The aims of this study were to determine if feeding frequency (FF) of milk replacer (MR; meals/d) alters starter intake, growth and efficiency of growth in nursery calves fed a conventional or accelerated MR.
We hypothesized that smaller and more frequent MR meals would increase starter intake and growth when greater amounts of MR nutrients are fed to nursery calves. Forty-eight Holstein and Holstein-cross heifer and bull calves were assigned to treatments in a 2×2 factorial arrangement of MR and FF. Treatments included:
- Standard 20 percent CP and 20 percent fat MR fed at 1.5 percent of body weight (BW; 2 meals/d; STD2)
- Standard 20 percent CP and 20 percent fat MR fed at 1.5 percent of BW (4 meals/d; STD4)
- Modified 26 percent CP and 18 percen fat MR fed at 2.0 percent of BW (2 meals/d; MOD2)
- Modified 26 percent CP and 18 percent fat MR fed at 2.0 percent of BW (4 meals/d; MOD4; n=12)
All calves were fed at 0600 and 1700h and STD4 and MOD4 calves were fed 2 additional meals at 1100 and 1400h, resulting in the same amount of MR offered for the 2× and 4× treatments. Treatments were fed from d 2 to 42 of age and all MR feeding rates were adjusted weekly to maintain MR solids intakes at 1.5 or 2.0 v of BW for STD and MOD diets, respectively, and were reconstituted to 15 percent total solids. Milk replacer FF was reduced by 50 percent on day 36 and calves were weaned on day 42. Calves were housed in hutches bedded with straw and offered water and a texturized 18 percent CP starter ad libitum. Calf body weight and body structure were measured weekly and starter intake and fecal scores were measured daily. Through both 42 and 56days, calves fed MOD had greater CP and fat intake, resulting in increased average daily gain, heart girth, circulating nonesterified fatty acids (NEFA), and muscle total lipid compared with calves fed STD diets. Calves fed MOD diets consumed less starter grain than STD calves but total dry matter intake was similar among treatments. Increased FF for STD calves resulted in greater starter intake at weaning but increasing FF of MOD calves did not have this effect. Due to differences in starter intake, total dry matter by calves through d 56 was similar across treatments.
Additionally, increased FF tended to increase serum NEFA concentrations. Serum NEFA concentration was negatively correlated with starter intake. The BW of calves fed STD2 and STD4 treatments almost doubled and the BW of calves on the MOD2 and MOD4 treatments doubled by day 56. Increased FF of the conventional MR program but not accelerated MR program increased starter intake. Increased FF did not affect growth, starter intake, or gain:feed ratio.
Source: Journal of Dairy Science/A.D. Kmicikewycz, D.N.L. da Silva, J.G. Linn, N.B. Litherland