| Abstrakt: |
We have previously reported that corn-dried distiller's grains plus solubles (DDGS) supplementation to low quality forage during late gestation results in a tendency for heavier calves at birth and larger weaning weights compared to no DDGS (CON). To investigate if birth and weaning weight differences were due to metabolite or hormonal status, calf blood samples were collected during early life. Multiparous beef cows (n= 27; 674 ± 17 kg) were divided randomly into 2 pens equipped with Insentec feeders to monitor individual intake of corn stover and silage. For 10 wk, both treatment groups were fed the basal diet for ad libitum intake while one group was supplemented (SUP; n= 12) with DDGS at 0.3% of BW during the last third of gestation. Following parturition, all cows received the same diet for an additional 8 wk. At calving (0 and 24 h) and weekly for 56 d, blood samples were obtained from calves for analysis of NEFA, urea, glucose, cortisol, thyroxine (T4) and triiodothyronine (T3). From 0 to 24 h, NEFA concentrations did not differ between treatment groups, but were greater at 0 h (571 vs. 366 ± 40 µM, P< 0.01). Neither urea nor cortisol differed by treatment or hour at 0 and 24 h, however, treatment interacted with time for glucose, where SUP calves had the greatest concentration at 24 h (6.83 ± 0.32 mM). Glucose decreased from birth onward (P< 0.01), with treatments beginning to separate near d 56. Both T3and T4decreased (P< 0.01) from birth to d 56. Neither NEFA nor cortisol differed (P≥ 0.95, P≥ 0.35, respectively) by day or treatment. Urea was influenced by day (P= 0.06), but with little overall deviation from concentrations at birth. While there was no impact of diet on dystocia (P= 0.39), calves from SUP cows were heavier (P= 0.01) at birth than CON calves, which may have impacted their greater glucose concentration at 24 h. It appears that heavier weaning weights observed in calves from SUP cows were not influential on the measured metabolites and hormone profiles at birth and through early life. |
