Agrégateur de flux
Un modèle de développement humainement usant
Le prix du lait à travers le monde en octobre 2018
Agrial renforce sa position sur le marché du fromage allemand
L'Europe donne les pleins pouvoirs aux organismes de sélection
Sans OGM : le standard de demain ?
Comment choisir ses variétés de maïs 2019?
C'est le moment de choisir ses varietes de mais fourrage pour 2019, premiere etape importante de l'itineraire technique. Choisir une precocite adaptee a son contexte est un premier pas vers la qualite. Valoriser le progres genetique est aussi un axe prioritaire pour des cultures rentables et un atout pour des elevages performants.
L'affouragement en vert a un coût
La sécheresse va peser lourd sur les trésoreries
Fonterra baisse son prix du lait prévisionnel
Symposium review: Intravital imaging of the lactating mammary gland in live mice reveals novel aspects of milk-lipid secretion
Milk fat comprises membrane-coated droplets of neutral lipid, which constitute the predominant source of lipids for survival of the suckling neonate. From the perspective of the dairy industry, they are the basis for the manufacture of butter and essential ingredients in the production of cheese, yogurt, and specialty dairy produce. To provide mechanistic insight into the assembly and secretion of lipid droplets during lactation, we developed novel intravital imaging techniques using transgenic mice, which express fluorescently tagged marker proteins.
The effect of the transition period and postpartum body weight loss on macrophage infiltrates in bovine subcutaneous adipose tissue
The transition period in dairy cattle is characterized by a rapid increase in metabolic demands due to the onset of lactation in parallel with a voluntary drop in dry matter intake, which slowly increases compared with the rapidly increasing milk production. The resulting deficit in energy intake is largely met by lipolysis of adipose tissue stores liberating nonesterified fatty acids (NEFA) as energy substrates to support milk production and for the synthesis of milk fat. Previous work in cattle and other species has documented an increase in adipose tissue macrophages (ATM) during periods of feed restriction and lipolysis; however, alterations in ATM during the transition period have only recently received interest because of the role that adipose tissue remodeling and inflammation may play during this time.
Hypertonic milk replacers increase gastrointestinal permeability in healthy dairy calves
Hypertonic milk replacers are commonly used in animal production systems and their effect on the gastrointestinal system of young animals is insufficiently studied. Total lactose inclusion or its partial replacement with dextrose increases intestinal osmotic pressure, which may compromise gastrointestinal barrier function. In this experiment, we investigated the effect of increased osmolality of calf milk replacer (CMR) on gastrointestinal permeability in 30 Holstein Friesian (n = 17) or crossbred (n = 13) bull calves.
Efficient and accurate computation of base generation allele frequencies
Allele frequencies are used for several aspects of genomic prediction, with the assumption that these are equal to the allele frequency in the base generation of the pedigree. The current standard method, however, calculates allele frequencies from the current genotyped population. We compared the current standard method with BLUP and general least squares (GLS) methods explicitly targeting the base population to determine whether there is a more accurate and still efficient method of calculating allele frequencies that better represents the base generation.
Probiotic Lactobacillus gasseri SBT2055 improves insulin secretion in a diabetic rat model
The probiotic Lactobacillus gasseri SBT2055 (LG2055) has a protective effect against metabolic syndrome in rats and humans. Metabolic syndrome increases the risk of type 2 diabetes mellitus. In this study, Goto-Kakizaki rats were used as a diabetic model and fed diets containing LG2055-fermented or nonfermented skim milk for 4 wk. Indices of diabetes such as blood glucose levels, serum glucagon levels, plasma levels of insulin, C-peptide, and glucagon-like peptide-1, tissue glycogen contents, and pancreatic mRNA levels were measured.
The effects of relative gain and age on peripheral blood mononuclear cell mitochondrial enzyme activity in preweaned Holstein and Jersey calves
Mitochondria are central to metabolism, nutrition, and health, but many factors can influence their efficiency. The objectives of this study were to determine if the mitochondrial enzyme activities of citrate synthase, complex I, complex IV, and complex V from peripheral blood mononuclear cells in Holstein and Jersey dairy calves were affected by age or relative gain as a percent of initial weight. Twenty-three Holstein and 23 Jersey heifer calves were enrolled between 3 and 6 d of age and whole blood samples were collected via jugular venipuncture at 1, 2, and 8 wk of age.
Genetics and genomics of reproductive disorders in Canadian Holstein cattle
In Canada, reproductive disorders known to affect the profitability of dairy cattle herds have been recorded by producers on a voluntary basis since 2007. Previous studies have shown the feasibility of using producer-recorded health data for genetic evaluations. Despite low heritability estimates and limited availability of phenotypic information, sufficient genetic variation has been observed for those traits to indicate that genetic progress, although slow, can be achieved. Pedigree- and genomic-based analyses were performed on producer-recorded health data of reproductive disorders, including retained placenta (RETP), metritis (METR), and cystic ovaries (CYST) using traditional BLUP and single-step genomic BLUP.
Evaluation of a filter system to harvest plasma for identification of failure of passive transfer in newborn calves
The objective of this study was to evaluate a filter system to harvest plasma to assess failure of passive transfer (FPT) in newborn calves. Blood samples (n = 227) for serum and plasma harvesting were collected via jugular vein puncture from Holstein calves aged 1 to 7 d from 4 commercial dairy herds in Northeast Germany. Serum IgG concentrations were determined using a sandwich ELISA. Failure of passive transfer was defined as IgG concentrations <10 mg/mL and used as a gold standard. One handheld optical refractometer (Euromex Holland, Arnhem, the Netherlands) and 2 digital Brix refractometers (device 1: HI 96801 digital refractometer, Hanna Instruments, Woonsocket, RI; device 2: Misco PA201, Misco, Solon, OH) were used to analyze total proteins in serum or plasma.
Expression patterns of hepatic genes involved in lipid metabolism in cows with subclinical or clinical ketosis
Dairy cows with ketosis are characterized by high blood concentrations of ketone bodies and hepatic lipid metabolism disorder. The discrepancies in the abundance of mRNA encoding a variety of hepatic candidate genes in varying degrees of ketotic cows represent specific responses of the liver to the challenge of fatty acids and ketone bodies. Importantly, the expression disorder of hepatic genes involved in lipid metabolism plays a promoting role in the onset and progression of ketosis. Thus, the aim of this study was to investigate the expression patterns of genes involved in the hepatic fatty acids uptake, transport, activation, β-oxidation, synthesis, and esterification in the cows with subclinical ketosis (SCK) or clinical ketosis (CK).
Evaluation of tetracycline in milk following extra-label administration of topical tetracycline for digital dermatitis in dairy cattle
Digital dermatitis (DD) is a painful infectious foot lesion commonly treated topically with extra-label tetracycline. Our objectives were to determine the concentrations of tetracycline in milk and plasma and to calculate a withdrawal interval following topical application at various doses. Another objective was to evaluate agreement between tests for measuring tetracycline in milk. A randomized block trial was conducted on 2 farms, where 50 cows with active DD lesions on 2 feet were allocated to 1 of 5 treatment groups (n = 10 cows per group).
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