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Ketosis, evidenced by hyperketonemia with elevated blood β‐hydroxybutyrate (BHB) levels, is a significant metabolic disorder of dairy cattle, typically diagnosed within the first 6 weeks post‐calving when high energy levels are essential to milk production. Our study aimed to identify genetic markers linked to hyperketonemia (HYK) patterns in Holstein cows during early lactation and compare these to HYK‐negative cows. We screened 964 cows for HYK using a threshold of BHB ≥1.2 mmol/L during the first 2 weeks postpartum (screening period, SP). Cows that tested negative initially were retested the following week. Cows were deemed HYK‐negative (CON group) if BHB levels were below 1.2 mmol/L in both tests, while those with BHB levels exceeding this threshold at any test were treated and classified as HYK‐positive (HYK+). Post‐treatment, HYK+ cows were monitored for two‐week follow‐up period (FP) and classified based on their recovery: cured (CUR; consistently low BHB), recurrent (REC; fluctuating BHB levels), severe (SEV; high initial BHB that decreased), or chronic (CHR; persistently high BHB). Using 489 cows that were genotyped, a GWAS was conducted using GCTA software, revealing significant associations of several SNPs across different HYK patterns when compared to the CON group. These SNPs were primarily linked to genes affecting milk traits and were enriched in biological pathways relevant to protein glycosylation, inflammatory response, glucose homeostasis, and fatty acid synthesis. Our findings highlight genomic regions, potential candidate genes, and biological pathways related to ketosis, underscoring potential targets for improving health management in dairy cattle. These insights could lead to better strategies for managing ketosis through genetic selection, ultimately enhancing dairy cattle welfare and productivity. Further research with a larger number of cows is recommended to validate these findings and help confirm the implicated SNPs and genes. [ABSTRACT FROM AUTHOR]

Up to now, little has been known about backfat thickness (BFT) in dairy cattle. The objective of this study was to investigate the lactation curve and genetic parameters for BFT as well as its relationship with body condition score (BCS) and milk yield (MKG). For this purpose, a dataset was analysed including phenotypic observations of 1929 German Holstein cows for BFT, BCS and MKG recorded on a single research dairy farm between September 2005 and December 2022. Additionally, pedigree and genomic information was available. Lactation curves were predicted and genetic parameters were estimated for all traits in first to third lactation using univariate random regression models. For BCS, lactation curves had nadirs at 94 DIM, 101 DIM and 107 DIM in first, second and third lactation. By contrast, trajectories of BFT showed lowest values later in lactation at 129 DIM, 117 DIM and 120 DIM in lactation numbers 1 to 3, respectively. Although lactation curves of BCS and BFT had similar shapes, the traits showed distinct sequence of curves for lactation number 2 and 3. Cows in third lactation had highest BCS, whereas highest BFT values were found for second parity animals. Average heritabilities were 0.315 ± 0.052, 0.297 ± 0.048 and 0.332 ± 0.061 for BCS in lactation number 1 to 3, respectively. Compared to that, BFT had considerably higher heritability in all lactation numbers with estimates ranging between 0.357 ± 0.028 and 0.424 ± 0.034. Pearson correlation coefficients between estimated breeding values for the 3 traits were negative between MKG with both BCS (r = −0.245 to −0.322) and BFT (r = −0.163 to −0.301). Correlation between traits BCS and BFT was positive and consistently high (r = 0.719 to 0.738). Overall, the results of this study suggest that BFT and BCS show genetic differences in dairy cattle, which might be due to differences in depletion and accumulation of body reserves measured by BFT and BCS. Therefore, routine recording of BFT on practical dairy farms could provide valuable information beyond BCS measurements and might be useful, for example, to better assess the nutritional status of cows. [ABSTRACT FROM AUTHOR]

Research objective was to study the influence of calcium‐chelating salts on colloidal properties of skimmed milk, which best meets the Brazilian regulation for UHT milk production. Citrate and different ortho‐ and polyphosphate sodium salts were added to milk at 5 concentrations (0.00 up to 0.20% w/w). Samples were heat‐treated (oil bath, 155°C, F0 = 1.43 min), cooled down and analysed. The main changes were caused by tetrasodium diphosphate and sodium triphosphate at 0.15% and 0.20% w/w, as they increased the pH, sequestering capacity and altered the particle size distribution, showing that the impacts on the colloidal structure are influenced by the salt concentration. [ABSTRACT FROM AUTHOR]

Mastitis is a significant and costly disease in dairy cows, reducing milk production and affecting herd health. Recent research highlights the role of gastrointestinal microbial dysbiosis in the development of mastitis. This review focuses on how microbial imbalances in the rumen and intestines can compromise the integrity of the gastrointestinal barriers, allowing harmful bacteria and endotoxins, such as lipopolysaccharide, to enter the bloodstream and reach the mammary gland, triggering inflammation. This process links gastrointestinal health to mammary gland inflammation through the gut–mammary axis. Furthermore, disruptions in glucose metabolism and immune responses are implicated in the progression of mastitis. This review underscores the potential for non‐antibiotic interventions aimed at restoring microbial balance to reduce mastitis incidence, providing new insights into improving dairy cow health and farm productivity. Our findings emphasise the critical need to explore preventive measures targeting the rumen and intestinal microbiota for effective mastitis control. [ABSTRACT FROM AUTHOR]

ABSTRACT The aim of the present study was to infer phenotypic responses and genetic parameters of the F1 calf diseases diarrhoea (DIAR) and pneumonia (PNEU) in dependency of the prenatal maternal health status (PMHS) of the dam and of the herd‐calving year. The PMHS considered diagnoses for the cow disease mastitis (MAST) and claw disorders (CD) during gestation of F0 dams. Furthermore, 305‐d milk production traits of F1 offspring from either healthy or diseased dam groups were compared. The study comprised 20,045 female calves (F1 = generation 1) and their corresponding dams (F0 = parental generation 0), kept in 41 large‐scale herds. All F1 calves were from their dams' 2nd parity, implying that all dam (maternal) diseases were recorded during the first lactation and dry period of the dams. The F1 calves were phenotyped for DIAR up to 30 days post‐partum, and for PNEU up to 180 days of age. At least one entry for the respective disease implied a score = 1 = sick, otherwise, a score = 0 = healthy, was assigned. Production records of the 10,129 F1 cows comprised 305‐d records in first lactation for milk yield (MY), protein yield (PY) and fat yield (FY). Linear and generalised linear mixed models were applied to infer phenotypic responses of F1 traits in dependency of the PMHS for CD and MAST. A diagnosis for MAST or CD in F0 cows during gestation was significantly (p ≤ 0.05) associated with an increased prevalence for DIAR and PNEU, with pairwise differences of least‐squares‐means between calves from healthy and diseased cow groups up to 3.61%. The effects of PMHS on 305‐d production traits in offspring were non‐significant (p > 0.05). In bivariate genetic analyses, DIAR and PNEU were defined as different traits according to the PMHS, i.e., DIAR‐MASThealthy and DIAR‐MASTdiseased, DIAR‐CDhealthy and DIAR‐CDdiseased, PNEU‐MASThealthy and PNEU‐MASTdiseased, and PNEU‐CDhealthy and PNEU‐CDdiseased. The direct heritabilities for DIAR and PNEU were quite similar in the healthy and respective diseased dam group. Slightly larger direct heritabilities in the diseased dam groups were due to increased genetic variances. Maternal heritabilities were quite stable and smaller than the direct heritabilities. In random regression models, genetic parameters for DIAR and PNEU were estimated along the continuous herd‐calving‐year prevalence scale, considering a prevalence for MAST and CD (based on the 20,045 dam records plus 16,193 herd contemporary records) in the range from 0% to 30%. Direct heritabilities for PNEU were quite stable along the herd‐calving‐year gradient for MAST and CD. For DIAR, we observed stronger estimate fluctuations, especially increasing direct heritabilities in dependency of the herd‐calving‐year prevalence for MAST from 0.13 (at a MAST prevalence of 0%) to 0.30 (at a MAST prevalence of 30%). Consequently, obvious genotype x herd‐calving‐year PMHS interactions were observed for DIAR on the prenatal MAST scale, with a minimal correlation of 0.48 between direct genetic effects at 0% MAST prevalence and at 30% MAST prevalence. The correlations between direct genetic and maternal genetic effects were antagonistic at all herd‐calving‐year prevalence levels, displaying strongest fluctuations for “DIAR‐MAST.” The genotype x herd‐calving‐year PMHS interactions for DIAR suggest consideration of specific sires according to the herd health status for CD and for MAST. [ABSTRACT FROM AUTHOR]

ABSTRACT Genomic selection (GS) and genome‐wide association studies (GWAS) have not been investigated in Vietnamese dairy cattle, even for basic milk production traits, largely due to the scarcity of individual phenotype recording in smallholder dairy farms (SDFs). This study aimed to estimate heritability (h2) and test the applicability of GS and GWAS for milk production, body conformation and novel heat tolerance traits using single test day phenotypic data. Thirty‐two SDFs located in either the north (a lowland vs. a highland) or the south (a lowland vs. a highland) of Vietnam were each visited for an afternoon and the next morning to collect phenotype data of all lactating cows (n = 345). Tail hair from each cow was sampled for subsequent genotyping with a 50K SNP chip at that same visit. Milk production traits (single‐test day) were milk yield (MILK, kg/cow/day), energy corrected milk yield adjusted for body weight (ECMbw, kg/100 kg BW/day), fat (mFA, %), protein (mPR, %) and dry matter (mDM, %). Conformation traits were body weight (BW, kg) and body condition score (BCS, 1 = thin to 5 = obese). Heat tolerance traits were panting score (PS, 0 = normal to 4.5 = extremely heat‐stressed) and infrared temperatures (IRTs, °C) at 11 areas on the external body surface of the cow (inner vulval lip, outer vulval surface, inner tail base surface, ocular area, muzzle, armpit area, paralumbar fossa area, fore udder, rear udder, forehoof and hind hoof), assessed by an Infrared Camera. Univariate linear mixed models and a 10‐fold cross‐validation approach were applied for GS. Univariate single SNP mixed linear models were applied for the GWAS. Estimated h2 (using the genotype information to build relationships among animals) were moderate (0.20–0.37) for ECMbw, mFA, mPR, mRE, BW, BCS and IRT at rear udder; low (0.08–0.19) for PS and other IRTs; and very low (≤ 0.07) for MILK, ECM and mDM. Accuracy of genomic estimated breeding values (GEBVs) was low (≤ 0.12) for MILK, ECM, mDM and IRT at hind hoof; and moderate to high (0.32–0.46) for all other traits. The most significant regions on chromosomes (BTA) associated with milk production traits were 0.47–1.18 Mb on BTA14. Moderate to high h2 and moderate accuracies of GEBVs for mFA, mPR, ECMbw, BCS, BW, PS and IRTs at rear udder and outer vulval surface suggested that GS using single test day phenotypic data could be applied for these traits. However, a greater sample size is required to decrease the bias of GEBVs by GS and increase the power of detecting significant quantitative trait loci (QTLs) by GWAS. [ABSTRACT FROM AUTHOR]

ABSTRACT Recently, the potential of using chitosan (CHI) as a feed additive to enhance ruminal fermentation and improve animal performance has gained increasing attention in ruminant nutrition. This study was undertaken to investigate the effect of dietary supplementation with increasing doses of CHI on rumen fermentation attributes and microbial composition, digestibility and milk performance in Dhofari goats. Twenty‐four lactating goats (27 ± 1.8 kg of initial live body weight) were fed a control diet comprising of Rhodes grass hay plus a concentrate feed mixture. Goats were assigned to one of three experimental treatments (n = 8 per treatment) as: (1) control diet with no supplement (CTRL), (2) control diet with 0.300 g/day CHI (CHI0.3) and (3) control diet supplemented with 0.600 g/day CHI (CHI0.6) for a 45‐day experimental period. Dietary supplementation with increasing doses of CHI decreased (p < 0.05) linearly ruminal pH (p = 0.023), total short chain fatty acids concentrations (p = 0.011), acetate (p = 0.013) and butyrate (p = 0.042) proportions, acetate to propionate ratio (p < 0.001), estimated methane (CH4) production (p < 0.001), ammonia nitrogen concentrations (p = 0.003) and protozoa abundance (p = 0.003). However, the ruminal propionate proportion augmented (p = 0.002) linearly with increasing doses of CHI in the diet. Increasing doses of CHI linearly increased the abundance of the ruminal propionate‐producing bacteria, while diminished acetate and CH4‐producing bacteria (p < 0.05). Serum total protein (p = 0.037) and glucose (p = 0.042) levels linearly increased as CHI doses increased in the diet. However, serum UREA levels decreased linearly (p = 0.002) by 21% with increasing CHI amounts in the diet. The digestibility of organic matter, crude protein and neutral detergent fibre increased linearly with the increasing CHI doses (p < 0.05). Neither linear nor quadratic responses (p > 0.05) were observed in daily milk yield and feed efficiency by supplementing the diet with CHI. In conclusion, supplementing the diet with CHI at a dose of 0.600 g/day as a feed additive for dairy goats reduced estimated CH4 generation and improved fibre and protein digestion, with no influence on feed intake, milk yield or composition. [ABSTRACT FROM AUTHOR]

Repeat breeder (RB) cows are clinically healthy animals with regular oestrous cycles that do not become pregnant after three or more services. This syndrome has an incidence ranging between 10.1% and 24%. Repeat breeder syndrome (RBS) in dairy cows leads to economic losses to dairy farmers by increasing the calving interval and consequently reducing milk and calf production. RBS has a complex oetiopathogenesis as many factors are involved in its onset. The causes can be grouped into two categories: causes leading to fertilisation failure and factors leading to early embryonic death. Accurate identification of the cause and early diagnosis of RBS is essential to minimise the problems that this issue brings to the farm, but is not always possible. Hypothesising the underlying aetiology of the syndrome is also crucial for targeted therapy, whether pharmacological or managerial. The aim of this review is to report the different therapies, proposed in the literature, for the treatment of RBS in cattle, based on the knowledge of possible aetiological causes. [ABSTRACT FROM AUTHOR]

Purpose Methods Findings Conclusion Implications for Nursing Practice To review and validate the elements of the nursing diagnosis (ND) “Insufficient breast milk production” (00216) based on the literature and expert consensus, and to construct operational definitions (ODs) for its defining characteristics (DCs).It is a methodological study carried out in two phases. In the first phase, a scoping review was conducted, and in the second, a committee of experts reviewed the elements’ content. Items with a Content Validity Index ≥0.8 were validated for relevance, clarity, and precision. Discussions were conducted until a consensus was reached on all items and criteria evaluated. The Ethics Committee approved the study.The final scoping review sample consisted of 61 articles, and 19 experts evaluated the content of the ND. All DCs were revised. Three at‐risk populations, three associated conditions, and one related factor were added. Three elements had their category changed, and an element was deleted. Experts also validated ODs developed for all DCs.“Insufficient breast milk production (00216)” was validated by experts. This study improved the ND through literature and expert consensus. New elements were added, and existing ones were revised.This study improves this ND based on scientific evidence and clinical expertise and potentially improves nurses’ diagnostic accuracy through ODs. [ABSTRACT FROM AUTHOR]

Extending lactation length reduces the frequency of critical calving events for the cow and herewith reduces the frequency of periods with increased risk for health problems. Moreover, breeding is postponed until a moment later in lactation, which is associated with better conception rates and less days open after start of the breeding period in most studies. Potential risks of an extended lactation are that milk yield of cows at the end of the lactation may be too low which may lead to cows being overconditioned at the end of the extended lactation. Therefore, extending lactation length might not fit every cow. Individual cow characteristics like parity, milk yield level, or body condition determine the response of the cow to an extended lactation. These individual cow characteristics can be used in customized management strategies to optimize lactation length for individual cows. Customized lactation length for individual cows could limit the impact at herd level of disadvantages concerning milk losses and overconditioning and maintain benefits for improved cow health and fertility, reduced number of surplus calves and increased work satisfaction for the farmer. In conclusion, extending lactation length has interesting perspectives for health and fertility of high‐producing dairy cows, although questions remain concerning management approaches to support lactation persistency of cows with an extended lactation, and consequences for calf health and development. Moreover, ongoing studies aim to develop decision support tools to select individual cows for a specific lactation length. [ABSTRACT FROM AUTHOR]

The objective of the study was to estimate genetic and phenotypic trends for first lactation production and reproduction traits in Murrah buffaloes. The information of pedigree and targeted traits of 640 Murrah buffaloes was collected for the period from 1997 to 2020. The first lactation production traits included first lactation milk yield (FLMY), 305 days first lactation milk yield (305FLMY), first lactation length (FLL), first lactation peak yield (FPY) whereas reproduction traits included first service period (FSP), first calving interval (FCI) and first dry period (FDP). Genetic and phenotypic trends were estimated. Phenotypic trends for FLMY, 305FLMY, FLL and FPY exhibited as 36.96 ± 8.58 kg/year, 31.93 ± 8.34 kg/year, 1.47 ± 0.55 days/year and 0.12 ± 0.02 kg/year, respectively and respective genetic trends exhibited as 3.73 ± 1.67 kg/year, 1.94 ± 0.76 kg/year, −0.15 ± 0.07 days/year and 0.01 ± 0.01 kg/year, respectively. It was revealed that there were significant (p < 0.05) and positive phenotypic trends for all production traits while genetic trends were significant (p < 0.05) for FLMY and 305FLMY traits. The phenotypic trends of studied reproductive traits indicated that only FDP trait significantly (p < 0.01) decreased (1.87 days/year) over time. For FSP and FCI traits, nonsignificant (p > 0.05) genetic and phenotypic trends indicated no change over time. This study highlighted potential challenges in maintaining reproductive efficiency alongside productivity improvements in Murrah buffaloes. [ABSTRACT FROM AUTHOR]

The metabolic changes that occur during the early post‐partum period in dairy cows can indeed lead to an imbalance in energy utilization, resulting in the production of excessive ketone bodies. This can have detrimental effects on the cow's health and milk production, leading to economic losses for dairy producers. The release of non‐esterified fatty acids into the blood due to increased lipolysis is a key factor in the development of ketosis. Abdominal adiposity is a key factor on these outcomes in modern dairy cows. The redirection of energy and glucose towards lactose synthesis and milk yield leaves a deficit of gluconeogenic precursors, leading to the conversion of acetyl‐CoA into ketone bodies instead of entering the Krebs cycle. These ketone bodies, including acetone, acetoacetate and β‐hydroxybutyrate, accumulate in the blood and can be detected in various bodily fluids, such as urine, blood and milk, allowing for diagnostic testing. Prevention is indeed crucial in managing ketosis in dairy cattle. Supplementation of propylene glycol in the diet or the use of monensin, either in the diet or in the form of a slow‐release bolus, can help prevent the occurrence of ketosis. However, avoiding high body condition (subcutaneous fat) and excessive abdominal adiposity during the dry period and parturition plus an adequate cow comfort are fundamental tasks to avoid ketosis and related disorders. These interventions aim to provide additional energy sources or enhance the cow's ability to utilize energy efficiently, thus reducing the reliance on excessive lipolysis and ketone body production. [ABSTRACT FROM AUTHOR]

Summary: In this article, we explore why dairy science, technology, and innovation will for the foreseeable future remain important, and some of the future trends we can expect in the field. Given the nutrient richness and density of milk, its ubiquitous production and utility of use to produce foods and food ingredients, dairy will almost certainly continue to play an important role in diets and the global food system. Annual milk production at over 900 billion litres represents approximately 8% of total food biomass but has a disproportionate contribution to global nutrient provision. The value of the global dairy market will reach over $860 billion in 2024, employing approximately 240 million people, and supporting the livelihoods of up to one billion. The importance and long history of dairy has fuelled a vast amount of research in dairy science and technology with hundreds of thousands of papers published in the field. Given the amount of existing dairy science and technology is there anything significant left to be done? However, with advances in numerous other fields such as materials, biology and biochemistry, analytical technology, computing technology, etc., the opportunities in dairy science and technology also advance. Future innovations in the dairy sector will include those relating to environmental science and technology, the food matrix, foods tailored to diets for life stages and lifestyles, developments based on our expanding knowledge of microbiomes, and new opportunities from the use of AI. Dairy is the target for technology‐enabled disruption by those looking to produce substitute products. Some of the technologies to produce dairy alternatives will feature in the future of dairy innovation but the impact is more likely to complement rather than disrupt the dairy sector. [ABSTRACT FROM AUTHOR]

Grass which grows during the autumn is perceived by some farmers to have a negative impact on the nutritive value of silage produced the following spring. The impact of removing herbage in the autumn using sheep, on silage yield and quality the following spring, and on performance of cows offered these silages, was investigated in two experiments. Following harvest of third‐cut silage in September, a grass sward was split into blocks which were either grazed by sheep during November and December or left ungrazed. Herbage was harvested and ensiled the following May and offered to late‐lactation Holstein cows in a two‐period balanced change‐over design feeding experiment comprising two 28‐d periods. In Experiment 1, silage quality was unaffected by autumn grazing treatment but in Experiment 2, silage from swards grazed in autumn had a higher metabolizable energy concentration (0.5 MJ kg−1 dry matter [DM]; p =.016). In Experiment 1, intakes were unaffected, while cows offered silage from the grazed sward (GS) had a greater milk (0.8 kg d−1; p <.001) and protein yield (0.03 kg d−1; p =.014) than cows offered silage from the ungrazed sward, but fat plus protein yield was unaffected. In Experiment 2, cows offered GS had greater DM intake (1.5 kg d−1; p <.001) and fat yield (0.15 kg d−1; p =.047), but fat plus protein yield was not significantly different between treatments. In conclusion, winter grazing using sheep has potential to improve silage quality, but with marginal benefits on individual cow performance. [ABSTRACT FROM AUTHOR]

Regular monitoring of body condition score (BCS) changes during lactation is a crucial management tool in dairy cattle; however, the current BCS measurements are often discontinuous and unevenly spaced in time. The aim of this study was to investigate the ability of random regression test‐day models (RR‐TDM) to predict BCS for the entire lactation in dairy cows even if the actual scoring is limited to one BCS record. The data consisted of test‐day records of milk yield (MY), fat percentage (FP), protein percentage (PP) and BCS (based on a 9‐point scale with unit increments; 1–9) collected from 2014 to 2022 in 128 herds in the Walloon Region of Belgium. In total, 20,698 test‐day records on 2166 first‐parity Holstein cows (2–12 with an average of 9.42 test‐day records per cow) were available for MY, FP and PP; and 7985 records on the same animals (2–12 with an average of 3.68 records per cow) were available for BCS. To estimate the solutions, only one randomly selected BCS record per animal along with all her MY, FP and PP records were used, which were then used to predict BCS data (calibration set). The remaining BCS (1–11 with an average 2.86 BCS records per animal) were used to evaluate the goodness of the predictions (validation set). Multiple‐trait RR‐TDM was used to estimate (co)variance components through the average information restricted maximum likelihood (AI‐REML) algorithm. Predicted BCS were grouped into nine classes as the original observed BCS used for comparison. Pearson correlation between the predicted and observed BCS, prediction error (PE), absolute prediction error (APE) and root mean squared prediction error (RMSE) were calculated. Mean (standard deviation; SD) BCS was 4.97 (1.01), 4.95 (1.07) and 4.98 (1.00) BCS units in the full, calibration and validation datasets, respectively. Pearson correlation between the observed and predicted BCS was 0.71, mean (SD) PE was 0.04 (0.52) BCS units, mean (SD) APE was 0.48 (0.53) BCS units and RMSE was 0.72 BCS units. These findings demonstrate the ability of RR‐TDM to predict BCS for the entire lactation using a single BCS record along with available test‐day records of milk yield and composition in Holstein dairy cows. [ABSTRACT FROM AUTHOR]

This study investigated the impact of temperature and humidity on milk production traits in Tunisian dairy cows, analysing population‐level trends and individual cow responses using various modelling techniques and heat stress (HS) indices. Two distinct datasets were used for this purpose: the first included 551,139; 331,654 and 302,396 test‐day records for milk, fat and protein yields, respectively. The second supplemented the production information with daily average (THIavg) and maximum (THImax) temperature‐humidity index (THI) data. Three main parts of analyses were conducted simultaneously: classical least squares, identification of HS thresholds and associated production losses and assessment of individual cow responses using random regression models (RRM) fitting various continuous functions that include/exclude individual effects. The best model, determined by goodness‐of‐fit measurements, was a cubic polynomial function that accounted for individual variation and THIavg as a heat load measure. HS thresholds were established at THIavg/THImax of 70/74 for milk yield, 50/55 for fat percentage, 59/66 for protein percentage, 54/63 for fat yield and 56/66 for protein yield. According to the fitted polynomial models, daily milk production traits showed a curvilinear decline with accelerated loss rates beyond the established thermal thresholds. However, for all models and thermal indices, maximum daily production losses remained below 164 g/day, 4.4 g/day and 6.1 g/day for milk, fat and protein yields, respectively. Despite these losses, the relatively high thermal thresholds and lower associated production losses suggest that Tunisian dairy cows can tolerate high heat loads. Moreover, observed variations in response patterns indicate potential for selecting heat‐tolerant individuals within this population. [ABSTRACT FROM AUTHOR]

The objective was to conduct a systematic review to clarify the effects of l‐arginine supplementation in pregnant and lactating sows on plasma hormone levels, milk production and composition, the body condition of sows and piglet performance. In April 2023, an online search and a systematic search were performed in the following databases: Embase, Scopus, SciELO, Web of Science, PubMed and Science Direct. The combinations of keywords used were sow and arginine and lactation; sow and arginine and lactating; sow and arginine and gestation; sow and arginine and gestating; sow and arginine and pregnancy; sow and arginine and reproduction; piglet and arginine; and sow and arginine and mammary gland. In total, 21 scientific articles with original data were selected according to preestablished criteria. Among the 21 articles, seven (33%) reported measurements of some plasma hormones, and among these, six reported an increase in the levels of at least one hormone, namely, estradiol, insulin‐like growth factor 1 (IGF‐1), insulin, follicle stimulating hormone, growth hormone or prolactin, with l‐arginine supplementation. The parameters of milk were evaluated in 11 studies (52%), one reported an increase in protein content, and one reported an increase in IGF‐1 content in milk with supplementation of this amino acid. Of the 14 studies that evaluated the performance parameters of piglets, only four reported improvements in some parameters of piglets from sows that received supplementation. Dietary supplementation of arginine for sows in the final third of gestation and/or lactation may alter the plasma levels of some hormones, which may reflect in greater development of the mammary gland tissue and, consequently, promote benefits on the performance of piglets. However, more studies are needed to evaluate the real impact of this amino acid supplementation on the physiology of the sows, in general, and the performance of suckling piglets. [ABSTRACT FROM AUTHOR]

The tolerance of 17 isolates of enterobacteria isolated from raw goat milk was evaluated against three sanitisers. All isolates were tolerant to sodium hypochlorite (1250 to >5000 ppm) and eight isolates were tolerant to peracetic acid (up to 1000 ppm). Two isolates were tolerant to all tested concentrations of quaternary ammonium with biguanide (>150/100 ppm). Although not all isolates are considered pathogens, they exert an important influence on the milk production chain. Sanitisers based on quaternary ammonium and biguanide seem to be more suitable for sanitisation in goat milk chain than sodium hypochlorite. [ABSTRACT FROM AUTHOR]

To enhance camel milk production, some breeders have transitioned from extensive to semi‐intensive breeding systems. This study investigates the effects of this transition on casein fractions by analyzing milk samples of targeted breeding. Various parameters, such as pH, Dornic acidity, dry matter, ash, total proteins, whey proteins, and caseins, were examined. The results revealed that semi‐intensive camel milk exhibited increased acidity and lower mineral content, while demonstrating significant elevations in total proteins, whey proteins, and particularly caseins. Transition to semi‐intensive system increased κ, β, and αs1‐caseins levels by 0.44, 4.85, and 1.81 g/L, respectively, as observed after FPLC, SDS‐PAGE, and MALDI‐ToF characterization. [ABSTRACT FROM AUTHOR]

Camel milk yoghurts were created using probiotic lactic acid bacteria (LAB) with exopolysaccharide (EPS) production capabilities. Lacticaseibacilluscasei ATCC 393, identified as the most efficient EPS producer, was incorporated into conventional yoghurt culture. We compared the effects of adding L. casei ATCC 393 with EPS powder (SLLP) against lactulose. Evaluations included LAB, yeast, mould, cytotoxicity and IC50 values in the samples. The results demonstrated increased bacterial counts, LAB viability, viscosity, antiproliferative effects and a lower IC50 in SLLP, indicating the potential application of EPS‐producing L. casei ATCC 393 and its derived EPS in the development of functional foods. [ABSTRACT FROM AUTHOR]

The aim was to estimate the relative contribution of imprinting effects from both paternal and maternal sides to phenotypic variation in milk production traits including 305 days milk yield (MY), average daily milk production (ADM), fat percentage (F%), protein percentage (P%), 305 days fat yield (FY), 305 days protein yield (PY), ratio of fat percentage to protein percentage (F:P) and somatic cell score (SCS) in Iranian Holstein cows. To do this, each trait was analysed with a series of four animal models, which were identical for fixed and additive genetic effects but differed for combinations of paternal and maternal imprinting effects. The log‐likelihood ratio test (LRT) and Akaike's information criteria (AIC) were used to select the best model for each trait. Correlations between traits due to additive and imprinting effects were estimated by bivariate analyses. For all traits studied, fitting the imprinting effect led to a better data fit. Also, it resulted in a noticeable decrease in additive genetic variance from 8% (SCS) to 28% (F:P). A significant maternal imprinting effect was detected on all traits studied. Estimates of maternal imprinting heritability (hmi2$$ {h}_{\mathrm{mi}}^2 $$) were 0.07 ± 0.02, 0.04 ± 0.01, 0.06 ± 0.01, 0.05 ± 0.01, 0.5 ± 0.01, 0.09 ± 0.02, 0.07 ± 0.02 and 0.06 ± 0.01 for MY, ADM, F%, P%, FY, PY, F:P and SCS, respectively. For F:P, in addition to the maternal imprinting effect, a significant paternal imprinting component was also detected with a 7% contribution to phenotypic variance of F:P. Estimates of direct heritability (ha2$$ {h}_{\mathrm{a}}^2 $$) were 0.29 ± 0.02, 0.17 ± 0.01, 0.22 ± 0.02, 0.11 ± 0.01, 0.18 ± 0.02, 0.22 ± 0.02, 0.15 ± 0.04 and 0.06 ± 0.01 for MY, ADM, F%, P%, FY, PY, F:P and SCS, respectively. Maternal imprinting correlations (rmi) were in a wide range between −0.75 ± 0.15 (P%‐SCS) and 0.95 ± 0.11 (MY‐ADM). Additive genetic correlations (ra) ranged between −0.54 ± 0.05 (MY‐P%) and 0.99 ± 0.01 (MY‐ADM) and phenotypic correlations (rp) ranged from −0.30 ± 0.01 (MY‐F%) to 0.93 ± 0.01 (MY‐ADM). The Spearman's correlation between additive breeding values including and excluding imprinting effects deviated from unity especially for top‐ranked animals implying re‐ranking of top animals following the inclusion of imprinting effects in the model. Since including imprinting effects in the model resulted in better data fit and re‐ranking of top animals, including these effects in the genetic evaluation models for milk production traits was recommended. [ABSTRACT FROM AUTHOR]

Enhancing reproductive performance is a key strategy to mitigate involuntary culling rates, thereby extending productive life (PL) and ultimately improving profitability in dairy cattle herds. A piecewise Weibull proportional hazards model was used to investigate the effect of several important reproductive traits on PL in Holstein dairy cows. Data comprised 200,747 lactation records from 82,505 cows sired by 1952 bulls across 36 dairy herds. PL was defined as the number of days from the first calving to the last milk record or censoring. The statistical model accounted for the time‐dependent fixed effects of changes in herd size, year‐season, milk production, fat and protein contents, and the time‐independent fixed effect of age at first calving. Herd‐year and sire effects were also included as random effects. Reproductive traits include calving traits such as calving ease (CE), calf size (CZ), and calf survival (CS), as well as female fertility traits such as number of inseminations per conception (NI), days from calving to first service (CFS), days from first service to conception (FSC), and days open (DO). All reproductive traits had a significant effect on PL (p < 0.001). Each reproductive trait was analysed separately. The relative risk (RR) of being culled increased as the severity of calving difficulties increased in both primiparous and multiparous cows. Cows that calved small or large calves showed a higher risk of being culled compared with those that calved medium size calves. The increased RR of culling was observed only for primiparous cows that gave birth to dead calves. In addition, cows that required more NI, a longer CFS, FSC, and DO had shorter longevity. These insights can deepen our comprehension of the factors affecting PL and provide information for refining management and breeding strategies, which could lead to increased profitability and sustainability in Iranian dairy farming. [ABSTRACT FROM AUTHOR]

This study's objective was to compare two options of pasture supplementation: corn silage (CS) alone or corn silage mixed with protein concentrate. The experiment was conducted with 18 lactating Holstein cows in mid‐lactation in a crossover design that included three treatments and three data collection periods. All cows had access to pasture for 17 h/day with an average herbage allowance of 16 kg dry matter (DM)/cow/day and were offered in‐barn corn silage, corn silage mixed with protein concentrate, or no supplementation. Cows were equipped with pH sensors residing in the reticulum and, during the 7‐day data collection periods, with a jaw movement recorder. Nonsupplemented cows produced 21.3 kg energy‐corrected milk (ECM) and ate 13.3 kg DM herbage at pasture. Cows supplemented with corn silage and corn silage plus protein produced 2.5 and 4.5 kg/day more ECM, respectively, consumed 3.4 and 3.3 kg/day more DM in total, respectively, ate for a shorter period of time, and ruminated longer than their nonsupplemented peers. Supplemented cows were almost able to cover their energy requirements and mobilised less body mass in contrast to the nonsupplemented cows. Cows offered corn silage plus protein showed increased ECM production, increased milk urea content and lower nitrogen use efficiency (NUE) compared to cows supplemented with corn silage only. Nonsupplemented dairy cows had the highest milk urea content and performed worst in terms of NUE. The best feed conversion efficiency resulted from the nonsupplemented dairy cows and those supplemented with corn silage plus protein. In nonsupplemented cows, the high feed conversion efficiency seemed to be due to the increased mobilisation of body mass. As a result of the starch‐rich supplementations, the ruminal acetic:propionic acid ratio became smaller, and the proportions of n‐butyric acid increased. The mean reticular pH values did not substantially vary across the three feeding treatments. For the choice of a supplementation option, herbage allowance and cost of supplement will have to be considered, but aspects of feed–food competition as well as animal welfare should not be ignored. [ABSTRACT FROM AUTHOR]

The study was done to determine additive, maternal and common permanent environmental effects and best‐suited model for some production traits using six univariate animal models that differed in the (co)variance components fitted to assess the importance of maternal effect using likelihood ratio test in Murrah buffaloes. Data from 614 Murrah buffaloes related to production traits were collected from history pedigree sheets maintained at the buffalo farm, Department of Livestock Production and Management (LPM), LUVAS, Hisar. The production traits under this study were 305 days milk yield (305DMY), peak yield (PY), lactation length (LL), dry period (DP), lactation milk yield (LMY) and wet average (WA). The heritability estimates were in the range of 0.33–0.44 for 305DMY, 0.25–0.51 for PY, 0.05–0.13 for LL, 0.03–0.23 for DP, 0.17–0.40 for LMY and 0.37–0.66 for WA. Model 1 was considered best for most of the traits, viz., 305DMY, PY, LL, LMY and WA followed by model 2 for DP. Covariance and correlated values within the traits caused inflation of heritability in model 3 and model 6. The maximum covariance between the additive and maternal effect was found in trait LMY, which was 14,183.90 in model 3 and the minimum value was also reported in the same trait for model 6, valued at −3522.37. Multivariate analysis showed that all production traits were moderate to high and positively correlated with each other except for DP, which was low and negative genetic and phenotypic correlated. Spearman's rank correlation coefficients of breeding value among all six models were high and significant, ranged from 0.78 to 1.00 for all the traits except DP, therefore any of the models could be taken into account depending upon the availability of data. [ABSTRACT FROM AUTHOR]

The current study sought to genetically assess the lactation curve of Alpine × Beetal crossbred goats through the application of random regression models (RRM). The objective was to estimate genetic parameters of the first lactation test‐day milk yield (TDMY) for devising a practical breeding strategy within the nucleus breeding programme. In order to model variations in lactation curves, 25,998 TDMY records were used in this study. For the purpose of estimating genetic parameters, orthogonal Legendre polynomials (LEG) and B‐splines (BS) were examined in order to generate suitable and parsimonious models. A single‐trait RRM technique was used for the analysis. The average first lactation TDMY was 1.22 ± 0.03 kg and peak yield (1.35 ± 0.02 kg) was achieved around the 7th test day (TD). The present investigation has demonstrated the superiority of the B‐spline model for the genetic evaluation of Alpine × Beetal dairy goats. The optimal random regression model was identified as a quadratic B‐spline function, characterized by six knots to represent the central trend. This model effectively captured the patterns of additive genetic influences, animal‐specific permanent environmental effects (c2) and 22 distinct classes of (heterogeneous) residual variance. Additive variances and heritability (h2) estimates were lower in the early lactation, however, moderate across most parts of the lactation studied, ranging from 0.09 ± 0.04 to 0.33 ± 0.06. The moderate heritability estimates indicate the potential for selection using favourable combinations of test days throughout the lactation period. It was also observed that a high proportion of total variance was attributed to the animal's permanent environment. Positive genetic correlations were observed for adjacent TDMY values, while the correlations became less pronounced for more distant TDMY values. Considering better fitting of the lactation curve, the use of B‐spline functions for genetic evaluation of Alpine × Beetal goats using RRM is recommended. [ABSTRACT FROM AUTHOR]

Background: The comprehensive understanding of microRNAs (miRNAs) in sheep milk during various lactation periods and their impact on milk yield and composition remains limited. Objectives: This study aimed to investigate the expression patterns of four highly expressed miRNAs in sheep milk and their association with milk composition and yield parameters during peak and late lactation stages. Methods: A total of 40 healthy 4‐year‐old Akkaraman (n = 20) and Awassi (n = 20) ewes registered with the Ministry of Agriculture and Forestry of the Republic of Türkiye were used in the present study. For miRNA isolation from milk, the Qiagen miRNeasy Serum/Plasma Advanced Kit was utilised following the manufacturer's instructions. The expression levels of miRNAs were assessed using Qiagen miRNA PCR Assays. Results: The significant fold changes in the expression levels of oar‐miR‐30a‐5p, oar‐miR‐148a and oar‐miR‐181a were observed between peak and late lactation periods in the Awassi sheep breed. Conversely, only oar‐miR‐30a‐5p and oar‐miR‐148a exhibited statistically significant changes in the Akkaraman sheep breed during the same lactation periods. Furthermore, oar‐miR‐21‐5p demonstrated a significant fold change exclusively in peak lactation compared to Akkaraman and Awassi ewes. Conclusions: The findings suggest that the expression of the analysed miRNAs is influenced by both the lactation stage and different sheep breeds. This study offers valuable insights into the relationship between key miRNA expressions in sheep milk and milk composition and yield parameters during peak and late lactation, contributing to the existing knowledge in this field. [ABSTRACT FROM AUTHOR]

The present study analyses the effect of age at first calving (AFC) on future fertility and productivity in Murrah buffaloes. The data of 314 buffalo heifers of animal farm section, ICAR‐CIRB, Hisar were collected over a period of 9 years from 2010 to 2018. The buffalo heifers were categorized into six groups according to the AFC named as 30–35, 36–41, 42–47, 48–53, 54–59 and 60–65 months. The influence of AFC on standard lactation milk (SLMY), peak yield (PY), days in milk (DIM), calving to first service, service per conception, calving to conception interval (CCI) and calving interval till fifth lactation were studied. The study revealed poor productive traits in buffalo heifers calved at younger age (30–35 months) during first parity. The productive value positively corresponded with increase in AFC. During successive lactations, higher mean milk yield (SLMY and PY) was found in groups with 36–41, 42–47 and 48–53 months. The mean number of services per conception was lower in buffalo heifers with 36–41 and 42–47 months following first calving till fifth lactation. Similarly, the said groups had lower mean calving to first service, CCI and CI up to fifth lactation. The survival rate was higher in heifers with AFC 36–41, 42–47, 48–53 and 54–59 months than with AFC 30–35 and 60–65 months. The buffalo heifers with 36–41 and 42–47 months of AFC had higher survival rate and better productive and reproductive traits till fifth parity in the current study. The study concluded that a minimum ideal AFC of 36–41 months yielded the highest productive gain. [ABSTRACT FROM AUTHOR]

The aim of this research was to assess genetic parameters for first lactation production and reproduction traits in Murrah buffaloes by employing additive and maternal effects. Data on pedigree and specific traits of 640 Murrah buffaloes were gathered from 1997 to 2020. These traits encompassed first lactation milk yield (FLMY), 305‐day first lactation milk yield (305FLMY), first lactation length (FLL), first lactation peak yield (FPY), first service period (FSP), first calving interval (FCI) and first dry period (FDP). Genetic evaluations employed six univariate animal models, accounting for both direct and maternal effects, facilitated by THRGIBBS1F90 and POSTGIBBSF90 programs. Fixed factors included in the analysis were period of calving, season of calving and age at first calving. The Bayesian estimates for direct heritability, derived from the most suitable model, were as follows: FLMY: 0.28 ± 0.01, 305FLMY: 0.30 ± 0.01, FLL: 0.19 ± 0.01, FPY: 0.18 ± 0.01, FSP: 0.12 ± 0.01, FCI: 0.14 ± 0.01 and FDP: 0.12 ± 0.01. Maternal effects were found significant, ranging from 5% to 10%, in first lactation traits under Model 2 and Model 5. Additionally, positive and significant genetic and phenotypic correlations were observed among the studied traits. In conclusion, selection based on 305‐day first lactation milk yield suggests potential for genetic enhancement in Murrah buffaloes, advocating its inclusion in breeding programmes to bolster early performance. Also, consideration of maternal influences is necessary for genetic progress of animals. [ABSTRACT FROM AUTHOR]

The study aimed to assess performance traits in Hardhenu cattle by analysing data from 445 animals born to 59 sires and 227 dams. The investigation focused on estimating (co)variance components and genetic parameters for reproduction and production traits in dairy cattle. Results from least‐squares analysis indicated a significant effect (p <.01) of the period of calving (POC) on key production traits, including first lactation milk yield (FLMY), 300‐day milk yield (FLMY300), first peak yield (FPY) and total lactation milk yield (TLMY) in studied population. The least squares means for these traits were reported as follows: FLMY (2665.68 ± 45.66 kg), FLMY300 (2425.52 ± 34.41 kg), FLL (312.95 ± 3.83 days), FPY (11.52 ± 0.15 kg) and TLMY (9282.44 ± 167.03 kg) in Hardhenu cattle. In the studied population, only additive genetic variability was found to be present and there was absence of any significant maternal effect with respect to targeted traits in the resource population. Direct heritability estimates (h2) for FLMY, FLMY300, FLL, FPY, TLMY and other traits ranged from 0.03 to 0.41 in Hardhenu cattle. These findings offer valuable insights into the genetic factors influencing performance traits, contributing to the enhancement of breeding and management practices in Hardhenu cattle. [ABSTRACT FROM AUTHOR]

Introduction: Although the primary function of a woman's breast is milk synthesis, only a few studies have evaluated the relationship between breast size and human milk composition, showing equivocal results. This study aims to test if breast size during fully established lactation is related to energy density and content of macronutrients in human milk. Materials and Methods: Mothers of healthy, born‐on‐term infants at stage III of lactogenesis (N = 137) provided breast milk samples. Milk composition was analyzed using midinfrared transmission spectroscopy. The breast size index was calculated by dividing the breast by the circumference below the breast. Results: Stepwise forward linear regression showed a negative association between breast size index and lactose concentration in breast milk (β = −.242, p =.003). The final model, which includes breast size index, feeding frequency, and maternal energy intake together explained around 13% of the variance in breast milk lactose content (R2adj =.126, p <.001). No statistically significant relationship was found between breast size index and milk's energy density, protein, and fat content. Conclusion: This is the first study that shows a negative relationship between breast size during fully established lactation and lactose concentration in milk in a large sample size. No relationship between other macronutrients and breast size indicates that large breast size is not necessary for adequate milk production; however, it may contribute to an altered lactose concentration. [ABSTRACT FROM AUTHOR]

This study in dairy cow feeding explored the effects of growth stage and chop length for grass‐clover silage, and of concentrate protein level, including the interactions of these three factors. The experiment was conducted with 48 Norwegian Red cows according to a cyclic change‐over design with four 4‐week experimental periods and eight dietary treatments in a 2 × 2 × 2 factorial arrangement. Round bale silage from a mixed sward of timothy, meadow fescue, and red clover was harvested at two growth stages (H1, H2) and offered to dairy cows either unchopped with median particle length of 152 mm or chopped to 19 mm median particle length before feeding. A low protein (LP) concentrate containing 7% lignosulphonate treated soybean meal (SBM) and a high protein (HP) concentrate containing 12% solvent extracted SBM were compared. Silage was offered ad libitum and supplemented with 8 kg concentrate per day. Silage dry matter intake was 2.0 kg higher for H1 than H2 silage, which supported a higher yield of milk, energy‐corrected milk and the milk constituents, fat, protein, and lactose. All these measures of milk production, as well as feed energy efficiency and N use efficiency, increased when silage was fed chopped rather than unchopped. Lignosulphonate treated SBM spared N in the diet without milk yield reductions. For efficient milk production with high energy and N utilisation, we recommend chopping to 20 mm for timothy, meadow fescue, and clover silages harvested in late stem elongation or in reproductive growth stages. [ABSTRACT FROM AUTHOR]

The Kazakh cattle in the Xinjiang Uygur Autonomous Region of China are highly adaptable and have multiple uses, including milk and meat production, and use as draft animals. They are an excellent original breed that could be enhanced by breeding and hybrid improvement. However, the genomic diversity and signature of selection underlying the germplasm characteristics require further elucidation. Herein, we evaluated 26 Kazakh cattle genomes in comparison with 103 genomes of seven other cattle breeds from regions around the world to assess the Kazakh cattle genetic variability. We revealed that the relatively low linkage disequilibrium at large SNP distances was strongly correlated with the largest effective population size among Kazakh cattle. Using population structural analysis, we next demonstrated a taurine lineage with restricted Bos indicus introgression among Kazakh cattle. Notably, we identified putative selected genes associated with resistance to disease and body size within Kazakh cattle. Together, our findings shed light on the evolutionary history and breeding profile of Kazakh cattle, as well as offering indispensable resources for germplasm resource conservation and crossbreeding program implementation. [ABSTRACT FROM AUTHOR]

Genetic research for the assessment of mastitis and milk production traits simultaneously has a long history. The main issue that arises in this context is the known existence of a positive correlation between the risk of mastitis and lactation performance due to selection. The transcriptome‐wide association study (TWAS) approach endeavors to combine the expression quantitative trait loci and genome‐wide association study summary statistics to decode complex traits or diseases. Accordingly, we used the farmgtex project results as a complete bovine database for mastitis and milk production. The results of colocalization and TWAS approaches were used for the detection of functional associated candidate genes with milk production and mastitis traits on multiple tissue‐based transcriptome records. Also, we used the david database for gene ontology to identify significant terms and associated genes. For the identification of interaction networks, the genemania and string databases were used. Also, the available z‐scores in TWAS results were used for the calculation of the correlation between tissues. Therefore, the present results confirm that LYNX1, DGAT1, C14H8orf33, and LY6E were identified as significant genes associated with milk production in eight, six, five, and five tissues, respectively. Also, FBXL6 was detected as a significant gene associated with mastitis trait. CLN3 and ZNF34 genes emerged via both the colocalization and TWAS approaches as significant genes for milk production trait. It is expected that TWAS and colocalization can improve our perception of the potential health status control mechanism in high‐yielding dairy cows. [ABSTRACT FROM AUTHOR]

The impact of beta‐carotene on cattle fertility has been investigated in various studies; however, consensus on this issue has not been reached. In the present study, we systematically reviewed and meta‐analysed 29 publications conducted between 1984 and 2022, focusing on seven fertility measures, clinical mastitis and milk yield in cows. We did not find statistically significant results in 8 out of 11 parameters (p >.05). Statistically significant results were observed for milk yield (MD: 216.25 kg in 305 days, p =.01, CI: 50.73–381.77), pregnancy at first service (OR: 1.38 CI: 1.08–1.76, p =.01) and clinical mastitis (OR: 0.59, CI: 0.44–0.80, p =.006) in favour of beta‐carotene supplementation. The meta‐regression revealed significant effects of 'plasma beta‐carotene levels' on 'service to per pregnancy' and dose on 'milk yield' (p =.04 and p = 0). In binary outcomes, 'dose × day' and 'plasma beta‐carotene concentration in the control group' positively influenced pregnancy at first service (p =.02 and.03). In conclusion, given the positive point direction observed for some variables and insignificant results for others, there is a need for more studies. We note the very high heterogeneity of outcomes and suggest caution in interpreting results. [ABSTRACT FROM AUTHOR]

This document provides abstracts of papers presented at the Society of Dairy Technology 80th Anniversary Conference, covering a range of topics in the dairy industry. One paper examines the impact of process conditions on water evaporation and energy usage in spray drying, while another explores the use of near-infrared spectroscopy to analyze the composition of raw milk. Other papers discuss the development of high-protein soft cheese alternatives, plant-based cheese analogues, and sustainable cleaning strategies in dairy facilities. The document also mentions a project focused on characterizing the milk metabolome and developing biomarkers for milk processability and methane production. Additionally, the document highlights a study that modified sediment quantification tests for dairy powders to improve image analysis capabilities, with promising results. Further research is planned to investigate the effects of robotic agitation and test additional powders. [Extracted from the article]

Biotin (BI) and cobalamin (CA) are essential for rumen propionate production and hepatic gluconeogenesis. The study evaluated the influence of BI or/and coated CA (CCA) on milk performance and nutrient digestion in cows. Sixty Holstein dairy cows were assigned in a 2 × 2 factorial arrangement and randomised block design to four groups. The factors were BI at 0 or 20 mg/day and CCA at 0 or 9 mg CA/day. Dry matter intake increased with BI addition but was unchanged with CCA supply. Addition of BI or CCA increased fat‐corrected milk, milk fat and milk protein yields and feed efficiency. Moreover, lactose yield was increased by CCA addition. Dry matter, organic matter, crude protein and acid detergent fibre total‐tract digestibility increased for BI or CCA supply. When CCA was supplemented, positive response of neutral detergent fibre digestibility to BI addition was enhanced. Supplementing BI did not affect pH, propionate content and acetate to propionate ratio, but increased total volatile fatty acids (VFA) and acetate contents. Supplementing CCA decreased pH and acetate to propionate ratio, but increased total VFA, acetate and propionate contents. Rumen protease and carboxymethyl‐cellulase activities and fungi, bacteria and Butyrivibrio fibrisolvens numbers increased for BI or CCA supply. In addition, protozoa increased for BI addition, and protease activity and Prevotella ruminicola increased for CCA supply. When CCA was supplemented, positive responses of R. albus and Ruminobacter amylophilus numbers to BI addition were enhanced. Blood glucose concentration was unchanged with BI supply, but increased for CCA supply. Blood nonesterified fatty acids and β‐hydroxybutyrate contents reduced with BI or CCA supply. Supplementation with BI or CCA increased blood BI or CA content. The results showed that supplementing BI or/and CCA improved lactation performance and nutrient digestion, and CCA supply did not enhance the lactation performance response to BI supply. [ABSTRACT FROM AUTHOR]

Cattle heat stress causes billions of dollars' worth of losses to meat and milk production globally, and is projected to become more severe in the future due to climate change. Tree establishment in pastoral livestock systems holds potential to reduce cattle heat stress and thus provide nature‐based adaptation. We developed a general model for the impact of trees on cattle heat stress, which can project milk and meat production under future climate scenarios at varying spatial scales. The model incorporates the key microclimate mechanisms influenced by trees, including shade, air temperature, humidity, and wind speed. We conducted sensitivity analyses to demonstrate the relative influence of different mechanisms through which trees can impact cattle heat stress, and how tree impacts are influenced by climatic context globally. Trees hold the greatest potential to reduce cattle heat stress in higher latitudes and altitudes, with minor benefits in the lowland tropics. We projected the future contributions of current trees in mitigating climate change impacts on the dairy and beef herds of Aotearoa—New Zealand (A‐NZ) in 2070–2080. Trees were simulated to contribute to A‐NZ milk yields by over 491 million liters (lower CI = 112 million liters, upper CI = 850 million liters), and meat yields by over 8316 tonnes (lower CI = 2431 tonnes, upper CI = 13,668 tonnes) annually. The total economic contribution of existing trees in mitigating future cattle heat stress was valued at $US 244 million (lower CI = $US 58 million, upper CI = $US 419 million). Our findings demonstrate the importance of existing trees in pastoral landscapes and suggest that strategic tree establishment can be a valuable adaptation option for reducing cattle heat stress under climate change. Tree establishment in the next few years is critical to provide adaptation capacity and economic benefit in future decades. [ABSTRACT FROM AUTHOR]

Crossbred cattle are commonly used for milk production in the tropics, combining the potential benefits of pure breeds with the heterosis effects of the offspring. However, no comprehensive assessment of lifetime productivity for crossbred versus purebred cattle in low‐altitude tropical environments has been carried out. The present study compares the lifetime productivity of purebred Holstein (HO, n = 17,269), Gyr (GY4, n = 435), and Brahman (BR4, n = 622) with crossbreds Gyr × Holstein (GY × HO, n = 5521) and Brahman×Holstein (BR × HO, n = 5429) cows from dairy farms located in low and medium altitude tropical regions in Costa Rica. The production traits of interest were age at first calving (AFC), days open (DO), milk production per lactation (TMP), lactation length (LLEN), age at culling (ACUL), and number of lactations (NLAC). Estimates of heterosis were also calculated. The AFC for GY × HO crosses (33–34 months) was not significantly different (p >.05) from HO (33.8 months). For BR × HO crosses, a significant (p <.05) decrease in AFC (BR3HO1 35.6 months, BR2HO2 34.5 months, and BR1H03 33.3 months) was observed as the fraction of HO breed increased. Estimates of heterosis for AFC were favourable for both crosses, of a magnitude close to 3%. The DO for F1 crosses (GY2HO2 94 days; BR2HO2 96 days) was significantly (p <.05) lower than HO (123 days). Estimates of heterosis for DO were also favourable and above 15% for both crosses. The TMP and LLEN were higher for HO (TMP = 5003 kg; LLEN = 324 days) compared with GY × HO (TMP = 4428 to 4773 kg; LLEN = 298 to 312 days) and BR × HO (TMP = 3950 to 4761 kg; LLEN = 273 to 313 days) crosses. Heterosis for TMP was favourable but low for both crosses, with a magnitude below 3.0%. The NLAC for HO (4.6 lactations) was significantly (p <.05) lower than F1 (GY2HO2, 5.8 lactations; BR2HO2, 5.4 lactations). Heterosis for NLAC was above 6.0% for both crosses. Overall, estimates of lifetime income over feed costs per cow on average were USD 2637 (30.3%) and USD 734 (8.4%) higher in F1 GY × HO and BR × HO, respectively, compared to HO. In conclusion, crossbred animals, specifically those with Gyr and Brahman genetics, extend the productive lifespan, increasing economic returns. [ABSTRACT FROM AUTHOR]

In this study, we examined whether the frequency of exogenous oestrogen treatment affects the induction of artificial lactation and milk production. Furthermore, we analysed changes in milk components obtained from artificially lactating sows. Pseudopregnant induced by treatment with 30 mg of estradiol dipropionate (EDP) on Day 10 (Day 0 = the last day of estrus) were divided into three groups: those administered 5 mg of EDP once on Day 39 (n = 5), twice on Days 32 and 39 (n = 5) and three times on Days 25, 32 and 39 (n = 6). All animals were treated with prostaglandin F2α (PGF2α) on Day 46 for induced lactation. Artificial lactation was induced in 66.7%–80.0% of sows, and the EDP treatment frequency before PGF2α administration had no significant effect on either the induction rate of artificial lactation or the milk yield during the experimental period. The milk composition (levels of crude protein, crude fat, crude ash, lactose and immunoglobulin) did not differ among the groups. In conclusion, the number of EDP treatments prior to PGF2α administration had no effect on either the efficiency of artificial lactation induction or milk production. [ABSTRACT FROM AUTHOR]

The document titled "Antimicrobial prescribing guidelines for dairy cattle" provides guidelines for the appropriate use of antimicrobial agents in the dairy industry. It emphasizes responsible use to prevent antimicrobial resistance and protect public health, animal health, welfare, and production. The guidelines cover various aspects such as disease prevention, accurate diagnosis, therapeutic objectives and plans, drug selection, dosage regimens, record-keeping, and post-treatment activities. The document acknowledges the role of dairy cattle veterinarians in promoting responsible use and urges them to apply the guidelines to safeguard antimicrobial efficacy and contribute to the global response to antimicrobial resistance. [Extracted from the article]

Milk yield and composition phenotypes are systematically recorded across several lactations in goats, but the majority of genome‐wide association studies (GWAS) performed so far have rather ignored the longitudinal nature of such data. Here, we have used two different GWAS approaches to analyse data from three lactations recorded in Murciano‐Granadina goats. In Analysis 1, independent GWAS have been carried out for each trait and lactation, while a single longitudinal GWAS, jointly considering all data, has been performed in Analysis 2. In both analyses, genome‐wide significant QTL for lactose percentage on chromosome 2 (129.77–131.01 Mb) and for milk protein percentage on the chromosome 6 (74.8–94.6 Mb) casein gene cluster region were detected. In Analysis 1, several QTL were not replicated in all three lactations, possibly due to the existence of lactation‐specific genetic determinants. In Analysis 2, we identified several genome‐wide significant QTL related to milk yield and protein content that were not uncovered in Analysis 1. The increased number of QTL identified in Analysis 2 suggests that the longitudinal GWAS is particularly well suited for the genetic analysis of dairy traits. Moreover, our data confirm that variability within or close to the casein complex is the main genetic determinant of milk protein percentage in Murciano‐Granadina goats. [ABSTRACT FROM AUTHOR]

Limited literature is available on the consequences of postpartum low blood calcium (Ca) concentration in crossbred cows. The research aimed to investigate the correlation between postpartum serum Ca levels and various parameters, including milk yield, serum energy metabolites, milk somatic cell count, and reproductive factors in crossbred cows. Following parturition, a total of 45 potential high-yielding F2 (HF × Sahiwal; Genotype: 75:25) dairy cows were enrolled. These cows were categorized based on plasma calcium concentrations into three groups: a low calcium group (Ca-L) with a calcium concentration of <5 mg/dL, a medium calcium group (Ca-M) with a calcium concentration ranging from 5 to 8.5 mg/dL, and a high calcium group (Ca-H) with a calcium concentration exceeding 8.5 mg/dL. The study parameters were measured over an 8-week period. The results indicated that overall milk yield and blood glucose were significantly higher in the Ca-H group compared to Ca-M and Ca-L (p < .01). Blood cholesterol was significantly higher in Ca-M (p < .01), while blood triglyceride was significantly lower in both Ca-M and Ca-H. Overall, blood cortisol did not show a significant change between these groups (p < .01); however, progesterone levels were higher (p < .01) in Ca-M and Ca-H cows. Furthermore, somatic cell count (SCC) significantly (p < .01) decreased in cows with Ca-H compared to Ca-L. Additionally, postpartum oestrous interval and interestrus interval decreased significantly (p < .01) in Ca-M and Ca-H compared to Ca-L. These findings suggest that cows with blood calcium levels exceeding 8.5 mg/dL exhibited significantly higher milk yield, blood metabolite levels, a lower likelihood of subclinical mastitis, and earlier reproductive activity after calving. [ABSTRACT FROM AUTHOR]

The current study was conducted to explore the productive performance and health status of lactating buffaloes fed diets supplemented with probiotic and/or fibrolytic enzymes. Forty multiparous lactating Egyptian buffaloes (body weight 451 ± 8.5 kg) were equally assigned to four experimental groups: (1) the first group fed control diet, (2) second experimental group fed control diet plus 4 g of probiotic/kg dry matter (DM) (probiotic), (3) third experimental group fed control diet plus 4 g of fibrolytic enzymes/kg DM (enzymes) and (4) fourth experimental group fed control diet plus 2 g of probiotic + 2 g fibrolytic enzymes/kg DM (Mix), The experiment was extended for 63 days. Nutrients digestibility was estimated, daily milk yield was recorded and milk samples were analyzed for total solids, fat protein, lactose and ash. Blood serum samples were analyzed for glucose, total protein, albumin, urea‐N, aspartate transaminase, alanine transaminase and cholesterol concentrations. Results showed that adding probiotic and/or fibrolytic enzymes improved nutrients digestibility (p < 0.05). The probiotic, enzymes and mix groups did not affect (p > 0.05) concentrations of serum total protein, albumin (A), globulin (G), albumin/globulin (A/G) ratio and urea‐N concentrations. An improvement in daily milk yield (p < 0.0001) and energy‐corrected milk (p = 0.0146) were observed with the probiotic and mix groups compared with the control. In conclusion, this study suggests that supplementing lactating buffaloes' diets with probiotic alone or in combination with fibrolytic enzymes would improve their productive performance without adversely impacting their health. [ABSTRACT FROM AUTHOR]

Gestation length (GL) can potentially affect health and performance of both the dam and the newborn calf, and it is controlled by two genetic components, direct and maternal. This means that both the calf (direct effect) and the cow (maternal effect) genotypes contribute to determine GL and its variability. The aims of the present study were to estimate direct and maternal variance components of GL, develop a routine genetic evaluation of GL in Italian Holstein and evaluate potential (un)favourable associations with traits for which selection is undertaken in this population. A multiple‐trait repeatability linear animal model was employed for the estimation of variance components considering GL in first and later parities as different traits. The posterior mean (PM) of heritability of the direct effect was 0.43 for first parity and 0.35 for later parities. The PM of heritability of the maternal effect was lower, being 0.08 for primiparae and 0.06 for pluriparae. The posterior standard deviation (PSD) of the heritability estimates was small, ranging from 0.001 to 0.005. The relationship of direct and maternal effects with important traits such as milk yield and fertility indicated that selecting for extreme GL, longer or shorter, may have negative consequences on several traits, suggesting that GL has an intermediate optimum in dairy cattle. In conclusion, this study reveals that selecting an intermediate GL in the Italian Holstein population is advisable. Although scarcely variable compared to other conventional traits for which Italian Holstein is selected, GL is heritable and a deeper knowledge can be useful for decision‐making at the farm level. [ABSTRACT FROM AUTHOR]

To address the issues of probiotic activity loss during storage and feeding, as well as the limited efficacy of single probiotics, a solution was devised by embedding a mixture of Bacillus coagulans SN‐8 (SN‐8) and Saccharomyces boulardii SN‐6 (SN‐6) in a gel. The initial step involved screening the probiotic microcapsules' preparation method and wall material. Using sodium alginate and β‐cyclodextrin as composite wall material and chitosan as the outer coating material allowed for an embedding rate of 82.11% in composite probiotic microcapsules prepared by the air atomization method. Next, in vitro, simulated digestion experiments were conducted to determine the number of viable bacteria and the release rate of the microcapsules. The results showed that compared to the free strain, the mixed probiotic microcapsules retained a survival rate of 67.5% after 3 h of simulated gastric juice exposure and 70.56% after 42 days of storage at 4°C. This demonstrated higher survival rates and storage stability. The prepared probiotic microcapsules were then administered to dairy cows. 16S rDNA gene sequencing showed that consumption of the microcapsules reduced the number of harmful bacteria, such as Paeniclostridium, in the intestinal tract of dairy cows while accelerating the growth of beneficial bacteria, such as Bifidobacterium. In particular, this resulted in a significant improvement in the lactation performance of the cows, with a 4.5% increase in milk fat content, a 92.5% increase in milk protein content, and a 3.5% increase in milk urea nitrogen content (6.75 mL/dL). In conclusion, probiotic microcapsules can effectively regulate intestinal flora, improving milk production, and quality in dairy cows. [ABSTRACT FROM AUTHOR]

Food safety is recognized as a major hurdle in the transition toward circular food production systems due to the potential reintroduction and accumulation of chemical contaminants in these food systems. Effectively managing these hazardous contaminants in a risk‐based manner requires quantitative insights into the factors influencing the presence and fate of contaminants in the entire circular food chain. A systematic literature review was performed to gain an up‐to‐date overview of the known factors and their influence on the transfer and accumulation of contaminants. This review focused on the terrestrial circular primary food production system, including the pathways between waste‐ or byproduct‐based fertilizers, soil, crops, animal feed, and farmed animals. This review revealed an imbalance in research regarding the different pathways: studies on the soil‐to‐crop pathway were most abundant. The factors identified can be categorized as compound‐related (intrinsic) factors, such as hydrophobicity, molecular weight, and chain length, and extrinsic factors, such as soil organic matter and carbon, pH, milk yield of cows, crop age, and biomass. Quantitative data on the influence of the identified factors were limited. Most studies quantified the influence of individual factors, whereas only a few studies quantified the combined effect of multiple factors. By providing a holistic insight into the influential factors and the quantification of their influence on the fate of contaminants, this review contributes to the improvement of food safety management for chemical hazards when transitioning to a circular food system. [ABSTRACT FROM AUTHOR]

Milk production is one of the most important economic utility of goats. Guanzhong dairy goat is a local dairy goat in Shaanxi Province of China and has high milk yield and quality. However, there are relatively few studies on molecular markers of milk production traits in Guanzhong dairy goats. In this study, we sequenced the whole genomes of 20 Guanzhong dairy goats, 10 of which had high milk yield (HM) and 10 of which had low milk yield (LM). We detected candidate signatures of selection in HM goats using Fst and π‐ratio statistics and identified several candidate genes including ANPEP, ADRA1A and PRKG1 associated with milk production. Our results provide the basis for molecular breeding of milk production traits in Guanzhong dairy goats. [ABSTRACT FROM AUTHOR]

This study investigated the impact of parity, period of calving, and season of calving on various production and reproduction traits in Hardhenu cattle. Third‐parity cows outperformed first and second‐parity cows, exhibiting significantly higher total milk yield (TMY), 305 days milk yield (305d MY), peak yield (PY), and artificial insemination per conception (AIPC) (p <.01). The Lactation length (LL) was inversely related to parity, with first‐parity cows having extended lactations (p <.05). The period of calving had a substantial influence on production traits. The season of calving was critical, affecting production traits differently across parities. First‐parity cows had the highest TMY and 305d MY during winter and summer calving, with summer calving associated with shorter LL (p <.05). Second‐parity cows showed higher TMY and 305d MY during summer calving, while third‐parity cows had higher TMY in winter (p <.01). PY followed similar patterns to TMY, with LL affected by the season of calving. Additionally, the study explored interactions between parity, period of calving, and season of calving on reproduction traits. Third‐parity cows had higher AIPC compared to first and second‐parity cows (p <.01). Reproduction traits were also significantly affected by the period of calving, with cows calving in the 2017–2021 period displaying longer service period (SP), calving interval (CI), dry period (DP), and AIPC (p <.01). These findings highlight the complex interplay of biological, environmental, and management factors in shaping the productivity and reproductive efficiency of Hardhenu cattle, emphasizing the need for multifaceted considerations to optimize herd performance. [ABSTRACT FROM AUTHOR]

Summary: In comparison to bovine milk, compositional differences in goat milk such as lower αs1‐casein and higher β‐casein content, small‐sized fat globules, higher mineral content and medium‐chain fatty acids generate difficulties in manufacturing goat milk products. Majorly, soft and fragile gel structure, lower yield, salty taste and goaty flavour result in decreased acceptability of goat milk products. Therefore, the present review discusses the technological challenges in preparation of goat milk‐based products, mainly yogurt and cheeses. Understanding the challenges involved in preparing goat milk products and overcoming them by modifying the processing parameters and product formulations could help to improve the quality of goat milk products. Thermal treatment, admixture with bovine milk, enzymatic modifications, and membrane processing have shown promising results in improving the final quality of goat milk products. This review strengthens the existing knowledge for producing goat milk products with improved textural and sensorial attributes. [ABSTRACT FROM AUTHOR]