Dietary Supplementation Of Organic Acids Research Articles

Impact of dietary supplementation of organic acids on the growth performance and immunity in broilers fed low protein diets

Impact of dietary supplementation of organic acids on the growth performance and immunity in broilers fed low protein diets

Effects of dietary acidification and acid source on fish growth and feed efficiency (Review)

The human population has increased considerably worldwide, including in the Philippines. Aquaculture is one of the main food sectors that provides a cheap source of protein in the Philippines. Changes in diet composition in aquaculture have brought about concerns regarding certain negative effects at the gastrointestinal levels. The replacement of fish meal with a plant protein source in a considerable proportion in the diet of the majority of cultured fish species has led to proliferative and inflammatory responses in the intestines of various (functionally) monogastric animals. In aquaculture feed, the dietary supplementation of organic acids and their salts as growth promoters has been established. The use of acidifiers in aquafeed requires a different approach due to diversified feeding habits and the wide variation in the digestive system structure and physiological function. Dietary organic acids can increase pancreatic enzyme production, decrease stomach pH levels, inhibit pathogens, provide energy, improve mineral utilization and improve nutrient digestibility, all of which improve fish development performance. Acidifiers are currently widely used in animal feed, including aquafeed, and several manufacturers have created next‑generation acidifiers with additional benefits. The present review article discusses the acidifiers, their mechanisms of action, growth, feed efficiency, immunity and future research opportunities. The fish growth rate and feed utilization efficiency are also reviewed as regards dietary acid sources, such as acetic acid, citric acid, hydrochloric acid and control‑no acid. In addition, the attractability of the diets for the fish at different pH levels and dietary acid sources was determined. The survival rates of cultured fishes were determined based on the various dietary acids used. Any acids at an optimum pH level, e.g., pH 4.6 in the diet of tilapia fry, which increase attractability, growth and feed efficiency, warrant further attention.

Effect of dietary organic acids supplementation on growth performance, nutrient digestibility, and gut morphology in weaned pigs

This study was conducted to investigate the effects of dietary supplementation with different organic acid (OA) mixtures on growth performance, nutrient digestibility, and gut morphology in weaned pigs. A total of 56 weaned pigs (7.93 ± 1.04 kg body weight) were assigned to four dietary treatments with seven replicates per treatment for a 35-day study conducted over two phases: phase 1 (day 1 to 14) and phase 2 (day 14 to 35). Diets consisted of (1) a corn–soybean meal basal diet without any additive (negative control, NC); (2) NC + formic and propionic acids (TRT1); (3) NC + butyric, formic, and propionic acids (TRT2); and (4) NC + antibiotic (positive control, PC). During the overall period, the gain to feed ratio of pigs fed the PC and TRT1 diets tended to be higher (P = 0.059) than that of those fed the NC diet. However, OA supplementation had no effects on nutrient digestibility. Jejunal villus height to crypt depth ratio was higher (P < 0.05) in pigs fed the TRT1 diet than those fed the NC diet. In conclusion, dietary OA supplementation tended to increase overall feed efficiency and improved gut morphology in weaned pigs.

PSXVI-29 Late-Breaking: Effect of dietary organic acids supplementation on growth performance, nutrient digestibility, and gut health in weaned pigs

Abstract This study was conducted to investigate the effects of dietary supplementation with different organic acid (OA) mixtures on growth performance, nutrient digestibility, and gut health in weaned pigs. A total of 56 weaned pigs (7.93 ± 1.04 kg BW) were assigned to 4 dietary treatments in a randomized complete block design with 7 replicates per treatment for a 35-d study conducted over two phases; phase 1 (d 1 to 14) and phase 2 (d 14 to 35). Each pen had two pigs balanced for sex. Diets consisted of 1) a corn-soybean meal-basal without any additive (negative control, NC); 2) NC + formic and propionic acids (TRT1); 3) NC + butyric, formic, and propionic acids (TRT2); and 4) NC + antibiotic (positive control, PC). Individual pig body weight and feed disappearance were recorded weekly. At the end of each phase, blood and feces were sampled. The female pig in each pen was euthanized on d 35 to collect digesta and intestinal tissue. Data were analyzed using the PROC MIXED of SAS. During the overall period, ADG tended to be lower (P = 0.069) in the TRT2 group than in the PC group. Diet had no effect on ADFI during the overall period, but G:F of pigs fed the PC and TRT1 diets tended to be higher (P = 0.059) than that of the NC diet. No effects of OA supplementation were observed on nutrient digestibility and blood cytokine. Jejunal villus height to crypt depth ratio was higher (P < 0.05) in TRT1-fed pigs than that of NC-fed pigs. Pigs fed the TRT2 diet had a higher (P < 0.05) fecal abundance of Bifidobacteria than those fed the PC diet in phase 1. In conclusion, dietary OA supplementation had positive effects on growth performance and gut health but no effect on nutrient digestibility in weaned pigs.

Effects of the Inclusion of Dietary Organic Acid Supplementation with Anti-Coccidium Vaccine on Growth Performance, Digestibility, Fecal Microbial, and Chicken Fecal Noxious Gas Emissions

A total of 792 conventional healthy 1-day-old Ross 308 broilers chicks (mixed gender) with average body weight of 42.30±1.14 g (mean ± SD) were used in the experiment, which lasted for 35 days. Chicks were randomly allotted into one of four treatment diets, each one having 11 replicate cages with 18 birds each, being fed corn-soybean meal (SBM) based diets. Dietary treatments were CON (basal diet with unvaccinated birds); OA = CON + 0.1% organic acids; ACB = CON + anti-coccidium vaccine; OAACV = CON + 0.1% organic acid + anti-coccidium vaccine. Significant results were observed, with improved body weight (p=0.059; 0.064; 0.034) during days 1-7, 8-21, and overall, respectively. Significant effects were also observed on the feed conversion ratio (p=0.037) through the overall experiment, with no effects on feed intake on OAACV as compared to other treatment groups. Total track digestibility of dry matter (p=0.049) improved significantly in the OAACV treatment group. Additionally, beneficial effects were observed in the OAACV treatment group, with improvements in fecal microbial population (increased lactobacillus) and reduced NH3 gas emissions. Broilers fed the OAACV treatment tended to display reduced drip loss in the meat samples analyzed on days 5 and 7 (p=0.067, 0.072). In summary, our findings revealed that dietary inclusion of organic acid supplementation with anti-coccidium had a beneficial effect on broilers affected by coccidian infection, also improving growth performance, digestibility, fecal Lactobacillus counts, and reducing NH3.

Effects of Microencapsulated Blend of Organic Acids and Essential Oils as a Feed Additive on Quality of Chicken Breast Meat.

Simple SummaryChicken meat is largely consumed around the world, with an increasing demand in recent years. Unfortunately, chicken meat is very susceptible to oxidative deterioration; therefore, poultry industries often use synthetic dietary additives to improve meat shelf-life. However, due to the public’s growing concern about the potential toxic effect of the synthetic additives, there is an increasing interest in natural antioxidant compounds. Among these, organic acids and essential oils could represent a favourable option to improve the characteristics of chicken meat. The aim of this study was to evaluate the dietary supplementation of organic acids (sorbic and citric) and essential oils (thymol and vanillin) on the quality and shelf-life of broiler meat. The additive was supplemented for the entire growing cycle at the level of 0.5% (as a feed additive). This dietary strategy led a reduction in intramuscular fat content and an overall improvement in fatty acid profile. Moreover, the dietary supplementation of organic acids and essential oils reduced the lipid oxidation in cooked meat, whereas minor changes were observed for colour and lipid stability and for microbial loads in raw meat.The present study aims to investigate the effect of dietary supplementation based on a blend of microencapsulated organic acids (sorbic and citric) and essential oils (thymol and vanillin) on chicken meat quality. A total of 420 male Ross 308 chicks were randomly assigned to two dietary treatments: the control group was fed with conventional diet (CON), while the other group received the control diet supplemented with 0.5% of a microencapsulated blend of organic acids and essential oils (AVI). In breast meat samples, intramuscular fat content and saturated/polyunsaturated fatty acids ratio were reduced by AVI supplementation (p < 0.05). Moreover, atherogenic (p < 0.01) and thrombogenic (p < 0.05) indices were lower in AVI than CON treatment. AVI raw meat showed a lower density of psychrotrophic bacteria (p < 0.05) at an initial time, and higher loads of enterococci after 4 days of refrigerated storage (p < 0.05). No contamination of Listeria spp., Campylobacter spp., and Clostridium spp. was found. TBARS values of the cooked meat were lower in the AVI treatment compared to CON (p < 0.01). Among colour parameters, a*, b* and C* values increased between 4 and 7 days of storage in AVI cooked meat (p < 0.05). Overall, organic acids and essential oils could improve the quality and shelf-life of poultry meat.

Effect of dietary supplementation of organic acids and clove essential oil on broiler performance

Gole, M.A., Manwar, S.J., Kuralkar, S.V., Waghmare, S.P. and Hajare, S.W. 2020. Effect of dietary supplementation of organic acids and clove essential oil on broiler performance. Indian Journal of Poultry Science, 55(1): 23–30.

Acidifiers in aquafeed as an alternate growth promoter: A short review

Optimum nutrient utilization is the key for accelerating the growth of fish and augmenting the production potential. Consumer preference for the antibiotic-free fish and fish products attracted the scientists to find out natural growth promoter, as an alternative to antibiotic growth promoters in aquafeed. Dietary supplementation of organic acids and their salts as growth promoter has been proven in animal feed and well documented. Aquafeed sector has equally benefitted with this novel additive though it was lately introduced. However, unlike animal feed the use of acidifier in aquafeed needs a different approach due to diversified feeding habit and wide variation in structure of the digestive system and physiological function. Dietary organic acids can stimulate secretion of pancreatic enzymes, lower gastric pH, in hibit pathogens, act as a source of energy, improve mineral utilization and enhance nutrient digestibility, which could lead to enhanced growth performance of fish. It is envisaged that intensive aquaculture will be the major focus in coming decades to supply the quality protein to the burgeoning population with the limited water, land and feed resources. As aquafeed sector has to depend more on plant based feed due to scarcity of fish meal, the gut health management is the most critical factor to be considered for sustainable aquaculture. Feeding of unconventional plant ingredients containing some anti-nutritional factors, adversely affect the gut microbiota of fish. In this context, feeding acidifier facilitate better nutrient digestion by restoring the microbial composition of gut. Now acidifier is commonly used in animal feed including aquafeed and some next generation acidifier has been introduced by many manufactures with added advantage. The present review describes the acidifiers, their mode of action, effect on growth and immunity with future research scope.

Effect of dietary supplementation of formic acid, butyric acid or their combination on carcass and meat characteristics of broiler chickens

The objective of the present study was to evaluate the impact of dietary supplementation of formic acid, butyric acid or their combination on carcass and meat characteristics of broiler chicks. A number of 288 day-old-chicks (Lohmann MB-202 meat broilers) were distributed to four groups, including CONT (basal diet with no additive as a control), FORM (basal diet containing 0.1% formic acid), BUTR (basal diet with 0.03% butyric acid) and FORM+BUTR (basal diet with 0.1% formic and 0.03% butyric acid). At day 35 the birds were slaughtered and eviscerated, and from which the breast meat was obtained. Carcass and cut yields of broilers were not different (P&gt;0.05) among CONT, FORM and BUTR birds. The combination of formic and butyric acids increased (P&lt;0.05) the relative weight of back of broilers. Meat pH value was higher (P&lt;0.05) in organic acids treated than in non-treated birds. Organic acids lowered (P&lt;0.05) drip loss of broiler meat. Butyric acid increased (P&lt;0.05) moisture and decreased (P&lt;0.05) the content of meat protein. Formic acid increased (P&lt;0.05), whereas butyric acid and combination of formic and butyric acids decreased (P&lt;0.05) lightness values of breast meat. Yellowness values of meat increased (P&lt;0.05) with organic acid administration. Intense bands of 25 kDa (phosphoglycerate mutase) was observed in most of meat samples from the treated birds, but not in meat from the control birds. In conclusion, dietary supplementation of organic acids was capable of improving the meat quality of broiler meats. The treatments may prevent the pale, soft and exudative (PSE)-like condition in broiler meats.

Efficacy of organic acids as an alternative to antibiotic growth promoters in weaned pigs

The objective of the experiment was to compare effects of dietary supplementation of organic acids (ProHacid Advance, PRO) and antibiotics on growth performance, diarrhea incidence, frequency of antibiotic treatment, and E. coli shedding in weaned pigs. A total of 224 crossbred weaned pigs [(Yorkshire x Landrace) x Duroc; 29 days old)] were allotted to 1 of 4 treatments with 7 replicate pens of 8 pigs each according to sex, litter origin and weight in an RCBD. The 4 dietary treatments included (1) basal diet + 50 mg/kg neomycin and 10 mg/kg enramycin (positive control, PC), (2) basal diet without antibiotics (negative control, NC), (3) As 2 + 0.25% PRO, and (4) As 2 + 0.5% PRO. Over a 4-week study, the results showed that there were no differences in the average daily gain and average daily feed intake of pigs among the 4 treatments (P = 0.328). However, pigs fed the PC diet (1.642) and 0.25% PRO-supplemented diet (1.641) had a lower feed to gain ratio (P &lt; 0.05) than those fed the NC diet (1.808). The diarrhea incidence of pigs fed the 0.25% PRO-supplemented diet (7.36%) was lower (P &lt; 0.01) than that of pigs fed the PC diet (11.61%), NC diet (16.70%), and 0.5% PRO-supplemented diet (10.08%). The frequency of antibiotic treatment of pigs consuming the 0.25% PRO-supplemented diet (4.67%) was lower (P &lt; 0.01) than that of pigs consuming the PC diet (7.33%), NC diet (9.53%) and 0.5% PRO-supplemented diet (7.65%). No differences were found in the number of fecal E. coli among the 4 treatments. In brief, 0.25% PRO added to a nursery pig diet would be considered a potential alternative to the use of antibiotics in feed, but further research on this aspect is needed

Effect of pad-fan cooling and dietary organic acid supplementation during late gestation and lactation on reproductive performance and antioxidant status of multiparous sows in hot weather.

A 2 × 2 factorial arrangement (rearing room with or without pad-fan cooling × diet with or without 2.5kg/t organic acid) was used to evaluate the effect of pad-fan cooling and dietary organic acid supplementation during perinatal period on reproductive performance and antioxidant status of sows in hot weather. This study was conducted in a subtropical city in Guangdong Province in South China between August and October, 2015. At day 85 of gestation, a total of 112 sows were randomly assigned to the four treatments with 28 sows per treatment, and maintained until day 21 of lactation, and the feeding trial lasted for 51days. During the experimental period, room temperature and humidity were recorded hourly. The lactation feed intake of sows (P = 0.109) and stillbirths (P< 0.05) increased when the sows were reared in the room with the pad-fan cooling against the room without pad-fan cooling. The number of weak newborns per litter and the malondialdehyde content in days 14 and 21 milk decreased (P< 0.05), while the lactation feed intake of sows, weaned litter weights, and individual pig weights increased when the sows were fed the organic acid (P< 0.05). In conclusion, pad-fan cooling in rearing room improved the lactation feed intake of sows, and dietary organic acid supplementation improved reproductive performance and milk antioxidant status of sows. Pad-fan cooling is recommended in farrowing room, but not in gestating room.

Influence of Dietary Supplementation of Organic Acids, Probiotics and Their Combinations on Growth, Carcass Traits and Serum Parameters in Broiler Chicken

The aim of the present study was to investigate the effect of dietary supplementation of probiotics, organic acids and their combination on the performance of broiler chicken. For this, day-old commercial male broiler chicks (120 No.) were randomly divided into four groups with six replicates of five birds each. The groups consisted of a control diet (flavomycin 650 g/tonne; T1), probiotics (Protexin @ 500 g/tonne; T2), commercial organic acid (Biotronic SE @ 3 kg/ton; T3) and combination of probiotics + acidifier (T4) at their respective inclusion rates and the study continued for 42 days. The weight gains and FCR was better (P<0.05) in probiotics and organic acid groups compared to control group. The values of carcass traits, blood glucose and triglycerides concentration were similar in all the treatments. On the other hand the values of abdominal fat percentage, serum total cholesterol and E. coli count in small intestine were lower (P<0.05) in all treatments compared to antibiotic added group.

Effects of commercial organic acid blends on male broilers challenged with E. coli K88: Performance, microbiology, intestinal morphology, and immune response

This study assessed the effects of 3 commercial organic acid (OA) preparations on growth performance, intestinal morphology, cecal microbiology, and immunity of Escherichia coli K88-challenged (ETEC) broiler chickens. One thousand one-day-old male broiler chickens were divided into 8 treatments of 5 replicate pens: Negative control (NC) birds received a basal diet (BD) and were not challenged with ETEC; positive control (PC) birds fed the BD and challenged with ETEC; BD + 0.2% (S1) or 0.4% (S2) of an OA mixture (Salkil) from one to 35 d; BD + 0.1, 0.075, and 0.05% (O1) of another OA mixture (Optimax) in the starter (one to 10 d), grower (11 to 24 d), and finisher (25 to 35 d) diets, respectively, or 0.1% (O2) from one to 35 d; BD + 0.07, 0.05, and 0.05% (P1) or 0.1, 0.07, and 0.05% (P2) of a further OA mixture (pHorce) in the starter, grower, and finisher diets, respectively. All groups (not NC) were challenged with one mL of ETEC (1 × 108 cfu/mL) at 7 d of age. The 3 OA mixtures are commercial formic and propionic acid preparations. Birds challenged with ETEC (PC) had reduced (P < 0.05) growth performance, ileal morphological parameters (not crypt depth, which was increased), cecal lactobacilli, and immune responses, and increased cecal E. coli compared with unchallenged, NC birds. The addition of OA to the diets of ETEC challenged birds (S1-P2) either numerically or significantly (P < 0.05) improved growth performance, ileal morphology and immune responses, increased cecal lactobacilli, and reduced cecal E. coli. For most OA additions, the assessed parameters were generally enhanced to equivalence to NC birds. The results suggest that dietary OA supplementation can enhance the growth performance, ileal morphology, cecal microbiota, and immunity of ETEC-challenged broilers to an extent that, under such circumstances, the formulations used in this study provided similar performance and assessed parameters as non-challenged birds.

Effect of Dietary Supplementation of Organic Acids in Combination on Performance and Carcass Traits of Broiler Chicken

The present study was carried out with an objective to investigate the production performance and carcass traits of broilers fed with different organic acid combination supplemented diets. Basal pre-starter, starter and finisher broiler diets were formulated as per the nutrient requirements (ICAR, 2013). Six experimental diets, viz. T1 (Basal diet), T2 (Basal diet+antibiotic @ 50 g/100 kg), T3 (Basal diet+20: 40: 40 combination of citric, formic and propionic acids @ 1.5 g/100g), T4 (Basal diet+30: 40: 30 combination of citric, formic and propionic acids @ 1.0 g/100g), T5 (Basal diet+ 30: 30: 40 combination of citric, formic and propionic acids @ 1.0 g/100g), T6 (Basal diet+10: 45: 45 combination of citric, formic and propionic acids @ 1.5 g/100g) were prepared. Two hundred and seventy day old, straight run commercial broiler chicks were distributed randomly to six treatments with three replicates of fifteen birds each and fed with the experimental diets from 0 to 42 days of age. Body weight gains and feed efficiency were significantly (P 0.05) difference in the ready-to-cookyields among the groups, but significantly (P<0.05) increased giblet yields on % live weight basis. The organic acid combination of citric, formic and propionic at 20: 40: 40 combination could be safely incorporated at 1.5% level in broiler diets for better performance.

Effects of dietary organic acid supplementation on the growth, nutrient digestibility and intestinal histology of the giant grouper Epinephelus lanceolatus fed a diet with soybean meal

The purpose of this study was to evaluate the effects of dietary organic acid (butyrate and lactate) supplementation on the growth, nutrient digestibility and intestinal histology of the giant grouper Epinephelus lanceolatus that was fed a diet containing soybean meal. The diet that included soybean meal, which replaced 40% fish meal protein, was used as the control. One percent butyrate and lactate were added to the control diet to form the two experimental diets. Also, the all fish meal diet without organic acid was also included for comparison. A total of four experimental diets were each fed to three groups of giant grouper (initial wt: 17.37±0.18g) in a recirculating rearing system for 8weeks. After the growth trial, the nutrient digestibility by the fish was determined by using 0.5% chromic oxide as an inert indicator. The fish fed the all fish meal diet gained more (P<0.05) weight than fish fed the control and the 1% lactate diets. The hepatic thiobarbituric acid reactive substance (TBARS) value was higher in the fish fed the control diet than that in other dietary treatments. Dry matter, lipid, copper (Cu), zinc (Zn), calcium (Ca) and phosphorus (P) digestibility were higher in fish fed the all fish meal diet, the 1% butyrate and lactate supplemented diets than the fish fed the control diet. The fish fed the control diet showed disordered lamina epithelialis and extended lamina propria comparing to the fish fed the all fish meal diet and 1% butyrate-diet. The results indicated that growth, nutrient digestibility and intestinal histology were adversely affected by replacement of the fish meal by soybean meal in giant grouper. The diet supplemented with 1% butyrate improved the negative effects excluding growth for the fish. Statement of relevanceTo evaluate feed additives on growth, nutrient digestibility and intestinal histology of giant grouper fed diets with soybean meal.

Effects of different organic acids on performance, ileal microflora, and phosphorus utilization in laying hens fed diet deficient in non-phytate phosphorus

The present study was conducted to investigate the effect of dietary supplementation of organic acids (OA) on performance and phytate phosphorus utilization in laying hens fed diets with different non-phytate phosphorus (NPP) levels. A total of 240 Hy-Line W-36 laying hens, 32-wk-old, were randomly allocated into the 8 dietary treatments with 5 cage replicates of 6 birds each. The main trial period lasted for 10 wk (34–44 wk of age), following a 2 wk adaptation period (32–34 wk of age). Dietary treatments consisted of a 4×2 factorial arrangement of treatments, including 4 supplemental OA (control, citric, butyric, or fumaric acids, 5g/kg of diet) and 2 different NPP levels (60 or 100% of Hy-Line W-36 recommended values). Results showed that dietary OA supplementation increased (P<0.05) egg production percentage, with the greatest values assigned to the hens fed citric and butyric acids-supplemented diets. Reducing dietary NPP level resulted in a marked decrease in egg production in control hens, while OA supplementation of the NPP-deficient diet could maintain egg production and egg mass, resulted in the significant (P<0.05) OA×NPP interactions. Although feed intake was not affected by dietary treatments, supplemental OA improved (P<0.05) feed conversion ratio in NPP-deficient hens (OA×NPP, P<0.05). Dietary OA supplementation increased (P<0.05) eggshell thickness; however, it had no marked impact on shell breaking strength. Serum lipid metabolites were influenced by dietary OA supplementation, so that supplemental OA decreased (P<0.01) serum cholesterol level and increased (P<0.001) serum high-density lipoproteins. Feeding the NPP-deficient diet decreased (P<0.01) tibia ash and increased (P<0.001) serum alkaline phosphatase activity. On the other hand, dietary supplementation of fumaric acid increased (P<0.01) tibial ash and Ca contents compared to the control hens. Tibia P content was lower (P<0.05) in hens fed the NPP-sufficient diet. Inclusion of citric acid into the NPP-deficient diet increased tibia P, resulted in a significant (P<0.001) OA×NPP interaction. Dietary supplementation of OA reduced (P<0.01) ileal enumeration of Salmonella, and the lowest (P<0.05) Escherichia coli count was observed for hens supplemented with butyric acid. The present findings indicate that dietary OA supplementation can increase egg production, egg mass, and eggshell thickness in hens fed the NPP-deficient diet. The beneficial impact of citric acid on tibia P content of NPP-deficient hens suggests that supplemental OA could improve P utilization even in young laying hens.

Effect of supplemental organic acids on performance, carcass characteristics, and serum biochemical metabolites in broilers fed diets containing different crude protein levels

The present study was conducted to investigate the effect of dietary supplementation of organic acids (OA) on performance and carcass characteristics of broiler chickens fed diets with different crude protein (CP) levels. A total of 540 day-old broiler chickens were assigned to 9 dietary treatments in a 3×3 factorial arrangement with 4 replicate pens and 15 broiler chickens per pen. Dietary treatments consisted of 3 different CP levels (high, medium, and low) and 3 dietary OA supplementation (control, 2.5g citric acid/kg, and 2.5g butyric acid/kg). Dietary CP levels in high-CP diets were 230, 210, and 190g/kg during starter, grower, and finisher periods, respectively. The respective values were 220, 200, and 180g/kg for medium-CP, and 210, 190, and 170g/kg for low-CP diets. The study lasted for 42 d. Performance variables including average daily gain (ADG), feed intake (ADFI), and feed conversion ratio (FCR) were measured biweekly. At the end of study, 2 randomly selected birds per pen were slaughtered to measure carcass traits. Furthermore, serum samples of 42-d-old broilers were analyzed for blood metabolites. Results showed that although ADFI and FCR values were not affected by CP levels, reducing dietary CP level (medium+low) decreased ADG during starter (P=0.092) and grower (P=0.053) periods. At the finisher phase, however, ADG was similar among different CP groups. Dietary supplementation of citric acid increased ADG (P=0.062) during starter period. In addition, OA supplementation of diets (citric+butyric) increased (P=0.002) ADG at the finisher period, resulting in improved (P=0.027) FCR values. Supplemental OA increased ADG only in broilers fed diets containing higher CP levels (high- and medium-CP diets), resulting in a CP×OA interaction (P=0.024) during the finisher period. The relative liver weight and carcass yield were decreased (P<0.05) by reducing dietary CP level (medium+low), while abdominal fat percentage was increased (P<0.001), with the greatest (P=0.004) abdominal fat allotted to broilers fed low-CP diet. Dietary OA supplementation (citric+butyric) increased (P=0.016) carcass yield, while reduced (P<0.001) relative gizzard weight. Although serum concentrations of high- and low-density lipoproteins and cholesterol were not affected by dietary CP level, feeding low-CP diet increased (P<0.001) serum triglyceride level compared with higher CP levels. Serum concentration of uric acid was decreased (P<0.001) as the result of reducing dietary CP level (medium+low). The present findings indicate that dietary CP level can be reduced by 2 percentage points if the most limiting amino acids are provided at the sufficient levels. On the other hand, dietary OA supplementation increased weight gain in the finisher period and carcass yield of broiler chickens.

Effects of organic acid supplementation on antioxidant capacity and immune responses of broilers challenged orally with &lt;i&gt;Salmonella enterica&lt;/i&gt; subsp. &lt;i&gt;enterica Typhimurium&lt;/i&gt;

Four commercial organic acids and a reference antibiotic, Neoxyval, were administered to commercial broilers to evaluate the efficacy of these products during pre- and post-challenge with Salmonella enterica subsp. enterica Typhimurium (S. Typhimurium) on selected indicators of their antioxidant status and immune responses in serum. Two hundred and eight broilers received one of the following seven treatments: positive control group (CTL+); negative control (CTL.); antibiotic Neoxyval, (NEOX); Gallimix (GALI); FormaXOL (FORMA); Fysal (FYS); and Selko-pH in drinking water (SELK). The chicks in treatments T2 to T7 were challenged with (3 x109 cfu/mL) of S. Typhimurium on day 16. Each treatment consisted of 10 cage replicates with four birds per cage for a starter (0 - 14 days of age) and a finisher (15 - 42 days of age) period. The results revealed that the total antioxidant capacity (TAC) value was highest when birds were supplemented with organic acids, with the highest value for FORMA (0.70 mM), which was not different from those of the FYS (0.67 mM), SELK (0.66 mM) and GALI (0.64 mM) treatments. Birds receiving treatment, CTL., produced the highest H2O2 value (75.9 iM), while, FYS, FORMA and SELK lowered H2O2 concentration significantly (51.1, 53.8 and 55.0 iM, respectively). Anti-Salmonella titre was significantly improved by dietary organic acid supplementation. The highest Salmonella titre was recorded for birds that received FORMA (1.54) as compared with all other treatments. Week of sampling showed a significant effect on Salmonella and Newcastle disease titres. In summary, the tested organic acids, especially FORMA, had a positive influence on TAC and Salmonella titres and reduced the H2O2 concentration in serum. Keywords : Broilers, immune responses, organic acids, oxidative stress, total antioxidant capacity

Effect of the commercial product Lumance™, a combination of partly esterified organic acids and plant extracts, on the productive performance of broiler chickens

SummaryThe present study was conducted to determine the effect of dietary supplementation of organic acids combined with synergistic components, using a commercial product Lumance™ (Innovad NV, Belgium) containing esterified butyrins, propionic acid and sorbic acid, with medium chain fatty acids (capric, caprylic, and lauric acid) and plant extracts, on the productive performance and mortality of growing broiler chickens. A total of 492, one day old broiler chicks (Ross 308) were randomly allocated to four experimental treatments either with an unsupplemented control or 0.05, 0.1 or 0.15% organic acid mixture in a pelleted corn/soyabean meal diet, which were offered ad libitum until 35 days of age. Results showed that birds in the 0.1% supplemented diet group gave significantly higher (P &lt; 0.05) body weights during the first two weeks of age and increased weight gain during the first three weeks of age. The inclusion had no effect on broiler mortality.

Effects of non-antibiotic feed additives on performance, immunity and intestinal morphology of broilers fed different levels of protein

In order to investigate the effects of the dietary supplementation of organic acids, prebiotics and probiotics on broiler chickens, a total of 288 day-old male Cobb chicks were allocated in a completely randomized design according to a 2 × 4 factorial, consisting of two levels of crude protein (recommended or low (85% of recommended)) and a four feed-additive programme. The basal diet without any feed additive served as control and one of the following additives, organic acids, a prebiotic and a probiotic, were added to the basal diet to form the other treatments. Starter and finisher diets were offered from 1 to 21 d and 22 to 42 d of age, respectively. The birds were reared in an open-sided house system under natural tropical conditions with the same housing and general management practices. Lowering the dietary protein level significantly decreased bird performance throughout the experiment. Additives had no significant effects on body weight, body weight gain and feed intake. Dietary supplementation with the prebiotic resulted in significant improvements in feed efficiency during 22 - 42 d and 1 - 42 d of age. At 21 and 42 d of age birds fed the diets containing the prebiotic had the longest duodenal villi compared to the other treatments. Jejunum villi, and duodenum and jejunum crypt depth were not influenced by additives. At 21 d of age the dietary addition of the prebiotic and organic acids significantly increased the antibody titres against Newcastle disease compared to the control group. It could be concluded that under the condition of the current study, the prebiotic affected performance, small intestinal morphology and immunity of broiler chickens significantly.