|Foote, Monica -|
|Miller, B -|
|Beitz, Donald -|
Submitted to: Journal of Dairy Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 12, 2010
Publication Date: June 20, 2010
Citation: Nonnecke, B.J., Foote, M.R., Miller, B.L., Beitz, D.C., Horst, R.L. 2010. Short Communication: Fat-Soluble Vitamin and Mineral Status of Milk Replacer-Fed Dairy Calves: Effect of Growth Rate during the Preruminant Period. Journal of Dairy Science. 93(6):2684-2690. Interpretive Summary: Growth-rate during the preruminant phase of development influences not only body composition and health of the milk replacer-fed calf but may also enhance later-in-life productivity. The present study evaluated the effects of three rates of gain [No-Growth (NG) = 0.11 kg/d; Low-Growth (LG) = 0.58 kg/d; or High-Growth (HG) = 1.16 kg/d] on fat-soluble vitamin and mineral status of milk replacer-fed calves over a 7-week period. Of the vitamins examined, only the availability of vitamin E, an essential antioxidant, appeared to be affected by growth rate. Vitamin E concentrations in HG calves were markedly lower than concentrations in LG and NG calves suggesting that the level of vitamin E in diets of calves on nutritional programs promoting high-growth rates needs to be re-evaluated. Copper, calcium, and phosphorous concentrations in the blood of HG calves exceeded concentrations in LG and NG calves during latter weeks of the study, likely due to increased consumption of milk replacer by HG calves. Vitamin and mineral concentrations for calves in all treatment groups remained within normal ranges for young dairy calves.
Technical Abstract: Effects of growth rate on fat-soluble vitamin and macro-/micro-mineral concentrations in the circulation of preruminant dairy calves were evaluated. Dietary treatments were designed to achieve three targeted rates of gain [No-Growth (NG) = 0.0 kg/d; Low-Growth (LG) = 0.55 kg/d; or High-Growth (HG) = 1.2 kg/d] over a 7-week period. Milk replacer intakes necessary to achieve these growth-rates were estimated using the NRC Nutrient Requirements of Dairy Cattle calf model computer program. All of the calves were fed a 30% crude protein, 20% fat, milk replacer reconstituted to 14% dry matter. The NG and LG calves were supplemented additionally with vitamins A, E, and D to compensate for treatment differences in dry matter intake relative to the HG calves; however, no attempt was made to adjust mineral intake on the basis of dry matter intake. Growth rates for NG (0.11 kg/d), LG (0.58 kg/d), and HG (1.16 kg/d) calves differed during the study. Health was minimally affected by growth rate and this was reflected by comparable and low-serum haptoglobin concentrations in all calves during the period. Serum retinol, 25-(OH)-vitamin D3 and Zn concentrations were unaffected by growth rate. The HG calves had lower tocopherol concentrations than NG and LG calves at wk 7 suggesting that the increased growth rate of HG calves was associated with increased utilization of vitamin E. Serum concentrations of all vitamins increased with age. Copper, calcium, and phosphorous concentrations in HG calves exceeded those in LG and NG calves during latter weeks of the study, likely due to increased milk replacer intake by HG calves. Fat-soluble vitamin and mineral concentrations for all treatment groups remained within ranges considered normal for preruminant calves.