Research Article

Sodium Formate, Acetate, and Propionate as Effective Feed Additives in Broiler Diets to Enhance Productive Performance, Blood Biochemical, Immunological Status and Gut Integrity

Hany M.R. Elsherif1, Ahmed Orabi2, Hussein M.A. Hassan3, Ahmed Samy3*

1Animal Production Department, Faculty of Agriculture, Cairo University, Giza, Egypt; 2Microbiology Department, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt; 3Animal Production Department, National Research Centre, 12622, Dokki, Cairo, Egypt.

Received | April 29, 2022; Accepted | May 21, 2022; Published | June 16, 2022

*Correspondence | Ahmed Samy, Animal Production Department, National Research Centre, 12622, Dokki, Cairo, Egypt; Email: Asamy1@yahoo.com

Citation | Elsherif HMR, Orabi A, Hassan HMA, Samy A (2022). Sodium formate, acetate, and propionate as effective feed additives in broiler diets to enhance productive performance, blood biochemical, immunological status and gut integrity. Adv. Anim. Vet. Sci. 10(6):1414-1422.

DOI | https://dx.doi.org/10.17582/journal.aavs/2022/10.6.1414.1422

ISSN (Online) | 2307-8316

Copyright: 2022 by the authors. Licensee ResearchersLinks Ltd, England, UK.

This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).

INTRODUCTION

Adding feed additives to a chicken’s diet is critical to its development and productivity (Abd-Elsamee et al., 2012; Hassan et al., 2016, 2018; Mohamed et al., 2016; Elsherif et al., 2021). Antibiotic as promoters for growth in feeding of animal and poultry have been used for many years to boost health and productivity (Huyghebaert et al., 2011). For a long time, antibiotics have been utilized as growth promoters, resulting in an increase in disease and bacterial resistance, as well as significant health risks (Qiao et al., 2018). As a result, in 2006, the EU outlawed the use of antibiotic growth promoters in chicken feed. Antibiotics are no longer utilized as growth enhancers in chicken feed, prompting a wider search for new solutions (Elsherif et al., 2021). Many of natural feed additives such as organic acids and their salts, extracts and metabolites of plants used as scavenge free radicals, antibacterial, antifungal, and growth enhancers in poultry nutrition (Ragaa and Korany, 2016; Elsherif et al., 2021). Organic acids are safe and therefore recommended for use as an alternative to antibiotics in poultry nutrition (Baaboua et al., 2018). Organic acids should now be used in broilers as a safe alternative to anti-biotics to boost immunity, antibacterial and growth promoter (Khan et al., 2022). Salts of organic acids are easily used and mixed well in feed, this is due to its properties not liquid or volatile and odorless (Huyghebaert et al., 2011). Furthermore, organic acids can be utilized to reduced intestinal pathogenic bacteria (Wolfenden et al., 2007). Christian and Mellor (2011) found that using potassium di-formate and sodium di-formate in animal diet significantly increased nutritive value. Furthermore, Tohru et al. (2011) concluded that adding 1% potassium di-formate to broiler feed increased significantly (P<0.05) body weight. Increases in broiler body weight, feed efficiency, and gut health were achieved by adding 0.5 % sodium butyrate or 1.0 % calcium propionate to their diets (Akbar et al., 2017). Sodium acetate (4g/Kg) added to broilers feed resulted in greater weight gain than that of control (Agboola et al., 2018). Organic acids and salts have been used in poultry feed to improve intestinal health, immunological condition, nutritional digestibility, and productivity (Yadav and Jha, 2019; Wu et al., 2020; Gao et al., 2021). Therefore, the purpose of this research was to see how sodium formate, sodium acetate, and sodium propionate affected productive performance, carcass traits, immunological condition, blood parameters, and intestinal microbiota in broiler chicks.

MATERIALS AND METHODS

Diets, housing, and management of birds

The farm experiment was done at Cairo University’s Faculty of Agriculture’s Poultry Nutrition Research Unit in Giza, Egypt. In three-layer batteries, 240 male Arbor acres broiler chicks weighing average 41 g at one day of age were randomly divided into four groups, each with six replicates of 10 chicks. Chicks were reared in a warm housing for the starter stage (1-14 days), then gradually lowered the temperature to fulfil the needs of the grower (14-28 days) and finisher (28-35 days). During the experiment, the light was on for 23 hours a day. Feed and water were continuous available. Avian influenza and New Castle vaccine protocols as well as Infectious Bronchitis (IB) and infectious bursal disease (IBD) immunization protocols were strictly adhered to throughout the trial. Four different experimental diets were established. Diet one consisted of a basal diet with no additives (control). Diets 2, 3, and 4 consisted of a basal diet supplemented with 1.5g sodium formate/Kg (SF), 1.5g sodium acetate/Kg (SA), and 1.5g sodium propionate/Kg (SP), respectively. Using the Arbor Acres guide, Table 1 depicts the formulation and nutrient composition of the diets.

 

Table 1: Starter, grower, and finisher diet formulation and nutrient composition.

Ingredients %	Starter (1-14 days)	Grower (14-28 days)	Finisher (28-35 days)
Yellow maize Soybean meal (44%) Corn gluten meal (60%) Soybean oil Monocalcium phosphate Limestone Vitamin & Mineral mix(1) Nacl L-lysine HCl DL-methionine Threonine NaHCO3 Choline chloride Phytase Energy enzymes	55.50 34.00 4.60 1.50 1.00 1.80 0.30 0.30 0.30 0.25 0.16 0.17 0.10 0.01 0.01	58.70 30.00 4.41 2.81 0.90 1.58 0.30 0.30 0.33 0.25 0.13 0.17 0.1 0.01 0.01	62.81 25.85 4.50 3.00 0.86 1.45 0.30 0.30 0.33 0.20 0.11 0.17 0.1 0.01 0.01
Total	100	100	100
Calculated composition (2) Crude protein % ME (Kcal/Kg) Ether extract% Crude fiber% Lysine % Methionine % Methionine + Cystine % Threonine % Calcium % Nonphytate P % Sodium% Chlorine%	23.02 2949 3.99 3.66 1.34 0.64 1.01 0.97 0.98 0.38 0.18 0.22	21.47 3076 5.38 3.45 1.26 0.61 0.97 0.88 1.00 0.35 0.18 0.22	20.01 3138 5.71 3.25 1.16 0.54 0.87 0.81 0.81 0.33 0.18 0.22

 

(1) Vitamin and mineral mix supplied/ Kg of diet: Vit D3, 2200 IU; Vit A, 12000 IU; Vit K3, 2 mg; Vit E, 10 mg; Vit B1, 1mg; Niacin, 20 mg; Vit B2, 4mg; Vit B12, 10µg; Vit B6, 1.5mg; Folic acid, 1 mg; Pantothenic acid, 10 mg; Choline chloride, 500 mg; I, 1mg; Biotin, 50 µg; Fe, 30 mg; Cu, 10 mg; Mn, 55 mg; Se, 0.1 mg and Zn, 50 mg. (2) According to NRC 1994.

 

Preparation of salts of organic acids

Formic acid and sodium hydroxide were used to make sodium formate.

Sodium acetate was synthesized by the reaction between acetic acid and sodium hydroxide.

Propionic acid and sodium hydroxide reacted to form sodium propionate.

Make sure the sodium hydroxide is completely dissolved by vigorously stirring it. Then stoichiometric moles of acids were added to start the reaction and stirring was continued for one hour, after reaching the neutralization of each solution, crystallization was done (Ouellette and Rawn, 2018).

Growth performance parameters

To determine feed conversion ratio (FCR) and weight gain (WG), the birds were weighed and feed consumption were recorded per replicate three times: at 14 days, 28 days and 35 days of age (Abd-Elsamee et al., 2012; Hassan et al., 2016; Mohamed et al., 2016; Elsherif at al., 2021). The carcass characteristics determined as following; each treatment included five birds of a similar weight taken at 35 days of age for carcass characteristics and intestinal measures to be analyzed. Before slaughter and feather removal, a percentage of a bird’s live body weight was recorded for the carcass weight, liver, heart, spleen and gizzard.

Gut integrity analysis

At 35 days of age, five birds from each group were inspected to assess the length and diameter of their small intestines (in the middle of the ileum) (Dahiya et al., 2005; Elsherif et al., 2021).

While for determination the lesion score appearance: Five birds from each group had their small intestines opened and graded from zero to four. There are no lesions in the serosa and mesentery when the score is 0, but there are numerous serosal and mesentery swellings when the score is 0.5. A thin-walled and friable intestine with few red petechial when the score is 1, The presence of a necrotic area in the score of 2, necrotic spots on the skin (1 to 2 cm long) when the score is 3, and Four is necrosis that is common in field cases (Dahiya et al., 2005; Elsherif et al., 2021).

For count of lactobacillus spp., Fresh digesta (1 g) was taken from the caecum and diluted in 9 mL of MRS broth. Micro aerobic incubation at 39oC for 48 hours resulted in the plating of three diluted samples on Oxoid MRS agar (CM0361) (Dahiya et al., 2005; Elsherif et al., 2021). While the count of Clostridium perfringens screened through, around 0.2 g of intestinal fresh digesta was applied to sheep blood agar plates and TSC (supplemented with D-cycloserine) agar (emulsified with egg yolk) with each dilution being serially diluted in sterile PBS to 1:100, 1:1000, and 1:10000. TSC agar or big dome-shaped colonies on blood agar plates with a twofold zone of hemolysis were counted as colony-forming units (CFUs) per g after 24 hours of anaerobic incubation at 37°C (Carrido et al., 2004; Elsherif et al., 2021).

Blood biochemical parameters

Five birds from each treatment had blood samples taken at 35 days of age during slaughter. A centrifuge at 1000 g for 10 minutes was used to separate the blood serum samples, which were then stored at -20oC until chemical analysis. Analysis of each individual serum sample for total protein (g/dL), albumin (g/dL) and from them calculated globulin (g/dl), urea (mol/L), aspartate aminotransferase (AST) (U/L), alanine aminotransferase (ALT)(U/L) and total antioxidant capacity (TAC) using biodiagnostic commercial kites. Commercial ELISA kits were used to quantify total T3 and T4 levels in the blood (My Bio Source, Inc., San Diego, CA). By dividing the T3 value by the T4 value, the T4/T3 ratio was determined.

Immune status assessment

At 35 days of age, serum from the five birds from each treatment used to investigate the impact on immunity. Blood serum samples were tested for antibody titers against ND and H5 vaccinations using haemagglutinating (HA) units in a haemagglutination inhibition (HI) test. The log of the reciprocal of the greatest haemagglutination dilution was used to determine all titers (Swayne et al., 1998).

Statistical analysis

SAS’s General Linear Model (one-way analysis of variance) was used to analyze the data (SAS, 2004). Duncan’s new multiple range test (P<0.05) was used to differentiate the treatments with the most significant variations in means (Duncan, 1955).

RESULTS

For the starter, grower, finisher, and the overall period, the effects of various nutritional treatments are shown in Table 2. At starting phase, all treatments significantly (P<0.05) outperformed the control in weight gain (WG) and feed conversion ratio (FCR). For grower phase, the WG was significantly boosted (P<0.05) with chicks fed a feed enriched with sodium propionate (SP) or sodium formate (SF). In comparison to the control, adding SF, SA, or SP to the finisher phase enhanced FCR considerably. As compared to the control at overall period, adding SF, SA, or SP significantly (P<0.05) enhanced total WG and FCR. Birds provided a feed containing SF gained the most weight and had the highest FCR, followed by those fed a diet supplemented with SP. Treatments and the control group had no significant differences in the amount of feed consumed at any given time. According to these findings, the addition of SF and SP had a greatest effect than the addition of SA. In order to increase the productivity of broilers as measured by WG or FCR, sodium formate or sodium propionate were utilized. Feed utilization was higher in broiler chicks fed such additive diets than in those on a control diet.

Carcass characteristics

Table 3 illustrates the impacts of SF, SA, and SP on carcass characteristics. Carcass weight was significantly enhanced (p<0.01) for birds fed a diet enriched with OAS’s. The dressing% were slightly improved (p>0.05) with OAS’s addition compared to control. No significant effect in the liver, heart, gizzard, and spleen percentages of live body weight were recorded due to the different treatments.

Intestinal length, diameter, and lesion score

At 35 days of age, chick’s intestinal length, width, and lesions shown in Figure 1. The effects of adding SF and SP to the diet on intestinal length, diameter, and lesion score were significant (P<0.05). The length of the intestines of birds fed diets enriched with SF or SP were significantly (P<0.05) increased (170 and 171 cm, respectively) compared to the control group (145 cm). While, chicks fed a meal supplemented with SA had comparable results to the control group (145 cm). The width of the gut was considerably increased (P<0.05) when SF or SP were added to the feed. Normal intestinal appearance without any lesion recorded for birds in treatments fed diets containing propionate and formate while the control group take one on this scale which refer to the intestinal is thin-walled and fragile intestines accompanied by small red petechiae.

 

Intestinal microbiota count

As broilers reached 35 days of age, Figure 2 shows the impact of dietary treatments on the intestinal microbiota (Lactobacillus and Clostridium perfringens). When compared to the control (4 log10 CFU/g), the number of Lactobacillus in the birds fed meals supplemented with SF or SP was significantly (P<0.05) increased (6.93 and 6.27 log10 CFU/g, respectively). The amount of intestinal colonization of C. perfringens was zero for chicks fed diets enriched with SP and SF, compared to the control (2 log10 CFU/g). The small intestine is an important element of the digestive system that aids in feed absorption, and its proper development is essential for bird health and performance.

 

Table 2: Growth performance of broiler chicks as a result of food treatments.

Item

Starter (1-14)

Grower (14-28)

Finisher (28-35)

Overall period (1-35)

WG

FI

FCR

WG

FI

FCR

WG

FI

FCR

WG

FI

FCR

Control

299b

395

1.33a

893b

1149

1.29

497

981

1.97a

1689b

2525

1.49a

Sod.formate

324a

360

1.11b

960a

1150

1.20

598

972

1.63b

1882a

2482

1.3­­2b

Sod. Acetate

334a

383

1.15b

907b

1145

1.27

574

1000

1.74b

1815a

2528

1.39b

Sod.propionate

339a

370

1.09b

948a

1155

1.22

557

991

1.78b

1844a

2516

1.36b

SE of means

±4.80

±6.54

±0.03

±8.57

±11.33

±0.01

±7.38

±8.99

±0.03

±16.70

±20.08

±0.02

Significances

***

NS

**

***

NS

NS

NS

NS

***

***

NS

**

 

a-bMeans assigned with the same letter within the same column are not significantly different at 0.05 probability level, **P<0.01), ***P<0.001, NS: Not significant (P>0.05).

 

Table 3: Nutritional treatment effects on carcass traits at 35 days of age.

Item	Carcass weight (g)	Dressing %	Giblets % (of LBW)			Spleen %
			Liver	Heart	Gizzard
Control	1289b	74.24	2.30	0.61	2.16	1.04
Sod.formate	1470a	76.62	2.19	0.60	2.40	1.27
Sod. Acetate	1398a	75.04	2.29	0.58	2.43	1.15
Sod.propionate	1420a	75.61	2.36	0.59	2.55	1.11
SE of means	±24.11	±0.66	±0.03	±0.01	±0.07	±0.07
Significances	**	NS	NS	NS	NS	NS

 

a-bMeans assigned with the same letter within the same column are not significantly different at 0.05 probability level, **P<0.01, NS: Not significant (P>0.05).

 

Table 4: Effects of feed interventions on various blood biochemical markers in 35-day-old broiler chicks.

Item	Total protein (g/L)	Albumin (g/L)	Globulin (g/L)	Albumin/ Globulin	Urea (µmol/L)	ALT (U/L)	AST (U/L)
Control	2.64b	1.39	1.25c	1.12a	2.67	13.97	207.66
Sod. formate	2.83a	1.30	1.53ab	0.85b	2.46	13.60	207.00
Sod. Acetate	2.67a	1.36	1.40bc	0.98ab	2.66	13.93	206.65
Sod.propionate	2.85a	1.30	1.55a	0.84b	2.53	13.63	205.67
SE of means	±0.03	±0.02	±0.04	±0.04	±0.05	±0.18	±1.58
Significances	*	NS	**	**	NS	NS	NS

 

a-cMeans assigned with the same letter within the same column are not significantly different at 0.05 probability level, NS: not significant, *(p<0.05), **(P<0.001). Aspartate aminotransferase (AST), alanine aminotransferase (ALT), uric acid (µmol/L).

 

 

Blood biochemical parameters

Table 4 shows the effects of several dietary treatments on blood biochemical. Adding OAS’s to broiler diets resulted in significant (P<0.05) improvements in total protein, globulin, and albumin/globulin ratio than the control. When SP or SF was added to the diets, blood total protein and globulin levels were improved compared to SA addition. While no significant difference in blood albumin levels. The additives did not adversely affect both liver and kidney functions, no influence on the levels of ALT, AST, or urea. Figure 3 shows the effects of several dietary treatments on total antioxidants capacity (TAC). Supplementation with SF or SP were significantly (P<0.05) increased TAC than control. Furthermore, broilers administered OAS’s showed a stronger immune response than control broilers, as demonstrated by higher blood globulin levels.

 

Thyroid hormones

Figure 4 shows the effects of OAS’s on thyroid hormones. The addition of OAS’s raised T3 and T4 levels considerably (P<0.05). Despite this, the T4/T3 ratio did not affect. Adding SF and SP to broiler diets enhanced metabolic and growth rates, according to these findings. In broilers, elevated thyroid hormone levels have been linked to feed changes that included the addition of salts of organic acids (SF, SA, and SP).

 

 

Immune status

The effects of OAS’s on immunological status are shown in Figure 5. A haemagglutination inhibition tests were used to assess antibody titer against avian influenza (H5) and Newcastle disease (ND) vaccinations. Against both the ND and H5 vaccines, the immunological status of the birds fed diets supplemented with SF, SA, or SP salts were significantly (P<0.05) improved. When SP was added to broiler, the immune response against the ND and H5 vaccination was improved.

DISCUSSION

Growth performance

According to the current study, the addition of salts of organic acid in broiler feed boosted weight gain and feed conversion ratio by 7.5-11.5 and 7-11 %, respectively. The results of this study are in agreement with previous studies. Body weight gain and FCR were increased by 5.5 and 12 %, respectively, when the broiler feed was supplemented with a mixture of organic acids (Hassan et al., 2010). Helen and Christian (2010) found that introducing diformate to broiler chickens at concentrations of 0.1, 0.3 and 0.5% improved WG and FCR. Addition of sodium butyrate to broiler chicks increased their performance by improving WG and FCR (Sikandar et al., 2017). Adding 0.5 % sodium butyrate or 1.0 % calcium propionate to broiler diets enhanced significantly (P<0.05) the productive performance and gut morphology, decreased Coliform bacteria (log10 CFU/g.), and increased Lactobacilli count when compared to the control group. According to Sabour et al. (2019) adding a mixture of organic acids (lactic acid, citric acid, formic acid, phosphoric acid, acetic acid, sodium butyrate and propionic acid) to a broiler diet improved growth performance. Improved gut microbiota, nutrient digestion, and broiler development performance can be achieved by the use of acidifiers (Wu et al., 2020). Gao et al. (2021) studied that adding phosphoric acid (0.1 and 0.2 g/kg) as acidifiers to broiler feed enhanced productive performance, intestinal parameters and meat analysis compared to the birds fed the basal diets. Organic acids or their salts may improve broiler performance by improving feed digestibility, reducing microbial infections, enhancing immunity, and lowering the production of gases (ammonia) (Khan et al., 2016). As a result of better utilization of nutrients, broilers treated with organic acid salts (OAS’s) gained more weight and less FCR.

Carcass characteristics

The results obtained are consistent with the results of Leeson et al. (2005), who found that birds given 0.2 % butyrate supplements significantly increased in carcass weight. Adding organic acids to broiler meals, according to Hassan et al. (2010), raised the dressing percentage, although liver, spleen, and thymus (% body weight) did not differ significantly across treatments.

Intestinal length, diameter, and lesion score

The results obtained were in line with the results of previous studies. Broilers fed diets containing organic acid had longer intestinal villi than those fed a control diet (Khatun et al., 2010). Could be owing to its role as a natural barrier against pathogenic bacteria and harmful compounds in the intestinal lumen, resulting in an increased villus height (Khan, 2013). Increased weight and length of the gastrointestinal tract and response to the ND vaccine were two benefits of feeding broilers sodium butyrate in their diet (Lan et al., 2020).

Intestinal microbiota count

The findings were consistent with those of prior research. The small intestine is an important element of the digestive system that aids in feed absorption, and its proper development is essential for bird health and performance. As a result, in order to maximize feed utilization and growth rate, gut health is the most critical aspect in broiler production. It is possible that altering the microbiota to reduce pathogenic bacteria may have a positive impact on the creation of the intestinal wall (Cengiz et al., 2012). Reduced intestinal mucosal permeability is a result of organic acids in broiler feed protecting epithelial cells from disturbance (Kumar et al., 2021). One theory is that, in addition to decreasing dangerous bacteria, organic acids may also regulate the bacteria that compete with birds for food resources (Lee, 2005). Dietary salts of organic acids reduce bacterial metabolites and prevent competing between microorganisms and their host on nutrients, allowing birds to gain weight and feed more efficiently. Salmonella typhimurium colonization was reduced in broiler chicks given a 0.9 % organic acid (mostly SF) (Adhikari et al., 2020). Organic acids appear to be more effective at preventing C. perfringens colonization in broilers than antibiotics (Kumar et al., 2021). Organic acids were added to broilers, which enhanced beneficial bacteria while reduced pathogenic bacteria (Rodjan et al., 2017; Sureshkumar et al., 2021). Different organic acids have antibacterial activity (Aljumaah et al., 2020). Most organic acids salts have different physical and chemical properties. Some organic acids have a narrow antibacterial spectrum (lactic acid is good for bacteria), while others have a broad spectrum (formic and propionic acids are more effective against pathogenic bacteria and fungal infections (Galli et al., 2021).

Blood biochemical parameters

The findings were in line with those of previous studies. Organic acid-fed broilers had higher globulin levels than those in the control group (Kamal and Ragaa 2014). Because of their inhibitory effects on harmful microbes in the stomach, dietary organic acids may enhance the immune system (Kim et al., 2015).

Thyroid hormones

The results of this study are in agreement with previous studies. Thyroid hormones, particularly T3, which regulate all major metabolic pathways, could be manipulated physiologically to enhance BW and FCR. Another reason for the enhanced in weight gain could be a rise in thyroid gland function, as demonstrated by the elevated T3 and T4 levels. In addition, thyroid hormones promote the protein synthesis (McAninch and Bianco, 2014; Cicatiello et al., 2018).

Immune status

The results obtained were in line with the results of previous studies. Antibody titers of ND were considerably (P<0.05) higher in broilers fed diets enriched with organic acid than in control (Houshmand et al., 2012). The immune systems of broilers are impaired as a result of their rapid growth. Organic acids boost the immune systems of broilers by reducing pathogenic microbes and increasing Lactobacillus in the intestine (Yang et al., 2018; Scicutella et al., 2021).

CONCLUSIONS

It could be concluded that Organic acid salts (OAS’s) have a great impact on broiler chick’s performance, carcass weight, and immunological state. In addition, dietary SF and SP supplementation improved gut microbiota by lowering pathogenic microorganisms. Not all OAS’s had the same impact on gut bacterial populations or performance. Based on these findings and previous discussion, salts of organic acids can be used as a powerful tool for gut microbiota in broiler diets, improving performance and immune status. The best results of productive performance, immunological state, intestinal parameters and microbiota recorded for birds fed SF or SP.

Novelty Statement

Sodium formate, acetate, and propionate were chemically synthesized to use them as effective feed additives to improve intestinal microbiota, immunological condition, and productive performance without causing any side effects.

Author’s Contribution

All authors contributed equally to study design, methodology, interpretation of results, and writing of the manuscript.

Conflict of interest

The authors have declared no conflict of interest.

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