The objective of this study was to compare the digestibility of energy and fatty acids (FA) in rice bran oil (RBO) and palm oil (PO) fed to growing Arbor Acre (AA) broilers. A corn-soybean meal basal diet and the basal diet supplemented with 8% RBO or PO were evaluated. A total of 72 AA male broilers (initial BW = 1,173 ± 6 g; age = 22 d) were randomly divided to 3 dietary treatments with 6 replicates of 4 broilers in each. The growth performance and the ME and FA digestibility in oils were compared with a balance experiment of broilers from d 22 to 28. The ME of the RBO diet was greater (P < 0.05) than PO diet and basal diet, and the ME of the PO diet was greater (P < 0.05) than basal diet. However, no statistical difference was observed in the ME intake of broilers fed basal, RBO, and PO diets. To maintain daily ME intake, broilers ingested more basal diet relative to other diets, resulting in increased CP intake (P < 0.01) and retention (P < 0.01) than broilers fed diets supplemented with RBO and PO. This finding resulted in greater (P < 0.01) BWG and ADG from d 22 to 28 for broilers fed the basal diet relative to other diets, but there was no difference for BWG and ADG across oil sources. However, broilers fed RBO had numerically greater BWD and ADG than those fed PO, likely because the RBO provided greater AME, AMEn, AME/GE, AMEn/GE (P < 0.01) as well as ether extract (EE) digestibility (P = 0.0536) relative to PO. The digestibility of palmitic (C16:0), stearic (C18:0), oleic (C18:1), and linoleic (C18:2) were greater (P < 0.01) in RBO than PO, which positively influenced the energy values for RBO. These results indicate RBO has greater ME and digestibility of EE and FA, which positively influenced the growth performance of AA broilers. Therefore, RBO can be used to replace PO in broiler diets.

Phytase activity can be impaired during pelleting because of extreme thermal conditions. This study investigated the effects of dose and source of phytase on phytase activity during the conditioning, pelleting, and cooling process. A split-plot design was used in two experiments, with five phytase doses (Exp. 1; 7560, 14310, 33830, 43590 and 61500 FTU/kg) or eight phytase sources (Exp. 2) as the main plot and steam conditioning temperatures (Exp. 1 and 2; 75 and 85 °C) as the subplot. Each treatment processed four batches, one batch per replicate. The results of Exp. 1 showed phytase dose in diets had no effect (p > 0.05) on the recovery rate of phytase activity after the conditioning, pelleting, or cooling process. The recovery rate of phytase activity in each process was higher (p < 0.05) at 75 °C than that at 85 °C for both Exp. 1 and 2. The phytase source significantly affected (p < 0.05) the recovery rate of phytase activity and had varied appearances of structure. In conclusion, the structure, phytase activity, and phytase recovery after steam conditioning–pelleting significantly varied across sources, but the stability of phytase was not affected by dose.

Background: Reduced nutrient digestibility due to low-protein (LP) diets occurring in the foregut or hindgut of pigs remains unclear. Methods: Growing barrows (21.7 ± 1.7 kg) were allotted into LP and high-protein (HP) diet treatments. Ileal digesta and feces were collected for in vitro cross-fermentation and microbial sequencing, and cross-feeding assessed nutrient digestibility. Results: No difference in foregut digesta flora and nutrient digestibility between treatments was observed. LP diet caused decreased total tract digestibility of dry matter (DM), organic matter (OM), gross energy (GE), neutral detergent fiber (NDF), and acid detergent fiber (ADF) compared with the HP diet (p < 0.05). The fermentation broth from LP diet-fed pigs induced less full fermentation digestion of DM, OM, crude protein, and GE than HP broth (p < 0.05). Additionally, LP broth fermentation presented lower fermentation gas and short-chain fatty acids (SCFAs) generation than HP group (p < 0.05). This situation above may be related to decreased abundances of Lachnospiraceae, Eubacterium_eligens_group, Roseburia, and Ruminococcaceae_UCG-009, which can efficiently ferment nutrients to produce SCFA. Conclusions: Change in the flora caused compromise in hindgut microbial fermentation digestion leads to decreased total tract nutrient digestibility in pigs fed an LP diet.

This study evaluated the effect of an emulsifier on the energetic values of lipids fed to yellow-feathered chickens and established prediction equations for the metabolizable energy (ME) of lipids fed with and without an emulsifier. One hundred and ninety-two Chinese yellow-feathered roosters [Wen’s Yellow A; initial body weight (BW) = 2.37 ± 0.33 kg] were individually weighed, divided into four BW blocks, and randomly assigned within block to the 16 dietary treatments with replicates of three roosters. The diets consisted of a corn basal diet or the basal diet supplemented with 8% of corn oil (CO), soybean oil (SO), cottonseed oil (CSO), rice bran oil (RBO), palm oil (PO), modified palm oil (MPO), or lard were evaluated with or without an emulsifier (0.02% of diet) in an 8 × 2 factorial arrangement. Diets were fed for 8 d, with 4 d for adaptation to diets and another 4 d for excreta collection. There was an interaction between lipid sources and emulsifier on ME (apparent ME and N-corrected apparent ME) of the lipids (P < 0.05). Addition of 0.02% emulsifier had no effect on the ME of CO, SO, PO, or lard, but reduced the ME of CSO (P < 0.05) and MPO (P < 0.05), and tended to increase the ME of RBO (0.05 ≤ P < 0.10). There was a quadratic relationship between ME and concentration of stearic (C18:0) (P < 0.05) or linoleic acid (C18:2) (0.05 ≤ P < 0.10), and a linear function between ME and concentration of oleic acid (C18:1) or monounsaturated fatty acids (P < 0.05) in diets without emulsifier. The ME of lipids could be predicted by the concentration of C18:0 with C18:1 or with monounsaturated fatty acid without an emulsifier. With an emulsifier, the ME concentration was affected linearly by the concentration of myristic acid (C14:0), palmitic acid (C16:0), C18:2, polyunsaturated fatty acids, unsaturated fatty acids, saturated fatty acids, and the ratio of unsaturated to saturated fatty acids (U:S) (P < 0.05). Prediction equations for the ME of lipid were established on the content of C18:0, C16:0, C14:0, SFA, and U:S. These results indicated that the ME of RBO is positively affected by emulsifiers, but the ME of CSO and MPO declines with emulsifiers. These inconsistent results may be influenced by the relationship between ME and concentration of fatty acid across sources of dietary lipids. Considering that commercial diets generally contain 3% to 8% added lipids to provide up to 20% metabolizable energy (ME) in broiler diets, the addition of emulsifier in diets was believed to improve the digestibility of fat. In this experiment, seven sources of lipid with or without emulsifier addition were evaluated for ME in yellow-feathered broilers. Without emulsifier addition, ME values were observed highest for cottonseed oil [4,129 kcal/kg∙ dry matter (DM)] and lowest for rice bran oil (4,036 kcal/kg∙DM) and lard (4,015 kcal/kg∙DM). With emulsifier addition, ME values were highest for soybean oil (4,177 kcal/kg∙DM) and lowest for modified palm oil (4,059 kcal/kg∙DM) and lard (4,024 kcal/kg∙DM). The emulsifier has a positive effect on the ME of rice bran oil, but the ME of cottonseed oil and modified palm oil declines with the addition of emulsifiers. These inconsistent results may be influenced by the relationship between ME and concentration of fatty acids across sources of dietary lipids. Lipids with high concentrations of unsaturated fatty acids are more easily emulsified and better digested than those rich in saturated fatty acids. Additionally, the concentration of C18:0 and C18:1 in lipids contributed to the main variance of ME prediction equation.

Recent studies have discovered that wheat bran could stimulate digestive tract development, modulate intestinal microbiota, and improve the digestibility of fibrous ingredients in broilers. Wheat bran varies greatly in its chemical constituents. The objective of this study is to investigate how different types of wheat bran influence growth performance, nutrient digestion, and gut health in broiler chickens. Eight types of wheat bran were sampled and analyzed for nine constituents. A principal component analysis demonstrated that the wheat bran could be clustered into three groups based on the first principal component, namely low-fiber (LF), medium-fiber (MF), and high-fiber (HF) wheat bran. Wheat bran from the LF, MF, and HF groups significantly differed in terms of the contents of NDF, acid detergent fiber (ADF), hemicellulose, in vitro digestible energy (IVDE), crude fat, and ash (p < 0.05). A total of 324 seven-day-old broiler chicks were grouped into six body weight blocks. Each block of birds was randomly divided into six treatments, fed either a corn–soybean meal basal diet or five experimental diets, including 3% wheat bran from the LF, MF, and HF groups, until d 21. The feed/gain ratio was increased, and the coefficients of dry matter (DM, p = 0.001), gross energy (GE, p = 0.005) digestion, energy (p = 0.039), and CP (p = 0.051) retention were reduced in the birds that were fed 3% HF wheat bran. In contrast, in the birds fed 3% LF wheat bran, the coefficients of nutrient digestion and retention of energy and CP were not affected, but the CP (p = 0.009) and the NDF (p = 0.059) digestion ability were increased when switched to the same diet. In the cecal digesta, Barnesiella was enriched in the birds from the LF group, while Lachnospiracea was enriched in the birds from the MF group. Adding a moderate amount of wheat bran from the LF group could promote protein and fiber digestion and increase the abundance of Barnesiella in broilers.