Comparative effects of triticale and alfalfa hay supplemented with pomegranate pulp extract on Holstein dairy calf performance

The comparative effects of alfalfa hay (AH, Medicago sativa L.) and winter-triticale hay (TH, × Triticosecale L.), which require less water, supplemented with pomegranate pulp extract (PPE), on feed intake, nutrient digestibility, growth performance, ruminal fermentation variables, estimated microbial-N synthesis (EMNS), blood biochemistry, and total antioxidant capacity (TAC) of dairy calves were evaluated. Forty-eight Holstein female calves (initial BW of 37.1 ± 2.6 kg) were randomly assigned to 4 treatments in a 2 × 2 factorial design. The diets consisted of: 1) solid feed containing 12% AH, 2) solid feed containing 12% AH + PPE (100 mL/d), 3) solid feed containing 12% TH, and 4) solid feed containing 12% TH + PPE (100 mL/d). All calves had free access to water and, starting at 4 d of age, received 4 L of milk daily until 62 d, when they were weaned, followed by a post-weaning period from 63 to 84 d of age. After weaning, calves received the above 4 dietary treatments without milk feeding. Solid feeds, without or with TH and PPE, were offered ad libitum during both pre- and post-weaning phases. Up to d 28, the number of days with abnormal feces was used to assess fecal health. Measurements included feed intake, growth parameters, digestibilities of DM and nutrients, rumen pH, ammonia-N, short-chain fatty acids (SCFA), rumen protozoa count, EMNS, and blood metabolites. Inclusion of PPE in the diet reduced the incidence of abnormal feces in calves. Neither hay type nor PPE inclusion affected feed intake, ADG, or feed efficiency during the pre-weaning period. After weaning, feed intake, nutrient digestibility, ADG, N retained, ruminal SCFA, EMNS, and blood TAC were all increased in calves fed TH-containing diets compared with those fed diets free of TH, but blood urea-N and ruminal ammonia-N and protozoa counts were reduced. Feed intake and ADG during the overall period were greater in calves fed TH than in those fed TH-free diets, but feed efficiency was not affected. Skeletal growth indicators, such as body length, heart girth, hip height and width, and withers height, were recorded at the end of the trial, with no significant differences observed among treatments. Results indicate that feeding TH at 12 g/100 g diet DM improved digestibility, feed intake, growth performance, rumen fermentation variables, and EMNS in post-weaning Holstein calves. It also lowered blood urea-N levels. Therefore, TH represents a practical alternative for farms with limited water for growing alfalfa. Additionally, administering PPE (100 mL/d) improved fecal consistency and increased blood antioxidant capacity in calves.