Stage Of Lactation Research Articles

Development of a capillary electrophoresis method with laser-induced fluorescence detection for the characterization of oligosaccharides in human milk

Breast milk is the most appropriate food for an infant in the first months of life - it provides the essential nutrients required for proper growth, with breast milk oligosaccharides (HMOs) being the third most abundant component. HMO concentrations vary based on factors like lactation stage and maternal health. They play crucial roles in infant health, acting as prebiotics, antimicrobials, and immune modulators. Analytical methods like capillary electrophoresis and liquid chromatography are the most often used in HMOs qualitative and quantitative analysis. Continuing research aims to enhance analytical techniques for comprehensive HMOs analysis, this work presents the development of a capillary electrophoresis method with laser-induced fluorescence detection along with derivatization and solid-phase extraction steps for the characterisation of major oligosaccharides in colostrum samples. Validation parameters, such as linearity (0.9949–0.9989), limits of detection (5.49–16.40 ng cm−3) and quantification (18.30–54.67 ng cm−3), intra- and inter-day precision (2.41–9.78% and 1.27—14.5%, respectively), trueness (− 8.4 to − 2.0%), and recovery (70.02–113.5%) and repeatability (2.22–10.58%) for solid-phase extraction stage were assessed. The method was evaluated using RGB additive colour model regarding the analytical and practical effectiveness and greenness of the method (achieving a brilliance score of 67.1%). Moreover, the developed method was successfully applied to determine three oligosaccharides (DSLNT, 3’SL, and 6’SL) in colostrum samples. Considering its effectiveness, the method has promise for this type of application.Graphical abstract

Genetic and environmental factors shaping goat milk oligosaccharide composition

Oligosaccharides (OS) in milk have been suggested to influence the health and development of the newborn by promoting growth of beneficial gut bacteria, stimulating brain development, and enhancing immune functions. Goat milk is a natural source of specific OS, which could be a potential beneficial ingredient for infant formula. In this study, goat milk oligosaccharide (gMOS) content from approximately 1,000 dairy goats across 18 commercial farms was studied. A genomic relationship matrix was used to unravel genetic and environmental factors shaping gMOS content. The most abundant gMOS identified was 3'-NGL, with a concentration of 32.05 mg/kg, while 3-FL exhibited the lowest concentration at 1.85 mg/kg. Acidic OS had a notably higher content (81.67 mg/kg) than neutral OS (24.88 mg/kg). High variability in gMOS content was observed among individual goats, which could for a large extent be attributed to genetic differences. Heritability estimates ranged from 31% for 3'-GL to 85% for 3-FL. High positive genetic correlations (>0.57) were estimated between 3'-SL and 6'-SL, and between 6'-GL and 3'-GL. The contribution of differences between farms to variation in milk OS content varied from 3% for 3'-NGL to 45% for 6'-SL. While gMOS like 3'-GL, 6'-GL, and 6'-NGL, were significantly influenced by systematic environmental factors such as the lactation stage, the impact of these factors was relatively minor compared with the importance of genetic and farm effects. This research, which stands out due to its relatively large sample size, underscores the pivotal role of genetics, and to a smaller extent farm practices like feed ration, in determining gMOS composition.

The Influence of Selected Environmental Factors on the Number of Somatic Cells in Cistern and Alveolar Milk of Polish Holstein-Friesian Cows.

The aim of the study was to evaluate the influence of the milking phase on somatic cell count (SCC) in milk obtained from the cisternal and alveolar parts of udders of selected Polish Holstein-Friesian cows. The study also assessed the impact of other genetic and environmental factors on SCC variability in cisternal and alveolar milk, including: the individual cow, lactation stage, age of cow, production level, milking speed, fat-to-protein ratio, and milking type. The research included 15 cows of Polish Holstein-Friesian breed at different ages, lactation stages, and with varying daily milk yield. A total of 210 milk observations were conducted, including 105 for 1 min milking and 105 for 8 min milking. The results obtained in the study indicated that milk obtained during two different milking phases exhibited similar SCC levels (F for LOGSCC = 0.79). The average actual SCC in milk produced by 15 cows in 105 observations for 1 min milking was 219,000 cells/mL, while for 8 min milking it was 229,000 cells/mL. The results were inconclusive, suggesting that SCC in cisternal and alveolar milk must be influenced by factors other than the milking phase. The analysis of variance conducted for this purpose provided the basis for stating a highly statistically significant effect of the individual cow (F for LOGSCC = 147.9), lactation stage (F for LOGSCC = 54.64), age of cow (F for LOGSCC = 12.39), daily production level (F for LOGSCC = 34.49), milking speed (F for LOGSCC = 17.56), and fat-to-protein ratio (F for LOGSCC = 22.99) on the variability of characteristics defining SCC in milk. In summary, SCC is characterized by high variability, influenced by a range of environmental and genetic factors such as the individual cow, lactation stage, age of cow, milking speed, and dietary fat-to-protein ratio. The influence of milking phase (1 min or 8 min) and milking type (morning or evening) should be considered inconclusive based on the entire population studied. For half of the cows, SCC in cisternal milk was higher than in alveolar milk, while for the other half, the situation was reversed. Further observations are required to confirm the hypothesis regarding the extent to which cows' immunological response to bacterial infections is concentrated in the cisternal or alveolar part of the udder under national environmental conditions.

Effect of Cottonseed Feeding on the Body Condition Score (BCS) of Murrah Buffaloes under Different Lactation Stages

The present study was envisaged to study the effect of cottonseed feeding on the Body Condition Score (BCS) of Murrah buffaloes. 54 lactating Murrah buffaloes were grouped into three lactation groups of early (0-3 months), mid (3-6 months) and late (>6 month), each group having 18 buffaloes which were further divided into three treatments consisting of dietary regimes of concentrate ration containing 0% cotton seed (T1- Control), concentrate ration containing 10% cottonseed (T2) and concentrate ration containing 15% cottonseed (T3). The feeding trial was performed for a period of 90 days for experimental buffaloes under different treatments of three different lactation stages. Fortnightly Body Condition Scores were recorded. While there were no significant differences in early lactation, in mid lactation there was a significant increase in T2 while T3 was comparable to T1, and in late lactation there was a significant increase in T3 while T2 was similar to control group.

Diet at birth is critical for healthy growth, independent of effects on the gut microbiota

BackgroundColostrum is the first milk for a newborn. Its high content in microbiota shaping compounds and its intake at the time of gut microbiota seeding suggests colostrum may be critical in the establishment of a healthy microbiota. There is also accumulating evidence on the importance of the gut microbiota for healthy growth. Here, we aimed to investigate the contribution of colostrum, and colostrum-induced microbiota to growth promotion. Addressing this question is highly significant because (1) globally, less than half of the newborns are fully colostrum fed (2) the evidence for the importance of the microbiota for the prevention of undernutrition has only been demonstrated in juvenile or adult pre-clinical models while stunting already starts before weaning.ResultsTo address the importance of diet at birth in growth failure, we developed a unique mouse model in which neonates are breastfed by mothers at an advanced stage of lactation who no longer provide colostrum. Feeding newborn mice with mature milk instead of colostrum resulted in significant growth retardation associated with the biological features of chronic undernutrition, such as low leptin levels, dyslipidemia, systemic inflammation, and growth hormone resistance. We next investigated the role of colostrum in microbiota shaping. At the end of the lactation period, we found a major difference in gut microbiota alpha diversity, beta diversity, and taxa distribution in control and colostrum-deprived mice. To determine the causal relationship between changes in microbiota and growth trajectories, we repeated our experiment in germ-free mice. The beneficial effect of colostrum on growth remained in the absence of microbiota.ConclusionOur data suggest that colostrum may play an important role in the prevention of growth failure. They highlight that the interplay between neonatal gut microbiome assembly and diet may not be as crucial for growth control in the developing newborn as described in young adults. This opens a paradigm shift that will foster research for colostrum’s bioactives that may exert a similar effect to microbiota-derived ligands in promoting growth and lead to new avenues of translational research for newborn-tailored prevention of stunting.98mWSFedBqCALfgBr5hPfAVideo

Reference limits for blood gas analysis performed from coccygeal vessels of multiparous Holstein dairy cows: Effects of stage of lactation and season of sampling

Blood gas analysis is a great support to the diagnostic process of critically ill patients. Its correct application to the medicine of dairy cows depends on the availability of specific reference intervals that are still difficult to find in the literature. They may vary according to the type of blood sampled, animals' age and production stage, and climatic conditions. This study aimed at calculating the reference limits for some blood gas parameters in the blood collected from the coccygeal vessels of multiparous Holstein dairy cows. This site of sampling implies the risk of withdrawing blood of unknown origin (venous, arterial, or mixed), but has a high practical interest for the easy and quick performance and the minimal animal restraint required. Data from 379 cows were used, and reference limits were produced for pH, partial pressure of carbon dioxide (pCO2), bicarbonate concentration (HCO3), total carbon dioxide concentration (tCO2), oxygen saturation (sO2), hemoglobin (Hb), hematocrit (Hct), base excess (BE), glucose, Na, K, and ionized calcium (iCa). The effects of stage of lactation (5 to 60 vs. > 60 DIM) and season of sampling (cold vs. hot) were investigated, and specific reference limits were produced for each variable and each level of the factors whenever a significant effect was detected. The pH, sO2, K, and iCa were not influenced by season or stage of lactation. All the other blood gas parameters were significantly affected by season of sampling, and Hb, Hct, glucose, and Na were also affected by stage of lactation. Reference limits provided in this study are specific to the site of sampling (coccygeal vessels) and the animal category considered. Further studies are needed to produce reference intervals for other blood gas parameters, cow categories, and blood types.

Factors Influencing Breast Milk Antibody Titers during the Coronavirus Disease 2019 Pandemic: An Observational Study.

The COVID-19 pandemic has highlighted the role of breastfeeding in providing passive immunity to infants via specific anti-SARS-CoV-2 antibodies in breast milk. We aimed to quantify these antibodies across different lactation stages and identify influencing factors. This prospective study involved mother-child dyads from Innsbruck University Hospital, Austria, with a positive maternal SARS-CoV-2 test during pregnancy or peripartum between 2020 and 2023. We collected breast milk samples at various lactation stages and analyzed anti-Spike S1 receptor-binding domain (S1RBD) immunoglobulins (Ig). Maternal and neonatal data were obtained from interviews and medical records. This study included 140 mothers and 144 neonates. Anti-S1RBD-IgA (72.0%), -IgG (86.0%), and -IgM (41.7%) were highly present in colostrum and decreased as milk matured. Mothers with natural infection and vaccination exhibited higher anti-S1RBD-IgA and -IgG titers in all milk stages. Mothers with moderate to severe infections had higher concentrations of anti-S1RBD-IgA and -IgG in transitional milk and higher anti-S1RBD-IgA and -IgM in mature milk compared to those with mild or asymptomatic infections. Variations in antibody responses were also observed with preterm birth and across different virus waves. This study demonstrates the dynamic nature of breast milk Ig and underscores the importance of breastfeeding during a pandemic.

Biochemical, Molecular, Postmortem and Histopathological Characterization of Bovine Theilerioses at Different Stages of Production and Reproduction

Theilerosis is the most important common vector (Tick) born and hemoprotozoan diseases (TBDS) which pose a serious threat to the livestock population in terms of mortality, reduced milk yield and lowered draft power. The disease is having impact on biochemistry and systemic functions affecting at different stages of production and reproduction of dairy cattle as well as there is lack of accurate diagnosis of this disease. A total 1900 cases were suspected for theileriosis on the basis of clinical signs and total 950 cases were found positive for theileriosis on the basis of blood smear examination. As per the stages of pregnancy and lactation, the cases were classified as cows in early pregnancy, cows in late pregnancy, cows in post parturient stage, cows in early and late lactation period. Biochemical alterations like increased AST, ALT and BUN level indicating liver and kidney dysfunctions in all the groups and significantly higher in post parturient group. The serum phosphorus, calcium and magnesium level decreased in all the affected groups and mostly in late pregnancy period and post parturient stage indicating metabolic disturbances during the disease which were aggravated during theileriosis. Through molecular diagnosis 114 cows (65.51%) were found positive for T. annulata and 41 cows (22.9%) were found positive for T. orientalis and 19 cows (10.9%) were found positive for both Theileria annulata and Theileria orientalis. Phylogenetic analysis revealed the accession number for Theileria annulata was OQ230445 which is having 100% similarity with puri isolate and 98% similarity with Khorda isolate and the accession number for T. orientalis was OQ 230446 having 85% similarity with Khorda isolate. On necropsy, the animals were weak, debilitated with atrophy of the muscles. In some cases, the liver was enlarged, markedly congested and in some cases yellowish tinged surface and cut edges with distension of gall bladder was evident. Abomasal ulcers were distinct and considered as pathognomonic. On histopathological examination, the liver revealed necrosis of hepatocytes with sinusoidal congestion and infiltration of mononuclear cells. In lymphnode, there was depletion of lymphocytes in lymphoid follicles with congestion and haemorrhage. Pulmonary edema was also evident in few cases. The combined approach involving biochemical, molecular, Post-mortem and histopathological characters were found to be fruitful in diagnosis of the bovine theileriosis at different stages of production and reproduction with optimum specificity.

The Assessment of Iodine Concentrations in Colostrum and Breast Milk Using ICP-MS: The Impact of Delivery Type, Thyroid Function and Gestational Diabetes-A Pilot Study.

Considering the spectrum of benefits of breast milk feeding, determining the essential components of an infant's only food-mother's milk-seems justified, especially in the case of those whose deficiency (e.g., iodine) may result in developmental disorders. The main aim of this study was the determination of the total iodine content of breast milk (including colostrum and mature milk). A secondary objective was to assess the influence of factors such as the type of delivery, hypothyroidism, gestational diabetes or the stage of lactation on this parameter. The study materials were colostrum and milk after 1 (n = 14), 2 and 3 months (n = 8) of lactation with a range of iodine concentrations (µg/L): 195-1648 and 170-842, 174-650 and 273-751, respectively. Iodine was determined using the inductively coupled plasma mass spectrometry (ICP-MS). Multivariate statistical analysis revealed, e.g., that delivery by caesarean section or dose of L-thyroxine taken by women to normalise thyroid hormones, had a significant effect on iodine concentrations in breast milk. Further research aimed at assessing the quality of breast milk should also include determining the factors influencing it.

Complete characterization of the fatty acid profile of mare milk from commercial semi-extensive farms during lactation

The present study aimed to thoroughly describe the profile of fatty acids in mare milk from farms with different management systems and changes during lactation. Eighteen mares belonging to three commercial farms (6 mares per farm) were milked during the complete lactation period (six months). Fat content was determined by infrared spectroscopy, while fatty acid methyl esters were analyzed using a GC-FID. Mare milk, in general, contained 47.5 % saturated, 25.3 % monounsaturated, and 26.5 % polyunsaturated fatty acids. A high proportion of 18:2n-6 and 18:3n-3 but a low concentration of their long-chain metabolites was observed, and seven branched-chain fatty acids were identified. Stage of lactation significantly influenced the content of most individual fatty acids, and in general, milk from mares managed under pasture-based feeding systems showed a higher content of n-3 polyunsaturated fatty acids. This study provides new insights into mare milk FA composition and into dynamics of mare milk nutritional quality as affected by lactation stage and grazing intensity.

Evaluation of Rumen Microbes For Milk Fat Yield in Cattle Based on 16S rRNA Amplicon Metagenomic Sequencing

Background: Ruminal microbes support growth, lactation and maintenance of animals by providing energy and protein yielding nutrients. Metagenomics is the study of microbial communities directly in their natural environments such as soil, water, gut samples etc. The 16S rRNA gene sequencing is one of the basic genetic markers for the characterisation of prokaryote microorganism community. Current study exploited complex gut microbial communities present in cattle rumen based on variation in milk fat yield. Methods: The study was conducted in cattle reared at University Livestock Farm, Kerala Veterinary and Animal Sciences University. Twelve healthy cattle in the initial stages of lactation (less than three months) were selected and divided into two groups of six each based on high and low milk fat composition. Rumen samples were collected and DNA was isolated. Amplicons of 16S rRNA has been generated from metagenomic DNA targeting V3 and V4 hyper variable regions. Qiime2 was used for analysis for 16S rRNA amplicon sequencing. Result: Results revealed that a total of 38,28,241 sequences were obtained after demultiplexing. Majority of sequence length ranged around 295 to 301 nucleotides for forward reads and 216 to 300 nucleotides for reverse reads. After denoising, a total of 6,62,498 sequences were obtained. Clustering (de-replication) produced 711 unique sequence features. In kingdom level of taxonomy, for bacterial kingdom, there was no significant difference in abundance of organisms for high milk fat yield and low milk fat yield cows. For archaea, significant difference observed between abundance of high milk fat and low milk fat groups at five per cent level in the current study.

Mammary fat globules as a source of mRNA to model alterations in the expression of some milk component genes during lactation in bovines

BackgroundThe milk's nutritional value is determined by its constituents, including fat, protein, carbohydrates, and minerals. The mammary gland's ability to produce milk is controlled by a complex network of genes.Thereby, the fat, protein, and lactose synthesis must be boost in milk to increase milk production efficiency. This can be accomplished by fusing genetic advancements with proper management practices. Therefore, this study aimed to investigate the association between the Lipoprotein lipase (LPL), kappa casein CSN3, and Glucose transporter 1 (GLUT1) genes expression levels and such milk components as fat, protein, and lactose in different dairy breeds during different stages of lactation.MethodsTo achieve such a purpose, 94 milk samples were collected (72 samples from 36 multiparous black-white and red-white Holstein–Friesian (HF) cows and 22 milk samples from 11 Egyptian buffaloes) during the early and peak lactation stages. The milk samples were utilized for milk analysis and genes expressions analyses using non- invasive approach in obtaining milk fat globules (MFGs) as a source of Ribonucleic acid (RNA).ResultsLPL and CSN3 genes expressions levels were found to be significantly higher in Egyptian buffalo than Holstein–Friesian (HF) cows as well as fat and protein percentages. On the other hand, GLUT1 gene expression level was shown to be significantly higher during peak lactation than early lactation. Moreover, lactose % showed a significant difference in peak lactation phase compared to early lactation phase. Also, fat and protein percentages were significantly higher in early lactation period than peak lactation period but lactose% showed the opposite pattern of Egyptian buffalo.ConclusionTotal RNA can be successfully obtained from MFGs. The results suggest that these genes play a role in glucose absorption and lactose synthesis in bovine mammary epithelial cells during lactation. Also, these results provide light on the differential expression of these genes among distinct Holstein–Friesian cow breeds and Egyptian buffalo subspecies throughout various lactation phases.

Comparative analysis of lipid composition in colostrum and mature milk from women of seven Chinese ethnic groups

This study compared the lipid content, total and sn-2 fatty acids, and the levels of 1, 3-dioleoy-2-palmitoyl glycerol (OPO), 1-oleoyl-2-palmitoyl-3-linoleoyl glycerol (OPL), and 1, 3-linoleoyl-2-palmitoyl glycerol (LPL) in colostrum and mature milk (n = 122) from seven ethnic groups in China. Compared with the Han breast milk, the content of saturated fatty acid (SFA) and trans fatty acid (TFA) in the breast milk of ethnic groups (especially in Uygur) was higher, while monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA) were lower. This disparity may be attributed to the higher consumption of meat and diary products. In terms of the distribution of fatty acids and the content of triacylglycerol (TAG), ethnic groups and Han showed consistency. The OPO, OPL, and LPL in colostrum (0.16 ± 0.06, 0.17 ± 0.08, 0.09 ± 0.04 g 100 mL−1) were significantly lower than those in mature milk (0.28 ± 0.11, 0.26 ± 0.09, 0.16 ± 0.07 g 100 mL−1). The results have shown that the composition and content of total and sn-2 FAs in breast milk were affected by lactation stage, ethnic minority background, and maternal diets. This study contributed to the enhancement of the Chinese breast milk lipid database and offered a scientific foundation for formulating lipid compositions in infant formulas tailored to specific ethnic groups.

The prevalence and factors associated with mastitis in dairy cows kept by small-scale farmers in Dodoma, Tanzania

Bovine mastitis is among the major diseases of economic importance in the dairy industry worldwide. Hygienic conditions during milking and housing are important determinants of mastitis infections. However, arid and semi-arid areas have a scarcity of water, which is an essential component of cleanliness. Thus, the study determined the prevalence of mastitis and associated factors in Dodoma, a semi-arid region in Tanzania. Three hundred and sixty-eight lactating cows were selected randomly from 114 farms in the Dodoma urban district for mastitis determination based on clinical signs and the California Mastitis Test. About 59.8 % of the cows had mastitis, and the subclinical type dominated. Factors associated with mastitis prevalence were cleanliness (hand and udder washing before milking), farmers' awareness of mastitis, the cow's parity and lactation stage, and herd size. Milk yield was not associated with the mastitis status of the cow but was related to the breed of the cow, whether warm or cold water was used to wash the cow's udder, parity, and lactation stage. Improvement in education on the importance of hygiene is necessary, as 38.6 % of the farmers were unaware of mastitis. Further detailed studies on microbiology, such as bacteriologic culture and polymerase chain reaction, are recommended to formulate interventions.

Multispecies pasture diet and cow breed impacts on milk composition and quality in a seasonal spring-calving dairy production system

In recent years, there has been significant emphasis on the composition of pasture-based cow feed and the potential benefits of incorporating multispecies swards to improve sustainability and biodiversity. This study compared the effects of a conventional perennial ryegrass (PRG) monoculture supported by high chemical nitrogen (N) usage with a low chemical N application multispecies sward system (MSS) on the composition and quality of milk across lactation using spring-calving Holstein-Friesian (HF) and Jersey Holstein-Friesian (JFX) cows. Bulk milk samples (n = 144) were collected from each group at morning and evening milking on a weekly basis (n = 36) throughout lactation and analyzed for gross composition and physico-chemical properties. Cow breed had a significant impact on milk profile, with milk from HF cows having significantly smaller milk fat globule (MFG) size, higher instability index values, higher yield, and lower total solids levels, compared with JFX cows. Notably, HF cows had increased milk total solids and fat levels when fed on MSS, as opposed to the PRG-fed HF cows. Feeding MSS pasture increased creaming velocity values in mid and late lactation, and resulted in similar milk gross composition to PRG. In comparison to PRG, MSS-fed groups showed significantly increased total solids yield, including higher levels of protein and fat yield. In late lactation, MSS feeding was associated with reduced MFG size. All physicochemical properties studied (MFG size, creaming velocity, instability index) showed decreasing values from early to late lactation stage. Overall, these findings demonstrate the significant effects of cow diet, breed and stage of lactation on compositional and physico-chemical characteristics of milk, with important implications for milk processing and dairy product quality.

Effect of Birth Season and Lactation Stages on the Level of Some Hormones and Milk Yield of Holstein x Janoubi Cows

Effect of Birth Season and Lactation Stages on the Level of Some Hormones and Milk Yield of Holstein x Janoubi Cows

Unmasking seasonal cycles in a high-input dairy herd in a hot environment: How climate shapes dynamics of milk yield, reproduction, and productive status

This study aimed to predict the annual herd milk yield, lactation, and reproductive cycle stages in a high-input dairy herd in a zone with prolonged thermal stress. Also, the impact of climatic conditions on milk yield and productive and reproductive status was assessed. An autoregressive integrated moving average (ARIMA) model was used in data fitting to predict future monthly herd milk yield and reproductive status using data from 2014 to 2020. Based on the annual total milk output, the highest predicted percentage of milk yield based on the yearly milk production was in February (9.1%; 95% CI = 8.3–9.9) and the lowest in August (6.9%; 95% CI = 6.0–7.9). The predicted highest percentage of pregnant cows for 2021 was in May (61.8; 95% CI = 53.0–70.5) and the lowest for November (33.2%; 95% CI = 19.9–46.5). The monthly percentage of dry cows in this study showed a steady trend across years; the predicted highest percentage was in September (20.1%; CI = 16.4–23.7) and the lowest in March (7.5%; 4.0–11.0). The predicted days in milk (DIM) were lower in September (158; CI = 103–213) and highest in May (220; 95% CI = 181–259). Percentage of calvings was seasonal, with the predicted maximum percentage of calvings occurring in September (10.3%; CI = 8.0–12.5) and the minimum in April (3.2%; CI = 1.0–5.5). The highest predicted culling rate for the year ensuing the present data occurred in November (4.3%; 95% CI = 3.2–5.4) and the lowest in April (2.5%; 95% CI = 1.4–3.5). It was concluded that meteorological factors strongly influenced rhythms of monthly milk yield and reproductive status. Also, ARIMA models robustly estimated and forecasted productive and reproductive events in a dairy herd in a hot environment.

Understanding the dynamics of mastitis in milk yield: decoding onset and recovery patterns in response to mastitis occurrence

No recent study attempted to model daily milk losses before and after mastitis onset and the moment when it begins. Thus, we aimed to describe the impact of mastitis on milk production based on mastitis level and moment of occurrence. We used data from 11 dairy farms, and the data set consisted of 885,759 daily individual milk test records from 3,508 cows in different lactations, with an average milk yield from January 2017 to December 2022. We modeled the impact of mastitis severity [i.e., 1 (mild) and 2 (severe)] based on the drop and recovery of milk yield following 3 steps. First, we removed milk recorded on the day of diagnosis of mastitis from the data set and fitted a Wood's Curve for each cow and parity. Second, we returned the mastitis data to the data set and estimated the residual milk loss due to mastitis from 15 d before to 30 d after the mastitis event. Third, we used generalized additive mixed effect models to estimate the residual milk loss, including farm as a random effect. In addition to the random effect of the farm, we also included the predicted value of mastitis, the day effect before and after mastitis incidence, and the interaction between the predicted value of mastitis and days. On average, mastitis level 2 resulted in a more severe milk yield drop in all represented stages of lactation (80, 170, and 260 d in milk), suggesting a higher loss close to the lactation peak, approximately 130 kg more than mastitis level 1. Moreover, the occurrence of mastitis case level 1 during early phase of lactation (DIM 80) can cause an average milk loss of 158 L and a ML 2, an average loss of 288 L. The estimations suggest that milk drop occurs 14 to 4 d before mastitis onset and can last until 15 to 25 d from the diagnosis, which would be the necessary time for a cow to reestablish their predicted milk yield. Therefore, our study brings new perspectives to investigate milk yield drop and recovery due to mastitis infections and how much mastitis can deplete and impair milk production.

Advancing Dairy Herd Health: Predictive Models for Hoof Trimming in Lameness Management

Hoof lesions and lameness in cattle is currently a serious problem in the dairy industry which significantly affects the health and welfare of animals. Predictive modelling offers a promising solution by leveraging data analytics to anticipate when an animal may require hoof trimming, thereby enhancing proactive lameness management strategies. The aim of this study was to develop models on hoof trimming intervention on lameness in dairy cattle before and after hoof trimming. In this study twenty lame cows were selected and lameness index score was given to them (0-5 score). Lameness index scores were recorded before week of hoof trimming (HT) and after hoof trimming intervention it was recorded on 0thday, 3rdday, 6thday, 8thday,11thday and 14thday. To predict the lameness, best fit models were constructed using different independent variables which were significantly influencing lameness. The reliable model was applied to draw the significant interference based on the coefficient of determination (R²). Only those independent variables which were significantly influencing lameness were used to construct prediction models. Among all the variables used for multiple regression analysis, age, parity, milk yield, milk pH, stage of lactation and dung pH was attributing significantly to the prediction of lameness in all studied lame dairy cows..

The study of the embryotoxic effect of the drug "Endoseptam"

Most diseases affecting cows in the early stages of lactation are of an inflammatory nature and are associated with a decrease in reproductive function. Unfavorable environmental factors cause metabolic disorders, hormonal disorders and a decrease in the body's resistance. Favorable conditions are created for the development of opportunistic microflora in the reproductive organs of cows, causing inflammatory processes that can lead to infertility, decreased milk productivity and large economic losses. All this justifies the great interest shown in the study of obstetric and gynecological pathology by veterinary specialists, who consider the development and implementation of preventive and therapeutic measures to combat infertility as an urgent and serious task. Postpartum endometritis is a common disease in dairy herds. Antibiotics in treatment regimens become ineffective because pathogens infecting the uterine cavity develop resistance to them. Complex remedies are needed that have antiseptic, myotropic, wound healing and anti-inflammatory effects. A therapeutic veterinary drug «Endoseptam» has been developed, its high effectiveness in the prevention and treatment of endometritis has been proven. Studies are being conducted to establish the safety profile of the product. This article presents the results of studying the embryotoxic effect of the newly developed drug. White rats were used in the experiment. The drug was administered to laboratory animals per os at doses of 2000 mg/ kg and 20,000 mg / kg during 19 days of pregnancy. On the 20th day of pregnancy, some of the animals were euthanized and autopsied to assess the effects of «Endoseptam» on developing embryos/fetuses. The remaining part of the animals in the experiment was monitored to record the growth and development of offspring. The data obtained confirm the absence of toxic effects on developing embryos/fetuses of a complex remedy for the prevention and treatment of endometritis. When observing the physical development of offspring, there were no violations of embryonic development manifested in the postnatal period of life. The drug «Endoseptam» does not have an embryotoxic effect.