Agrégateur de flux

Assessing fertility: Development of a selection index for fertility in Italian Jersey cattle

Journal of Dairy Science -

Selection for increased milk yield in dairy cattle has led to a decline in fertility due to unfavorable genetic correlation. However, fertility remains crucial in dairy farming for maintaining a regular productive cycle, ensuring continuous milk supply, and reducing costs related to nonproductive cows. For this reason, the aim of this study was to estimate genetic parameters for fertility traits and to assess their genetic correlation with production traits in the Italian Jersey cattle breed. Days open (DO) as a fertility trait, and kg/305-d milk (MY), protein (PY), and fat yields (FY) were considered as production traits, respectively.

Terpene transfer to milk from fresh leaves of hemp (Cannabis sativa L.) and savory (Satureja hortensis L.)

Journal of Dairy Science -

This study aimed to investigate the transfer of terpenes from fresh aromatic plants, hemp (Cannabis sativa L.) and savory (Satureja hortensis L.), into cow milk, quantify their transfer efficiency, and explore their dynamics. Six Simmental dairy cows were allocated to a single concurrent 3 × 3 Latin square design with 3 dietary treatments: a TMR as control (CTRL) and the same ration supplemented with fresh hemp (HEMP) or savory (SAV) leaves. Each period lasted 14 d, with herb supplementation administered from d 1 to d 6 at increasing doses (0.2–0.8 kg/d DM).

Single-step genomic evaluation for production and type traits in the Italian Mediterranean Buffalo

Journal of Dairy Science -

Single-step GBLUP (ssGBLUP) is becoming the most used method to predict breeding values in livestock, offering several advantages in terms of computational efficiency and simplifying the genetic evaluation process by integrating genomic, pedigree, and phenotypic information in a single step. Genomic information is now available for the Italian Mediterranean Buffalo (IMB), and its inclusion in the genetic evaluation system could increase both evaluation accuracy and genetic progress of the breeding objectives.

Monosaccharide profiling and osmoprotective effects of camel milk: Implications for protein stability and therapeutic use

Journal of Dairy Science -

This study analyzed monosaccharides in cow and camel milk using GC-MS/MS with full scan mode after freeze-drying, N,O-Bis(trimethylsilyl)trifluoroacetamide derivatization, and SPME extraction. Camel milk exhibited a distinct monosaccharide profile, notably enriched in myo-inositol, a known osmolyte. To evaluate its functional role, BSA and α-Amylase were used as model proteins. Fluorescence spectroscopy and enzymatic assays showed that both camel milk and myo-inositol stabilized BSA under heat (37, 50, and 70°C) and salt stress (1 M NaCl), whereas cow milk led to structural changes.

Mesoscale fractal whey protein particles derived from microscale linear-shaped protein assemblies (Part 1): Manufacturing method and particle characteristics

Journal of Dairy Science -

Whey protein isolates (WPI) are widely used in processed foods for their versatile functional properties. Modifying the structural properties of proteins by assembling them into mesoscale or microscale particles may improve their functionality and broaden their applications. This study aims to manufacture and characterize mesoscale whey protein particles (WPP) derived from WPI. Two types of WPP, WPP1 (0.05 mL/min) and WPP2 (0.25 mL/min), were prepared through a multistep approach involving liquid antisolvent (LAS) precipitation, heat treatment, and microfluidization.

Genetic parameter estimation and fine-mapping of milk-production traits and somatic cell score in Chinese Simmental cattle

Journal of Dairy Science -

Chinese Simmental cattle serve as an important dual-purpose breed in sustainable livestock systems. Despite their economic value, the genetic architecture underlying milk-production traits in this breed under temperate conditions remains poorly characterized. In this study, we estimated genetic parameters and identified associated genomic loci for 9 milk-production traits in a Chinese Simmental population. Our dataset consisted of 17,556 test-day records from 1,788 cows (parities 1 to 3), including whole-genome sequencing data for 781 individuals.

Energy metabolism of lactating dairy cows fed 2 formaldehyde- and formic acid–treated forages with 2 nonstructural carbohydrate sources

Journal of Dairy Science -

The partial efficiency of ME used for net energy by growing ruminants is greater when fed alfalfa (ALF) than orchard grass (OG), but is unknown for lactating cows and may be influenced by varying the nonstructural carbohydrate (NSC) grain source. The NSC sources evaluated were corn grain (CG) and barley grain (BG). Individual treatments were ALF-CG, ALF-BG, OG-CG, and OG-BG arranged in a 4 × 4 Latin square having a 2 × 2 factorial arrangement of forage (FOR) and NSC sources. Four multiparous lactating Holstein dairy cows (milk = 33.8 ± 4.5 kg/d; BW = 599 ± 25.8 kg; DIM = 82 ± 20 d) were selected to measure whole-body energy balance via calorimetry.

Costs of production of all year-round vs block calving herds in the UK

Journal of Dairy Science -

The UK's climate and topography enables multiple different calving patterns to operate within the same market, facilitated by industry infrastructure that allows for a variety of milk purchasing arrangements. All year round (AYR) calving is most common, and with current labor challenges spring block (SB), autumn block (AB) and twin block (TB) calving systems could potentially become more popular, but research comparing the efficiency of AYR with block calving systems operating within the same market conditions is limited.

Physiological changes during the evolution of diarrhea in preweaning calves prior to the onset of clinical signs

Journal of Dairy Science -

Neonatal calf diarrhea remains a major issue in terms of mortality, economic, and animal welfare losses. In addition to different infectious and pathogenic causes, nonpathogenic factors, particularly stress and nutritional and management practices, also contribute significantly to the incidence of diarrhea in calves. This study aimed to investigate changes in blood metabolites and fecal parameters (pH value, short-chain fatty acids, and triglyceride content) preceding the onset of diarrhea signs in neonatal calves.

Portable visual platform integrates polymerase spiral amplification and CRISPR/Cas12a for foodborne bacteria point-of-care testing

Journal of Dairy Science -

Staphylococcus aureus, a prominent global foodborne pathogen, frequently triggers epidemics with severe public health impacts. Timely and reliable detection of S. aureus is crucial for mitigating the disease burden in low- and middle-income countries. However, conventional laboratory-based detection methods remain impractical in resource-limited settings, highlighting the urgent need for accessible point-of-care solutions. Here, we present an inner-outer-tube (IOT) assay that synergistically integrates the polymerase spiral amplification (PSR) technology for enhanced sensitivity with the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated 12a (Cas12a) system for sequence-specific identification.

Machine learning–based prediction of clinical mastitis in dairy cows: A comparative analysis of 9 algorithms using production and management data

Journal of Dairy Science -

Mastitis represents one of the most formidable challenges in modern dairy farming, posing significant threats to individual cow health and causing substantial economic losses throughout the dairy production chain. Traditional disease diagnosis methods are often reactive and costly, creating an urgent need for advanced predictive technologies. To address these issues, we proposed a novel machine learning–based mastitis prediction system that breaks through conventional diagnostic paradigms by deeply integrating data science with veterinary medicine.

Excessive lipolysis and inflammatory response in adipose tissue are associated with elevated serum growth hormone in dairy cows with clinical ketosis

Journal of Dairy Science -

Excessive lipolysis and inflammatory response are critically involved in the pathogenesis of ketosis in periparturient dairy cows. Evidence has been growing for participation of the growth hormone (GH) in the metabolic regulation of adipose tissue. However, the potential role of GH in promoting lipolysis and proinflammatory signaling activation in bovine adipocytes remains to be elucidated. The objective of this study was to investigate the regulatory effects of GH on the lipolysis and inflammatory response of bovine adipocytes.

Effects of fat level and coconut-to-palm fat ratio in milk replacer on solid feed intake and performance of pre- and postweaning dairy calves

Journal of Dairy Science -

This study investigated the effects of varying fat levels and ratios of coconut-to-palm fat in milk replacer on solid feed intake and performance of male Holstein calves fed a high milk replacer allowance. Calves were individually housed and enrolled in a 91-d (study 1; n = 128) and 84-d (study 2; n = 128) experiment at the same research facility divided into 3 phases: preweaning (1–42 d), weaning (43–63 d), and postweaning (64-study end). In study 1, calves were randomly assigned to 1 of the 3 treatments, consisting of a milk replacer containing a spray-dried blend of 20% coconut-to-80% palm fat with: 1) low fat (17%; LF-17%; n = 42; BW = 47.64 ± 2.62 kg), 2) moderate fat (23%; MF-23%; n = 43; BW = 47.69 ± 3.42 kg), and 3) high fat (29%; HF-29%; n = 41; BW = 47.04 ± 3.74 kg) in relation to 26% CP level.

Genetic variance components for alternative definitions of fatty acids in dairy cow milk expressed either as a concentration or yield

Journal of Dairy Science -

The extent of genetic variability in fatty acids in bovine milk has, to date, generally focused on its concentration in either milk or milk fat. Selection for ratio traits, such as fatty acid concentration, is statistically and biologically problematic because it can distort relationships between component traits and lead to unintended genetic responses. The objective of this study was to explore the degree of genetic variability in the total yield of individual fatty acids, including when adjusted to a common fat yield.

Replacing hexane with 2-methyloxolane for defatting soybean meal fed to dairy cows: Effects on ruminal and milk fatty acid profiles and health indicators

Journal of Dairy Science -

Replacing hexane with 2-methyloxolane (MeOx) for defatting soybean meal (SBM) requires adaptations of the SBM production process. These modifications may increase the concentration of Maillard reaction products and reduce the residual oil content in MeOx-defatted SBM compared with hexane-defatted SBM. In addition, despite desolventization, solvent residues may still be present in the SBM when fed to livestock. This study aims to ensure that the replacement of hexane with MeOx for defatting SBM does not affect the ruminal and milk fatty acid profiles nor the liver activity, liver functionality, and inflammatory status in dairy cows.

Effects of supplementing a Bacillus-based direct-fed microbial on ex vivo fermentation traits and on performance of lactating Holstein dairy cows

Journal of Dairy Science -

Three studies evaluated the effects of a Bacillus-based direct-fed microbial (DFM) on ex vivo fermentation traits, as well as on performance of lactating dairy cows. In experiment 1, rumen-fistulated lactating Holstein-Friesian cows (6.6 ± 2.3 parity; 630 ± 37.2 kg BW; 18.9 ± 3.35 kg milk/d) were fed an unsupplemented ration (CON; n = 5) or supplemented with 3 g/cow per d of a Bacillus-based DFM (BAC; n = 5) for 14 d before rumen sampling and subsequent ex vivo evaluation of fermentation characteristics of 2 different substrates (vetch hay [Vicia sativa] and perennial ryegrass herbage [Lolium perenne L.]).

Accuracy of local ancestry inference and its impact on genomic prediction in admixed dairy cattle populations

Journal of Dairy Science -

Accurate local ancestry (LA) inference is important for genomic evaluations in admixed dairy cattle. This study had 2 main objectives: to compare the performance of 3 LA inference software: AllOr, BreedOrigin, and ChromoPainter, and to evaluate the impact of LA inference errors on genomic prediction accuracy. Two simulated admixed populations were used: a structured DairyCross population created through three-way rotational crossbreeding and a Red Dairy cattle (RDC) population representing historical admixture among multiple breeds.

Graduate Student Literature Review: Significance of extracellular vesicles in the interaction between host and microbiota in the ruminant gastrointestinal tract*

Journal of Dairy Science -

The gastrointestinal tract (GIT) plays a crucial role in maintaining overall health and performance in ruminants, with the rumen functioning as fermentation chamber for plant biomass. Intestinal epithelial cells are exposed to billions of microorganisms that significantly affect the epithelial barrier by activating complex metabolic and immune pathways. The interaction between microbiota and host is mediated by signaling compounds such as metabolites and peptides, and also extracellular vesicles (EV).

Secondary analysis of feed intake, calcemia, and assessment of immune function in the subsequent periparturient period of cows that responded to high and low-energy diets during late lactation

Journal of Dairy Science -

The purpose of this study was to use a secondary analysis to investigate the use of feeding high and low-energy diets to alter BCS at dry-off, and to assess the subsequent changes in BCS on feed intake, calcemia, and assessment of immune function, including inflammation, during the periparturient period. Multiparous Holstein lactating dairy cows at 150 d of gestation were blocked by expected calving date and randomly assigned to receive one of 2 dietary treatments during late lactation until dry-off, aiming to maintain or decrease BCS.

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