and then profiled using exploratory multiple reaction monitoring. Milk metabolite content varied significantly across lactation days. Diet and parity influenced milk metabolites on D0, ECP on D3, and parity on D14. The 55 metabolites increased between D0 and D3, linked to phenylalanine, tyrosine and tryptophan biosynthesis, starch, sucrose and galactose metabolism, while the 93 decreased metabolites were associated with protein synthesis and gut development, including phenylalanine, tyrosine and tryptophan biosynthesis and alanine, aspartate and glutamate metabolism. Between D3 and D14, 148 metabolites increased and reflected alanine, aspartate and glutamate and galactose metabolism, while the 21 decreased included L-leucine, creatine, myo-inositol, hypoxanthine and acetyl-carnitine. The 116 metabolites impacted by parity in D0 samples, were elevated in primiparous compared to multiparous sows, and linked to arginine biosynthesis, amino acid metabolism, and purine metabolism. On D14, parity affected 52 metabolites related to alanine, aspartate and glutamate metabolism, arginine biosynthesis and pyrimidine metabolism. ECP on D3 reduced 104 metabolites involved in the citrate acid cycle, cysteine and methionine metabolism, and pyrimidine metabolism. Milk metabolite content changed significantly between the three phases of milk production, reflecting mammary secretory activity and potentially the changing nutritional needs of piglets and maternal physiological adjustments throughout lactation. These findings highlight the dynamic nature of milk composition and the potential for dietary and environmental interventions to modulate milk metabolite content under heat stress conditions.

The change of lactation periods is a physiological process in the life of a lactating cow, but it can also be a predisposing factor for the udder inflammation development. Signaling proteins play a leading role in the mechanisms of this inflammation, due to disturbances in the general nonspecific immune system. This article presents the results of studies examining indicators of general nonspecific immunity in cows at various physiological stages of lactation (early postpartum period, 100-120 days of lactation, and the cow drying off period).

Lipid metabolism is crucial for the development of insulin resistance. Leucine supplementation enhances insulin sensitivity and lipid metabolism. Soybean oil has the potential to improve insulin sensitivity. A comprehensive investigation of the effects and potential mechanisms of leucine and soybean oil supplementation is warranted. This study aims to investigate the effects and underlying mechanisms of maternal soybean oil and leucine intake on lipid metabolism, insulin sensitivity in both dams and offspring. Sixty-eight multiparous sows (parities 3 to 5, 228.44 ± 8.19 kg) were randomly divided into four groups from the 107th day of gestation to the 21st day of lactation (n = 17). The experimental was designed as a 2 × 2 factorial arrangement, which included the level of soybean oil (crude fat 5% or 10%) and leucine (0 or 1%) in the diet. Supplementing soybean oil during late pregnancy and lactation significantly enhanced insulin sensitivity (P < 0.05). Both soybean oil and leucine altered the intestinal microbiota of sows, and significantly improved plasma lipid metabolism (P < 0.05). Additionally, inflammation in sows before and after farrowing was reduced by lowering the relative abundance of pro-inflammatory bacterial genus such as Catenisphaera, Terrisporobacte and Peptococcus (P < 0.05). The weaning weight of piglets was significantly increased (P < 0.05), along with enhanced insulin sensitivity, increased immune (IL10RA, DDX58), and improved lipid metabolism (PPARA, SLC27A2) and rhythmic gene expression (LGR4, KLF9). Our study provides evidence that dietary supplementation with soybean oil and leucine affects offspring growth by modulating lipid metabolism and insulin sensitivity in sows and pigs, and by altering intestinal microbiota.

The basis for a cow’s future milk production is laid during the period of active growth and development of replacement heifers. Therefore, many scientists and specialists studying the productivity of current dairy herds worldwide emphasize the need for a meticulous approach to feed selection and rearing techniques for heifers planned for subsequent integration into the main production herd. The purpose of this research was to analyze the effectiveness of using the complex functional additives Rumenfit 100 and Rumenfit 50 in a replacement heifer feeding program and their subsequent impact on the milk production of first-calf heifers. The results of a scientific and economic experiment carried out on animals of Holstein breed from birth to the end of their first lactation at a modern livestock complex have been presented in the article. The active phase of the experiment involved the formation of one control and two experimental groups of 10 animals in each. in each. The housing, microclimate system and care of the experimental animals were identical, the only difference was that in the period from 2 to 6 months of age, the heifers of the 1st experimental group received a complex functional additive Rumenfit 100 as part of the starter compound feed at a rate of 10 g/head day, and the heifers of the 2nd experimental group received a complex functional additive Rumenfit 50 at a rate of 5 g/head/day. At the same time, the growth and development indicators of the heifers were monitored, and the future reproduction indicators were assessed. Finally, the milk productivity of fi rst-calf heifers at the end of lactation was assessed. It was found that first-calf heifers of the control group were inferior in milk yield for 305 days of lactation to their herdmates in the 1st and 2nd experimental groups by 945.5 and 579.5 kg.

Short dry period improves postpartum energy balance and reproduction but reduces milk yield in dairy cows.