title: Effects of a mixture of steam-flaked corn and extruded soybeans on performance, ruminal development, ruminal fermentation, and intestinal absorptive capability in veal calves.
abstract: This study investigated the effects of a mixture of steam-flaked corn and extruded soybeans on performance, ruminal development, ruminal fermentation variables, and intestinal absorptive capability in Holstein male calves (n = 39). Calves were assigned to 1 of 3 treatments (13 calves per treatment): 1) milk replacer (MR), 2) one-half of the amount of MR in treatment 1, plus a mixture of 62.1% steam-flaked corn and 30.5% extruded soybeans provided ad libitum (HMCS), or 3) a mixture of 62.1% steam-flaked corn and 30.5% extruded soybeans provided ad libitum (CS). All the calves were started at 2 ± 1 d of age and studied for 150 d. Each 30 d was defined as 1 period. Dry matter intake and growth were measured daily and monthly, respectively. All calves were harvested at 150 d of age, after which rumen fluid was collected. Rumen and intestine samples were gathered. Calves fed MR exhibited greater BW (P = 0.001) and ADG (P < 0.001), compared with calves fed HMCS and CS from period 2 to 3; however, from period 4 to 5, CS calves had greater (P < 0.04) ADG than MR calves. The treatments did not differ in final BW (P = 0.72) and ADG (P = 0.20) from period 2 to 5. Compared with HMCS and MR calves, CS calves had the greatest DMI (P < 0.001) and the least feed efficiency (P < 0.001) from period 2 to 5. For ruminal fermentation parameters, CS calves had decreased (P = 0.04) rumen pH than MR calves. The NH3 concentrations were greater (P = 0.03) in calves fed HMCS than calves fed MR and CS. Total VFA concentrations were greatest in CS calves (P = 0.02). Calves fed CS had the greatest molar concentrations of propionate, butyrate, and valerate (P < 0.002), and calves fed HMCS had the greatest molar concentrations of isobutyrate (P = 0.001) and isovalerate (P = 0.001). The CS calves exhibited greater empty rumen weight (P = 0.001), papillae length (P < 0.001), papillae width (P < 0.001), rumen wall thickness (P = 0.012), and papillae density (P = 0.003). The greatest villus heights in the jejunum (P = 0.04) and ileum (P = 0.005) were observed in CS calves. Compared with HMCS calves, calves fed CS had greater villus:crypt ratios in the duodenum (P = 0.001) and jejunum (P = 0.001). Results indicate that CS improves ADG in period 4 to 5 and positively contributes to ruminal development, ruminal fermentation, and intestinal absorptive capability in veal calves.
authors.affiliation: State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing 100193 PR China.
authors.forename: X X
authors.initials: XX
authors.lastname: Xie
authors.forename: Q X
authors.initials: QX
authors.lastname: Meng
authors.forename: P
authors.initials: P
authors.lastname: Liu
authors.forename: H
authors.initials: H
authors.lastname: Wu
authors.forename: S R
authors.initials: SR
authors.lastname: Li
authors.forename: L P
authors.initials: LP
authors.lastname: Ren
authors.forename: X Z
authors.initials: XZ
authors.lastname: Li
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000818:Animals; D002417:Cattle / Q000033:anatomy & histology* / Q000254:growth & development / Q000502:physiology*; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D007422:Intestines / Q000033:anatomy & histology / Q000187:drug effects* / Q000254:growth & development; D008297:Male; D011897:Random Allocation; D012417:Rumen / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology; D013025:Glycine max / Q000737:chemistry*; D003313:Zea mays / Q000737:chemistry*