Effects of DGAT1 K232A polymorphism and milking frequency on milk composition and spontaneous lipolysis in dairy cows

Autor: Jocelyne Guinard-Flament, Elise Vanbergue, Jean-Louis Peyraud, Catherine Hurtaud, Yves Gallard, C. Charton, S. Barbey, Rachel Lefebvre
Přispěvatelé: Physiologie, Environnement et Génétique pour l'Animal et les Systèmes d'Elevage [Rennes] (PEGASE), Institut National de la Recherche Agronomique (INRA)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Génétique Physiologie et Systèmes d'Elevage (GenPhySE ), École nationale supérieure agronomique de Toulouse [ENSAT]-Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Vétérinaire de Toulouse (ENVT), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Domaine expérimental animal du Pin (SEA), Institut National de la Recherche Agronomique (INRA), Génétique Animale et Biologie Intégrative (GABI), Institut National de la Recherche Agronomique (INRA)-AgroParisTech
Rok vydání: 2016
Předmět:
0301 basic medicine
medicine.medical_specialty
Lipolysis
[SDV]Life Sciences [q-bio]
Glyceride
Biology
medicine.disease_cause
Milking
once-daily milking
03 medical and health sciences
Animal science
Internal medicine
milk composition
Genotype
Genetics
medicine
Animals
Lactation
[INFO]Computer Science [cs]
Diacylglycerol O-Acyltransferase
DGAT1
chemistry.chemical_classification
[SDV.GEN]Life Sciences [q-bio]/Genetics
Lipoprotein lipase
Polymorphism
Genetic
dairy cow
0402 animal and dairy science
Environmental factor
Caseins
food and beverages
Fatty acid
spontaneous lipolysis
04 agricultural and veterinary sciences
040201 dairy & animal science
[SDV.GEN.GA]Life Sciences [q-bio]/Genetics/Animal genetics
Milk
030104 developmental biology
Endocrinology
Enzyme
chemistry
Cattle
Female
Animal Science and Zoology
Food Science
Zdroj: Journal of Dairy Science
Journal of Dairy Science, American Dairy Science Association, 2016, 99 (7), pp.5739-5749. ⟨10.3168/jds.2015-10731⟩
ISSN: 0022-0302
DOI: 10.3168/jds.2015-10731
Popis: International audience; Milk spontaneous lipolysis (SL) of milk triglycerides is induced by the lipoprotein lipase, a milk native enzyme, and leads to an accumulation of partial glycerides and free fatty acids that are responsible for the deterioration of the taste of milk products. The gene coding for diacylglycerol acyltransferase 1 (DGAT1), an enzyme implicated in triglycerides synthesis, has an important polymorphic site at the K232A locus. This gene is well known to modulate milk composition. No data are available on the effects of DGAT1 on SL. Thus, a trial was carried out to evaluate the effects of DGAT1 K232A polymorphism on milk SL upon milking frequency variations [once- (ODM) and twice-daily milking (TDM)]. Twenty-one cows were divided into 3 groups according their DGAT1 K232A genotype: 8 cows had the KK genotype of DGAT1 (KK cows), 8 had the KA genotype (KA cows), and 5 had the AA genotype (AA cows). The trial consisted in 3 successive periods: 3 wk of TDM, 3 of ODM, and 4 of TDM. Samples were collected for fat and protein contents, SL, fatty acid, and protein profiles determinations. The KK cows presented higher fat and protein contents, lower milk production, and higher κ-casein percentage. No significant difference in fatty acid composition was noted between groups. The SL was twice as high for KK cows in TDM situations (1.13 vs. 0.59 and 0.63 mEq/100 g of fat, respectively, for KK, KA, and AA cows during the first period of TDM, and 0.46 vs. 0.25 and 0.21 mEq/100 g of fat, respectively, for KK, KA, and AA during the second period of TDM). The SL remained sharply lower in TDM2 than in TDM1. During ODM, no difference in SL was found between groups and SL remained below 0.2 mEq/100 g of fat. These results demonstrate the existence of a correlation between DGAT1 genotypes and spontaneous lipolysis, in interaction with an environmental factor, milking frequency, although it has not been possible to clarify the causal mechanism at this stage.
Databáze: OpenAIRE
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