title: Effect of particle size and partial replacement of alfalfa hay by soya bean hulls on nutrient intake, total tract digestibility and rumen degradability of diets by Holstein steers.
abstract: This study examined the effect of alfalfa hay (AH) particle size and the replacement of soya bean hull (SH) for AH within the diet of restricted fed Holstein steers on dry matter intake (DMI), total tract digestion, ruminal digestion, ruminal pH and ammonia nitrogen content, and faecal pH. Four rumen-cannulated Holstein steers averaging 353 ± 9.6 kg of BW were assigned to a 4 × 4 Latin square experiment with four periods and a 2 × 2 factorial arrangement of treatments. Factor A was AH particle size (fine vs. coarse) and factor B was diet SH content (0% vs. 10%; substituted for AH). Steers were fed at 1% of body weight of TMR containing 400 g/kg forage and 600 g/kg concentrate. Chopping of AH to fine particles decreased (p = 0.01) amount of dietary materials retained on the medium sieve (8 mm). The inclusion of SH significantly increased (p = 0.01) materials retained on the 1.18-mm sieve and tended to decrease (p = 0.07) materials on 19-mm sieves. The inclusion of SH increased (p = 0.01) ether extract (EE) intake and increased (p = 0.07) DMI. Inclusion of SH increased (p = 0.01) EE digestion and decreased (p < 0.01) faecal pH. Neither AH particle size nor SH inclusion in diets affected (p > 0.10) the in situ ruminal degradability coefficients of DM ('a', 'b', 'c' or 'a+b'). No interaction of AH×SH was seen on nutrient intake, digestibility and in situ ruminal degradability of Holstein steers.
authors.affiliation: Nuclear Science & Technology Research Institute, Karaj, Iran.
authors.forename: M
authors.initials: M
authors.lastname: Behgar
authors.affiliation: Faculty of Agriculture, Excellence Center in Animal Science, Ferdowsi University of Mashhad, Mashhad, Iran.
authors.forename: R
authors.initials: R
authors.lastname: Valizadeh
authors.affiliation: Faculty of Agriculture, Excellence Center in Animal Science, Ferdowsi University of Mashhad, Mashhad, Iran.
authors.forename: A A
authors.initials: AA
authors.lastname: Naserian
authors.affiliation: Technical and vocational university, Tehran, Iran.
authors.forename: S
authors.initials: S
authors.lastname: Ghasemi
authors.affiliation: Agriculture and Agri-Food Canada, Lacombe Research and Development Centre, Lacombe, AB, Canada.
authors.forename: P
authors.initials: P
authors.lastname: Vahmani
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D002417:Cattle / Q000502:physiology*; D004032:Diet / Q000662:veterinary*; D004063:Digestion; D005247:Feeding Behavior; D005511:Food Handling; D008297:Male; D000455:Medicago sativa; D012417:Rumen / Q000502:physiology*; D013025:Glycine max
keywords: Holstein steer; degradability; faecal pH; particle size; soya bean hull