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Introducing forage in the young calf diet during the milk-feeding period stimulates rumen development. It was hypothesized that performance in dairy calves would depend on forage provision and starter physical form such that the textured starter (TS) feed with corn silage (CS) supplementation would benefit calf performance. This study evaluates the effects of the physical form of starter diets and CS supplementation on performance, rumen fermentation characteristics, and structural growth of dairy calves. Forty-eight 3-d-old Holstein dairy calves with a mean starting BW of 42.1 kg (SD 2.4) were used in a 2 × 2 factorial arrangement with the factors dietary CS level (0 or 15% on DM basis) and physical form of starter (mashed vs. textured). Individually housed calves were randomly assigned ( = 12 calves per treatment: 6 males and 6 females) to 4 treatments: 1) a mashed starter (MS) feed with no CS (MS-NCS), 2) a MS feed with CS (MS-CS), 3) a TS feed with no CS (TS-NCS), and 4) a TS feed with CS (TS-CS). The calves had ad libitum access to water and starter throughout the study. All calves were weaned on d 56 of age and remained in the study until d 66. The interaction of the physical form of the starter and CS provision was significant ( < 0.01) for the starter intake, with the greatest intake for TS-CS treatment during the preweaning and overall periods. Regardless of the physical form of starter, starter intake, ADG, weaning BW, final BW, ruminal pH, the molar proportion of acetate, and the acetate-to-propionate ratio were greater ( < 0.01) for CS-supplemented calves compared with unsupplemented calves. No interaction ( > 0.05) was detected between the physical form of starter and CS provision with respect to the rumen fermentation parameters and body measurements. Total rumen VFA concentration and the molar proportion of propionate were greater ( < 0.01) in calves fed TS compared with MS-fed calves. In conclusion, independent of the physical form of starter, inclusion of 15% CS in starter diets improves the performance of dairy calves.

This study evaluated the interaction of RUP and fat levels on growth, rumen fermentation, and blood metabolites of Holstein calves. Forty 3-d-old calves (20 females and 20 males) with a starting BW of 40.6 ± 2.8 kg were used in a completely randomized design with a 2 × 2 factorial arrangement of treatments. Within sex treatments were: (1) high RUP and low fat (HRUP-LF); (2) low RUP and high fat (LRUP-HF); (3) high RUP and low fat (HRUP-LF); and high RUP and high fat (HRUP-HF). Low-RUP starter contained 21.5%, whereas high RUP starter contained 34.3% RUP as % of CP, whereas low fat starter contained 2.9% and high starter contained 5.8% crude fat based on DM. Isonitrogenous levels in the starter grain were maintained by replacing solvent soybean meal with heat treated soybean meal while fat levels were increased by the addition of prilled fatty acids. Calves were housed individually and had ad libitum access to water and calf starter throughout the study. All calves were weaned on d 60 of age but remained in the study until d 70 for final measurements. Overall, there was no interaction between RUP and fat levels for measured variables. Starter intake tended ( = 0.09) to be greater for calves fed low fat starter during the postweaning period, although over the whole experiment and during the preweaning period, differences in starter intake were not different. Although there were no differences for most VFA concentrations, the molar proportion of butyrate tended ( < 0.08) to be greater in the rumen of calves fed low-fat starter compared to those fed high-fat starter. Serum total protein was lower ( < 0.05) and serum cholesterol was greater ( < 0.01) for calves fed high-fat starter by d 65 of life. The concentration of alanine aminotransferase was also lower ( < 0.05) for calves fed high-fat starter compared to those fed low-fat starter on d 65, and these levels tended to increase with the addition of RUP ( < 0.07). In conclusion, no effects were attributable to feeding a high-RUP starter. However, feeding a calf starter with over 3% fat appeared to decrease starter intake as growth progressed.

Our objective was to compare the effects of grinding versus steam-rolling of barley grain at 30 or 35% of diet dry matter on feed intake, chewing behavior, rumen fermentation, and milk production in high-producing lactating cows. Eight multiparous Holstein cows (85 +/- 9 d in milk) were used in a replicated 4 x 4 Latin square design experiment with four 21-d periods. Each period included 14 d of adaptation and 7 d of sampling. Treatments included grinding (GB) or steam-rolling (SB) of barley grains at either 35 or 30% of dietary dry matter. Diets were prepared as a total mixed ration and delivered twice daily at 0730 and 1600 h. Neither processing method nor dietary barley grain inclusion rate affected dry matter intake, daily eating, ruminating and chewing times, rumen pH and major volatile fatty acid molar percentages, or milk percentages and yields of fat and protein. Energy-corrected milk yield increased for SB compared with GB at 35% but not at 30% barley grain. Feed efficiency was increased by SB, but was unaffected by dietary barley grain level. Results suggest that at 30% dietary barley grain, GB resulted in similar lactation performance as SB and that SB did not affect productivity when dietary barley grain increased from 30 to 35%. Regardless of barley grain level, grinding effectively maintained dry matter intake and rumen pH at 4 h postfeeding, whereas steam-rolling increased feed efficiency. Increasing barley grain from 30 to 35% of diet dry matter did not improve feed intake and milk production.

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