Histomorphology of bursa of Fabricius: effects of stock densities on commercial broilers

Abstract

During the past few years, there has been considerable interest on the effects of stocking density on broiler behavior and immunity. Stress may cause immunodeficiency by affecting cell and humoral responses, as well as body weight decrease, and foot-pad dermatitis. The aim of this study was to study histomorphological changes of the bursa of Fabricius in broilers submitted to three different stocking densities (10, 15, and 20 birds/m²) from one to 42 days of age. Three birds from each group were sacrifieced on days 7 and 42. The bursa was collected, fixed, and processed for histomorphometric assessment using a Kontrom KS 400 image analyzer. Data were analyzed by Biostat 3.0 (Tukey Test). The results of average cortical area percentage in bursal follicles of 6-week-old birds were 45.12a (10 birds/m²), 30.43b (15 birds/m²), and 23.77b (20 birds/m²). Average body weight was 2.58a kg (10 birds/m²), 2.56a Kg (15 birds/m²), and 2.47b Kg (20 birds/m²), respectively. The percentage of foot-pad dermatitis in 6-week-old birds was 3.33a (10 birds/m²), 17.76b (15 birds/m²), and 49.17c (20 birds/m²). These differences were statistically significant at a P<0.05 level. Under these experimental conditions,, it was concluded that the best stocking density to produce broilers is between 10-15 birds per square meter

Effects of Dietary Threonine Levels and Stocking Density on the Performance, Metabolic Status and Immunity of Broiler Chickens

“…As shown in Table 2, broiler LBW, BWG and feed intake were affected negatively by high stocking density. Similarly, other researchers (Elwinger, 1995;Thomas et al, 2004;Muniz et al, 2006;EL-Gogary and Azzam, 2014) indicate that increasing the No. of birds per unit depresses growth rate and feed intake.…”

Effect of Stocking Density on the Performance and Immunity of 1- to 14-d- Old Broiler Chicks

“…Broilers are housed at different stocking densities, depending on local regulations, production system, and target body weight, aiming at minimizing fixed costs and maximizing profitability (Puron et al, 1995;Muniz et al, 2006;Buijs et al, 2009;Skomorucha et al, 2009). However, it is well documented that high stocking densities adversely affects broiler performance, health, livability, and immunity (Puron et al, 1995;Pettit-Riley & Estevez, 2001;Heckert et al, 2002;Thaxton et al, 2006;Estevez, 2007;Pandurang et al, 2011), mostly as a result of reduced access to feed and water (Jones et al, 2005;Thaxton et al, 2006).In addition, air flow at bird level is reduced, hindering the dissipation of body heat (Ravindran et al, 2006;Pandurang et al, 2011).…”

Efeito da densidade de alojamento sobre a incidência de pododermatite e características ósseas de frangos de corte criados em aviários Dark House

“…Quanto à ausência (score A), grau leve (score B) ou grave (score C) de lesões para densidade de 15,00 aves/m² houve aumento das lesões graves de forma linear até os 42 dias de idade. Os resultados do presente estudo estão de acordo com os encontrados por Muniz et al (2006), mostrando haver uma relação direta entre densidade por metro quadrado e a percentagem de lesões de pés devido ao volume de excretas eliminado, interferindo negativamente na saúde e bem-estar das aves. Feddes et al (2002) constataram que o consumo de água foi maior em altas densidades de alojamento, o que resultou em excretas mais liquidas e consequentemente contribuiu para o aumento na umidade da cama.…”

“…Diversas empresas têm aumentado a densidade de alojamento com o objetivo de maximizar a produção e diminuir os custos na criação de frangos de corte. No entanto, essa prática está associada ao aparecimento das lesões de pododermatite (BILGILI et al, 2006 (GOPINGER et al, 2015). Estudos relacionados a fragilidade óssea também têm demostrando haver correlação negativa entre aumento de densidade de alojamento e qualidade óssea (KUN et al, 2009;MENDES et al, 2012).…”