Bucket-Fed, Automate-Fed and Calves Suckling on Their Dams: Effects of Feeding Colostrum and Milk with Different Frequency and Intensity

Colostrum (C) provides high amounts of nutrient and non-nutrient substances, which are important for health and development of neonatal calves. To study the effects of different feeding frequency and intensity of C and milk on growth performance, metabolic and endocrine traits during the first month of life calves (n = 7, respectively) were fed twice daily by bucket (GrBR), restricted amounts (GrAR; pair-fed with GrBR) or unlimited amounts (GrAL) several times per d with an automate, or were suckling their dams (GrSL). Calves fed by bucket or automate received C powder for 3 d, then milk powder (d 4 – d 14) and milk up to d 28. In groups fed by automate software was available to continuously register the time points and amounts of ingested feed up to the age of 11 d. Body weight (BW) was measured immediately after birth and then once weekly. Blood samples were taken on d 1, 2, 3, 7, 14, 21 and 28 after birth. Plasma concentrations of total protein (TP), IgG, albumin, urea, glucose, NEFA and triglycerides were measured photometrically. Plasma concentrations of insulin, glucagon and insulin-like growth factor-I (IGF-II) and growth hormone (GH) were measured by radioimmunoassay. Data were evaluated by analysis of variance using a mixed model with treatment and time as fixed effects and the individual calves as random effects. Preprandial triglyceride concentrations on d 7 were higher (P < 0.05) in GrAR than in GrBR. Insulin concentrations on d 7 tended to be higher (P < 0.1) in GrAR than in GrBR. Concentrations of GH on d 7 were higher (P < 0.05) from 120 to 140 min and were lower (P < 0.05) from 240 to 360 min after start of feeding in GrAR than GrBR. Concentrations of IGF-I were higher (P < 0.05) on d 7, 14, and 28 in GrAR than in GrBR. There were no significant differences in growth performance during the first month of life compared with GrBR. In GrAL dry matter intakes and meal sizes per visit were higher (P < 0.05), but total visits (with and without milk intake) at the automat were lower (P < 0.05) than in GrAR. Feed intake in GrAL increased (P < 0.05) up to d 4, then remained stable and was always higher (P < 0.05) than in GrAR. Weight gain was greater (P < 0.05) in GrAL than GrAR in wk 1, but metabolic and endocrine differences were small in the first week of life. In GrSL concentrations of TP and IgG were higher (P < 0.05) during the whole study and albumin concentrations were higher (P < 0.05) in the first 2 wk of life than in GrAL. Urea concentrations were lower (P < 0.05) on d 3 and 21 in GrSL than in GrAL. On d 3, triglyceride, glucose and insulin concentrations were higher (P < 0.01), whereas concentrations of glucagon and GH were lower (P < 0.05) in GrSL than in GrAL. Growth performance during the first three weeks of life was comparable in GrAL and GrSL, and only slightly increased in GrSL at the end of the first month of life. In conclusion, high feeding frequency and suckling improved the metabolic and endocrine status, but barely affected growth performance. In contrast, unlimited feed intake at the automat enhanced growth performance, but barely influenced the metabolic status.