Desempenho, eficiência de utilização dos nutrientes e estrutura do trato digestório de pintos de corte alimentados na fase pré-inicial com rações de diferentes formas físicas

Abstract

RESUMO -Este estudo foi realizado com o objetivo de avaliar o efeito da forma física da ração sobre o desempenho, a utilização dos nutrientes das rações e o desenvolvimento do trato disgestório de pintos de corte na primeira semana de vida.Foram utilizados 150 pintos machos Cobb distribuídos ao acaso em três tratamentos com cinco repetições de dez aves. Os tratamentos consistiram das formas físicas farelada, triturada e peletizada de uma ração pré-inicial comercial. Com exceção da moela, os órgãos do trato digestório e a estrutura morfométrica do intestino não foram influenciados pela forma física da ração. Maior digestibilidade do N foi obtida com a ração peletizada, enquanto a ração triturada possibilitou maior digestibilidade do EE. A energia metabolizável determinada para a ração farelada foi menor que a obtida nas demais formas físicas da ração.As aves alimentadas com ração farelada tiveram menor consumo de ração e ganho de peso e pior conversão alimentar. Ingeriram ainda menos energia, apresentaram menores retenções de proteína, gordura e energia corporal e utilizaram maior proporção da energia ingerida para produção de calor. As rações pré-iniciais na forma peletizada ou triturada possibilitam maior aproveitamento dos nutrientes da ração pelos pintos e melhor desempenho.Palavras-chave: energia metabolizável, produção de calor, ração farelada, ração peletizada, ração triturada Performance, efficiency of nutrient utilization and gastrointestinal structures of broiler chick fed in prestarter phase with ratios with different physical formABSTRACT -This experiment was conducted to evaluate the effect of different physical form of pre-starter diet on performance, nutrient utilization and development of gastrointestinal tract of broiler chicks during the first week of age. A total of 150-day-old male broiler chicks was allotted to a completely randomized design with three treatments and five replicates of 10 birds each. Treatments consisted of three physical forms of a commercial pre-starter diet: mashed, crumbled and pressed into pellets. Except for gizzard, the other organs of the digestive tract and morphologic structures of the small intestine were not affected by the physical form of the diet. The highest N digestibility was observed in birds fed pellet diet, while crumbled diet showed the highest digestibility of EE. The metabolizable energy determined for mashed diet was lower than those determined for the other physical forms of the diet. Birds fed mashed diet had the lowest feed intake and body weight gain and the worse feed conversion. These birds also showed lower intake of energy and less protein, fat and energy retention in the body. They used a higher proportion of the energy consumed for heat production. Pre-starter diets prepared as pellets or crumbles allow better nutrient utilization and improve chick performance.

Feeding behaviour of broiler chickens: a review on the biomechanical characteristics

“…The physical form of pre-start diet (1-7 days) influences the performance of broilers until the end of the initial phase (8-21 days old), but the effects diminish until slaughter age with no effect on carcass characteristics (Freitas et al, 2009). Several studies are in line with the increase of broiler performance when processed diets are offered, which is mostly explained both by improvements in weight gain and feed conversion (Jones et al, 1995;Scott et al, 1997;Leeson et al, 1999;Lecznieski et al, 2001;Vargas et al, 2001;Greenwood et al, 2004;Silva et al, 2004;Maiorka et al, 2005;Lara et al, 2008); development of the digestive tract (Shamoto & Yamauchi, 2000; Feeding Behaviour of Broiler Chickens: a Review on the Biomechanical Characteristics Engberg et al, 2002;Dahlke et al, 2003;Zang et al, 2009); increasing of feed density leading both to nutrient intake and to growth rate (Engberg et al, 2002;McKinney & Teeter 2004;Lemme et al, 2006;Freitas et al, 2008;Meurer et al, 2008;Freitas et al, 2009); greater nutrient digestibility (Moreira et al, 1994;Vargas et al, 2001;Goodband et al, 2002;Freitas et al, 2008;Zang et al, 2009); reduction on particles selectivity by the birds and better palatability (Gadzirayi et al, 2006;Lara et al, 2008); minimization of energy expenditure during feeding (Nir, et al, 1994c;Leeson et al, 1999;Jensen, 2000;López et al, 2007); decreasing of wastage (Jensen, 2000;…”

Efecto del transporte y de un sistema automático de alimentación sobre la calidad física y química de los piensos granulados para pollos de engorde

“…Physical analyses involved weighing 300 g (± 20 g) of the sample for further cascade screen-tance (Abdollahi et al, 2013). The supply of pelleted or mash feed for broiler chicks in the initial phase allows greater consumption, metabolization and retention of energy intake (Freitas et al, 2008), as well as improves nutrient digestibility and reduces feeding time, which favors weight gain (Engberg et al, 2002). Pellet integrity indexes of 60-64 % may result higher feed conversion, greater weight gain and better feed efficiency of broiler chickens (Mckinney & Teeter, 2004;Corzo et al, 2011).…”

Levels of metabolizable energy and digestible lysine for broiler chicks 1-10 days of age

“…The number of villi is associated with the enterocytes of the villi, and their size increase reflects a greater absorption of food (MACARI; MAIORKA, 2000). Freitas et al (2008) reported that most villus height is related to performance results, and that poultry with larger villi have higher weight gains and better feed conversion. Thus, the larger the size of the villi, the greater the ability of digestion and absorption of nutrients, due to the larger contact area and the level of enzyme effectiveness between the mucosa and intestinal lumen.…”