Behavior and Immune Response of Conventional and Slow-Growing Broilers to \u3ci\u3eSalmonella\u3c/i\u3e Typhimurium

Fast growth rate in broiler chickens comes with welfare concerns and the contribution of growth rate to pathogen resistance and sickness behavior is relatively unknown. The objective of this study was to evaluate physiological and behavioral responses of conventional (CONV) and slow-growing (SG) male broilers challenged with Salmonella Typhimurium. CONV (n = 156) and SG (n = 156) chicks were raised in a pen with wood litter shavings until day 7 of age, when birds were transferred to 24 isolators (n = 11 chicks/isolator). On day 14 of age, half of the birds (n = 12 isolators) were challenged with S. Typhimurium (ST) and the other half (n = 12 isolators) received a control (C). On days 7, 13, 17, 21, and 24, body weight was recorded, and blood, jejunum and ileum sections were collected from 2 birds/isolator (n = 48 birds/sampling) to measure plasma IgA and IgG and intestinal histomorphology, respectively. On days 12, 16, 21, and 23, video was recorded to evaluate bird postures (sitting, standing, or locomoting) and behaviors (eating, drinking, preening, stretching, sham foraging, allopreening, and aggression). CONV birds were 70 g heavier (p = 0.03) on day 21 and 140 g heavier (p = 0.007) on day 24 than SG. On day 7, CONV jejunum villus height and crypt depth were 22 and 7 μm greater (p ≤ 0.001), respectively, than SG. On day 24, ST ileum villus height was 95 μm shorter (p = 0.009) than C. IgA increased after day 17 for all birds and at day 21, CONV IgA was greater (p = 0.01) than SG. Although SG IgG was 344 μg/ml greater (p = 0.05) than CONV on day 7, CONV IgG increased with age (p \u3c 0.0001) to greater (p ≤ 0.03) concentrations than SG on day 21 and day 24 by 689 μg/ml and 1,474 μg/ml, respectively, while SG IgG remained at similar concentrations after day 13. Generally, a greater proportion of birds sham foraged as they aged (p \u3c 0.0001). A greater proportion of CONV tended to sit (p = 0.09) and fewer locomoted (p \u3c 0.0001) than SG as they aged. The results illustrate conventional and slow-growing broilers differ in their behavior, immunity, and response to Salmonella

Behavior and Immune Response of Conventional and Slow-Growing Broilers to Salmonella Typhimurium

Fast growth rate in broiler chickens comes with welfare concerns and the contribution of growth rate to pathogen resistance and sickness behavior is relatively unknown. The objective of this study was to evaluate physiological and behavioral responses of conventional (CONV) and slow-growing (SG) male broilers challenged with Salmonella Typhimurium. CONV (n = 156) and SG (n = 156) chicks were raised in a pen with wood litter shavings until day 7 of age, when birds were transferred to 24 isolators (n = 11 chicks/isolator). On day 14 of age, half of the birds (n = 12 isolators) were challenged with S. Typhimurium (ST) and the other half (n = 12 isolators) received a control (C). On days 7, 13, 17, 21, and 24, body weight was recorded, and blood, jejunum and ileum sections were collected from 2 birds/isolator (n = 48 birds/sampling) to measure plasma IgA and IgG and intestinal histomorphology, respectively. On days 12, 16, 21, and 23, video was recorded to evaluate bird postures (sitting, standing, or locomoting) and behaviors (eating, drinking, preening, stretching, sham foraging, allopreening, and aggression). CONV birds were 70 g heavier (p = 0.03) on day 21 and 140 g heavier (p = 0.007) on day 24 than SG. On day 7, CONV jejunum villus height and crypt depth were 22 and 7 μm greater (p ≤ 0.001), respectively, than SG. On day 24, ST ileum villus height was 95 μm shorter (p = 0.009) than C. IgA increased after day 17 for all birds and at day 21, CONV IgA was greater (p = 0.01) than SG. Although SG IgG was 344 μg/ml greater (p = 0.05) than CONV on day 7, CONV IgG increased with age (p &amp;lt; 0.0001) to greater (p ≤ 0.03) concentrations than SG on day 21 and day 24 by 689 μg/ml and 1,474 μg/ml, respectively, while SG IgG remained at similar concentrations after day 13. Generally, a greater proportion of birds sham foraged as they aged (p &amp;lt; 0.0001). A greater proportion of CONV tended to sit (p = 0.09) and fewer locomoted (p &amp;lt; 0.0001) than SG as they aged. The results illustrate conventional and slow-growing broilers differ in their behavior, immunity, and response to Salmonella.</jats:p

146 Effects of feeding soluble fiber (dextrin) to pigs pre- and post-weaning on growth performance and volatile fatty acid (VFA) production

Abstract Thirty-two barrows were used in a 35-d experiment with the objective of evaluating effects of supplemental soluble fiber (dextrin) pre- and post-weaning on growth performance and VFA production. Pigs were blocked by genetics and BW, and randomly allotted to treatments in a 2x2 factorial design with or without fiber pre-weaning and with or without fiber post-weaning. Fiber was suspended in chocolate milk and administered orally through a syringe from 14 d prior to weaning until 4 d post-weaning, after which it was included in the diet at 1%. At weaning, pigs were group housed by treatment and allowed ad libitum access to a common starter diet. On d 4 post-weaning, pigs were moved to individual pens and fed diets with or without 1% fiber. Weights and feed intake were recorded 14 and 3 d prior to weaning and on d 0, 4, 11, and 21 post-weaning. On d 21 post-weaning, pigs were euthanized, and large intestine contents were collected for VFA analysis. Data were analyzed using the GLM procedure of SAS with pig as the experimental unit. Growth performance was not affected (P &gt; 0.10) by treatment. A trend for an interaction of pre- and post-weaning fiber supplementation was observed for acetate (P = 0.052) and butyrate (P = 0.087) concentrations in large intestine contents. Pigs fed fiber only in the nursery had the highest acetate concentration, while pigs never receiving fiber had the lowest concentration. Pre-weaning fiber supplementation followed by no fiber in the nursery resulted in the highest butyrate concentrations with all other treatments being similar. Fiber supplementation pre-weaning tended (P = 0.053) to reduce isobutyrate concentrations. Pigs not receiving fiber post-weaning had increased valerate concentrations (P = 0.0245). There were no changes observed in propionate or isovalerate concentrations (P &gt; 0.10). Fiber supplementation caused alterations in VFA concentrations when fed during pre- and post-weaning, indicating possible shifts in the microbiome, immune status and barrier function of the intestinal tract.</jats:p