Supplementation of different fat sources affects growth performance and carcass composition of finishing pigs

Background: There are various fat sources with different energy values and fatty acid compositions that may affect growth performance and carcass composition of grow-finishing pigs. A higher net energy was recently reported in choice white grease compared with soybean oil. Therefore, two experiments were conducted to determine whether practical responses confirm that difference between choice white grease and soybean oil, and to extend the observations to other fat sources.Results: In Exp. 1, pigs fed fats had lower(P < 0.05) average daily feed intake in phase II and overall period,greater(P < 0.05) gain:feed in phase I, phase II, and overall period than pigs fed the control diet. Pigs fed fats tended(P = 0.057) to have thicker backfat depth at the last rib than those fed control. Pigs fed 6% fats had greater(P < 0.01) gain:feed in phase II and overall period than pigs fed 3% fats. During phase I, pigs fed choice white grease grew faster(P < 0.05) than pigs fed soybean oil. In Exp. 2, pigs fed dietary fats(soybean oil, choice white grease, animal-vegetable blend, palm oil, or tallow) had greater(P < 0.01) gain:feed in each phase and overall period, greater(P < 0.01) average daily gain in phase I, but lower(P < 0.01) average daily feed intake in phase II an overall than pigs fed the control diets. The choice white grease also increased(P < 0.05) average daily gain during phase I compared with soybean oil. Pigs fed palm oil had thicker(P < 0.05) backfat depth at the 10 thrib than those fed soybean oil, animal-vegetable blend, or tallow.Conclusions: Inclusion of 6% dietary fat improved feed efficiency of finishing pigs, while different fats produced different practical results that may be consistent with their different energy values. Results from the early stage indicate that dietary fats with relatively more saturated fatty acids may provide greater energy than those with relatively more unsaturated fatty acids for growing pigs.

Integrated transcriptome analysis for the hepatic and jejunal mucosa tissues of broiler chickens raised under heat stress conditions

Background:Heat stress(HS)is one of the most important threats for the current poultry industry.Therefore,many efforts have been made to ameliorate the adverse effect of HS on poultry production;however,physiological and molecular mechanisms pertaining to HS are still limited in poultry.Therefore,the objective of the current study was to investigate functional alterations based on individual and integrated transcriptomes in the liver and jejunal mucosa tissues of broiler chickens exposed to HS conditions.Results:Broiler chickens exposed to HS showed decreased growth performance and increased corticosterone concentrations in the feather.In the transcriptome analysis,the number of differentially expressed genes(DEGs)were identified in the liver and jejunal mucosa by HS conditions.In the liver,genes related to amino acid oxidation,tryptophan metabolism,lipid metabolism,oxidative phosphorylation,and immune responses were altered by HS,which support the reason why heat-stressed poultry had decreased productive performance.In the jejunal mucosa,genes related to defense systems,glutathione metabolism,detoxification of xenobiotics,and immune responses were differently expressed by HS conditions.The integrated transcriptome analysis with DEGs found in the liver and jejunal mucosa showed a considerable connectivity between the core nodes in the constructed networks,which includes glutathione metabolism,xenobiotic metabolism,carbon metabolism,and several amino acid metabolisms.Conclusions:The core network analysis may indicate that increased requirement of energy and amino acids in the jejunal mucosa of broiler chickens exposed to HS conditions is likely compromised by increased oxidation and synthesis of amino acids in the liver.Therefore,our results may provide comprehensive insights for molecular and metabolic alterations of broiler chickens raised under HS conditions,which can aid in the development of the novel strategies to ameliorate the negative effect of HS on poultry productivity and health.

Increasing concentrations of dietary threonine,tryptophan,and glycine improve growth performance and intestinal health with decreasing stress responses in broiler chickens raised under multiple stress conditions

The current study aimed to compare the effects of increasing concentrations of dietary threonine(Thr),tryptophan(Trp),and glycine(Gly)on growth performance,stress biomarkers,and intestinal function in broiler chickens under multiple stress conditions.Five hundred sixty broiler chickens at 21 d old were randomly allotted to 5 treatments with 8 replicates.Birds in a positive control(PC)treatment were raised under low stock density(16.9 birds/m^(2) per cage)with recommended environmental conditions,whereas birds in 4 treatments were subjected to multiple stress conditions:a cyclic heat stress of 30±0.3℃ for 10 h and 23±0.2℃ for 14 h per day with high stock density(25.3 birds/m^(2) per cage).A basal diet was assigned to both PC and negative control(NC)treatments.Three additional diets were individually formulated to contain double concentrations of digestible Thr,Trp,or Gly+Ser compared with their concentrations in the basal diet.The experiment lasted for 14 d.Results showed that NC treatment had less growth performance(P<0.001),jejunal goblet cell counts(P=0.018),and trans-epithelial electrical resistance(TEER;P<0.001),but greater(P=0.026)feather corticosterone(CORT)concentrations than PC treatment.Thr treatment showed the least(P<0.001)feed conversion ratio(FCR)among treatments under multiple stress conditions.Thr,Trp,and Gly treatments had less(P=0.026)feather CORT concentrations,but had greater(P<0.001)TEER than NC treatment.In conclusion,increasing concentrations of dietary Thr,Trp,or Gly improve the growth performance and intestinal health in broiler chickens with decreasing stress response under multiple stress conditions.

Comparative standardized ileal amino acid digestibility and metabolizable energy contents of main feed ingredients for growing pigs when adding dietary β-mannanase

The present study was conducted to test whether the dietary supplementation of β-mannanase affects amino acids(AA) digestibility,metabolizable energy(ME) contents of corn,wheat,soybean meal,distillers dried grains with solubles,and palm kernel meal(PKM),nutrient digestibility,and growth performance of pigs.In Exp.1,22 cannulated pigs were used for 10 dietary treatments including 5 feed ingredients and 2 β-mannanase concentrations(0 and 0.5 g/kg of the diet) in 6 periods in an incomplete Latin square design to determine the AA and energy digestibility.In Exp.2,200 growing pigs were randomly allotted to 4 treatments with 2 nutrient levels(high and low) and 2 concentrations of β-mannanase(2×2 factorial arrangement) in 2 phases(phase 1,d 0 to 21;and phase 2,d 22 to 42).In Exp.1,β-mannanase increased the mean standardized ileal digestibility(SID) of AA in all feed ingredients.The amount of digestible energy was increased(P <0.05) in β-mannanase-treated PKM.Pigs fed β-mannanase showed a greater(P <0.05) digestibility of gross energy(GE).The feed-to-gain(F:G) ratio was improved(P <0.01) in pigs fed high-nutrient diets.Pigs fed β-mannanase in the diets had greater(P <0.05) average daily gain and F:G.In phase 2,the concentration of fecal ammonia was decreased(P <0.05) in pigs fed β-mannanase.Considering the 2 experiments,it can be concluded that β-mannanase increases the SID of AA,which has to be considered in balancing the rations.