Strain-level diversity in aroma formation remains undercharacterized in Lactiplantibacillus plantarum, a key adjunct culture in dairy fermentation. We screened 351 isolates from traditional Chinese fermented foods for diacetyl production and identified wide phenotypic variation, with strain WJ108 producing 26.85 ± 0.72 mg/kg, which is more than double that of known high producers. Selected strains representing high, medium, and low diacetyl yields were analyzed using GC-MS, revealing ketone enrichment in high producers and aldehyde and alcohol accumulation in low producers.

To address the long-standing dual challenges in the camel milk industry, namely, the difficulty in identifying adulteration and the severe lag in nutritional component detection, this study analyzed the variation patterns of the dielectric constant (ε′) and dielectric loss factor (εʺ) of camel milk fat, protein, and lactose. Based on the dielectric spectrum, detection models were constructed using partial least squares (PLS), convolutional neural network (CNN), long short-term memory network (LSTM), CNN-LSTM, and an optimized CNN-LSTM fused with the crested porcupine optimizer (CPO) and squeeze-and-excitation network (CPO-CNN-LSTM-SEN) for camel milk quality detection.

The aim of this study was to evaluate the effects of feed restriction and refeeding on metabolic and AA profiles in blood serum, and on cerebrospinal fluid (CSF) profiles during the feed restriction period, using a controlled feeding model. Additionally, the study aims to identify metabolic signals generated during feed restriction that may help explain individual variability in the feed intake recovery. Following 2 wk of adaptation, 8 primiparous Holstein cows housed in individual stalls with free access to water were fed ad libitum for 5 d (basal period), followed by 50% feed restriction for 5 d, and then returned to ad libitum feeding for 5 d (refeeding period).

There are a growing number of scientific reports on the production and extraction of new alternatives for milk-clotting enzymes (MCE), as a result of the growing demand for cheese and the limited availability of rennet. This article reviews the different types of microbial MCE, sources of their origin, and the effects of different factors on their milk clotting activity (MCA) and proteolytic activity (PA). The influence of microbial enzymes on the final product quality and production efficiency are considered.

Heat stress has been associated with promoting a systemic and local proinflammatory response, which could involve impaired intestinal structure and function in growing dairy calves. We hypothesized that heat stress–induced reduction of the intestinal barrier function would be associated with changes in immune cell counts, and the administration of the glucocorticoid dexamethasone would attenuate the proinflammatory response and restore intestinal barrier function. The objective of the study was to determine the effect of reducing the proinflammatory response on systemic and local immune cell concentrations, focusing on the major leukocyte types (neutrophils and lymphocytes), as well as structural and functional changes in the intestine of dairy calves exposed to heat stress.

Cytological endometritis (CYTO), characterized by an elevated number of polymorphonuclear neutrophils in the endometrium, negatively affects reproductive outcomes in dairy cows. In this study, we investigated the associations between insulin resistance (IR) during the transition period and the occurrence of CYTO. We measured insulin sensitivity and adipose tissue gene expression on d −21 and d 21 and a selection of blood metabolites weekly from d −21 to d 42 relative to calving of 39 Holstein dairy cows.

The objective of this study was to evaluate the effects of replacing finely ground dry corn grain (DGC) with reconstituted finely ground corn grain (RCG) or high-moisture rolled corn grain (HMC) on nutrient intake, apparent partial and total-tract digestibility, rumen fermentation profile, milk yield and composition, and blood variables of dairy cows. A total of 9 Holstein dairy cows, 6 of which were rumen-cannulated, with mean (±SD) BW of 639 ± 15.1 kg, milk production of 30.4 ± 1.58, parity of 2.2 ± 0.54, and DIM of 100 ± 10.7 were blocked for milk yield and DIM.

The objective of this experiment was to study the effects of protein source and seaweed supplementation on intake, milk concentration, and transfer efficiency of minerals from feed to cow milk. Twelve multiparous Nordic Red cows were used in a cyclic change-over study with a 2 × 3 factorial arrangement of treatments. The cows were divided into block 1 (DIM 151 ± 12.7 d, milk yield 29.7 ± 4.08 kg/d) and block 2 (DIM 115 ± 15.1 d, milk yield 39.5 ± 3.45 kg/d). The study consisted of three 17-d periods with an 18-d washout between periods.

As unique genetic resources, the differential characteristics of whey proteins and their derived peptides between Binglangjiang and Dehong buffaloes remain unclear. This study employed an integrated proteomics and peptidomics approach to elucidate the similarities and differences in whey proteins and their derived peptides between the 2 buffalo species. Proteomic analysis identified 405 proteins in total, 15 unique proteins and 390 common proteins (6 showed significant expression differences), indicating high similarity in whey protein composition between the 2 species.

Even though dairy calves are susceptible to heat stress, they are commonly overlooked for heat abatement strategies. The objectives of this study were to examine the effectiveness of a positive pressure tube ventilation (PPTV) system adapted for preweaning dairy calves housed outdoors during a subtropical summer (June 30 to July 6, average temperature-humidity index [THI] >79). Two-week old Holstein heifers were individually housed in wire pens under a shade cloth structure with a PPTV system at ground level to provide consistent horizontal airflow with daytime misting (PPTV-CL group, n = 24) or without the PPTV system (control heat-stressed group, CON-HS; n = 21).

Inbreeding depression (InD) refers to the mean reduction in trait values due to inbreeding, with detrimental effects on survival, production, and reproduction traits that have been observed in many natural and domesticated populations. Despite efforts to measure how much reduction in the traits of interest was caused by InD, the genetic and molecular basis of these declines remains unclear, particularly in dairy cattle. In this research, we used a linear mixed model to partition the InD of 3 production traits in 245,517 genotyped Jersey cows from the Council on Dairy Cattle Breeding (Bowie, MD) database.

Societal and economic pressure to reduce nitrogen use in the dairy cow sector is increasing. One potential contributing solution is to breed more nitrogen-efficient dairy cows that excrete less nitrogen. Although genetic variability for nitrogen utilization has been documented in dairy cows, how the phenotypic variance is partitioned into its causal components across lactation has not been previously explored in dairy cows. The objective, therefore, of the present study was to use 4,600 nitrogen utilization phenotypes across 2,255 lactations from 1,296 grazing dairy cows to explore whether the genetic variation in nitrogen utilization changes throughout lactation.

The objectives of this study were 2-fold: (1) to investigate the associations among variables derived from automated milking systems (AMS), rumination collars (SCR Heatime), and public weather stations; and (2) to assess how combinations of specific data types (e.g., AMS, SCR, or weather data) influence the predictive accuracy of 7-d average milk yield (DMY7) using different machine learning methods. Data were collected from 1,312 lactating cows in a freestall system with AMS at a commercial dairy farm in Chowchilla, California.

Monitoring urine composition is a valuable method for identifying metabolic disorders and diseases noninvasively. This study analyzed urination events, urine amounts, and urine composition in dairy calves during their first week of life, comparing calves fed dam's milk to calves fed milk replacer. Calves (n = 18) were housed individually in calf hutches and fed twice daily in unlimited amounts their dams' milk for the first 6 feedings, then switched to milk replacer or continued receiving dam's milk.

Declining male fertility poses significant challenges to both human health and livestock production. In this study, we investigated cases of bull subfertility that occurred despite normal semen quality and quantity metrics. Analysis of fertility records and genotype-based kinship among hundreds of inseminating bulls revealed familial clustering of subfertility, supporting a monogenic component. Whole-genome sequencing identified a polymorphism in the AHR gene present in affected bulls but absent in controls.

The objectives of this experiment were (1) to identify associations between nutritional and non-nutritional factors and bulk tank milk fat concentration and (2) to develop a multivariable model capable of predicting herd-level milk fat concentration for Irish commercial spring-calving grazing dairy herds. An observational experiment comprising 25 commercial spring-calving dairy herds was conducted over a 2-yr period. Farms were visited 10 times per year, which coincided with each grazing rotation.

The size of fat globules in ruminant milk to some extent affects the nutritional quality of dairy products and plays potential roles in infant and adult health. Lipid droplets (LD) in mammary epithelial cells are the precursors of milk fat globules (MFG). However, it is unclear what happens to proteins during the transformation process from LD to MFG, and little is known about the regulation of LD diameter in vivo. In this study, 12 mid-lactation Saanen dairy goats were randomly divided into 2 groups: a control group fed a basal diet and an experimental group fed a basal diet supplemented with CLA at 90 g/d.

The variability of milk spectra within and between dairy animals reflects the complex biological processes underlying milk production. Studying this variability may offer insights into an animal's physiological or health status and help elucidate relationships between specific genes and milk's chemical structure. Over 4 yr, biweekly Fourier transform infrared spectra were recorded on 41,075 sheep milk samples collected from 1,256 Sarda ewes at morning and evening milkings. Individual variance components for absorbance at wavenumbers between 5,000 and 925 cm−1 were estimated using a REML procedure with a repeated measures mixed model.

The rumen microbiome plays a pivotal role in nutrient metabolism and host health, ultimately influencing production performance in ruminants, including dairy goats. Although enterotypes—distinct clusters of gut microbiota—have been identified, their effect on rumen fermentation and milk production in dairy goats remains poorly understood. This study aimed to characterize rumen microbial enterotypes and investigate their associations with fermentation characteristics and milk production traits in lactating dairy goats.

Plastic is widespread in our lives, releasing various microplastics (MP) with toxicity. In recent years, the potential threat of MP on the reproductive system has aroused public concern. Numerous reports have focused on its damage to spermatogenesis. Nevertheless, the toxicity of MP on female reproduction is unclear. Here, we explored this question using bovine oocyte. Through immunofluorescence staining, the results revealed that MP disrupts spindle organization, chromosome alignment, and actin assembly, leading to failed maturation of bovine oocytes.