Effects of dietary Original XPC (XPC) in commercial layer pullets challenged with the virulent, low passage R strain of Mycoplasma gallisepticum (R low MG) were investigated. Hy-Line W-36 pullets sourced from MG-clean breeders were fed a basal diet with or without (CON) XPC (1.25 kg/metric ton) from hatch until 12 wk of age (woa). At 8 and 10 woa, half of the birds in each dietary treatment were challenged with R low MG. Body weight was recorded at 3, 8, and 12 woa, and ovary, ceca, and bursa weights were recorded at 3 and 12 woa. Blood samples were taken immediately before the initial R low MG challenge at 8 woa and again at 12 woa to test for IgM and IgG antibody production against MG. All birds were evaluated for MG lesion scores at 12 woa. Regardless of challenge, inclusion of XPC in the diet did not significantly alter BW at 3 or 8 woa or relative organ weights at 3 or 12 woa. However, at 12 woa, BW of XPC-fed birds, regardless of challenge was significantly ( P = 0.0038) heavier than CON by 25.7 g. All birds tested negative for MG antibodies before the 8 woa challenge. Respective percentage serum plate agglutination and ELISA positive birds at 12 woa were 0 and 0% (CON, nonchallenged), 1.4 and 0% (XPC, nonchallenged), 100 and 47.2% (CON, challenged), and 100 and 50.0% (XPC, challenged). Diet did not significantly affect ELISA titers, but they were significantly ( P < 0.0001) increased due to challenge. Furthermore, lesion scores were significantly higher for R low MG-challenged birds ( P = 0.0012), and dietary treatment with XPC in challenged birds numerically reduced MG lesion scores from 0.278 to 0.194. In conclusion, although dietary XPC did not significantly alter the humoral immune response, antibody titer levels, or severity of MG lesions in layer pullets that were or were not challenged with R low MG, it led to an increase in their rate of growth through 12 woa.

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Corn distillers dried grains with solubles (DDGS) are now being further processed to remove corn oil, which may be used as a dietary energy source for poultry. The objectives of this study were to compare the effects of a poultry fat (PF) and a new DDGS-derived corn oil blend (CO) on live performance and carcass characteristics of 49-d-old broilers. Four corn-soybean meal based diets were formulated with differing blends of PF and CO. All diets contained the same percentage of total fat, but differed in the fat source. One diet had the sole source of fat as PF (100:0% PF:CO) and was then replaced with 25% CO, 75% CO, and a 100% replacement of CO. Each of the diets was fed in a 3-phase feeding program to 6 replicate pens. At day of hatch, Ross × Ross 708 broilers were randomly allocated to 24 pens composed of 42 birds of equal sex. On d 49, 10 birds from each pen were processed, and carcass, abdominal fat pad, and breast muscle components were determined. There were no significant differences in live performance for the starter phase (0-18 d). For the grower phase (19-35 d), birds fed 75:25% PF:CO significantly (P ≤ 0.05) increased BW, BW gain, and decreased feed conversion compared with the control (100:0% PF:CO). Birds fed 0:100% PF:CO also observed similar improvements in BW, BW gain, and feed conversion during the grower phase. There were no significant differences for the finisher phase (36-48 d). On d 49, live weights for birds fed the 0:100% PF:CO diets were significantly lower compared with other treatments. A trend for lower carcass and breast weights and increased abdominal fat was also observed for birds fed the 0:100% PF:CO. The addition of CO led to significant improvements in pellet durability for grower and finisher pellets. The results of this study indicate that DDGS-derived CO can be used to partially replace PF in broiler diets without any detrimental effects.

Effects of dietary Original XPC ( XPC ) on 17 selected blood variables in commercial layer pullets challenged with the virulent, low-passage R strain of Mycoplasma gallisepticum ( R low MG ) were investigated. Hy-Line W-36 pullets sourced from M. gallisepticum –clean layer breeders were fed a basal diet with XPC (1.25 kg/metric ton) or without from hatch until 12 wk of age ( woa ). At 8 and 10 woa, half of the birds in each dietary treatment were challenged with R low MG. Blood samples were taken immediately before the initial R low MG challenge at 8 woa and again at 12 woa (4 wk after challenge). At 8 woa, blood pH was lower and glucose concentration was higher in the preassigned challenge treatment groups. At 12 woa, the concentration of oxygen dissolved in the blood was significantly lower in the R low MG-challenged group than the unchallenged group of birds regardless of dietary treatment. The R low MG challenge significantly increased blood carbon dioxide partial pressure, calcium, sodium, anion gap, osmolality, glucose, and corticosterone levels but significantly decreased blood oxygen partial pressure, oxyhemoglobin concentration, concentration of oxygen dissolved in the blood, chloride, and pH levels. Because blood pH and glucose concentration at 8 woa were examined before challenge, their baseline values were biased with respect to challenge treatment before treatment was applied. However, the lack of a significant main effect due to diet at 8 woa for blood pH and glucose concentration, along with the other 15 blood variables, indicate that the baseline data with respect to dietary treatment were unbiased, allowing for real dietary effects to be accurately assessed. In conclusion, layer pullets challenged with R low MG undergo a stress response associated with changes in various physiological blood variables, and a decrease in pH and increase in carbon dioxide partial pressure, in association with a lack of change in bicarbonate, indicates that the stress response caused by the R low MG challenge was associated with respiratory acidosis. Nevertheless, feeding XPC did not influence the effects of challenge treatment on these postchallenge physiological blood values.