title: Effects of dry period length and dietary energy source on metabolic status and hepatic gene expression of dairy cows in early lactation.
abstract: In a prior study, we observed that cows with a 0-d dry period had greater energy balance and lower milk production compared with cows with a 30- or 60-d dry period in early lactation. The objective of the current study was to evaluate the influence of dry period length on metabolic status and hepatic gene expression in cows fed a lipogenic or glucogenic diet in early lactation. Holstein-Friesian dairy cows (n=167) were assigned randomly to 3×2 factorial design with 3 dry period lengths (n=56, 55, and 56 for 0-, 30-, and 60-d dry, respectively) and 2 early lactation diets (n=84 and 83 for glucogenic and lipogenic diet, respectively). Cows were fed a glucogenic or lipogenic diet from 10d before the expected calving date and onward. The main ingredient for a glucogenic concentrate was corn, and the main ingredients for a lipogenic concentrate were sugar beet pulp, palm kernel, and rumen-protected palm oil. Blood was sampled weekly from 95 cows from wk 3 precalving to wk 8 postcalving. Liver samples were collected from 76 cows in wk -2, 2, and 4 relative to calving. Liver samples were analyzed for triacylglycerol concentrations and mRNA expression of 12 candidate genes. Precalving, cows with a 0-d dry period had greater plasma β-hydroxybutyrate, urea, and insulin concentrations compared with cows with a 30- or 60-d dry period. Postcalving, cows with a 0-d dry period had lower liver triacylglycerol and plasma nonesterified fatty acids concentrations (0.20, 0.32, and 0.36mmol/L for 0-, 30-, and 60-d dry period, respectively), greater plasma glucose, insulin-like growth factor-I, and insulin (24.38, 14.02, and 11.08µIU/mL for 0-, 30-, and 60-d dry period, respectively) concentrations, and lower hepatic mRNA expression of pyruvate carboxylase, compared with cows with a 30- or 60-d dry period. Plasma urea and β-hydroxybutyrate concentrations were greater in cows fed a lipogenic diet compared with cows fed a glucogenic diet. In conclusion, cows with a 0-d dry period had an improved metabolic status in early lactation, indicated by lower plasma concentrations of nonesterified fatty acids, greater plasma concentrations of glucose, insulin-like growth factor-I, and insulin, and lower mRNA expression of pyruvate carboxylase in the liver, compared with cows with a 30- or 60-d dry period. Independent of dry period length, the glucogenic diet also improved the metabolic status compared with the lipogenic diet.
authors.affiliation: Adaptation Physiology Group, Department of Animal Science, Wageningen University, PO Box 338, 6700 AH Wageningen, the Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: Chen
authors.affiliation: Veterinary Physiology, Vetsuisse Faculty, University of Bern, Bremgartenstrasse 109a, CH-3001 Bern, Switzerland.
authors.forename: J J
authors.initials: JJ
authors.lastname: Gross
authors.affiliation: Veterinary Physiology, Vetsuisse Faculty, University of Bern, Bremgartenstrasse 109a, CH-3001 Bern, Switzerland.
authors.forename: H A
authors.initials: HA
authors.lastname: van Dorland
authors.affiliation: Livestock Research, Wageningen University and Research Centre, PO Box 65, 8200 AB Lelystad, the Netherlands.
authors.forename: G J
authors.initials: GJ
authors.lastname: Remmelink
authors.affiliation: Veterinary Physiology, Vetsuisse Faculty, University of Bern, Bremgartenstrasse 109a, CH-3001 Bern, Switzerland.
authors.forename: R M
authors.initials: RM
authors.lastname: Bruckmaier
authors.affiliation: Adaptation Physiology Group, Department of Animal Science, Wageningen University, PO Box 338, 6700 AH Wageningen, the Netherlands.
authors.forename: B
authors.initials: B
authors.lastname: Kemp
authors.affiliation: Adaptation Physiology Group, Department of Animal Science, Wageningen University, PO Box 338, 6700 AH Wageningen, the Netherlands. Electronic address: Ariette.vanKnegsel@wur.nl.
authors.forename: A T M
authors.initials: AT
authors.lastname: van Knegsel
mesh_terms: D020155:3-Hydroxybutyric Acid / Q000378:metabolism; D000821:Animal Feed / Q000032:analysis*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001786:Blood Glucose; D002417:Cattle / Q000502:physiology*; D004032:Diet / Q000662:veterinary*; D004734:Energy Metabolism / Q000187:drug effects* / Q000502:physiology; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D005947:Glucose / Q000378:metabolism; D007328:Insulin / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D007774:Lactation / Q000502:physiology*; D008099:Liver / Q000378:metabolism*; D008892:Milk / Q000378:metabolism; D011766:Pyruvate Carboxylase / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012417:Rumen / Q000378:metabolism; D013997:Time Factors
chemical_list: D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D007328:Insulin; D012333:RNA, Messenger; D007334:Insulin-Like Growth Factor I; D011766:Pyruvate Carboxylase; D005947:Glucose; D020155:3-Hydroxybutyric Acid
keywords: continuous milking; energy metabolism; glucogenic diet; lipogenic diet; liver