Effects of feeding frequency and protein source in milk replacer for Holstein calves

摘要

Whey proteins are a primary component of milk replacers(MR) and are considered the gold standard forcalves. Alternative protein sources may decrease MRcost if calf performance is similar. A blend of bovineplasma protein and modified wheat protein might bea good partial replacement for whey protein. UsuallyMR is fed twice daily, but feeding 3 times daily mightincrease efficiency of nutrient use, especially with MRcontaining alternate proteins. Therefore, our objectivewas to determine the effects of 2 MR, containing eitherentirely whey protein (CON) or a combination of wheyprotein, bovine plasma protein, and modified wheatprotein (WBP), when fed in either 2 or 3 meals dailyon calf growth and health. Female and male Holsteincalves (n = 103) housed in individual hutches werestudied for the first 63 d of life, with additional measurementsobtained at wk 12 of life in group housing.The MR contained 25% CP, 17% fat, and a Lys: Metratio of 3.1:1. Individual treatments arose from the 2× 2 factorial arrangement of MR formulation and frequencyof feeding. After colostrum, calves were fed MR(12.5% solids) at daily rates of dry matter dependenton age. Amounts were as follows: d 3 to 10 = 0.52kg/d (2× = 0.259 kg, 3× = 0.173 kg per feeding); d11 to 20 = 0.68 kg/d (2× = 0.341 kg, 3× = 0.227 kgper feeding); d 21 to 42 = 0.84 kg/d (2× = 0.42 kg,3× = 0.28 kg per feeding); d 43 to 46, 47, 49, and 51= 0.42 kg/d, with both 2× and 3× changed to 1 feedingdaily and skip days (d 48 and 50) between wherecalves were not given MR; and d 52 = calves weaned.Starter was fed and intake was measured from d 1 untild 63. Intakes, health scores, attitude scores, and fecalscores were measured daily. Body weight (BW) andgrowth measurements were obtained weekly until wk8 and again at wk 12. Blood samples were obtained at0, 24, and 48 h and then on d 5, 14, 28, and 42 of age.Starter intake was greater for calves fed WBP versusCON during wk 7 to 9. Final BW and hip width at wk12 were greater for calves fed WBP than for calves fedCON. Calves fed 2× had greater mean and final BW towk 6 and greater feed efficiency (gain: feed ratio) thancalves fed 3×. Blood variables supported the generallysimilar growth outcomes. Health outcomes did not differbetween diets or feeding frequencies. Overall, calvesfed WBP had increased starter intake and greater BWgains during wk 7 to 12 than calves fed CON, andcalves fed 2× had increased growth and feed efficiencycompared with those fed 3×.