Early feeding and dietary lipids affect broiler tissue fatty acids, vitamin E status, and cyclooxygenase-2 protein expression upon lipopolysaccharide challenge
ABSTRACT Newly hatched chicks are often subjected to delayed access to feed and water because of shipment distances and hatchery practices, which may reduce growth and development of the immune system. The current study investigated the effects of early vs. late access to feed and dietary lipids (n-3 vs. n-6) on lipopolysaccharide (LPS)-induced alterations in tissue fatty acids, vitamin E status, and cyclooxygenase-2 (COX-2) protein expression. The chicks (n = 16/group) were fed a high or low n-3 diet within 5 to 5 h 30 min (early) or after 48 h (late) of hatching. Feeding high n-3 diets increased eicosapentaenoic acid (EPA, 20:5 n-3), docosapentaenoic acid (22:5 n-3), and docosahexaenoic acid (DHA, 22:6 n-3) in the liver, spleen, and plasma (P < 0.05). Feeding low n-3 diets increased arachidonic acid in the liver and plasma (P < 0.05). Early access to feed led to increases in liver oleic acid and reduction in arachidonic acid as compared with late-fed birds (P < 0.05). No effect of time of feeding on fatty acids in the spleen was observed. Early feeding led to significant increases in linoleic and arachidonic acids in the plasma (P < 0.05). Stearic acid was higher in the plasma of low n-3 early-fed as opposed to low n-3 late-fed birds (P < 0.05). The LPS challenge led to an increase in liver total fat content (P < 0.05). The total fat content in the spleen and plasma were not affected by LPS injection (P > 0.05). The LPS-injected birds had decreases in oleic acid in the liver and plasma as compared with saline-injected birds (P < 0.05). Stearic acid increased upon LPS injection in the spleen and plasma (P < 0.05). Liver vitamin E content was significantly higher in saline-injected birds from the early high n-3 group compared with all treatment groups, except for the late low n-3 saline-injected birds (P < 0.05). Plasma vitamin E was highest in the early low n-3 LPS-injected birds compared with all other treatment groups (P < 0.05). The COX2:actin ratio in the early high n-3 LPS-injected birds was higher than that of the saline-injected birds of the same treatment (P < 0.05). However, no difference in COX-2 expression was observed between LPS- or saline-injected fed early low n-3, late high n-3, or late low n-3 diets (P > 0.05). No effect of diet, time of feeding, or LPS challenge on plasma isoprostanes was observed (P > 0.05). These results suggest that dietary and management strategies directed at modulating tissue polyunsaturated fatty acid status may offer the promise of modulating lipid metabolism and COX-2 expression in commercial poultry.
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ABSTRACT: Two experiments were conducted to determine the influence of adding neutralized sunflower soapstock (NSS) or soybean oil (SO) to the broiler diet. In experiment 1, one hundred five 15-d-old Ross 308 broiler chickens were used to evaluate the AMEn of NSS by the difference method. In experiment 2, a completely randomized design was used to evaluate the effects of fat source and level on broiler live performance, carcass characteristics, and fatty acid composition of thigh meat. A 2 × 3 factorial arrangement with 2 types of fat (NSS and SO) at 3 levels of inclusion (2, 4, and 6%) was used with 5 replicates per treatment using total of 750 birds. The average AMEn of the NSS was determined as 8,530 kcal/kg. Performance of birds was unaffected by the dietary fat sources. Increasing the fat level from 2 to 6% improved the overall BW gain (P < 0.0001) and FCR (P < 0.001) of broilers, whereas feed intake was unaffected by different fat levels. Hot carcass yield and rib cage weight were higher for SO-fed birds than NSS-fed birds (P < 0.05). Wings and rib cage weights were higher in birds fed the 6% fat diet (P < 0.05). Leg quarter yield decreased with increased levels of fat inclusion (P < 0.01), whereas breast yield increased (P < 0.05). Dietary fat type modified fatty acids of thigh meat, resulting in significantly higher content of C14:0, C16:0, C16:1, C18:1, sum of saturated fatty acids, and sum of monounsaturated fatty acids in birds fed NSS diets, whereas C18:2, C18:3, C20:0, and sum of polyunsaturated fatty acid contents decreased with NSS inclusion (P < 0.05). Saturated fatty acids and monounsaturated fatty acids significantly decreased and polyunsaturated fatty acids increased when dietary fat level increased (P < 0.0001). In conclusion, NSS can be included in broiler diets without any major differences in live performance by modifying the fatty acid profile of meat.The Journal of Applied Poultry Research 01/2013; 22(1):118-131. DOI:10.3382/japr.2012-00656 · 0.59 Impact Factor