Agrégateur de flux
Impact of varying levels of pasture allowance on the nutritional quality and functionality of milk throughout lactation. By Timlin et al., page 6597. There is a general perception that grass-fed dairy systems produce milk that is more nutritionally beneficial for human consumption than that derived from intensive mixed ration feeding systems, primarily due to its fatty acid profile. Previous research has investigated the composition of milks derived from mixed ration and grass-only diets; however, these grass-only diets fail to integrate concentrate supplementation, which is commonly incorporated to ensure the energy demands of the animals are achieved.
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Heat stress-associated changes in the intestinal barrier, inflammatory signals, and microbiome communities in dairy calves
Recent studies indicate that heat stress pathophysiology is associated with intestinal barrier dysfunction, local and systemic inflammation, and gut dysbiosis. However, inconclusive results and a poor description of tissue specific changes must be addressed to identify potential intervention targets against heat stress illness in growing calves. Therefore, the objective of this study was to evaluate components of the intestinal barrier, pro- and anti-inflammatory signals, and microbiota community composition in Holstein bull calves exposed to heat stress.
Investigating the potential for genetic selection of dairy calf disease traits using management data
Genetic selection could be a tool to help improve the health and welfare of calves, however, to date, there is limited research on the genetics of calfhood diseases. This study aimed to understand the current impact of calf diseases, by investigating incidence rates, estimating genetic parameters, and providing industry recommendations to improve calf disease recording practices on farms. Available calf disease data comprised of 69,695 Holstein calf disease records for respiratory problems (RESP) and diarrhea (DIAR), from 62,361 calves collected on 1,617 Canadian dairy herds from 2006 to 2021.
Effects of dietary rumen-protected choline supplementation to periparturient dairy cattle on inflammation and metabolism in mammary and liver tissue during an intramammary lipopolysaccharide challenge
The objective of this experiment was to examine the effects of supplementation and dose of rumen-protected choline (RPC) on markers of inflammation and metabolism in liver and mammary tissue during an intramammary lipopolysaccharide (LPS) challenge. Parous Holstein cows were blocked by calving month and randomly assigned within block to receive 45 g/d of RPC (20.4 g/d of choline ions; CHOL45), 30 g/d of RPC (13.6 g/d of choline ions; CHOL30), or no RPC (CON) as a top-dress starting 24 d before expected calving until 21 d postpartum.
The use of Lentilactobacillus buchneri PJB1 and Lactiplantibacillus plantarum MTD1 on the ensiling of whole-plant corn silage, snaplage, and high-moisture corn
Experiments were conducted over a 3-year period to evaluate the effects of bacterial inoculants on the fermentation profile and aerobic stability of whole-plant corn silage (WPC), snaplage (SNP), and high-moisture corn (HMC). Whole-plant corn was inoculated with Lentilactobacillus buchneri PJB1 in combination with Lactiplantibacillus plantarum MTD1or with L. plantarum alone (Experiments 1 and 2). Snaplage (Experiment 3) and HMC (Experiments 4 and 5) were inoculated with L. buchneri in combination with L.
Effects of cashew nut-shell extract and monensin on in vitro ruminal fermentation, methane production, and ruminal bacterial community
The objective of this study was to evaluate the effects of cashew nut-shell extract (CNSE) and monensin on ruminal in vitro fermentation, CH4 production, and ruminal bacterial community structure. Treatments were: control (CON, basal diet without additives); 2.5 μM monensin (MON); 100 ppm CNSE granule (CNSE100); and 200 ppm CNSE granule (CNSE200); each incubated with 52 mL buffered ruminal content and 500 mg of total mixed ration for 24 h using serum vials. The experiment was done as a complete randomized block design with 3 runs.
Genetic parameters and genome-wide association studies for mozzarella and milk production traits, lactation length, and lactation persistency in Murrah buffaloes
Genetic and genomic analyses of longitudinal traits related to milk production efficiency are paramount for optimizing water buffaloes breeding schemes. Therefore, this study aimed to: 1) compare single-trait random regression models under a Single-step Genomic Best Linear Unbiased Prediction (ssGBLUP) setting based on alternative covariance functions (i.e., Wood – WD, Wilmink – WL, and Ali-and-Schaeffer – AS) to describe milk (MY), fat (FY), protein (PY), and mozzarella (MZY) yields, fat-to-protein ratio (FPR), somatic cell score (SCS), lactation length (LL), and lactation persistency (LP) in Murrah dairy buffaloes (Bubalus bubalis); 2) combine the best functions for each trait under a multiple-trait framework; 3) estimate time-dependent SNP effects for all the studied longitudinal traits; and, 5) identify the most likely candidate genes associated with the traits.
Effects of two gradual debonding strategies on machine milk yield, flow and composition in a cow-driven cow-calf contact system
This controlled study compared the effects of 2 different gradual debonding strategies on machine milk yield, flow and composition in a cow-driven cow-calf contact (CCC) system with automatic milking. Cows had 24 h/d access to their calves during the first weeks of lactation. In the long debonding (LD) treatment (n = 16), a gradual reduction of cows' access to their calves was initiated 4 weeks after calving over a total period of 28 d; first to 12 h/d (14 d), and then to 6 h/d (14 d). In the short debonding (SD) treatment (n = 14), gradual reduction was initiated 6.5 weeks after calving over a total period of 10 d; first to 12 h/d (5 d), and then to 6 h/d (5 d).
Sirtuin 3 mitigates oxidative-stress-induced apoptosis in bovine mammary epithelial cells
Ketosis is often accompanied by a reduction in milk production in dairy cows, but the molecular mechanism has not been fully elucidated. Ketotic cows possess systemic oxidative stress (OS), which may implicate apoptosis in mammary glands. Sirtuin 3 (SIRT3) is a vital regulator of cellular redox homeostasis and is under the control of AMP-activated protein kinase (AMPK) signaling in nonruminants. Thus, we aimed to investigate (1) the AMPK-SIRT3 and apoptosis status of mammary glands from ketotic cows, (2) the effect of SIRT3 on OS-induced apoptosis in bovine mammary epithelial cells (BMEC), and (3) the role of AMPK signaling on SIRT3-mediated effects on apoptosis.
La FIDOCL et ses partenaires avancent sur le stress thermique
La FIDOCL et les Conseil Elevage à Cournon !
Dietary delivery of glycomacropeptide within the whey protein matrix is not effective in mitigating tissue ceramide deposition and obesity in high fat fed mice
Obesity is often accompanied by heightened circulating and tissue inflammation along with an increase in sphingolipids (e.g., ceramides) in metabolically active and insulin-sensitive organs. Whey protein isolate (WPI) has been shown to decrease inflammation and increase insulin sensitivity when given during a high-fat diet (HFD) intervention in rodents. The whey protein bioactive peptide glycomacropeptide (GMP) has also been linked to having anti-inflammatory properties and regulating lipogenesis.
The therapeutic effects of fermented milk with lactic acid bacteria from traditional Daqu on hypertensive mice
Lactic acid bacteria (LAB), a type of microorganisms widely utilized in functional foods, have gained significant research attention in recent years. Certain strains possess the proteolytic ability to release potentially antihypertensive peptides from dairy proteins, which prompted us to explore the LAB strains from an understudied and unique ingredient, Daqu. We screened for 67 strains of LAB strains from traditional Daqu using the calcium dissolution ring method. Sixteen strains exhibiting ACE inhibition (ACE-I) activity exceeding 50% were chosen for 16S rDNA sequencing and safety assessment.
Peripheral blood mononuclear cell mitochondrial enzyme activity in calves is associated with average daily gain, reproductive outcomes, lactation performance, and survival
Mitochondria are central to metabolism and are the primary energy producers for all biosynthesis. The objective of this study was to determine if the mitochondrial enzyme activity of peripheral blood mononuclear cells in heifers were associated with ADG, reproductive outcomes, first lactation milk production and survival. Twenty-three Holstein and 23 Jersey heifer calves were enrolled, and blood and body weight data were collected at 1, 2, 8, 36, 52 and 110 wk of age. Respiratory and fecal scores were recorded daily for the first 30 d of life.
Functionality of process cheese made from Cheddar cheese with various rennet levels and high-pressure processing treatments
There is growing interest in process cheese in many developing countries due to its versatility and shelf stability. The main structural component (base) of most processed cheese formulations is young Cheddar cheese that has high levels of intact casein (CN). Exporting natural Cheddar cheese base from the US to distant overseas markets would require the aging process to be slowed or reduced. As Cheddar cheese ripens, the original structure is broken down by proteolysis and solubilization of insoluble calcium phosphate.
The marker effects of a single-step random regression model for four test-day traits in German Holstein
Single-step genomic model has become the golden standard for routine evaluation in livestock species, like Holstein dairy cattle. The single-step genomic model with direct estimation of marker effects has been proven to be efficient in accurately accounting for millions of genotype records. For diverse applications including frequent genomic evaluation updates on a weekly basis, estimates of the marker effects from the single-step evaluations play a central role in genomic prediction. In this study we focused on exploring the marker effect estimates from the single-step evaluation.
The impact of automated, constant incomplete milking on energy balance, udder health, and subsequent performance in early lactation of dairy cows
Incomplete milking (IM) is one way of mitigating the negative energy balance (NEB) that is characteristic for early lactation and may increase the risk for disease. Our objectives were to test the effects of IM in early lactation on energy balance (EB), metabolic status, udder health, and subsequent performance. To facilitate the practical application, an automated system was used to remove the milking clusters once a pre-defined amount of milk is withdrawn. Forty-six Holstein cows were equally allocated to either the treatment (TRT, starting on 8 DIM) or the control group (CON; conventional cluster removal at milk flow rate <0.3 kg/min).
Effect of dipotassium phosphate addition and heat on proteins and minerals in milk protein beverages.
Our objective was to determine the effects of dipotassium phosphate (DKP) addition, heat treatments (no heat, HTST: 72°C for 15 s, and direct steam injection UHT: 142°C for 2.3 s), and storage time on the soluble protein composition and mineral (P, Ca, K) concentration of the aqueous phase around casein micelles in 7.5% milk protein-based beverages made with liquid skim milk protein concentrate (MPC) and micellar casein concentrate (MCC). MPC was produced using a spiral wound polymeric membrane and MCC was produced using a 0.1µ ceramic membrane by filtration at 50°C.
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