Evaluating the effects of benzoic acid on nursery and finishing pig growth performance

Three studies were conducted evaluating the use of benzoic acid in swine diets. In experiment 1, 350 weanling barrows (DNA 200 × 400; initially 5.9 ± 0.04 kg) were allotted to one of the five dietary treatments with 14 pens per treatment. Diets were fed in three phases: phase 1 from weaning to day 10, phase 2 from days 10 to 18, and phase 3 from days 18 to 38. Treatment 1 contained no benzoic acid throughout all three phases (weaning to day 42). Treatment 2 included 0.50% benzoic acid throughout all three phases. Treatment 3 contained 0.50% benzoic acid in phases 1 and 2, and 0.25% benzoic acid in phase 3. Treatment 4 contained 0.50% benzoic acid in phases 1 and 2, and no benzoic acid in phase 3. Treatment 5 contained 0.50% benzoic acid in phase 1, 0.25% benzoic acid in phase 2, and no benzoic acid in phase 3. For the overall period, pigs fed 0.50% in the first two phases and 0.25% benzoic acid in the final phase had greater (P < 0.05) average daily gain (average daily gain) than pigs fed no benzoic acid through all three phases, or pigs fed 0.50% in the first two phases and no benzoic acid in the final phase, with pigs fed the other treatments intermediate. Pigs fed 0.50% in the first two phases and 0.25% benzoic acid in the final phase had improved (P < 0.05) gain-to-feed ratio (G:F) compared with pigs fed no benzoic acid throughout all three phases, pigs fed 0.50% in the first two phases and no benzoic acid in the third phase, or pigs fed 0.50%, 0.25%, and no benzoic acid, respectively. For experiment 2, a 101-d trial was conducted using two groups of 1,053 finishing pigs (2,106 total pigs; PIC 337 × 1,050; initially 33.3 ± 1.9 kg). Dietary treatments were corn-soybean meal-dried distillers grains with solubles-based with the addition of none, 0.25%, or 0.50% benzoic acid. Overall, pigs fed increasing benzoic acid had a tendency for increased average daily feed intake (linear, P = 0.083) but decreased G:F (linear, P < 0.05). In experiment 3, 2,162 finishing pigs (DNA 600 × PIC 1050; initially 31.4 ± 2.2 kg) were used in a 109-d trial. Dietary treatments were formulated with or without 0.25% benzoic acid. For the overall experimental period, pigs fed benzoic acid had increased (P < 0.05) G:F. In summary, feeding benzoic acid elicits improved growth performance when fed throughout the entire nursery period while improved G:F in growing-finishing pigs was observed in one experiment, but not in the other.

Effects of Dietary Lactic Acid Supplementation on the Activity of Digestive and Antioxidant Enzymes, Gene Expressions, and Bacterial Communities in the Intestine of Common Carp, Cyprinus carpio

The present study investigated the effects of dietary lactic acid (LA) supplementation on the growth performance, intestinal digestive/antioxidant enzymes' activities, gene expression, and bacterial communities in common carp, Cyprinus carpio. Four diets were formulated to contain 0 g/kg LA (control), at 2.5 g/kg LA (2.5LAC), 5 g/kg LA (5LAC), and 10 g/kg LA (10LAC) and offered to the fish over a period of 56 days. The results showed that dietary 5 g/kg LA supplementation improved growth performance and feed efficiency in the fish. All LA treatments exhibited significant elevations in the intestinal trypsin and chymotrypsin activities, whereas the intestinal lipase, amylase, and alkaline phosphatase activities exhibited significant elevations in the 5LAC and 10LAC treatments. All LA treatments exhibited significant elevations in the intestinal heat shock protein 70, tumor necrosis factor-alpha, interleukin-1 beta, and defensin gene expressions, and the highest expression was observed in the 5LAC treatment. Additionally, dietary LA treatment significantly increased the lysozyme expression and Lactobacillus sp. population in the intestine of the fish, and the highest values were observed in the 5LAC and 10LAC treatments. Aeromonas sp. and Vibrio sp. populations decreased in the LA treatments, and the lowest Aeromonas sp. population was observed in the 10LAC treatment. The intestinal mucin2 and mucin5 expressions, and the hepatic reduced glutathione content, significantly increased, whereas hepatic glutathione peroxidase, glutathione reductase, and malondialdehyde significantly decreased in the 5LAC and 10LAC treatments. In conclusion, dietary 5 g/kg LA is recommended for common carp feeding to improve growth rate, antioxidant capacity, and intestinal health.

The effect of acidifier supplementation on egg production performance and intestinal histology of Japanese quail (Coturnix japonica)

BACKGROUND

Acidifier are substances with antibacterial, antifungal, antimicrobial, performance and health benefits that are frequently employed in feed acidification, especially in poultry diet. Meanwhile, the most important factor for acidifier efficiency is the proportion of different acids in the final product.

OBJECTIVES

This study aimed to investigate the effect of dietary supplementation of a commercial acidifier on egg production and histology of the small intestine in laying Japanese quail.

METHODS

One-hundred and sixty female quails at 15 weeks of age were divided into four groups and fed basal diet supplemented with different levels of acidifier (0, 1, 2 and 3 gr acidifier/kg of basal diet) for 8 weeks. Egg production, egg quality attributes and body weight (BW) were measured every 2 weeks. Histology of the small intestine and bacterial population of cecum as well as pH of crop, duodenum, jejunum, ileum and cecum contents were also investigated at the end of the experiment.

RESULTS

Feed conversion ratio (FCR), yolk height, shell thickness, pH of the duodenum, jejunum, ileum, cecum; duodenum, villus width (VW), villus height (VH), crypt depth (CD); jejunum VH, VW and ileum VH to CD ratio (VCR) were linearly improved by the increasing levels of acidifier supplementation (P < 0.05). Duodenum VH increased in a linear and quadratic manner in response to increasing levels of acidifier. Egg weight, yolk diameter, jejunum CD, ileum CD, ileum VW, duodenum CD and jejunum VCR quadratically improved by grading levels of acidifier (P < 0.01). BW, albumen height, Haugh unit, ileum VH and ileum VCR were cubically enhanced (P < 0.05). Acidifier supplementation enhanced egg production, FCR, jejunum, ileum and cecum pH and VH, CD and VW of duodenum and jejunum, compared to the control group (P < 0.05); however, dietary acidifier did not affect egg mass, gizzard pH, ileum VH and bacterial count of the cecum (P > 0.05).

CONCLUSIONS

In conclusion, as calculated, the supplementation of 1 and 2.6 g acidifier per kg of diet was associated with beneficial effects on egg production and quality, gastrointestinal tract pH and histology of the small intestine in laying quails.

Bio-Fermented Malic Acid Facilitates the Production of High-Quality Chicken via Enhancing Muscle Antioxidant Capacity of Broilers

Malic acid, an intermediate of the tricarboxylic acid (TCA) cycle, is a promising acidifier with strong antioxidant capacity. This study aimed to evaluate the effects of bio-fermented malic acid (BFMA) on promoting the body health, performance and meat quality of broilers. A total of 288 one-day-old Arbor Acres male broiler chicks were randomly divided into four treatments with six replicates in each. Every replicate had 12 chicks. Four experimental diets contained 0, 4, 8, and 12 g/kg BFMA, respectively. During the 42-day trial, mortality was recorded daily, feed intake and body weight of each replicate being recorded every week. Blood samples were collected on days 21 and 42 for chemical analysis. After slaughter at the age of 42 days, the carcass traits and meat quality of the broilers were measured, breast muscle samples were collected for the determination of antioxidant capacity, and cecal digesta were pretreated for microbiota analysis. Dietary BFMA significantly increased feed intake and daily gain, and decreased feed conversion ratio and death and culling ratio of the broilers at the earlier stage. The water-holding capacity of breast muscle indicated by the indexes of dripping loss and cooking loss was significantly increased by BFMA, especially at the addition level of 8 g/kg. Dietary BFMA significantly decreased the activity of superoxide dismutase and contents of immunoglobulin A and glutathione, and increased contents of immunoglobulin G and M in serum of the broilers. The contents of glutathione, inosinic acid, and total antioxidant capacity and the activities of glutathione-Px and superoxide dismutase were significantly increased by dietary BFMA, with the level of 8 g/kg best. The diversity of cecal microbiota of broilers was obviously altered by BFMA. In conclusion, as one of several acidifiers, addition of BFMA in diets could improve the performance and body health of broilers, probably by reinforcing immunity and perfecting cecal microbiota structure. As one of the intermediates of the TCA cycle, BFMA increases the water-holding capacity of breast muscle of broilers, probably through reducing lactate accumulates and enhancing antioxidant capacity.

Drinking Water Supplemented with Acidifiers Improves the Growth Performance of Weaned Pigs and Potentially Regulates Antioxidant Capacity, Immunity, and Gastrointestinal Microbiota Diversity

This study evaluated the potential effects of adding acidifiers to the drinking water on the growth performance, complete blood count, antioxidant indicators, and diversity of gastrointestinal microbiota for weaned pigs. A total of 400 weaned pigs were randomly divided into four treatments. Pigs were fed the same basal diet and given either water (no acidifier was added, control) or water plus blends of different formulas of acidifiers (acidifier A1, A2, or A3) for 35 days. On d 18 and 35 of the experimental period, 64 pigs (four pigs per pen) were randomly selected to collect blood for a CBC test (n = 128) and an antioxidant indicators test (n = 128); 24 pigs (six pigs per group) were randomly selected to collect fresh feces (n = 48) from the rectum for 16S rRNA gene sequencing. Compared to the control, supplementing the drinking water with acidifiers improved the growth performance and survival rate of weaned pigs. Acidifier groups also increased serum catalase (CAT) and total antioxidant capacity (T-AOC) activities, while also displaying a decreased malondialdehyde (MDA) concentration compared to the control. The relative abundance of Firmicutes in the acidifier A1 group was greater than that in the control group (p < 0.05) on d 35; the relative abundance of Lactobacillus in the acidifier A1 group was greater than that in the control group (p < 0.05) on d 18 and 35. The microbial species Subdoligranulum or Ruminococcaceae_UCG-005 had significantly positive correlations with ADG and ADFI or with serum antioxidant indicators, respectively. These findings suggest that supplementing the drinking water with an acidifier has a potential as an antioxidant, which was reflected in the improvement of growth performance, immunity, antioxidant capacity, and intestinal flora.

Evaluation of microencapsulated organic acids and botanicals on growth performance of nursery and growing-finishing pigs

A total of 1,215 pigs (L337 × 1050, PIC, Hendersonville, TN) were used to determine the effect of microencapsulated organic acids and botanicals (MOB; AviPlus; Vetagro, Inc. Chicago, IL), on growth performance from weaning to market. Pigs were weaned at approximately 21 d of age and placed in pens based on initial body weight (BW) with 27 pigs per pen in a randomized complete block design. During the 42-d nursery period, pigs were allotted to one of two treatments in an unbalanced treatment structure with 15 pens (replications) fed the control diet and 30 pens (replications) fed diets containing 0.30% MOB from days 0 to 21 and 0.10% from days 21 to 42. On day 42, pigs were transported as intact pens from the nursery to the finishing facility. During the finishing period, three treatments were applied which included: 1) pigs on the control diet in nursery remained on control diets; 2) 50% of pigs provided MOB in nursery were then fed 0.05% MOB throughout finishing, and 3) 50% of pigs provided MOB in nursery were then fed the control diet throughout finishing. All pens of pigs on treatments 2 and 3 were allotted based on ending nursery BW to the finishing treatment. There were 15 replications per treatment in the finishing period. From days 0 to 21, pigs fed diets with MOB had a tendency for increased (P < 0.058) gain:feed (G:F) when compared to pigs fed the control diet; however, there was no evidence of difference (P > 0.05) for average daily gain (ADG), average daily feed intake (ADFI), or day 21 BW. From days 21 to 42, there was no evidence of difference (P > 0.05) for ADG, ADFI, or G:F. For the overall nursery period (days 0 to 42), pigs fed diets with MOB had increased (P < 0.05) G:F (660 vs. 670 g/kg) when compared with pigs fed the control diet, but there was no evidence of difference (P > 0.05) for day 42 BW, ADG, or ADFI between treatments. From d 42 to 106, there was no evidence of difference (P > 0.05) for ADG, ADFI, and G:F. For the overall finishing period (days 42 to 156) and overall experimental period (days 0 to 156), there was no evidence of difference (P > 0.05) for BW, ADG, ADFI, or G:F. For mortality and removals, there was no evidence of difference (P > 0.05) observed during the nursery, finishing, or overall. In summary, providing MOB during the nursery phase increased G:F in the early and overall nursery phase, but there was no effect on overall wean-to-finish performance.

Evaluating dietary acidifiers as alternatives for conventional feed-based antibiotics in nursery pig diets

A total of 360 weanling pigs (DNA 200 × 400; initially 9.7 ± 0.23 kg BW) were used in a 21-d experiment with 6 pigs/pen, 10 replicate pens/treatment, and 2 separate nursery rooms, each with 30 pens. Pigs were weighed and allotted to pens based on BW in a completely randomized block design to one of six treatment diets: 1) Negative control (no organic acids or antibiotics) and the control with 2) 0.25% acidifier A; 3) 0.3% acidifier B; 4) 0.5% acidifier C); 5) 50 g/ton carbadox; and 6) 400 g/ton chlortetracycline (CTC). Upon weaning, a common diet with no antibiotics or additives was fed for 21 d (Phases 1 and 2; days −21 to 0), followed by a 21-d experimental period (Phase 3; days 0 to 21) where treatment diets were fed. Pigs and feeders were individually weighed on a weekly basis to calculate average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (G:F). Data were analyzed using the PROC GLIMMIX procedure of SAS (v 9.4, SAS Inst., Cary, NC) with pen as the experimental unit, treatment as a fixed effect, and room as a random effect. Dietary treatment had a significant impact (P < 0.05) on ADG, ADFI, and G:F each week and for the overall experimental period (days 0 to 21). Specifically, from days 0 to 7, pigs fed CTC had increased (P = 0.001) ADG compared with those fed acidifier B, acidifier C, and carbadox, whereas pigs fed the negative control and acidifier A diets were intermediate. Additionally, pigs fed the CTC diet had improved (P = 0.0002) ADFI when compared with all other treatments. From days 7 to 14 and days 14 to 21, pigs fed the carbadox diet had decreased (P < 0.0001) ADG compared with all other treatments. During the overall period (days 0 to 21), pigs fed diets containing carbadox had reduced ADG and ADFI (P < 0.0001), whereas pigs fed CTC had improved (P < 0.0001) ADG compared with all other treatments. Additionally, blood parameters, fecal consistency, and fecal microbial populations were analyzed on a subset of pigs (n = 5 pigs/treatment). Dietary treatment significantly affected (P < 0.05) concentrations of protein, globulin, phosphorus, alkaline phosphatase, and sorbitol dehydrogenase in the blood. Treatment also significantly impacted (P = 0.0005) fecal score but did not affect (P = 0.59) fecal microbial growth from days 0 to 21. In summary, CTC continues to be a valuable additive to improve performance in the nursery. Further investigation surrounding the efficacy of dietary acidifiers as antibiotic alternatives is warranted given inconclusive evidence in this study.

Impact of microbial waste additives and glucose on ammonia emissions from broiler litter in the lab

Ammonia (NH₃) produced inside livestock houses can adversely affect animal welfare and performance and degrade the environment. In broiler houses, NH₃ levels are mitigated by applying acidifiers to the litter but acidifiers provide short-term NH₃ suppression requiring heavy or repeated applications. Microbial additives may provide longer-term NH₃ control through nitrogen (N) immobilization and nitrification. The objective of this 50-d lab study was to evaluate the impact of two microbial additives (Environoc 301 and Environoc 501), 2% glucose, and distilled water (control) treatments applied to broiler litter on NH₃ emissions and litter properties. During the first 34 d, glucose significantly but modestly reduced NH₃ emissions vs. the other treatments which were not significantly different from one-another. For the entire study, when glucose was excluded (due to lost replicates), the three treatments were not significantly different. The unreplicated glucose treatment had higher final litter nitrate concentration than the other treatments. Litter properties were unaffected by the two microbial additive and control treatments. The effectiveness of glucose in reducing NH₃ emission could have been due to greater N immobilization and nitrification vs. the other treatments. More research on cost-effective labile carbon sources and higher application rates to achieve greater NH₃ reduction is required.

Effect of 2-hydroxy-4-(methylthio) butanoic acid and acidifier on the performance, chyme pH, and microbiota of broilers

This study was aimed to explore the comparative acidifying properties of 2-hydroxy-4-(methylthio) butanoic acid (HMTBA) and a combination of DL-methionine (DLM) and acidifier in male broiler production. A total of 480 1-day-old broiler chicks were randomly divided into four treatments: A (low HMTBA, 0.057% HMTBA); B (low acidifier, 0.05% DLM + 0.057% acidifier); C (high HMTBA, 0.284% HMTBA); and D (high acidifier, 0.25% DLM + 0.284% acidifier). At 21 d, growth performance, chyme pH, digestive enzyme activities, and intestinal microflora were measured. The pH of crop, gizzard, and ileum contents was higher in the HMTBA treatment group than in DLM + acidifier treatment group. Furthermore, acidifier supplementation promoted growth of butyrate-producing bacteria such as Faecalibacterium, whereas high HMTBA (0.284%) inhibited the proliferation of acid-producing bacteria including Roseburia and Collinsella. The chymotrypsin activity was lower in the HMTBA group than in the DLM + acidifier group. In contrast, high-level HMTBA group showed higher average daily gain and average daily feed intake than the DLM + acidifier group. These results suggested that HMTBA work through different pathways with DLM plus acidifier.

Potential Effects of Acidifier and Amylase as Substitutes for Antibiotic on the Growth Performance, Nutrient Digestion and Gut Microbiota in Yellow-Feathered Broilers

This study was conducted to evaluate the effects of acidifier (benzoic acid, BA), amylase (AL) and their combination as substitutes for antibiotics on growth performance, antioxidation, nutrient digestion and gut microbiota of yellow-feathered broilers. A total of 1440 twenty-one-day-old broilers were randomly allocated to six treatments. Broilers in the control group (CON) were fed a basal diet, whereas birds in the other five groups were fed the basal diet supplemented with antibiotic (zinc bacitracin, AT, 40 mg/kg), BA (2000 mg/kg), low level AL (AL-L, 300 mg/kg), high level AL (AL-H, 500 mg/kg) and the combination of AL-H and BA (BA+AL-H). The experimental animals were killed at the end of the trial (21 day-63 day) then blood samples were collected from two birds per pen. Bird weight, feed intake and survival rate were recorded on pen basis. Growth performance was not significantly influenced by AT, BA, AL-L, AL-H or BA+AL-H. Plasma uric acid (UA) was decreased from CON by all treatments; the activity of AKP in plasma was also lowered by AT, BA, AL-H and BA+AL-H. Plasma activity of LDH was reduced by BA. In the jejunal mucosa, Na+K+-ATP activity was increased by BA, AL-L, AL-H and BA+AL-H. Mucosal activities of T-AOC and CAT were increased with AL-L and AT supplementation, respectively. Additionally, the relative abundance of Escherichia coli (E. coli) in the cecal contents was reduced by BA+AL-H and, with the exception of AL-H, all treatments increased the relative abundance of Lactobacillus. In conclusion, dietary AT, BA, AL-L, AL-H or BA+AL were effective in improving the antioxidant capacity, nutrient digestion and gut microbiota composition. No significant differences were observed in the tested variables between AT and other treatments, indicating that BA, AL and their combination may be alternatives to dietary inclusion of zinc bacitracin. Dietary addition of 500 mg/kg AL and 2000 mg/kg BA was an optimum supplementation dose.

Dietary Phytogenic Combination with Hops and a Mixture of a Free Butyrate Acidifier and Gluconic Acid Maintaining the Health Status of the Gut and Performance in Chickens

Additives with bioactive properties can improve chickens' gut health. This study investigated the physiological status of the gut, including its morphological structure and microbiome activities in chickens fed diets supplemented with phytogenic ingredients with hops (Anta^®Phyt) or a mixture of a free butyrate acidifier and gluconic acid (PreAcid). In this study, 1155 broilers were distributed to three dietary treatments with 5 replicate pens per treatment, 77 birds each. Anta^®Phyt was added at 400/300/200/200 mg/kg diet whereas PreAcid was added at 3/2/1/1 g/kg starter/grower I/grower II/finisher diet respectively. Dietary treatments did not compromise body weight in different growth periods. In the birds fed PreAcid-supplemented diet, higher gut concentration of butyric acid was observed, particularly in the early stage of growth, while the profile of the short-chain fatty acids was maintained among the treatments. Neither additive significantly affected cecal bacterial enzyme activities. Feeding the birds with Anta^®Phyt and PreAcid had beneficial effects on gut morphostructure indices, including intestinal wall thickness, crypt depth and the villus height to crypt depth ratio, in 35- and 42-day old birds. In conclusion, the feeding Anta^®Phyt- or PreAcid-supplemented diet exerted beneficial effects on the indices determining the physiological status of the gut and maintained good performance of birds of different ages.

Feed acidification and steam-conditioning temperature influence nutrient utilization in broiler chickens fed wheat-based diets

Two experiments were conducted to examine the effects of conditioning temperature (CT) and the interactive influence of feed acidification (FA) and CT on the performance, coefficient of apparent ileal digestibility (CAID) of nitrogen (N), starch, fat calcium (Ca) and phosphorus (P), and AME in broilers. In both experiments, each treatment was randomly allocated to 6 cages (8 birds per cage) and fed from 1 to 21 D posthatch. In experiment 1, the effect of CT was evaluated using a wheat-based diet at 3 CT: unconditioned, conditioned at 60°C or 90°C. All the diets by-passed the pellet press and collected in mash form. Birds fed the diet conditioned at 90°C consumed more (P < 0.05) feed and tended (P = 0.087) to have higher feed per gain (F:G) than those fed the unconditioned diet but similar to those fed the diet conditioned at 60°C. A tendency was noted for CT to affect the CAID of N (P = 0.071) and starch (P = 0.093), with reduced digestibility values in the diet conditioned at 90°C. Conditioning at 90°C resulted in lower (P < 0.05) AME. In experiment 2, three inclusions of an acidifier (0.0, 7.0, and 10 g/kg) and 2 CT of 60°C and 90°C were evaluated in a 3 × 2 factorial arrangement of treatments using pelleted diets. Neither the main effects nor the interaction between acidifier addition and CT was significant for weight gain, feed intake, and F:G. The FA increased (P < 0.05) the CAID of N, fat, and P at both inclusion levels and of starch at 10 g/kg. Conditioning at 90°C reduced (P < 0.05) the CAID of starch, fat, and Ca, regardless of FA level. Overall, the present data showed that the application of high CT for broiler feed manufacture can impair nutrient utilization and, consequently the feed efficiency in broilers. Feed acidification imparts some benefits to nutrient digestibility in broilers fed pelleted wheat-based diets.

Effect of an organic acids based feed additive and enrofloxacin on the prevalence of antibiotic-resistant E. coli in cecum of broilers

Increasing antibiotic resistance is a major public health concern. Fluoroquinolones are used to treat and prevent poultry diseases worldwide. Fluoroquinolone resistance rates are high in their countries of use. The aim of this study was to evaluate the effect of an acids-based feed additive, as well as fluoroquinolone antibiotics, on the prevalence of antibiotic-resistant E. coli. A total of 480 broiler chickens (Ross 308) were randomly assigned to 3 treatments: a control group receiving a basal diet; a group receiving a feed additive (FA) based on formic acid, acetic acid and propionic acid; and an antibiotic enrofloxacin (AB) group given the same diet, but supplemented with enrofloxacin in water. A pooled fecal sample of one-day-old chicks was collected upon arrival at the experimental farm. On d 17 and d 38 of the trial, cecal samples from each of the 8 pens were taken, and the count of E. coli and antibiotic-resistant E. coli was determined.The results of the present study show a high prevalence of antibiotic-resistant E. coli in one-day-old chicks. Supplementation of the diet with FA and treatment of broilers with AB did not have a significant influence on the total number of E. coli in the cecal content on d 17 and d 38 of the trial. Supplementation with FA contributed to better growth performance and to a significant decrease (P ≤ 0.05) in E. coli resistant to ampicillin and tetracycline compared to the control and AB groups, as well as to a decrease (P ≤ 0.05) in sulfamethoxazole and ciprofloxacin-resistant E. coli compared to the AB group. Treatment with AB increased (P ≤ 0.05) the average daily weight compared to the control group and increased (P ≤ 0.05) the number of E. coli resistant to ciprofloxacin, streptomycin, sulfamethoxazole and tetracycline; it also decreased (P ≤ 0.05) the number of E. coli resistant to cefotaxime and extended spectrum beta-lactamase- (ESBL-) producing E. coli in the ceca of broilers.