title: Ingestive behavior of grazing steers fed increasing levels of concentrate supplementation with different crude protein contents.
abstract: This study aimed to evaluate the ingestive behavior of steers on Brachiaria brizantha pasture fed diets with increasing levels of concentrate supplementation. Thirty-two crossbred steers in the finishing phase with average weight of 420 ± 8 kg were distributed in a completely randomized design with four treatments and eight replicates per treatment. Their behavior was assessed every 5 min for 24 h, in the middle of the experimental period. Variance and regression analyses at 0.05 % probability were adopted. The times spent grazing and ruminating reduced linearly (P <0.05), whereas the times spent at the trough (eating) and on other activities increased linearly (P <0.05) as the supplementation levels were elevated. The total feeding and chewing times decreased linearly (P <0.05) as the concentrate levels in the diet were elevated. By increasing the supplementation levels, the number of bites per day decreased linearly (P <0.05), and the feed efficiency of dry matter increased quadratically. Rumination efficiency of dry matter increased linearly (P <0.05) with increasing levels of concentrate supplementation. Grazing and rumination activities are reduced when the time devoted to other activities and at the trough are increased, as a result of the substitution effect.
authors.affiliation: Universidade Estadual do Sudoeste da Bahia (PPZ-UESB), Itapetinga, BA, Brazil, fabricio.bacelar@hotmail.com.
authors.forename: Fabrício Bacelar Lima
authors.initials: FB
authors.lastname: Mendes
authors.forename: Robério Rodrigues
authors.initials: RR
authors.lastname: Silva
authors.forename: Gleidson Giordano Pinto
authors.initials: GG
authors.lastname: de Carvalho
authors.forename: Fabiano Ferreira
authors.initials: FF
authors.lastname: da Silva
authors.forename: Túlio Otávio Jardim D Almeida
authors.initials: TO
authors.lastname: Lins
authors.forename: Anderson Luiz Nascimento
authors.initials: AL
authors.lastname: da Silva
authors.forename: Venício
authors.initials: V
authors.lastname: Macedo
authors.forename: George
authors.initials: G
authors.lastname: Abreu Filho
authors.forename: Sinvaldo Oliveira
authors.initials: SO
authors.lastname: de Souza
authors.forename: Joanderson Oliveira
authors.initials: JO
authors.lastname: Guimarães
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002417:Cattle / Q000502:physiology*; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements; D005247:Feeding Behavior; D011506:Proteins / Q000008:administration & dosage*
chemical_list: D011506:Proteins