Abstract #W250

# W250
Effects of different feeding intensities during the first weeks of rearing on the metabolic status and on the circulating concentrations of adiponectin in dairy calves until 110 days of age.
Julia Kesser1, Miriam Hill1,2, Christian Koch2, Marion Piechotta3, Jürgen Rehage3, Klaus Eder4, Hassan Sadri1, Ute Müller1, Helga Sauerwein*1, 1Physiology and Hygiene Group, Institute for Animal Science, University of Bonn, Bonn, Germany, 2Lehr- und Versuchsanstalt Neumühle, Münchweiler an der Alsenz, Germany, 3Clinic for Cattle, University of Veterinary Medicine Hannover, Hannover, Germany, 4Animal Nutrition, University of Giessen, Gießen, Germany.

Dairy calves are commonly reared at restrictive levels of feeding, but greater allowances of feed intake may yield beneficial effects for both animal welfare and later milk production. We aimed to test the hypothesis that different feeding levels in early life will continue to affect the circulating concentrations of metabolically relevant hormones beyond the time of differential feeding. After receiving colostrum for the first 3 d of life, 57 German Holstein calves were randomly allocated to 3 groups fed either restrictively (r) with milk replacer (MR) (group MRr: 130 g MR/L, 6 L/d, n = 20), or MR ad libitum (al) (MRal: 160 g MR/L, n = 17) or whole milk (MI) al (MIal, n = 20). All calves received colostrum from their dams for the first 3 d of life, and were then fed according to their group regimen from d 1 – 27 (phase (P) 1). Thereafter all calves were fed according to the MRr plan and were gradually weaned from d 56 - 70 (P2). Calves were further observed for the subsequent P3, i.e., d 71 – 109. All calves had free access to hay, water and concentrate and received a TMR in P3. Blood samples were collected on d 0 (before colostrum feeding), and on 10 other d covering P1-P3 to assess the concentrations of glucose, NEFA, leptin and adiponectin (bovine specific ELISA). Data were analyzed using the linear mixed model (SPSS). Differences (P < 0.05) between the groups were largely limited to the time of differential feeding (P1): glucose was greater in Mlal than in MR fed groups (glucose: 1.1-fold), insulin was greater in MRal and MIal than in MRr (2.3-fold), whereas NEFA were lower in MRal than in MRr (0.65-fold). Leptin was not different between the groups at any time. Adiponectin concentrations did not differ between groups in P1, but tended (P < 0.1) to lower values in MRr as compared with MRal and Mlal in P2. In P3 the MRal group had higher values (P < 0.05) than MRr and MIal, thus supporting continued effects of the differential feeding. In view of the insulin-sensitizing effects of adiponectin, feeding intensity in early life might thus affect insulin sensitivity at older ages.

Key Words: adiponectin, dairy calves, insulin sensitivity