title: The effect of incomplete milking or nursing on milk production, blood metabolites, and immune functions of dairy cows.
abstract: During the transition from pregnancy to lactation, the sudden increase in nutrient demand for milk production causes metabolic perturbations and is associated with immunosuppression and a high incidence of metabolic and infectious diseases in high-yielding cows. In this study, we examined whether limiting milk harvest postpartum while maintaining milking stimulus could improve the metabolic status of cows without reducing overall milk production. Forty-seven Holstein cows were milked completely twice a day from calving (control); milked incompletely (about one-third of expected milk production was collected) twice a day until d 5 after calving (incomplete); or left to nurse their calf until d 5 and milked once a day from d 3 to d 5 (nursing). All cows were milked twice a day from d 6 to the end of the experiment (d 61). During the treatment period (d 1 to 5), milk production averaged 27.3 and 9.7 kg/d for the control and incomplete treatments, respectively. We observed no residual effect of treatment on milk production, which averaged 47.8, 45.7, and 46.4 kg/d for the control, incomplete, and nursing treatments, respectively, between wk 2 and 9. The dry matter intake of the cows was similar during and after treatment. From wk 2 to 9, milk protein and lactose percentage were not affected by treatments, but milk fat tended to be higher in control cows than in cows milked partially (incomplete + nursing). Blood concentrations of glucose and phosphorus were lower and concentrations of nonesterified fatty acids and β-hydroxybutyrate were higher in control cows than in partially milked cows during the treatment period. The positive effects on glucose and β-hydroxybutyrate remained significant up to d 28. Peripheral blood mononuclear cell (PBMC) proliferation and secretion of IL-4 were depressed during the postpartum period, and proliferation tended to be greater for cells incubated in serum from cows in the incomplete treatment on d 5 but lower on d 61. We observed no effect of treatments on polymorphonuclear neutrophilic leukocyte chemotaxis or phagocytosis. Proliferation and IL-4 secretion of PBMC were negatively correlated with concentration of serum nonesterified fatty acids. Reducing milk harvest postpartum while maintaining milking stimuli reduced metabolic stress without compromising productivity of high-yielding dairy cows.
authors.affiliation: Département de Biologie, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada, J1K 2R1.
authors.forename: E
authors.initials: E
authors.lastname: Carbonneau
authors.forename: A M
authors.initials: AM
authors.lastname: de Passillé
authors.forename: J
authors.initials: J
authors.lastname: Rushen
authors.forename: B G
authors.initials: BG
authors.lastname: Talbot
authors.forename: P
authors.initials: P
authors.lastname: Lacasse
mesh_terms: D020155:3-Hydroxybutyric Acid / Q000097:blood; D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D002417:Cattle / Q000097:blood / Q000276:immunology / Q000502:physiology*; D003612:Dairying / Q000379:methods*; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D006854:Hydrocortisone / Q000097:blood; D015847:Interleukin-4 / Q000097:blood; D007774:Lactation / Q000097:blood / Q000276:immunology / Q000502:physiology*; D007785:Lactose / Q000032:analysis; D008892:Milk / Q000737:chemistry / Q000378:metabolism; D008894:Milk Proteins / Q000032:analysis; D009504:Neutrophils / Q000276:immunology; D010758:Phosphorus / Q000097:blood; D049590:Postpartum Period / Q000097:blood / Q000502:physiology; D011247:Pregnancy; D014508:Urea / Q000097:blood
chemical_list: D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D008894:Milk Proteins; D015847:Interleukin-4; D010758:Phosphorus; D014508:Urea; D007785:Lactose; D020155:3-Hydroxybutyric Acid; D006854:Hydrocortisone