Agrégateur de flux

Characterization of a novel flavored yogurt enriched in γ-aminobutyric acid fermented by Levilactobacillus brevis CGMCC1.5954

Journal of Dairy Science -

This study developed and characterized a γ-aminobutyric acid (GABA)-enriched yogurt fermented by Levilactobacillus brevis CGMCC1.5954. The GABA content in the yogurt was 147.36 mg/100 mL, which was 317.06% higher than that of the control group. Furthermore, there was a significant improvement in the aroma, hardness, adhesion, cohesiveness, and gelatinousness of yogurt. The chromatography and metabolomics analyses further confirmed the high GABA content in yogurt and its nutritional value, and the metabolic pathway for GABA production by L.

Regression trees to identify combinations of farming practices that achieve the best overall intrinsic quality of milk

Journal of Dairy Science -

Many studies over the last 30 years have shown the effects of farming practices on milk compounds. Combinations of practices may have antagonistic or synergistic effects on milk compounds, but these combination effects remain underinvestigated. Research needs to focus on overall intrinsic milk quality (including sensory, technological, health, and nutritional dimensions) and identify the combinations that can optimize it. The aim of this study was to identify which combinations of farming practices achieved the best scores for sensory, technological, health, and nutritional dimensions and for overall intrinsic milk quality.

Comparison of 2 types of milk flow meters for detecting bimodality in dairy cows

Journal of Dairy Science -

The primary objective of this observational study was to investigate whether incremental milk flow rates (in the 0–15 s, 15–30 s, 30–60 s, and 60–120 s intervals) from electronic on-farm milk flow meters can be used to detect bimodal milk flow curves in dairy cows compared with the use of a portable milk flow meter. Our second objective was to study the concordance between an electronic on-farm milk flow meter and a portable milk flow meter for assessing the 2-min milk yield and total milk yield.

Evaluation of reticuloruminal temperature for the prediction of clinical mastitis in dairy cows challenged with Streptococcus uberis

Journal of Dairy Science -

Automated monitoring devices have become increasingly utilized in the dairy industry, especially for monitoring or predicting disease status. While multiple automated monitoring devices have been developed for the prediction of clinical mastitis (CM), limitations in performance or applicability remain. The aims of this study were to (1) detect variations in reticuloruminal temperature (RRT) relative to an experimental intramammary challenge with Streptococcus uberis and (2) evaluate alerts generated automatically based on variation in RRT to predict initial signs of CM in the challenged cows based on severity of clinical signs and the concentration of bacteria (cfu/mL) in the infected quarter separately.

Effect of animal activity and air temperature on heat production, heart rate, and oxygen pulse in lactating Holstein cows

Journal of Dairy Science -

A linear relationship between heart rate (HR) and oxygen consumption (VO2) has been reported in homeothermic animals, indicating that is possible to estimate heat production through HR measurements. This relationship may depend on the animal activity and environmental conditions. The main objective of the present study was to evaluate the effect of the air temperature and animal posture and activity on heat production and VO2 in relation to HR. In addition, as a secondary objective, the energy cost of eating and ruminating versus idling and standing versus lying down was determined.

A meta-analysis of effects of 3-nitrooxypropanol on methane production, yield, and intensity in dairy cattle

Journal of Dairy Science -

Ruminants, particularly dairy and beef cattle, contribute to climate change through mostly enteric methane emissions. Several mitigating options have been proposed, including the feed additive 3-nitrooxypropanol (3-NOP). The objectives of this study were to explain the variability in the mitigating effect of 3-NOP and to investigate the interaction between diet composition and 3-NOP dose, using meta-analytical approaches. Data from 13 articles (14 experiments) met the selection criteria for inclusion in the meta-analysis, and 48 treatment means were used for the analysis.

Changes in genetic trends in US dairy cattle since the implementation of genomic selection

Journal of Dairy Science -

Genomic selection increases accuracy and decreases generation interval, accelerating genetic changes in populations. Assumptions of genetic improvement must be addressed to quantify the magnitude and direction of change. Genetic trends of US dairy cattle breeds were examined to determine the genetic gain since the implementation of genomic evaluations in 2009. Inbreeding levels and generation intervals were also investigated. Breeds included Ayrshire, Brown Swiss, Guernsey, Holstein (HO), and Jersey (JE), which were characterized by the evaluation breed the animal received.

Decision-support tool for global allocation of dairy sire semen based on regional demand, supply constraints, and genetic profiles

Journal of Dairy Science -

An artificial insemination (AI) company seeks to allocate semen units globally by balancing perceived demand with uncertain product supply, in what is an arduous subjective process. This study aimed to objectivize this process by providing a user-friendly linear programming model to allocate bulls' semen units to regions for the next trimester sales period based on maximum revenue, and to describe the features and outcomes of this model when applied to a sample bull herd and global demand scenario reflective of a leading AI company.

Sirtuin 3 relieves inflammatory responses elicited by lipopolysaccharide via the PGC1α-NFκB pathway in bovine mammary epithelial cells

Journal of Dairy Science -

Excessive inflammation in bovine mammary endothelial cells (BMEC) due to mastitis leads to disease progression and eventual culling of cattle. Sirtuin 3 (SIRT3), a mitochondrial deacetylase, downregulates pro-inflammatory cytokines in BMEC exposed to high concentrations of nonesterified fatty acids by blunting nuclear factor-κB (NFκB) signaling. In nonruminants, SIRT3 is under the control of PGC1α, a transcriptional cofactor. Specific aims were to study (1) the effect of SIRT3 on inflammatory responses of lipopolysaccharide (LPS)-challenged bovine mammary epithelial cells (bovine mammary alveolar cells-T, MAC-T) models, and (2) the role of PGC1α in the attenuation of NFκB signaling via SIRT3.

Feeding behavior in relation to ovarian cyclicity in cows with no or a short dry period

Journal of Dairy Science -

The objective of this study was to investigate relations between feeding behavior (FB) variables focusing on intake of the basal ration during 3 wk prepartum until 3 wk postpartum, and postpartum onset of luteal activity (OLA) in dairy cows subjected to no (0-d) or a short (30-d) dry period (DP). Feeding behavior of the basal ration intake (concentrate intake excluded) was continuously recorded by computerized feeders for 123 dairy cows and analyzed from 3 wk prepartum to 3 wk postpartum. Cows were subjected to a DP length: 0-d DP (n = 81), or 30-d DP (n = 42).

Effects of corn silage supplementation strategy and grazing intensity on herbage intake, milk production, and behavior of dairy cows

Journal of Dairy Science -

Effects of corn silage supplementation on milk production of grazing dairy cows depend in part on the substitution rate between the 2 forages, which may be influenced by grazing management. The aim of this study was to compare 2 grazing management strategies for measuring substitution rate between herbage and corn silage, in interaction with grazing intensity. Six treatments were compared, with 2 grazing intensities and 3 supplementation strategies investigated at both grazing intensities. The 2 grazing intensities were severe and light grazing, defined by either (1) herbage allowance (HA) of 15 (severe) or 30 (light) kg dry matter (DM)/cow per d at 3 cm above ground level or (2) postgrazing sward height, depending on the supplementation strategy.

Grazing season length and stocking rate affect milk production and supplementary feed requirements of spring-calving dairy cows on marginal soils

Journal of Dairy Science -

The objective of this study was to investigate the effect of increasing stocking rate (SR) and extending grazing season (GS) length on pasture and animal productivity on a marginal, poorly draining soil type. The study was a multiyear (2017 to 2020, inclusive) whole farm systems evaluation with a 2 × 2 factorial experimental arrangement of treatments. The systems evaluated comprised 2 GS lengths, average (AGS; 205 d) and extended (EGS; 270 d), and the 2 whole farm stocking rates were medium (2.5 cows/ha) and high (2.9 cows/ha).

INTERPRETIVE SUMMARIES, DECEMBER 2022

Journal of Dairy Science -

Invited review: Current enteric methane mitigation options. By Beauchemin et al., page 9297. Mitigation of enteric methane production from ruminants is important to rapidly curb global warming. Here, we review and analyze the current stage of implementation and barriers for adoption of various strategies to reduce enteric methane emissions. We identify and discuss opportunities, obstacles, and research needs for the adoption of different enteric methane mitigation strategies in intensive and extensive production systems.

2022 Fellows of the American Dairy Science Association®

Journal of Dairy Science -

The 2022 elected fellows were recognized at the Awards Program of the American Dairy Science Association held on June 21, 2022. Election to Fellow is one of the highest honors that the Association bestows. The Fellow Award recognizes ADSA members for their distinguished service to the dairy industry for 20 years or more. Each nominee must have made exceptional contributions to the dairy industry, to a dairy-related discipline, or to ADSA; must have had professional membership in ADSA for a minimum of 20 years; and must be in good standing with the Association.

ADSA® Presidential Report

Journal of Dairy Science -

As the past president of ADSA, I can think of no better adjective to describe the past year than “momentous,” a year of great consequence. I vividly recall the deep contentment that I felt at the 2022 Annual Meeting when I officially handed over the baton of the ADSA presidency to the incoming president; so much had been accomplished, and the association is positioned to accomplish so much more. Today, there is no question in my mind that the current ADSA leadership team, headed by President Normand St.

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