This study aimed to investigate the effect of dietary supplementation with xylanase and probiotics on growth performance and intestinal health of nursery pigs challenged with enterotoxigenic Escherichia coli (ETEC). Sixty-four newly weaned pigs (32 barrows and 32 gilts with 7.9 ± 0.4 kg BW) were allotted in a randomized complete block design (2 × 2 factorial). Two factors were ETEC challenge (oral inoculation of saline solution or E. coli F18 + at 6 × 10 9 CFU) and synbiotics (none or a combination of xylanase 10,000 XU/kg and Bacillus sp. 2 × 10 8 CFU/kg). All pigs were fed experimental diets following NRC (2012) in two phases (P1 for 10 d and P2 for 11 d). The ETEC was orally inoculated on d 7 after weaning. Feed intake and BW were measured on d 7, 10, 15, and 20. On d 20, pigs were euthanized to collect samples to measure gut health parameters and microbiome. Synbiotics increased (P < 0.05) ADG in phase 1 and ETEC reduced (P < 0.05) ADG and G:F in the post-challenge period. ETEC increased (P < 0.05) the fecal score of pigs from d 7 to 13; however, synbiotics reduced (P < 0.05) it at d 9 and 11 in challenged pigs. ETEC increased (P < 0.05) mucosal MDA, IL-6, Ki-67 + , and crypt depth, whereas synbiotics tended to reduce TNFα (P = 0.093), protein carbonyl (P = 0.065), and IL-6 (P = 0.064); reduced (P < 0.05) crypt depth and Ki-67 + ; and increased (P < 0.05) villus height. ETEC reduced (P < 0.05) the relative abundance of Bacteroidetes and Firmicutes and increased (P < 0.05) the relative abundance of Proteobacteria. In conclusion, ETEC challenge reduced growth performance by affecting microbiome, immune response, and oxidative stress in the jejunum. Synbiotics enhanced growth performance by reducing diarrhea, immune response, and oxidative stress in the jejunum.

The floor density required for optimal growth performance of different avian species and varieties is highly variable. Little is known of the required floor density for optimum performance of the French guinea fowl (Numida meleagris) broiler. The objective of this study was to assess the effect of varying floor densities on growth performance and carcass characteristics of the French guinea broiler. In 3 replicates, 687 one-day-old French guinea keets were weighed individually and randomly assigned to floor pens covered with pine wood shavings at 69, 60, 53, and 47 birds/pen, equivalent to densities of 15.6, 13.6, 12, and 10.7 birds/m(2), respectively. Birds in these floor densities were allowed feeder space of 2.7, 3.1, 3.5, and 4 cm/bird, respectively, and water space of 1.4, 1.6, 1.8, and 2.0 cm/bird, respectively. All birds received a 23-h lighting regimen and were fed the same diet comprising 3,100 kcal of ME/kg of diet and 23% CP from 1 d old to 4 wk of age (WOA) and 3,150 kcal of ME/kg of diet and 21% CP at 5 to 8 WOA. Feed and water were provided for ad libitum consumption. Body weight and feed consumption were measured weekly, whereas carcass characteristics were evaluated at 8 WOA. Overall, feed consumption was significantly higher (P < 0.05) in birds raised in 10.7 birds/m(2) than other treatment groups. Birds in floor densities of 12 and 15.6 birds/m(2) also consumed 6% more feed than those raised at 13.6 birds/m(2). Mean BW gain of birds in floor density of 15.6 birds/m(2) was significantly lower (P < 0.05) than that of birds in other floor densities. In general, significantly lower feed conversion ratios and higher carcass yields were observed in birds raised in floor densities of 13.6 and 12 birds/m(2) than those raised in floor densities of 15.6 and 10.7 birds/m(2). Therefore, French guinea broilers exhibited superior performance when raised at floor densities of 13.6 and 12 birds/m(2) than those reared at floor densities of 15.6 and 10.7 birds/m(2).

The identities of genes that underlie population variation in adipose tissue development in farm animals are poorly understood. Previous studies in our laboratory have suggested that increased fat tissue involves the expression modulation of an array of genes in broiler chickens. Of special interest are eight genes, FGFR3, EPHB2, IGFBP2, GREM1, TNC, COL3A1, ACBD7, and SCD. To understand their expression regulation and response to dietary manipulation, we investigated their mRNA levels after dietary manipulation during early development. Chickens were fed either a recommended standard or a high caloric diet from hatch to eight weeks of age (WOA). The high caloric diet markedly affected bodyweight of the broiler birds. mRNA levels of the eight genes in the abdominal adipose tissue were assayed at 2, 4, 6, and 8 WOA using RT-qPCR. Results indicate that (1) FGFR3 mRNA level was affected significantly by diet, age, and diet:age interaction; (2) COL3A mRNA level was repressed by high caloric diet; (3) mRNA levels of EPHB2, ACBD7, and SCD were affected by age; (4) mRNA level of TNC was modulated by age:diet interaction; (5) changes in GREM1 and IGFBP2 mRNA levels were not statistically different.

No abstract