The effect of restricted milk feeding through conventional or step-down methods with or without forage provision in starter feed on performance of Holstein bull calves1

Abstract

The objective of the current study was to examine whether step-down (STP) milk feeding method together with forage provision would improve performance, rumen fermentation, nutrient digestibility, blood metabolites, and structural growth of calves. Holstein bull calves ( = 40) were randomly assigned to 1 of 4 treatments in a completely randomized design with a 2 × 2 factorial arrangement. Treatments were 1) conventional (COV) milk feeding without forage provision (COV-NF), 2) COV milk feeding with forage provision, 3) STP milk feeding without forage provision, and 4) STP milk feeding with forage provision. Calves in the COV method ( = 20) received 5.5 L/d milk until d 56 of age followed by 2 L/d milk from d 56 to 59 of age. Calves in the STP method ( = 20) received 7 L/d milk until d 35, 4 L/d milk from d 35 to 48, and 2 L/d milk from d 50 to 59 of age. All the calves received the starter ration from d 3 of the study until d 74 of age. Forage-supplemented calves ( = 10/milk feeding method) received 15% alfalfa hay mixed with finely ground starter as a total mixed ration. All calves were weaned on d 60 of age and remained in the study until d 74. Regardless of the milk feeding method, the final BW (92.54 vs. 83.14 kg/d), starter intake (0.90 vs. 0.65 kg/d), total DMI (1.43 vs. 1.17 kg/d), and ADG (0.73 vs. 0.60 kg/d) were greater ( < 0.01) in forage-supplemented calves than those that received no forage during the preweaning, postweaning, and overall periods. Milk feeding method had no effect on ruminal pH, total VFA, acetate, or acetate:propionate ratio as well as body measurements. Ruminal pH and the molar proportions of acetate were greater ( < 0.05) in the forage-supplemented calves than those that received no forage during the pre- and postweaning periods. Regardless of forage provision, STP methods increased ( < 0.05) the postweaning numbers of monocytes and lymphocytes. Overall, there was no interaction between milk feeding methods and forage provision with respect to BW, DMI, G:F, apparent nutrient digestibility (DM, OM, and CP), and body measurements. The interaction of milk feeding method and forage provision was significant for the rumen concentration of butyrate ( < 0.05), with the highest concentration for the COV-NF treatment on d 35 of the study. In conclusion, independent of the milk feeding method, inclusion of 15% alfalfa hay in starter diets enhances the performance of dairy calves.

Effects of forage offering method on performance, rumen fermentation, nutrient digestibility and nutritional behaviour in Holstein dairy calves

“…In this study, no differences were observed across treatments for total‐tract apparent DM, OM and NDF digestibilities, which may explain the absence of differences in feed efficiency among treatments. Apparent digestibility of nutrients measured in this trial are in the range previously reported in weaned calves (Terré et al., ; Hill et al., ; Daneshvar et al., ). Generally, high DMI (Zanton and Heinrichs, 2008) and high fibre diets (Porter et al., ) compromise diet digestibility.…”

Effects of different forage sources as a free‐choice provision on the performance, nutrient digestibility, selected blood metabolites and structural growth of Holstein dairy calves

“…Apparent digestibility of nutrients measured in this trial is in the range previously reported in weaned calves (Terré et al., ; Hill et al., ; Daneshvar et al., ). Generally, high DMI (Zanton and Heinrichs, ) and high‐fibre diets (Porter et al., ) compromise diet digestibility.…”

“…Results from some previous investigations in the effect of AH on starter intake have been inconsistent. Previous studies (Beiranvand et al., ; Daneshvar et al., ; Jahani‐Moghadam et al., ; Mirzaei et al., ) have found that the addition of chopped AH (as TMR) increased starter intake; however, Hill et al. () did not observe differences in starter intake when part of the starter feed was substituted by AH in dairy calves.…”

“…Results from some previous investigations in the effect of AH on starter intake have been inconsistent. Previous studies (Beiranvand et al, 2014;Daneshvar et al, 2015;Jahani-Moghadam et al, 2015;Mirzaei et al, 2015) have found that the addition of chopped AH (as TMR) increased starter intake; however, Hill et al (2010) did not observe differences in starter intake when part of the starter feed was substituted by AH in dairy calves. However, Hill et al (2010) mixed the forage source with the starter feed, and thus, calves were also forced to consume predetermined fixed forage to concentrate ratio that was also lower (up to 15%) than the ratio freely chosen by calves herein.…”

Effects of physical form of starter and forage provision to young calves on blood metabolites, liver composition and intestinal morphology

“…In the current study, ruminal pH was similar among the dietary treatments (GS, TS and PS), except for the GS + AH treatment, which was the highest. The ruminal pH observed in this study was comparable to those observed in previous studies (Beiranvand et al, 2014;Daneshvar et al, 2015;Nemati et al, 2015a,b). Our findings are in agreement with Porter et al (2007) who found that the rumen pH was similar for neonatal calves fed a coarse meal diet compared with calves fed a finely ground diet.…”