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A comprehensive recent study by Trommelen et al. demonstrated that muscle tissue exhibits a greater capacity to incorporate exogenous exogenous protein-derived amino acids into bound muscle protein than was previously appreciated, at least when measured in "anabolically sensitive," recreationally active (but not resistance-trained), young men following resistance exercise. Moreover, this study demonstrated that the duration of the postprandial period is modulated by the dose of ingested protein contained within a meal, that is, the postexercise muscle protein synthesis response to protein ingestion was more prolonged in 100PRO than 25PRO. Both observations represent important scientific advances in the field of protein metabolism. However, we respectfully caution that the practical implications of these findings may have been misinterpreted, at least in terms of dismissing the concept of protein meal distribution as an important factor in optimizing muscle tissue anabolism and/or metabolic health. Moreover, based on emerging evidence, this idea that the anabolic response to protein ingestion has no upper limit does not appear to translate to resistance-trained young women. [ABSTRACT FROM AUTHOR]

Precise protein supplementation strategies for muscle improvement are still lacking. The timing or type of protein supplementation has been debated as a window of opportunity to improve muscle mass, strength, and physical performance. We conducted a network meta-analysis of randomized controlled trials with protein supplements and resistance training. PubMed, Web of Science, Cochrane Library, and SPORTDiscus databases were searched until May 1, 2023. We included 116 eligible trials with 4,711 participants that reported on 11 timing and 14 types of protein supplementation. Compared with placebo, protein supplementation after exercise (mean difference [MD]: 0.54 kg [95% confidence intervals 0.10, 0.99] for fat-free mass, MD: 0.34 kg [95% confidence intervals 0.10, 0.58] for skeletal muscle mass) and at night (MD: 2.85 kg [0.49, 5.22] for handgrip strength, MD: 12.12 kg [3.26, 20.99] for leg press strength) was most effective in improving muscle mass and strength, respectively (moderate certainty). Milk proteins (milk, whey protein, yogurt, casein, and bovine colostrum), red meat, and mixed protein were effective for gains in both muscle mass and strength (moderate certainty). No timing or type of protein showed a significant enhancement in physical performance (timed up-to-go test, 6-min walk test, and gait speed). Pre/postexercise and Night are key recommended times of protein intake to increase muscle mass and strength, respectively. Milk proteins are the preferred types of protein supplements for improving muscle mass and strength. Future randomized controlled trials that directly compare the effects of protein timing or types are needed. This trial was registered at International Prospective Register of Systematic Reviews as CRD42022358766. [ABSTRACT FROM AUTHOR]

Summary: Milk proteins are known for their exceptional nutritional and technological attributes, making them a staple in the food industry. Nonetheless, the partial substitution of milk proteins with plant‐based proteins in dairy products may be an effective strategy to meet the increasing consumer demand for a reduction in the consumption of animal‐derived proteins. This study aimed to evaluate the impact of partial substitution (25% and 50%) of milk proteins with pea protein on the manufacturing and technological attributes of high‐protein yogurt during refrigerated storage. The replacement of up to 50% of the milk proteins with pea protein did not alter the fermentation time and all yogurts had a total lactic acid bacteria count greater than 107 CFU g−1 after manufacturing. However, replacing 50% of milk proteins with pea protein affected the pH, syneresis, water holding capacity, consistency, firmness, viscosity index, and cohesiveness of the yogurts. In turn, no effect was observed on the pH, syneresis, water holding capacity, firmness, and cohesiveness of the product after replacing 25% of the dairy base with pea protein (P >0.05). Hence, the findings indicate that substituting 25% of the milk protein with pea protein in high‐protein yogurts can be achieved without compromising the product's stability. [ABSTRACT FROM AUTHOR]

Summary: This study investigated the perception of Uruguayan consumers towards hybrid dairy‐like products, including beverages and yogurts made with a mix of milk and plant proteins from canola, hemp, or soy. The study was conducted online with 261 participants, using a 2 × 4 experimental design to analyse consumer responses to product type and protein source. Results showed that dairy yogurt was the most preferred. Among plant protein ingredients, canola and hemp were the most and least preferred, respectively. Consumers rated each product on purchase intention, environmental friendliness, and other attributes through a comprehensive questionnaire. Findings indicated significant variation in purchase intentions based on product and protein type. Canola‐based products were seen as more environmentally friendly compared to soy. Attributes such as 'Healthy', 'Contains calcium', and 'Contains proteins' positively affected purchase intentions, while negative perceptions about flavour impacted intentions adversely. Cluster analysis revealed significant differences across clusters regarding protein preferences and product types. [ABSTRACT FROM AUTHOR]

Summary: Precision fermented dairy (PFD) is a novel technology used to produce milk proteins that can be used to replicate conventional dairy (CD) products. With PFD products likely to be available soon in the United Kingdom, this study aimed to explore consumer acceptance of these products. Specifically, the effect of sharing information related to the process and environmental impact of PFD on overall liking and emotional response for yoghurts labelled as CD and PFD. Overall, all participants (n = 62) were willing to try the yoghurts labelled as PFD, and no significant difference in liking between yoghurts labelled as CD and PFD was found, indicating acceptance and trust. However, sharing information slightly increased liking for PFD yoghurt and evoked more positive emotions ('understanding', 'adventurous' and 'enthusiastic'). In contrast, information decreased liking for CD yoghurt and had minimal impact on the emotional response, but made participants feel slightly 'guilty'. In particular, sharing information led high food‐neophobic and food technology‐neophobic individuals to be more 'understanding' towards PFD in comparison to the low‐neophobic groups. Findings suggest emotional responses can provide deeper insights beyond liking, which will benefit the food industry when reviewing consumer attitudes. The results show promise that consumers will accept PFD products when available, provided the novel technology can mimic the sensory properties of CD. Furthermore, when marketing products, sharing information may increase liking for sustainable products, but future studies would benefit from exploring the effect of different types of information on consumer acceptance. [ABSTRACT FROM AUTHOR]

Sepsis-induced myopathy (SIM) has been recognized as a critical risk factor for the development of acquired muscle weakness among patients in the intensive care unit. These individuals frequently encounter inadequate dietary intake and malnutrition. With the aggravation of the severity of the person's condition, leading to increased skeletal muscle protein breakdown and reduced synthesis, which is an urgent problem to be solved in clinical nutritional treatment. Whole milk protein powder (WMPP) has promising bioactive nutrients and holds promising potential for enhancing skeletal muscle mass. The study was designed to delve into the potential effects and mechanisms of WMPP intervention for increaseing skeletal muscle mass on SIM mice. Our results clearly show that the intervention with WMPP can significantly improve the exercise capacity and skeletal muscle mass in SIM mice. It significantly increases the diameter and cross-sectional area (CSA) of skeletal muscle fibers, while effectively reducing the excessive aggregation of collagen fibers and the abnormal accumulation of adipose tissue in the skeletal muscle of SIM mice. Moreover, WMPP intervention also significantly alleviated the oxidative stress status of mitochondria, which subsequently enhanced the expression of mitochondrial metabolic enzymes. The mechanism may be associated with decreased AMPK phosphorylation in skeletal muscle tissue and simultaneously increased phosphorylation of mTOR, p70S6K1, and 4EBP-1 in SIM mice. In summary, the WMPP intervention significantly enhances exercise capacity and skeletal muscle mass while mitigating the oxidative stress status of mitochondria. Furthermore, it regulates skeletal muscle anabolism via the AMPK/mTOR signaling pathway in SIM mice. [ABSTRACT FROM AUTHOR]

Bovine milk peptides are the protein fragments with diverse bioactive properties having antioxidant, anticarcinogenic, other therapeutic and nutraceutical potentials. These peptides are formed in milk by enzymatic hydrolysis, gastrointestinal digestion and fermentation processes. They have significant health impact with high potency and low toxicity making them a suitable natural alternative for preventing and managing diseases. Antibiotic resistance has increased the quest for better peptide candidates with antimicrobial effects. This article presents a comprehensive review on well documented antimicrobial, immunological, opioid, and anti-hypertensive activities of bovine milk peptides. It also covers the usage of computational biology tools and databases for prediction and analysis of the food-derived bioactive peptides. In silico analysis of amino acid sequences of Bos taurus milk proteins have been predicted to generate peptides with dipeptidyl peptidase IV inhibitory and ACE inhibitory properties, making them favorable candidates for developing blood sugar lowering drugs and anti-hypertensives. In addition to the prediction of new bioactive peptides, application of bioinformatics tools to predict novel functions of already known peptides is also discussed. Overall, this review focuses on the reported as well as predicted biologically active peptide of casein and whey proteins of bovine milk that can be utilized to develop therapeutic agents. [ABSTRACT FROM AUTHOR]

Milk protein sensitivity is a major challenge in infant feeding, especially for infants who cannot receive adequate breastfeeding. Hydrolyzed milk protein is a mainstream way to address this difficulty. The aim of this study was to assess the effect of differences in whey protein concentrate (WPC) source and the degree of hydrolysis on blocking allergy and to analyze the possible mechanisms by which hydrolyzed infant formula (IF) blocks allergy through colony‐metabolism–immunity response. First, we prepared six groups of goat's milk IF with unhydrolyzed, partially, and extensively hydrolyzed WPC, which come from cow's milk WPC and goat's milk WPC. Subsequently, we evaluated their effects on allergy. The results showed that the hydrolyzed IF improved the allergic characteristics of mice, including low levels of total immunoglobulin E (IgE), specific IgE, histamine, and mucosal mast cell protease‐1 (mMCP‐1). Furthermore, the hydrolyzed IF promoted the immune response of T helper 1 (Th1) and regulatory T (Treg) cells by enhancing the messenger RNA (mRNA) expression of T‐box transcription factor 21 (T‐bet) and forkhead box protein P3 (Foxp3), which in turn suppressed the T helper 2 (Th2) overexpressed immune response in allergy (GATA‐binding protein 3 (GATA‐3) and retinoic‐acid‐receptor‐related orphan receptor gamma t (RORγt) mRNA expression, as well as interleukin 4 (IL‐4) and interleukin 5 (IL‐5) levels). Hydrolyzed IF promoted an increase in beneficial gut microbe Lactobacillus and Alistipes, which in turn promoted an increase in intestinal butyrate levels. The beneficial bacteria and their metabolized butyrate may have suppressed the abundance of the allergy‐characterizing bacterium Rikenellaceae‐RC9‐gut‐group. The final result we obtained was that for both cow's milk WPC and goat's milk WPC, at similar levels of hydrolysis, they did not bring about a significant effect on allergy symptoms. The hydrolyzed IF improved the allergic characteristics of mice, the deeper the degree of hydrolysis of WPC, the more obvious the effect of reducing allergic symptoms in model mice. [ABSTRACT FROM AUTHOR]

The six major bovine milk proteins are encoded by highly polymorphic chromosomes. Genetic variation has become a topic of interest and controversy in recent years due to supposed adverse health effects, beginning with the A2 variant of β‐casein. The functional implications of genetic variants have been well characterised, specifically heat stability and coagulation (i.e. rennet and acid) properties of milk, which have found that the B variant of β‐casein, κ‐casein and β‐lactoglobulin are the most beneficial. Genetic variants of milk proteins provide considerable potential to create new dairy products to add value to milk. [ABSTRACT FROM AUTHOR]

The growth of bacteria and fungi may cause disease inf human or spoilage of food. New antimicrobial substances need to be discovered. Lactoferricin (LFcin) is a group of antimicrobial peptides derived from the N-terminal region of the milk protein lactoferrin (LF). LFcin has antimicrobial ability against a variety of microorganisms, which is significantly better than that of its parent version. Here, we review the sequences, structures, and antimicrobial activities of this family and elucidated the motifs of structural and functional significance, as well as its application in food. Using sequence and structural similarity searches, we identified 43 new LFcins from the mammalian LFs deposited in the protein databases, which are grouped into six families according to their origins (Primates, Rodentia, Artiodactyla, Perissodactyla, Pholidota, and Carnivora). This work expands the LFcin family and will facilitate further characterization of novel peptides with antimicrobial potential. Considering the antimicrobial effect of LFcin on foodborne pathogens, we describe the application of these peptides from the prospective of food preservation. [ABSTRACT FROM AUTHOR]

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

In Holstein cows, β-casein, one of the most critical proteins in milk, exists in two main genotypes, A1 and A2. Herein, 45 Holstein cows [categorized into three groups based on β-casein A1A1, A1A2, and A2A2 genotypes (N = 15)] with the same feeding management and litter size were enrolled to explore differences in rumen microflora and metabolites across various β-casein genotypes. Rumen fluids were collected for metagenomics and metabolomics analyses. Metabolomics and weighted gene co-expression network analysis (WGCNA) revealed that arachidonic acid (AA), adrenic acid (AdA), glycocholic acid (GCA), and taurocholic acid (TCA) were significantly and positively correlated with milk fat % in dairy cows (p < 0.05). Furthermore, macro-genomics and Spearman's correlation analysis revealed significant positive correlations (p < 0.05) between the characteristic flora (g_Acetobacter, g_Pseudoxanthomonas, g_Streptococcus, and g_Pediococcus) and the five characteristic metabolites in the rumen of A2A2 dairy cows. Moreover, functional enrichment analysis revealed more genes enriched to the TRP channel's inflammatory mediatorregulated pathway and the mTOR signaling pathway in A2A2 genotyped cows. Additionally, the regulatory effects of AA on bovine mammary epithelial cells (BMECs) were examined using CCK-8, EdU, and qRT-PCR assays, revealing that AA promoted triglyceride (TG) synthesis and upregulated the milk fat marker genes including SREBF1, ACSS2, AGPAT6, and FASN. Overall, we identified characteristic microorganisms and metabolites in A2A2 Holstein cows and established that AA could be a biomarker for higher milk fat %. [ABSTRACT FROM AUTHOR]

Introduction: The use of dairy x dairy crossbreeding has increased in Sweden. This study aimed to compare crosses between Swedish Red (R), Holstein (H), Jersey (J), and Montbéliarde (M) to purebred R, H, and J for fertility, calving, production, and survival traits. The focus was on F1 crosses between either H or R on the one hand and J or M on the other hand, but three-breed crosses were also studied. Material and methods: There were 2,154,241 observations collected from the official cattle recording database for cows that calved between 2005 and 2020 in 7,390 herds. The dataset was separated into first and second parity and analyzed using a mixed linear model including fixed effects of breed group, herd, and year-season and a random effect of herd-year. Results and discussion: Fertility traits were improved in the F1 crosses with J or M compared with R or H (i.e., JR and MR vs. R; JH and MH vs. H), especially in the first parity. In parity 2, the difference was often not significant. Crossing R or H with Jersey gave lower calving difficulty than in the pure breeds in the first parity. However, crossing with Montbé liarde rather tended to give slightly more calving difficulties, albeit not significantly so. Generally, there was no significant change in stillbirths when crossing purebred R or H with J or M. There was a general tendency for better survival in the F1-crosses, however, only significantly so for Jersey crosses in parity 2 with respect to R or H. F1 between J and H (JH) had a higher 305-day fat yield than H, but lower milk and protein yields. MH had higher fat and protein yields than H and MR had higher 305-d milk and protein yields than R. In conclusion, crossing R or H with either Jersey or Montbeéliarde can be expected to improve fertility and probably also survival. Depending on the current situation, one could choose to improve fat yield (crossing with J) or protein yield (crossing with M), however, depending on the breed, there could be a trade-off, e.g., in milk yield. For other traits, one would not expect any deterioration. [ABSTRACT FROM AUTHOR]

To quickly achieve nondestructive detection of protein content in fresh milk, this study utilized a network analyzer and an open coaxial probe to analyze the dielectric spectra of milk samples at 100 frequency points within the 2–20 GHz range, focusing on the dielectric constant ε' and the dielectric loss factor ε''. Feature variables were extracted from the full dielectric spectra using the successive projections algorithm (SPA), uninformative variables elimination (UVE), and the combined UVE‐SPA method. These variables were then used to develop partial least squares regression (PLSR), support vector machine (SVM), decision tree (DT), random forest (RF), and least squares boosting (LSBOOST) models for predicting protein content. The results showed that ε' decreased monotonically with increasing frequency, while ε'' increased monotonically. The UVE‐SPA method for feature extraction demonstrated superior performance, with the UVE‐SPA‐PLSR model being the best for predicting milk protein content, achieving the highest RC2 = 0.998 and RP2 = 0.989 and the lowest RMSEC = 0.019% and RMSEP = 0.032%. This study provides a theoretical reference for evaluating milk quality and developing intelligent detection equipment for natural milk. [ABSTRACT FROM AUTHOR]

ABSTRACT Fat and protein derived from milk are prime ingredients in a frozen dessert such as ice cream conferring multiple desirable functionalities. However, this frozen dairy dessert is not suitable for individuals having lactose intolerance, cow milk allergy, or vegans. Hence, the study aimed to formulate dairy‐free frozen desserts using plant oils and plant proteins and compare their physicochemical characteristics and sensory acceptance against an ice cream containing milk fat and milk protein. Results indicated that the types of protein significantly influenced the physicochemical properties and sensory acceptance of the frozen dessert samples. Frozen desserts containing brown rice, pea, and soy protein showed greater resistance to melting (0.29, 0.12, and 0.19%/min vs. 1.95%/min), but they scored lower in sensory quality than ice cream made with milk protein; although they remained at an acceptable level. When compared among the plant proteins, the physicochemical characteristics of frozen desserts containing brown rice, pea, and soy protein varied because of the differences in the respective protein composition. Frozen dessert with brown rice protein showed higher overrun (47.50% vs. 40.78% and 37.8%), lower hardness (20.02 N vs. 22.24 and 26.37 N), and higher melting rate (0.29%/min vs. 0.19 and 0.12%/min) than frozen desserts containing soy and pea protein. Additionally, the brown rice protein frozen dessert received lower sensory acceptance than soy and pea protein frozen desserts. In summary, brown rice, pea, and soy proteins showed potential to be used as viable alternatives to milk protein for dairy‐free frozen dessert applications. [ABSTRACT FROM AUTHOR]

Practical Application Whey protein concentrate (WPC) is consumed for its high protein content. The structure and biological functionality of whey proteins in WPC powders may be affected by the drying technique applied. However, the specific impact of spray drying and freeze drying on the overall protein profile of whey protein derived from sweet whey streams at scale is unknown. Herein, we examine the effects of commercial‐scale freeze drying and spray drying on WPC to determine which method better preserves bioactive whey proteins, with the goal of helping the dairy industry create high‐value products that meet the growing consumer demand for functional dairy products. WPCs were produced from pasteurized liquid whey using either a commercial spray dryer or freeze dryer. A variety of analytical techniques, including enzyme‐linked immunosorbent assay, polyacrylamide gel electrophoresis, and bottom‐up proteomics using liquid chromatography‐tandem mass spectroscopy were used to identify, quantify, and compare the retention of bioactive proteins in WPC before and after spray drying and freeze drying. In addition, the extent of denaturation was studied via solubility testing, differential scanning calorimetry, and hydrophobicity assessment. There was little to no difference in the retention or denaturation of key bioactive proteins between spray‐dried and freeze‐dried WPC powders. There was a higher percentage of select Maillard modifications in freeze‐dried and spray‐dried powders than in the control. The lack of significant differences between spray drying and freeze drying identified herein indicates that freeze drying does not meaningfully improve retention of bioactive proteins compared with spray drying when performed after multiple pasteurization steps.This study aimed to provide insight into the impacts of spray drying versus freeze drying on whey proteins. Overall, our results indicate that for commercial dairy processing that involves multiple rounds of pasteurization, freeze drying does not meaningfully improve the retention of bioactive proteins compared with spray drying. These findings may help the food and dairy industry make informed decisions regarding the processing of its whey protein products to optimize nutritional value. [ABSTRACT FROM AUTHOR]

Summary: Insufficient sleep is a growing global problem, with poor sleep associated with many negative health and performance outcomes. Previous reviews investigating the effect of diet on sleep have highlighted the amino acid tryptophan as a promising sleep‐promoting nutrient, with the richest food source of tryptophan, ⍺‐lactalbumin, requiring further investigation. Therefore, this systematic review aimed to review the existing evidence of association between ⍺‐lactalbumin and sleep. Four electronic databases (CINAHL Complete, Embase, MEDLINE Complete, and SPORTDiscus with Full Text) were searched from database inception to March 2023, with primary research articles included if they contained α‐lactalbumin as an independent variable, an outcome measure of sleep or sleepiness, and participants were ≥ 18 years old. Eight studies were reviewed, with four studies recruiting athletic populations (50%) and four recruiting healthy participants (50%). Sleep or sleepiness was measured objectively in six studies (75%), with two studies employing polysomnography and four utilizing actigraphy to assess sleep. Across the studies, 20–60 g of ⍺‐lactalbumin was supplemented, with five studies (63%) observing a positive association between α‐lactalbumin and sleep. Sleep‐onset latency was the primary sleep metric improved following evening supplementation of α‐lactalbumin (≤ 3.5 hr pre‐sleep), with no studies observing any negative associations with sleep. Data from this review suggest that individuals that have difficulty initiating sleep may benefit most from pre‐sleep α‐lactalbumin supplementation. Further research is required to establish the effect that α‐lactalbumin has on sleep architecture, through the use of more comprehensive sleep analysis tools such as portable electroencephalography or polysomnography, in combination with stringent dietary controls. [ABSTRACT FROM AUTHOR]

Simple Summary: Providing high-quality feeds is required to maintain goat kids' health and improve their growth performance during their early growth phase, such as milk protein, fish meal, or extruded feed. The present study demonstrates that supplementation with 2% fermented feather meal–soybean meal product in the diet can promote the growth of goat kids by improving crude protein digestibility, diarrhea status, and immunity: therefore, it can completely replace the fish meal as a starter. These findings provide potential for practices of nutrition and immunity in goat kids, benefiting the livestock industry. This study investigates the effects of replacing fish meal with fermented feather meal–soybean meal product (FFSMP) from Bacillus amyloliquefaciens CU33 in the starter on growth performance, relative health performance, and digestibility of Alpine goat kids. In trial 1, thirty-two Alpine goat kids (male) were randomly assigned to dietary supplementation of 2% feather meal–soybean meal mix (FSM), 2% fish meal, or replacing fish meal with 50% or 100% FFSMP (FFSMP-50 or FFSMP-100) in starter (n = 8). In trial 2, sixteen goat kids were selected after trial 1 and used in this digestion trial which began from 12 weeks old. The treatments were the same as in trial 1 (n = 4). In trial 1, the growth performance of the FFSMP groups was better than the FSM group at 0 to 10 weeks (p < 0.05). The fecal consistency index of the FFSMP-100 group was better than the FSM group at 0 to 5 weeks and 5 to 10 weeks. In trial 2, the crude protein (CP) digestibility of the FSM group decreased (p < 0.05). In conclusion, dietary supplementation with 2% FFSMP in goat kids' diets can improve the growth performance, the CP digestibility, and diarrhea status, and it can completely replace the fish meal in starter diets. [ABSTRACT FROM AUTHOR]

Identifying genomic regions under selection is essential for understanding the genetic mechanisms driving species evolution and adaptation. Traditional methods often fall short in detecting complex, spatially varying selection signals. Recent advances in deep learning, however, present promising new approaches for uncovering subtle selection signals that traditional methods might miss. In this study, we utilized the deep learning framework DeepGenomeScan to detect spatially varying selection signatures across 15 bovine populations worldwide. Our analysis uncovered novel insights into selective sweep hotspots within the bovine genome, revealing key genes associated with physiological and adaptive traits that were previously undetected. We identified significant quantitative trait loci linked to milk protein and fat percentages. By comparing the selection signatures identified in this study with those reported in the Bovine Genome Variation Database, we discovered 38 novel genes under selection that were not identified through traditional methods. These genes are primarily associated with milk and meat yield and quality. Our findings enhance our understanding of spatially varying selection's impact on bovine genomic diversity, laying a foundation for future research in genetic improvement and conservation. This is the first deep learning-based study of selection signatures in cattle, offering new insights for evolutionary and livestock genomics research. [ABSTRACT FROM AUTHOR]

Background: Dairy cow milking practices require cleaning and disinfection of the teat skin before and after milking to ensure the safety and quality of milk and prevent intramammary infections. Antimicrobial proteins of natural origin can be valuable alternatives to traditional disinfectants. In a recent field trial, we demonstrated that a teat dip based on a nisin A-producing Lactococcus cremoris (L) had comparable efficacy to conventional iodophor dip (C) in preventing dairy cow mastitis. Here, we present the differential shotgun proteomics investigation of the milk collected during the trial. Methods: Four groups of quarter milk samples with low (LSCC) and high somatic cell count (HSCC) collected at the beginning (T0) and end (TF) of the trial were analyzed for a total of 28 LSCC (14 LSCC T0 and 14 LSCC TF) and 12 HSCC (6 HSCC T0 and 6 HSCC TF) samples. Milk proteins were digested into peptides, separated by nanoHPLC, and analyzed by tandem mass spectrometry (LC-MS/MS) on an Orbitrap Fusion Tribrid mass spectrometer. The proteins were identified with MaxQuant and interaction networks of the differential proteins were investigated with STRING. The proteomics data have been deposited to the ProteomeXchange Consortium via the PRIDE partner repository with the dataset identifier PXD045030. Results: In healthy milk (LSCC), we detected 90 and 80 differential proteins at T0 and TF, respectively. At TF, the Lactococcus group showed higher levels of antimicrobial proteins. In mastitis milk (HSCC), we detected 88 and 106 differential proteins at T0 and TF, respectively. In the Lactococcus group, 14 proteins with antimicrobial and immune defense functions were enriched at TF vs. 4 proteins at T0. Cathelicidins were among the most relevant enriched proteins. Western immunoblotting validation confirmed the differential abundance. Conclusions: At T0, the proteomic differences observed in healthy milk of the two groups were most likely dependent on physiological variation. On the other hand, antimicrobial and immune defense functions were higher in the milk of cows with mammary gland inflammation of the Lactococcus-treated group. Among other factors, the immunostimulatory action of nisin A might be considered as a contributor. [ABSTRACT FROM AUTHOR]

Lički Škripavac is a traditional Croatian cheese characterised by its soft and rubbery texture and the squeaky sound attained during chewing. Traditionally, it can be produced using two different salting methods: dry salting of curd grains and salting of milk before coagulation. The aim of this study was to determine the effects of the salting method on the chemical composition, yield, texture and sensory properties of Škripavac cheese. Five batches of Škripavac cheese were produced from 40 L of raw cow milk. Milk was divided into two equal parts and cheeses were produced applying the above-mentioned salting methods. Cheeses produced from milk salted before coagulation had significantly (p<0.05) higher water content, significantly (p<0.01) lower protein content and significantly (p<0.01) higher pH value compared to cheeses with salted curd grains. Also, these cheeses had a higher milk fat recovery (p<0.05) and a higher actual (p<0.0001) and adjusted yield (p<0.01). In terms of textural properties, the cheeses that were produced by adding salt to the curd grains were significantly (p<0.05) harder, less crumbly and less elastic than those produced by salting the milk. The method of salting had no significant effect on sensory characteristics of the Škripavac cheese. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. Brown Swiss (BS) cows have greater urea concentrations in milk and blood compared with Holstein (HO) cows. We tested the hypothesis that BS and HO cows differ in kidney function and nitrogen excretion. Blood, saliva, urine, and feces were sampled in 31 multiparous BS and 46 HO cows kept under identical feeding and management conditions. Samples were collected at different lactational stages after the monthly DHIA control test-day. To test the glomerular filtration rate (GFR) and urea excretion, concentrations of creatinine and urea were measured in serum, urine, and saliva. As an additional marker to estimate GFR, we determined symmetric dimethylarginine (SDMA) in serum. Feces were analyzed for DM content and nitrogen concentration. Data on milk urea and protein concentrations and daily milk yield were obtained from the monthly DHIA test-day records. The effects of breed, time, and parity number on blood, saliva, urine, feces, and milk parameters were evaluated with the GLM procedure of SAS, with breed, time, and parity number as fixed effects. Differences between BS and HO were assessed by the Tukey-corrected t -test. Concentrations of urea, creatinine, and SDMA in serum, were greater in BS than in HO cows: 5.46 ± 0.19 versus 4.72 ± 0.13 mmol/L (urea), 105.96 ± 2.23 versus 93.07 ± 1.50 mmol/L (creatinine), and 16.78 ± 0.69 versus 13.39 ± 0.44 µg/dL (SDMA). We observed a greater urea concentration in BS cows (25.8 ± 0.7 vs. 21.8 ± 0.7 mg/dL) and protein content in milk (3.70% ± 0.08% vs. 3.45% ± 0.07%) than in HO cows. Urea and creatinine concentrations in urine and saliva did not differ between breeds. No differences between BS and HO were observed for milk yield, fecal DM, and fecal nitrogen content. Dry matter intake and BW were similar in BS and HO cows. Despite greater urea, creatinine, and SDMA concentrations in blood, as well as a higher milk urea content in BS compared with HO, respective concentrations in urine did not differ between breeds. In conclusion, our results demonstrate a lower renal GFR in BS compared with HO cows, thereby contributing to the greater plasma urea concentration in BS cows. However, estimation of nitrogen excretion via milk, urine, and feces does not entirely reflect nitrogen turnover within the animal. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. Most trace minerals (TM) are fed above dairy cow requirements in commercial herds but their fate and effects on dairy cows have not been well documented. In this study, we evaluated the effects of feeding short-term sulfate TM above recommendations on apparent total-tract digestibility of nutrients, rumen fermentation characteristics, serum concentrations, and milk yield and composition, as well as milk, fecal, and urinary TM excretion in midlactation dairy cows. Eight multiparous Holstein cows with an average body weight (± SD) of 684 ± 29 kg at 82 ± 10 DIM in a quadruple 2 × 2 crossover design were fed a basal diet, differing in sulfate TM supplement concentrations, to provide either 0.11, 17, and 63 (control; CON) or 0.95, 114, and 123 (high trace minerals; HTM) mg of dietary Co, Mn, and Zn per kilogram of DM, respectively. Each experimental period had a 21-d adaptation to the diet, followed by a 10-d sample collection period. Feed ingredients and total feces and urine were collected during 4 consecutive d and rumen fluid was collected 0, 1, 2, 4, and 6 h relative to feeding. Milk yield was recorded daily, and milk samples were collected on 4 consecutive milkings. Ingestion of Co, Mn, and Zn was higher for the HTM group compared with the CON group by 216%, 233%, and 93%, respectively. Dry matter intake averaged 25.0 (SE = 0.6) kg/d, and apparent total-tract digestibility of major nutrients was similar between treatments. High trace minerals had no measurable effect on ruminal pH, major volatile fatty acids, and protozoa counts. Isovalerate molar proportion was 9.4% greater for the HTM group compared with the CON group. Neither milk yield (43.5 kg/d; SE = 0.8) nor milk fat and protein concentrations differed between treatments. Milk urea nitrogen concentration was significantly higher for HTM (11.7 mg/dL) compared with CON (9.7 mg/dL; SE = 0.7). Fecal excretion of Co, Mn, and Zn increased by 223%, 198%, and 75%, respectively, for the HTM group compared with the CON group. Urinary excretions of TM were marginal compared with feces, and only urinary Co and Mn were significantly higher for HTM cows than CON cows, as was similarly obtained for serum Co and Mn concentrations. Milk TM yields were not modified by treatments. In summary, short-term dietary sulfate TM supply over the recommendation did not improve cow performance but significantly increased fecal TM excretion, which could affect TM accumulation in soils where manure is applied and could potentially result in leaching into nearby watersheds. Further studies are needed to evaluate the impact of high fecal TM excretion on the environment using the One Health approach. Moreover, the effects of TM oversupply on milk production and cow health should be evaluated by long-term experiments. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. Mitochondrial dysfunction has been reported to occur in the mammary gland of dairy cows suffering from ketosis. Prohibitin 2 (PHB2) plays a crucial role in regulating mitophagy, which clears impaired mitochondria to maintain normal mitochondrial function. Therefore, the current study aimed to investigate how PHB2 mediates mitophagy, thereby influencing mitochondrial function in the immortalized bovine mammary epithelial cell line (MAC-T cells). First, mammary gland tissue and blood samples were collected from healthy cows (n = 15, BHB <0.6 m M) and cows with clinical ketosis (n = 15, BHB >3.0 m M). Compared with healthy cows, cows with clinical ketosis exhibited lower DMI, milk production, milk protein, milk lactose, and serum glucose. In contrast, milk fat, serum nonesterified fatty acids (NEFA) and BHB were greater in cows with clinical ketosis. The protein abundance of PHB2, peroxisome proliferator activated receptor-γ coactivator-1α (PGC-1α), mitofusin 2 (MFN2) in whole cell lysates (WCL), as well as PHB2, sequestosome-1 (SQSTM1, also called p62), microtubule-associated protein 1 light chain 3-II (MAP1LC3-II, also called LC3-II), and ubiquitinated proteins in mitochondrial fraction were significantly lower in cows with clinical ketosis. The ATP content of mammary gland tissue in cows with clinical ketosis was lower than that of healthy cows. Second, MAC-T were cultured and treated with NEFA (0, 0.3, 0.6, 1.2 m M). The MAC-T treated with 1.2 m M NEFA displayed decreased protein abundance of PHB2, PGC-1α, and MFN2 in WCL, as well as protein abundance of PHB2, p62, LC3-II, and ubiquitinated proteins in mitochondrial fraction. The content of ATP and JC-1 aggregates in 1.2 m M NEFA group were lower than in the 0 m M NEFA group. Additionally, 1.2 m M NEFA disrupted the fusion between mitochondria and lysosomes. The MAC-T were then pretreated with 100 n M rapamycin, followed by treatment with or without NEFA. Rapamycin alleviated impaired mitophagy and mitochondria dysfunction induced by 1.2 m M NEFA. Third, MAC-T were transfected with small interfering RNA to silence PHB2 or a plasmid for overexpression of PHB2, followed by treatment with or without NEFA. The silencing of PHB2 aggravated 1.2 m M NEFA-induced impaired mitophagy and mitochondrial dysfunction, whereas the overexpression of PHB2 alleviated these effects. Overall, this study provides evidence that PHB2, in regulation of mitophagy, is a mechanism for bovine mammary epithelial cells to counteract NEFA-induced mitochondrial dysfunction. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. Mare milk has a unique protein composition that makes it a preferred option for adult and infant nutrition. Several functional properties have been attributed to this milk, but with little current evidence. In fact, knowledge on mare milk composition is still limited. In particular, studies addressing the performance of mare milk proteins during human gastrointestinal digestion are scarce, which limits the understanding of mare milk nutritional quality and functionality. For this reason, the present study describes the digestibility of mare milk proteins and the release of peptides as affected by management and lactation stage, factors which are known to affect milk composition. Mare milk samples from 3 different farms collected during 6 mo of lactation (n = 54) were subjected to a static in vitro gastrointestinal model to measure peptide release and protein digestibility. In the present study, a detailed description of protein and individual amino acid behavior during the digestion process was given. For the first time, digestion of the 2 equine β-lactoglobulin isoforms (I and II) was described individually. In addition, it was found that lactation stage and management system can significantly affect protein digestibility and peptide release during gastrointestinal digestion of mare milk. Presumably, differences in the composition of mare milk influence the protein structure and enzyme accessibility, which might have an impact on digestion behavior. Although no specific bioactive peptides were identified, several precursors of previously described bioactive peptides were found. These findings could support the idea of mare milk as a food with added value. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. Determination of energy requirements for growth depends on measuring the composition of BW gain. Previous studies have shown that the composition of gain can be altered in young dairy calves by the composition of the milk replacer diet. Here, our objective was to determine body composition and the composition of empty body gain in young calves fed increasing amounts of a milk replacer containing adequate CP. Male Holstein calves underwent an adjustment period of 14 d after birth in which they were fed whole-waste milk at 10% of BW. Calves were then stratified by BW and randomly assigned to either an initial slaughter group (n = 11) or to groups fed 1 of 3 milk replacer amounts and slaughtered after 35 d of growth. Calves in all treatments consumed the same milk replacer containing 24.8% CP (DM basis; from all milk proteins) and 18.9% fat, reconstituted to 12.5% solids. Treatments were milk replacer fed at 1.25% of BW (DM basis; n = 6), 1.75% of BW (n = 6), or 2.25% of BW (n = 8), adjusted weekly as calves grew. Calves fed at 1.25% or 1.75% of BW were fed twice daily and those fed 2.25% of BW were fed 3 times daily. No starter was offered. Postslaughter, the bodies of calves were separated into 4 fractions: carcass; total viscera minus digesta; head, hide, feet, and tail;, and blood. The sum of those 4 fractions was empty BW (EBW), which increased linearly as the amount of milk replacer increased. Final heart girth and body length, but not withers height, increased linearly as intake increased. Gain:feed increased linearly with increasing milk replacer. Feeding more milk replacer increased the amounts of lean tissue and fat in the body. The percentages of water and protein in the final body decreased linearly, whereas fat percentage and energy content increased linearly as intake increased. As gain increased, the percentage of protein in gain decreased and the percentage of fat increased, resulting in an increase of energy content of EBW gain. Efficiency of energy use (retained energy:gross energy intake) increased linearly but retained energy:ME available for growth was not different among treatments. Efficiency of protein use increased quadratically as feeding rate increased; there was no further increase at 2.25% of BW. Plasma insulin-like growth factor 1, insulin, and glucose increased linearly, whereas urea-N decreased linearly, as milk replacer intake increased. Our data document changes in body composition that affect estimates of retained energy in the bodies of calves slaughtered at a common age. These data are important for calculations of energy requirements for young calves. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. Products of lipolysis released during digestion positively affect the metabolism of newborns. In contrast to the 3-layer biological membranes covering human milk (HM) fat, the lipid droplets in infant milk formula (IMF) are covered by a single membrane composed of casein and whey proteins. To reduce the differences in lipid structure between IMF and HM, studies have used milk fat globule membrane (MFGM) components such as milk polar lipids (MPL) to prepare emulsions mimicking HM fat globules However, few studies have elucidated the effect of membrane proteins (MemP) on lipid digestion in infants. In this study, 3 kinds of emulsions were prepared: one with MPL as the interface of lipid droplets (RE-1), one with membrane protein concentrate (MPC; RE-2) as the interface of lipid droplets, and one with both MPL and MPC (1:2) as the co-interface of lipid droplets (RE-3). The interfacial coverage of the emulsions was confirmed by measuring the contents of MPL and MPC at the lipid droplet interface, and by confocal laser scanning microscopy analysis. By controlling the homogenization intensity, the specific surface area of lipid droplets was controlled at the same level among the 3 emulsions. The stability constants of the emulsions varied, and RE-1 was the most stable. During simulated in vitro infant gastrointestinal digestion, the amount of free fatty acids (FFA) released from the lipid droplets was significantly higher from those with MPC at the interface (RE-2, RE-3) than from that with MPL at the interface (RE-1). The amount of FFA released at the end of intestinal digestion of RE-1, RE-2, and RE-3 was (mean ± SD; n = 3) 255.00 ± 3.54 µmol, 328.75 ± 5.30 µmol, 298.50 ± 9.19 µmol, respectively. Compared with the lipid droplets in RE-2, those with MPL at the interface (RE-1, RE-3) released more UFA during digestion. The emulsifying activity index was highest in RE-3 (MPL and MPC co-interface). The presence of MPL at the emulsion interface increased the release of UFA, and the presence of MPC increased the release of FFA. These results show that both MPL and MemP are indispensable in the construction of MFGM. Understanding their effects on digestion can provide new strategies for the development of infant foods. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. The purpose of this experiment was to determine if nicotinic acid (NA) effects on dairy cows and rumen microbial characteristics are forage-type dependent (corn silage, CS; grass silage, GS). Four late-lactation (DIM = 225 ± 12 d) Holstein cows were used in a 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments. The main effects were a CS (66.10% CS) based diet or a GS (79.59%) based diet with or without 12 g/d NA. Each experimental period lasted for 28 d. Milk production and milk components, blood metabolites, apparent total-tract nutrient digestibilities, minutes rumen pH were below 5.8 as an indicator of ruminal acidosis, and body temperature changes were analyzed as indicators of heat stress. Nicotinic acid supplementation did not improve apparent total-tract nutrient digestibility. Feeding a GS-based diet improved NDF and hemicellulose digestibility. Feeding a CS-based diet increased the apparent total-tract digestibility of fat, and minutes rumen pH below 5.8 for a greater proportion of the time. The CS-based diet also improved milk yield, milk fat and protein yields, and ECM yield; however, somatic cell count and BHB were also increased. Supplementing NA tended to decrease nonesterified fatty acids, especially when combined with GS where DMI was low. There was a trend for the total protozoa population to increase when GS and NA were fed but decreased when CS and NA were fed. Nicotinic acid tended to decrease rumen protozoal populations of Dasytricha , but increased populations of Ophryoscolex and Diplodiniinae with GS diets and decreased with CS diets. Entodiniinae were increased with CS but NA had no effect. Body temperature was increased when a CS-based diet was fed when compared with a GS-based diet. More research is needed to determine how NA can affect rumen microbial protein synthesis and what kind of diets will provide the optimum effect. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. The study investigated the effects of dietary protein level and the inclusion of hydroponic barley sprouts (HB) on lactation performance, blood biochemistry and N use efficiency in mid-lactation dairy cows. Treatments were arranged in a 2 × 2 factorial design with 2 CP levels (16.8% and 15.5% of DM), with HB (4.8% of DM, replacing 4.3% of alfalfa hay and 0.5% of distillers dried grains with solubles [DDGS]) or without HB. Forty-eight multiparous Holstein dairy cows (146 ± 15 DIM, 40 ± 5 kg/d of milk) were randomly allocated to 1 of 4 diets: high-protein diet (16.8% CP, HP), HP diet with HB (HP+HB), low-protein diet (15.5% CP, LP), or LP diet with HB (LP+HB). An interaction between CP × HB on DMI was detected, with DMI being unaffected by HB inclusion in cows fed the high-protein diets, but was lower in cows fed HB when the low-protein diet was fed. A CP × HB interaction was also observed on milk and milk protein yield, which was higher in cows fed HB with HP, but not LP. Inclusion of HB also tended to reduce milk fat content, and feeding HP resulted in a higher milk protein and MUN content, but lower milk lactose content. Feed efficiency was increased by feeding HP or HB diets, whereas N use efficiency was higher for cows fed LP or HB diets. There was an interaction on the apparent total-tract digestibility of DM and CP, which was higher when HB was fed along with HP, but reduced when fed with LP, whereas the digestibility of ADF was increased by feeding low-protein diets. In conclusion, feeding a low-protein diet had no adverse effect on cow performance, while feeding HB improved milk and milk component yield, and N efficiency when fed with a high-CP diet, but compromised cow performance with a low-CP diet. [ABSTRACT FROM AUTHOR]

Inhibition of dipeptidyl peptidase IV (DPP-IV) is an effective pharmacotherapy for the management of type 2 diabetes. Recent findings have suggested that various dietary proteins can serve as precursors to peptides that inhibit DPP-IV. Although several DPP-IV inhibitory peptides derived from food materials have been reported, more effective inhibitory peptides remain to be discovered. This study aimed to identify potent DPP-IV inhibitory peptides that earlier approaches had overlooked by employing a screening method that combined peptide arrays and neutralizing antibodies. Octa-peptides covering the complete amino acid sequences of four casein proteins and two whey proteins were synthesized on arrays via a solid-phase method. These peptides were then reacted with a monoclonal antibody specifically engineered to recognize glucagon-like peptide 1 (GLP-1), a substrate of DPP-IV. The variable region of the anti-GLP-1 monoclonal antibody is utilized to mimic the substrate-binding region of DPP-IV, enabling the antibody to bind to peptides that interact with DPP-IV. Based on this feature, 26 peptides were selected as DPP-IV inhibitory peptide candidates, 11 of which showed strong DPP-IV inhibitory activity. Five of these peptides consistently contained cysteines positioned two to four residues from the N-terminus. Treatment with disulfide formation decreased the DPP-IV inhibitory activity of these cysteine-containing peptides, while the inhibitory activity of α-lactalbumin hydrolysates increased with reducing treatment. These results revealed that the thiol group is important for DPP-IV inhibitory activity. This study provides a useful screen for DPP-IV inhibitory peptides and indicates the importance of reductive cysteine residues within DPP-IV inhibitory peptides. [Display omitted] • The DPP-IV inhibitory peptides were identified using a peptide array-based assay from milk proteins. • The monoclonal antibody that recognized GLP-1 was utilized to mimic the substrate-binding region of DPP-IV. • Eleven novel DPP-IV inhibitory peptides were identified by employing an anti-GLP-1 antibody and peptide arrays. • Five of these peptides consistently contained cysteines positioned two to four residues from the N-terminus. • This study revealed that the thiol group is important for DPP-IV inhibitory activity. [ABSTRACT FROM AUTHOR]

Incorporating plant protein isolates into milk can enhance probiotic culture growth by providing essential nutrients and altering the physicochemical properties of fermented milk. This study investigated the effects of adding 1.5% or 3.0% soy, pea, and whey protein isolates on the growth of Lacticaseibacillus casei and Lactobacillus johnsonii monocultures, as well as the physicochemical (acidity, syneresis, color) and organoleptic properties of fermented milk during 21 days of refrigerated storage. The results showed that 1.5% SPI and WPI did not significantly alter milk acidity compared to controls. Still, pH increased with 1.5% and 3.0% PPI. Storage time significantly affected pH in L. casei fermented milk. The initial addition of WPI at 1.5% and 3.0% reduced syneresis in L. casei fermented milk compared to other samples. Color components were significantly influenced by isolates. Initial L. casei cell counts were lower with SPI (LCS1.5 and LCS3) and 1.5% PPI (LCP1.5) compared to controls. Increasing isolate concentration from 1.5% to 3% enhanced L. johnsonii growth in WPI-milk but reduced L. casei in LCW3 compared to LCW1.5. Only increased pea protein concentration significantly increased L. casei growth. Probiotic populations generally were reduced during extended storage. Moreover, isolates impacted milk organoleptic evaluation. This research demonstrates the potential of protein isolates in creating health-promoting and diverse fermented products and offers insights into their interaction with probiotic cultures to advance functional food technologies. [ABSTRACT FROM AUTHOR]

The mammary gland, crucial for milk production in mammals, presents challenges for in vitro study due to its complex structure and limited cell lifespan. We addressed this by introducing the SV40 large T antigen into primary mammary epithelial cells (MECs) from sheep, creating an immortalized T‐tag MEC line. This line, stable for over 50 passages, maintained typical epithelial cell morphology during long‐term culture. Through transcriptome sequencing and validation, we discovered 3833 differentially expressed genes between MECs and T‐tag MEC line, encompassing key biological processes and signaling pathways like cell cycle, p53, and cancer. The cell line, expressing MEC markers (KRT8, KRT18, proliferating cell nuclear antigen, SV40, CSN2, and acetyl‐CoA carboxylase alpha), proved capable of synthesizing milk fat and protein. Despite its infinite proliferation potential, the T‐tag MEC line showed no tumor formation in mice or cell migration in vitro, indicating stability. This development offers a valuable resource for studying MECs in dairy sheep, facilitating the advancement of long‐term culture systems and in vitro lactation bioreactors. [ABSTRACT FROM AUTHOR]

Summary The distinct techno‐functional and sensory attributes conferred by milk proteins and fat are fundamental in defining the structure, texture and flavour of dairy products. Thus, reproducing cheese‐like characteristics in plant‐based alternatives while ensuring consumer acceptance is a major challenge. This study aimed to evaluate the sensory profile of commercial cream cheese and plant‐based analogues, quantifying consumer perception and discrimination, and correlating with instrumental texture analysis. For that, two milk‐based (MB1 and MB2) and three plant‐based products (PB1, PB2 and PB3) were evaluated for their proximate composition, texture profile (spreadability and firmness) and sensory properties by combining Flash Profile method (n = 13), Check‐All‐That‐Apply (CATA) test, and Rate‐all‐that‐apply (RATA) test (n = 102) with global acceptance. Milk‐based cream cheeses (MB1 and MB2) did not differ significantly from each other and presented greater spreadability when compared to all plant‐based cream cheeses (PB1, PB2 and PB3). The texture parameters of the samples were inversely related: the greater the firmness, the lower the spreadability. All forty‐two sensory attributes allowed discrimination of the samples into three distinct clusters, with no difference between the milk‐based products. The results of the CATA test showed that the attributes most correlated with the sample MB1 were the most desirable for good acceptance of the product. In turn, PB3 showed lower acceptance scores when compared to the plant‐based samples PB1 and PB2, and the attributes rancid flavour, vegetable oil aroma and nut aroma mostly contributed to the lower acceptance of PB3. Milk‐based products were very close to the ideal product, presenting a creamy and spreadable texture as key attributes for product characterisation and acceptance. The results of RATA test showed a significant difference (P < 0.05) in the intensity of nineteen sensory attributes. Milk‐based cream cheeses were more accepted than their plant‐based counterparts. The instrumental assessments of firmness and spreadability exhibited a negative correlation, once they were inversely proportional and strongly correlated to sensory data of firm and spreadable texture, respectively. The sensory characteristics of cream cheese analogues may present a barrier to their acceptance by consumers. Attributes such as coconut and flour flavour, artificial cheese aroma and flavour, and spreadable texture played a key role in differentiating dairy products from plant‐based ones, contributing to the lower acceptance of the latter. [ABSTRACT FROM AUTHOR]

BACKGROUND RESULTS CONCLUSION While yogurt is the leading fermented milk product, kefir is at the top of the beverage scale. Milk proteins, on the other hand, show specific functions that positively affect healthy nutrition due to the bioactive components, that they provide the necessary amino acids for growth and development.In our study, kefir, a functional product enriched with whey proteins, casein and skimmed milk powder, which are the natural components of milk, was produced. Added‐protein kefir samples were applied the in vitro digestion protocol, static method. In order to observe different protein behaviors, samples were taken pre‐digestion, at 120th minute and at 240th minute of digestion protocol. ACE and Antioxidant capacity determination analyzes were carried out. While ACE inhibition values were in the range of 78.63–90.30% pre‐digestion, they changed in the range of 86.97–96.38% after gastrointestinal digestion. It was determined that the ACE inhibition values of the control sample remained at the lowest level at all stages of digestion and that the difference between all of samples was significant (P < 0.05). Antioxidant activity value ranging from 0.3615–0.5512 meq Ascorbic acid/μg before digestion was determined as 1.3796–1.9313 meq Ascorbic acid/μg after gastrointestinal digestion (P < 0.05).Kefir samples containing whey protein stand out with their high potential in terms of both antioxidant activity capacity and ACE inhibition activity at all stages of digestion. Considering their therapeutic effects in fermented products, it is thought that whey proteins among milk proteins will be important alternative sources to enrich the protein content in kefir production. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The objective of the present study was to characterize the nutritional composition, fatty acid profile, and IgG concentration of the milk produced by Chilean Corralero horse (CCH) mares from breeding farms located in southern Chile. Forty-five milk samples were collected from three of the biggest breeding farms (coded as A, B and C) specialized in breeding and selection of CCH in Chile (15 mares sampled per farm). Farms differed in days in milk (DIM). A negative association between DIM and ash, milk protein, milk solids, saturated fatty acids (SFA), and gross energy (GE) was found, whereas DIM had a positive association with monounsaturated fatty acids (MUFA). Milk components like fat, lactose, and energy content varied independently of DIM, indicating other influencing factors such as farm-specific management practices. Offspring sex moderately affected GE content, with milk from mares bearing female offspring having higher GE. Macronutrient profiles of the CCH mares' milk were within the reported range for other horse breeds but tended to have lower fat and total solids. Compared to cow and human milk, horse milk is richer in lactose and lower in fat and protein. Immunoglobulin G concentration was only affected by the farm (B > A) which could be linked to dietary factors and pasture composition rather than maternal parity or other known factors. Overall, CCH mare milk has notable nutritional characteristics, with implications for both foal health and potential human consumption, posing less cardiac risk compared to cow's milk as indicated by lower atherogenic and thrombogenic indices. [ABSTRACT FROM AUTHOR]

Simple Summary: Dimensional conformation traits of dairy cows, which are in connection with their individual body features and production, are an important functional trait regulating feed efficiency and energy balance. That is why the scientific importance of these traits has increased recently. In this study, the genetic determination, association, and trend of selected dimensional traits, i.e., stature, chest width, body depth, and rump width, in Holstein Friesian cows were evaluated. Based on the results, according to positive but weak correlations and trends, the examined production and conformation traits did not result in meaningful change in the latter along with the increase in production yield. The objective of this study was to estimate the heritability of dairy production traits and that for dimensional traits and to calculate the correlation between the two heritability values in a Holstein Friesian cow herd bred in Hungary. Data of 15,032 Holstein Friesian cows born in the period 2008–2018 from 666 sires were collected for the study in 6 large dairy herds. Among the conformation traits, stature (ST), chest width (CW), body depth (BD), and rump width (RW), and for production traits, in the first lactation of cows, the 305-day milk yield (MY), milk butterfat yield (FY), and milk protein yield (MY) were evaluated. Heritability estimates of ST, CW, BD, and RW were 0.49, 0.25, 0.31, and 0.30, and those of MY, FY, and PY were 0.40, 0.35, and 0.30, respectively. BD and RW had no phenotypic (b = −0.01) or genetic (b = 0.00–0.01) change. The production traits (MY, FY, PY) increased to a greater extent (b = 2.2–43.3) than the examined conformation traits over time. Consequently, it is indicated that the selection for dairy production did not result in an increase in the studied dimensional traits. [ABSTRACT FROM AUTHOR]

In grazing systems, feeds other than pasture are often used to increase dry matter intake and milk production. The study aimed to evaluate the effect of individually feeding pasture-grazed dairy cows near peak lactation based on their individualised milk production compared with a flat-rate feeding regime. All cows in the flat-rate treatment were offered 4 kg wet weight (3.6 kg DM) of concentrate/d. In the individualised feeding treatment, cows were offered 6, 4, and 2 kg wet weight/d (5.4, 3.6 and 1.8 kg DM/d) in the high, moderate, and low production groups, respectively. Individualised feeding of concentrates based on cow milk production did not alter milk or milk component yield at a herd level, but increased milk yield and tended to increase yield of fat, protein, and lactose in cows in the medium milk yield tertile. Individualised feeding reduced milk protein yield in cows in the low milk yield tertile, compared with flat rate feeding. The results do not support individualised feeding in grazing dairy systems where the maximum level of concentrate offered/ is ≤ 6 kg DM/d and milk production/cow ≤30 kg milk/d or ≤2.5 kg fat and protein/d. [ABSTRACT FROM AUTHOR]

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This study explored the polymorphism of the leucine aminopeptidase (LAP3) gene and its relationship with milk quality characteristics in Gannan yak. A cohort of 162 Gannan yak was genotyped utilizing the Illumina Yak cGPS 7K BeadChip, and the identified single nucleotide polymorphisms (SNPs) were evaluated for their association with milk protein, casein, lactose, and fat concentrations. The results showed that four SNPs (g.4494G > A, g.5919A > G, g.8033G > C, and g.15,615A > G) in the LAP3 gene exhibited polymorphism with information content values of 0.267, 0.267, 0.293, and 0.114, respectively. All four SNPs were in Hardy–Weinberg equilibrium (p > 0.05). The g.4494G > A and g.5919A > G SNPs were significantly associated with protein content (p < 0.05), with homozygous genotypes showing significantly higher protein content than heterozygous genotypes (p < 0.05). The g.8033G > C SNP was significantly associated with casein content, protein content, non-fat solids, and acidity (p < 0.05), with the CC genotype having significantly higher casein, protein, and non-fat solids content than the GG and GC genotypes (p < 0.05). The g.15,615A > G SNP was significantly associated with average fat globule diameter (p < 0.05). In general, the mutations within the LAP3 gene demonstrated a positive impact on milk quality traits in Gannan yak, with mutated genotypes correlating with enhanced milk quality. These results indicate that the LAP3 gene could be a significant or candidate gene affecting milk quality traits in Gannan yak and offer potential genetic markers for molecular breeding programs in this species. [ABSTRACT FROM AUTHOR]

Casein is among the most abundant proteins in milk and has high nutritional value. Casein's interactions with polysaccharides, polyphenols, and metal ions are important for regulating the functional properties and textural quality of dairy foods. To improve the functional properties of casein-based foods, a deep understanding of the interaction mechanisms and the influencing factors between casein and other food components is required. This review started by elucidating the interaction mechanism of casein with polysaccharides, polyphenols, and metal ions. Thermodynamic incompatibility and attraction are the fundamental factors in determining the interaction types between casein and polysaccharides, which leads to different phase behaviors and microstructural types in casein-based foods. Additionally, the interaction of casein with polyphenols primarily occurs through non-covalent (hydrogen bonding, hydrophobic interactions, van der Waals forces, and ionic bonding) or covalent interaction (primarily based on the oxidation of proteins or polyphenols by enzymatic or non-enzymatic (alkaline or free radical grafting) approaches). Moreover, the selectivity of casein to specific metal ions is also introduced. Factors affecting the binding of casein to the above three components, such as temperature, pH, the mixing ratio, and the fine structure of these components, are also summarized to provide a good foundation for casein-based food applications. [ABSTRACT FROM AUTHOR]

With hyperlipidemia posing a significant cardiovascular risk, innovative strategies are essential to unlock new therapeutic possibilities. Probiotic fermentation of milk proteins offers a natural and effective means to produce peptides with hypolipidemic properties, providing a promising approach to lowering lipid levels and reducing cardiovascular risk. In this study, fermented cattle milk (FCTM), fermented camel milk (FCM), fermented goat milk (FGM), and fermented sheep milk (FSM) were produced using a total of five probiotic bacterial strains to investigate the release of bioactive peptides (BAPs) with hypolipidemic potential via in vitro inhibitory activity toward pancreatic lipase (PL) during a 14-day refrigerated storage study. The PL inhibitory activities of these fermented milk (FM) varied according to the types of probiotic strains and milk types used. Overall, the Pediococcus pentosaceus MF000957 (PP-957) strain showed the highest PL inhibitory activity spanning across all milk types, and therefore, PP-957-derived fermented samples were analyzed for BAP identification by LCMS-QTOF. The identified BAPs were further analyzed using in silico and bioinformatics approaches for bioactivity prediction, molecular docking, and drug pharmacokinetic studies. Overall, four peptides derived from FCTM, one from FCM, and two peptides common in FGM and FSM were predicted as active PL inhibitors based on their binding energy and number of binding sites on the PL enzyme. All peptides were non-toxic, non-carcinogenic, and had appropriate drug-like properties. The outcomes of this study suggest that FM-derived peptides from animal milk are anticipated to be useful for combating hypercholesterolemia. [ABSTRACT FROM AUTHOR]

[Objectives] Cow mastitis is a common disease in the process of dairy farming. This study aimed to investigate the effectiveness of acoustic pulse therapy (APT) in treating cow mastitis. [Methods] Based on the results of pathogen and milk somatic cell detection, 100 cows with clinical mastitis and subclinical mastitis from a farm in Jiangsu Province were selected. Among them, there were 60 cows with clinical mastitis, including 20 in the APT treatment group, 20 in the antibiotic treatment group, and 20 in the combined APT and antibiotic treatment group. Twenty cows with subclinical mastitis (latent mastitis) were treated with APT. Twenty healthy cows were used as the negative control group. The effectiveness of APT in treating cow mastitis was explored through comparative experiments. [Results] After cows suffered from mastitis, productive performance indicators such as somatic cell count significantly increased (P<0.05), and daily milk production significantly decreased (P<0.05). The number of white blood cells in the blood significantly increased (P<0.05), with a significant increase in lymphocyte count and neutrophil count (P<0.01). The content of inflammatory factors IL-1β significantly increased (P<0.05), while the content of inflammatory factors IL-6 and IL-8 significantly increased (P<0.01), and the content of glucocorticoids significantly increased (P<0.05). After APT treatment, the somatic cell counts significantly decreased (P<0.05), and daily milk production significantly increased (P<0.05). There were no significant changes in milk fat, milk protein, lactose, non-fat solids, total solids, and urea nitrogen (P>0.05). The number of white blood cells, neutrophils, and lymphocytes significantly decreased (P<0.05), while the other health blood physiological indicators did not change significantly (P>0.05). In the subclinical group, the inflammatory factor IL-1β significantly decreased (P<0.05), and the inflammatory factors IL-6 and IL-8 significantly decreased (P<0.05), while glucocorticoids in the subclinical group significantly decreased (P<0.05). [Conclusions] APT as a new kind of dairy cow mastitis treatment technology, can effectively cure the cow mastitis with no loss of production. [ABSTRACT FROM AUTHOR]

Background: Immunomodulatory proteins in human milk (HM) can shape infant immune development. However, strategies to modulate their levels are currently unknown. This study investigated whether maternal prebiotic supplementation alters the levels of immunomodulatory proteins in HM. Methods: The study was nested within the SYMBA double‐blind randomized controlled trial (ACTRN12615001075572), which investigated the effects of maternal prebiotic (short‐chain galacto‐oligosaccharides/long‐chain fructo‐oligosaccharides) supplementation from <21 weeks gestation during pregnancy until 6 months postnatal during lactation on child allergic disease risk. Mother–child dyads receiving prebiotics (n = 46) or placebo (n = 54) were included in this study. We measured the levels of 24 immunomodulatory proteins in HM collected at 2, 4, and 6 months. Results: Cluster analysis showed that the overall immunomodulatory protein composition of milk samples from both groups was similar. At 2 months, HM of prebiotic‐supplemented women had decreased levels of TGF‐β1 and TSLP (95% CI: −17.4 [−29.68, −2.28] and −57.32 [−94.22, −4.7] respectively) and increased levels of sCD14 (95% CI: 1.81 [0.17, 3.71]), when compared to the placebo group. At 4 months, IgG1 was lower in the prebiotic group (95% CI: −1.55 [−3.55, −0.12]) compared to placebo group. Conclusion: This exploratory study shows that prebiotic consumption by lactating mothers selectively alters specific immunomodulatory proteins in HM. This finding is crucial for understanding how prebiotic dietary recommendations for pregnant and lactating women can modify the immune properties of HM and potentially influence infant health outcomes through immune support from breastfeeding. [ABSTRACT FROM AUTHOR]

Milk boasts an array of potent bioactive compounds, such as lactoferrin (Lf), immunoglobulins, and functional proteins, all delivering substantial therapeutic benefits. In this study, Immune Powder (a functional dairy formulation) and its primary component called Fractionated Milk Protein (FMP) containing Lf, zinc, and immunoglobulins and formulated by Ausnutria Pty Ltd. were evaluated for their potential broad-spectrum pharmacological activity. In particular, this study investigated the antibacterial (against pathogenic Escherichia coli), prebiotic (promoting Lactobacillus delbrueckii growth), anti-inflammatory (inhibition of NO production in RAW264.7 macrophages), and antiviral (against human coronavirus 229E) effects of the samples. In addition, the impact of simulated gastric digestion on the efficacy of the samples was explored. LCMS-based proteomics was implemented to unveil cellular and molecular mechanisms underlying antiviral activity. The Immune Powder demonstrated antibacterial activity against E. coli (up to 99.74 ± 11.47% inhibition), coupled with prebiotic action (10.84 ± 2.2 viability fold-change), albeit these activities diminished post-digestion (p < 0.01). The Immune Powder effectively mitigated NO production in lipopolysaccharide-stimulated RAW264.7 macrophages, with declining efficacy post-digestion (p < 0.0001). The Immune Powder showed similar antiviral activity before and after digestion (p > 0.05) with up to 3-fold improvement. Likewise, FMP exhibited antibacterial potency pre-digestion at high concentrations (95.56 ± 1.23% inhibition at 125 mg/mL) and post-digestion at lower doses (61.82 ± 5.58% inhibition at 3906.25 µg/mL). FMP also showed enhanced prebiotic activity post-digestion (p < 0.0001), NO inhibition pre-digestion, and significant antiviral activity. The proteomics study suggested that the formulation and its primary component shared similar antiviral mechanisms by inhibiting scavenger receptor binding and extracellular matrix interaction. [ABSTRACT FROM AUTHOR]

Simple Summary: The aim of this study was to evaluate the effect of conjugated linoleic acid on the milk fat globule size and the ruminal microbiome of goats. In the present study, we found that dietary conjugated linoleic acid supplementation significantly and dose-dependently decreased the milk fat content and fat globule size in Saanen dairy goats, accompanied by an increase in the proportion of small-sized fat globules. Moreover, the dairy goats occurred in parallel with significant changes in the relative abundance of some ruminal bacterial populations. The milk fat content and fat globule size were correlated with the relative abundance of some bacteria, including members of Firmicutes and Bacteroidetes. Notably, our study was the first to analyze the correlation between the ruminal microbiota and fat globule size. These results constitute the first evidence for explaining the mechanism underlying diet-induced fat globules from the perspective of the ruminal microbiome in dairy goats. The aim of this study was to evaluate the effect of conjugated linoleic acid (CLA) on milk fat globule (MFG) size and the ruminal microbiome of goats. Twenty-four mid-lactation Saanen dairy goats weighing 49 ± 4.5 kg (168 ± 27 d in milk, 1.2 ± 0.1 kg milk/d, 2–3 years old) were randomly divided into four groups—a control (CON) group, which was fed a basal diet, and three CLA supplementation groups, in which 30 g CLA (low-dose group, L-CLA), 60 g CLA (medium-dose group, M-CLA), or 90 g CLA (high-dose group, H-CLA) was added to the basal diet daily. The experiment lasted for 21 days, during which time goat milk was collected for composition and MFG size analysis. On day 21 of feeding, ruminal fluid was collected from the CON and H-CLA groups for analysis of the changes in microorganismal abundance. The results showed that CLA supplementation did not affect milk production, milk protein, or lactose content in the dairy goats (p > 0.05), but significantly reduced the milk fat content (p < 0.01) compared with the CON group. The CLA supplementation significantly decreased the D[3,2] and D[4,3] of the MFGs in a dose-dependent manner (p < 0.01). Moreover, dietary CLA inclusion increased the proportion of small-sized MFGs and decreased that of large-sized ones. The results of 16S rRNA gene sequencing showed that CLA-induced milk fat depression in dairy goats was accompanied by significant changes in the relative abundance of ruminal bacterial populations, most of which belonged to the Firmicutes and Bacteroidetes phyla. The relative abundance of Rikenellaceae_RC9_gut_group and Prevolellaceae_UCG-003 in Bacteroidetes and UCG-002, Succiniclasticum, and norank_f__norank_o__Clostridia_vadinBB60_group in Firmicutes was significantly higher in the CON group than in the H-CLA group. In contrast, the relative abundance of norank_f__UCG-011, norank_f_Eubacterium_coprostanoligenes_group, unclassified_f__Lachnospiraceae, and UCG-001 in Firmicutes and norank_f__Muribaculaceae in Bacteroidetes was significantly higher in the H-CLA group than in the CON group. Correlation analysis showed that the milk fat content was negatively correlated with the relative abundance of some bacteria, including members of Firmicutes and Bacteroidetes. Similarly, MFG size (D[3,2] and D[4,3]) was negatively correlated with several members of Firmicutes and Bacteroidetes, including Lachnospiraceae, norank_f__UCG-011, UCG-001, norank_f__Eubacterium_coprostanoligenes_group (Firmicutes), and norank_f__Muribaculaceae (Bacteroidetes), while positively correlated with the relative abundance of some members of Firmicutes and Bacteroidetes, including Mycoplasma, Succiniclasticum, norank_f__norank_o__Clostridia_vadinBB60_group, UCG-002 (Firmicutes), and Rikenellaceae_RC9_gut_group (Bacteroidetes). Overall, our data indicated that CLA treatment affected milk fat content and MFG size in dairy goats, and these effects were correlated with the relative abundance of ruminal bacterial populations. These results provide the first evidence to explain the mechanism underlying diet-induced MFG from the perspective of the ruminal microbiome in dairy goats. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. Increasing nutrient supply to dairy calves has well known benefits; however, the effects of milk replacer (MR) composition when supplied in higher amounts are not fully understood, particularly in the first weeks of life. To better understand the metabolism of macronutrient supply in young calves (21 d old), we investigated diurnal patterns of heat production and substrate oxidation in young calves fed MR with an incremental supply of fat, lactose, or protein. Thirty-two groups of 3 mixed-sex Holstein-Friesian newborn calves (3.4 ± 1.6 d of age), were randomly assigned to one of 4 dietary treatments and studied for 21 d. Diets consisted of a basal MR (23.3% CP, 21.2% EE, and 48.8% lactose of DM) fed at 550 kJ/kg BW0.85 per day (CON; n = 24), or the basal MR incrementally supplied with 126 kJ of digestible energy/BW0.85 per day as milk fat (+FAT; n = 23), lactose (+LAC; n = 24), or milk protein (+PRO; n = 23). Calves were fed MR in 2 daily meals and had ad libitum access to water, but were not supplied with any calf starter nor forage. After 2 weeks of adaptation to the diets, groups of 3 calves were placed for 1 wk in an open-circuit respiration chamber for nitrogen and energy balance measurements (lasting 7 d). On d 3, glucose oxidation kinetics was estimated by using [U-13C]glucose. Measurements included total heat production (total energy [HP], activity [H act ] expenditure, resting metabolic rate [RMR]), respiration quotient (RQ), carbohydrate (COX) and fat oxidation (FOX) in 10 min. intervals and averaging these values per hour over days. Incremental supply of lactose and fat increased body fat deposition, with observed patterns in RMR indicating that this increase occurred primarily after the meals. Specifically, the average daily RMR was highest in the +PRO group and lowest in the CON treatment. The HP was higher in the +PRO group and throughout the day, hourly means of HP were higher in this treatment mainly caused by an increase in H act. The recovery of 13CO 2 from oral pulse-dosed [U-13C]glucose was high (77%), and not significantly different between treatments, indicating that ingested lactose was oxidized to a similar extent across treatments. Increasing lactose supply in young calves increased fat retention by reduction in fatty oxidation. Calves fed a MR with additional protein or fat raised RMR persistently throughout the day, whereas the extra lactose supply only affects RMR after the meal. Dietary glucose was almost completely oxidized (77% based on (13C) glucose measurement) regardless of nutrient supplementation. Extra protein supply increased HP and FOX compared with similar intakes of fat and lactose. Fasting heat production (FHP) of young, group-housed calves is comparable to literature values and unaffected by energy intake. Overall, these findings deepen our understanding of how different nutrients affect metabolic processes, fat retention, and energy expenditure in young dairy calves. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. The presence of an autocrine factor in milk that can trigger mammary gland involution was proposed more than 50 yr ago. To provide evidence for the existence of one or more autocrine factors, 10 multiparous cows in late lactation were quarter-milked for 7 d. Following this baseline period, the right front quarter of each cow was left unmilked, and the other quarters were milked for 7 d. Before the last milking of that period, milk (mammary secretions) was collected aseptically from both front quarters. After that milking, 250 mL of the collected samples were infused in the cows' respective rear quarters. No quarters were milked for the following 7 d (milk stasis period), and quarter milking was then resumed in all quarters for the last 7 d of the experiment (remilking period). Quarter milk samples were collected during the baseline period, before the milk stasis period, and during the remilking period. These samples were used for measuring milk components and the concentration of involution markers (SCC, BSA, and lactoferrin). Samples of mammary secretions were collected manually from the quarters during the milk stasis period for involution marker determination. We extracted RNA from samples collected from front quarters before the last milking before the milk stasis period for microRNA (miRNA) determination. As anticipated, the longer milk stasis period implemented for the right front quarter resulted in a more advanced involution than in the left front quarter, based on the concentration of involution markers in the mammary secretions, lower milk production recovery, and changes in milk composition during the remilking period. All 3 involution marker concentrations in the mammary secretions increased in both rear quarters, but were greater in the right quarter secretions than in the left quarter secretions. Resuming milking reinitiated milk production in all quarters, but milk production recovery in the right rear quarters was less robust than that in the left rear quarters (54.3 ± 1.4% vs. 61.6 ± 1.4%, respectively). Milk from the quarters infused with mammary secretions (right rear) had a lower lactose content, but a higher milk protein content and higher SCC than the quarters infused with milk. We detected a total of 359 miRNAs, 76 of which were differentially expressed in milk and mammary secretions. Expression of bta-miR-221 and bta-miR-223 was upregulated in mammary secretions 34- and 40-fold, respectively. The results of the present experiment support the contention that milk stasis leads to the accumulation of one or more factors that trigger involution. The results also indicate that milk stasis leads to changes in the miRNA profile of the milk, but whether such changes are a cause or a consequence of the involution process remains to be established. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. Ruminant milk composition can be affected by many factors, primarily interspecies differences, but also environmental factors (e.g., season, feeding system, and feed composition). Pasture-based feeding systems are known to be influenced by seasonal effects on grass composition. Spring pasture is rich in protein and low in fiber compared with late-season pasture, potentially inducing variability in the composition of some milk metabolites across the season. This study aimed to investigate interspecies and seasonal differences in the milk metabolome across the 3 major commercial ruminant milk species from factories in New Zealand: bovine, caprine, and ovine milk. Samples of bovine (n = 41) and caprine (n = 44) raw milk were collected monthly for a period of 9 mo (August 2016–April 2017), and ovine milk samples (n = 20) were collected for a period of 5 mo (August 2016–January 2017). Milk samples were subjected to biphasic extraction, and untargeted metabolite profiling was performed using 2 separate liquid chromatography high-resolution mass spectrometry analytical methods (polar metabolites and lipids). Major differences in the milk metabolome were observed between the 3 ruminant species, with 414 of 587 (71%) polar metabolite features and 210 of 233 (87%) lipid features being significantly different between species. Significant seasonal trends were observed in the polar metabolite fraction for bovine, caprine, and ovine milk (17, 24, and 32 metabolites, respectively), suggesting that the polar metabolite relative intensities of ovine and caprine milk were more susceptible to changes within seasons than bovine milk. We found no significant seasonal difference for the triglycerides (TG) species measured in bovine milk, whereas 3 and 52 TG species changed in caprine and ovine milk, respectively, across the seasons. In addition, 4 phosphatidylcholines and 2 phosphatidylethanolamines varied in caprine milk within the season, and 8 diglycerides varied in ovine milk. The interspecies and seasonal metabolite differences reported here provide a knowledge base of components potentially linked to milk physiochemical properties, and potential health benefits of New Zealand pasture-fed dairy ingredients. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. The AA profile of MP affects mammary gland metabolism and milk N efficiency of dairy cattle. Further, the frequency of dietary protein supplementation may influence N partitioning leading to reduced N excretion. This study investigated the effect of source and frequency of rumen-protected (RP) protein supplementation on apparent total-tract digestibility, milk production, mammary gland AA metabolism, and N balance of dairy cattle. Twenty-eight Holstein-Friesian cows (2.3 ± 0.9 lactations; 93 ± 27 DIM; mean ± SD) were used in a randomized complete block design and fed a basal TMR consisting of 41% corn silage, 32% grass silage, and 27% concentrate (DM basis) and formulated to meet 100% and 95% of net energy and MP requirements, respectively. Cows were adapted to the basal TMR in a freestall barn for 7 d, moved to individual tiestalls for 13 d of adaptation to dietary treatments, and then moved into climate respiration chambers for a 4-d measurement period. Treatments consisted of the basal TMR (CON; 159 g CP/kg DM) or the basal TMR including 1 of 3 iso-MP supplements: (1) 315-g mixture of RP soybean meal and RP rapeseed meal fed daily (ST-RPSR), (2) 384-g mixture of RP His, RP Lys, and RP Met fed daily (ST-RPAA), and (3) 768-g mixture of RP His, RP Lys, and RP Met fed every other day (OS-RPAA). The basal TMR with the addition of treatment supplements was designed to deliver 100% of required MP over a 48-h period. The mixture of His, Lys, and Met was formulated to deliver digestible AA in amounts relative to their concentration in casein. Compared with ST-RPSR, ST-RPAA increased milk protein and fat concentration, increased the arterial concentration of total His, Lys, and Met (HLM), decreased mammary clearance of HLM, and increased clearance of Phe, Leu, and Tyr (tendency for Leu and Tyr). Rumen-protected protein source did not affect N balance, but the marginal use efficiency (efficiency of transfer of RP protein supplement into milk protein) of ST-RPAA (67%) was higher than that of ST-RPSR (17%). Milk protein concentration decreased with OS-RPAA compared with ST-RPAA. Arterial concentration of HLM increased on the nonsupplemented day compared with the supplemented day with OS-RPAA, and there was no difference in arterial HLM concentration across days with ST-RPAA. Mammary uptake of HLM tended to increase on the nonsupplemented day compared with the supplemented day with OS-RPAA. Supplementation frequency of RP AA did not affect N balance or overall milk N efficiency, but the marginal use efficiency of OS-RPAA (49%) was lower compared with ST-RPAA. Overall, mammary glands responded to an increased supply of His, Lys, and Met by reducing efflux of other EAA when RP His, RP Lys, and RP Met were supplemented compared with RP plant proteins. Mammary glands increased sequestration of EAA (primarily HLM) on the nonsupplemented day with OS-RPAA, but supplementing RP AA according to a 24-h oscillating pattern did not increase N efficiency over static supplementation. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. Urine output and urinary urea-N excretion (UUN e) excretion are critical measures to accurately evaluate N metabolism in lactating dairy cows and environmental concerns related to manure N. The objectives of this study were: (1) to compare estimates of UUN e , urine output, and related variables from 3 pre-established measurement protocols (bladder catheterization, external collection cup, and spot sampling) and from dietary salt supplementation, (2) to study temporal variation in UUN e , urine output, and related variables as affected by measurement protocol, and (3) to evaluate urine specific gravity as a predictor of urine output. Twelve multiparous Holstein cows were used in a split-plot, Latin square design. Cows were randomly assigned to a diet (main plot) containing either 0.7% or 1.6% NaCl (DM basis) and then assigned to a sequence of 3 protocols (subplot) in a balanced 3 × 3 Latin square with 14-d period. For each protocol, measurements were conducted every 4 h for 3 consecutive days. Urine output was determined gravimetrically for bladder catheterization and external collection cup or based on measured cow BW, measured urinary creatinine concentration, and the assumed creatinine excretion of 29 mg/kg BW per day for spot sampling. Urine specific gravity was measured by refractometry. When averaged over a 3-d measurement period and compared with bladder catheterization, spot sampling underestimated urine output (6.8 kg/d; 20%) and UUN e (26 g/d; 13%) but exhibited greater concentration of urinary urea-N (+58 mg/dL; 10%). There were no differences in any measurements determined via bladder catheterization or external cup device protocols, except for urine output that tended to be 3.7 kg/d lower for collection cup compared with bladder catheterization. The 2 gravimetric protocols yielded lower urinary creatinine concentration than spot sampling (64.7 vs. 88.1 mg/dL) and lower creatinine excretion (25.3 mg/kg BW per day) than the value of 29 mg/kg BW per day generally assumed in the spot sampling protocol. Salt supplementation tended to increase urine output (+5.2 kg/d) and decrease urinary urea-N concentration (−93 mg/dL), urinary creatinine concentration (−9.5 mg/dL), milk protein concentration (−0.19 percentage unit) and milk protein yield (−70 g/d). There was greater temporal variation of urine output when measured via the collection cup compared with bladder catheterization in the first 2 d but not the third day of sampling, suggesting that an extended period of adaptation might have improved data quality of the collection cup protocol. The R2 of the linear regression to predict urine output with urine specific gravity was 67%, 73%, and 32% for bladder catheterization, collection cup, and spot sampling, respectively. In this study, spot sampling underestimated both urine output and UUN e , but UUN e determination did not differ between external collection cup and bladder catheterization. However, our data suggested the need to investigate the adaptation protocol, required days of measurements and the conversion of urine mass to urine volume to improve accuracy and precision of urine collection protocols. [Display omitted] [ABSTRACT FROM AUTHOR]