Comparison of Different Antibiotic Alternatives for Safe Broiler Production



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Submitted Aug 1, 2024
Published Nov 8, 2024
10.24018/ejfood.2024.6.6.852

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The use of growth-promoting antibiotics in broiler feed, once widespread, is now recognized as risky due to antibiotic resistance and residue concerns in meat. To mitigate these risks, the goal of this study was to compare different alternative additives like organic acids, neem, enzymes, and probiotics for producing a safe broiler. A total of 360 Cobb-500-day-old broiler chicks were indiscriminately assigned into six treatment groups, i.e., Control (T1), Basal feed + Antibiotic (T2), Basal feed + Organic acid (T3), Basal feed + Enzyme (T4), Basal feed + Probiotic (T5), and Basal feed + Medicinal plant (T6) having four replications of 15 birds in each. During the experiment, significant differences (P < 0.05) in body weight (BW), body weight gain (BWG), feed intake (FI), and feed conversion ratio (FCR) among the experimental groups were observed only in the 5th week. At the end of the study, the highest BW, BWG, and FCR were found in organic acid, followed by the enzyme, antibiotic, probiotic, neem, and control group. There were no significant differences (P > 0.05) in BW, BWG, and FI among the dietary groups during the 1st, 2nd, 3rd, and 4th weeks. No significant differences (P > 0.05) in meat yield (drumstick meat, thigh meat, wing weight, and breast meat), bone development, and dressing parameters were observed among the dietary groups. Supplementation of different additives significantly (P < 0.05) affects cholesterol and glutamic oxaloacetic transaminase content, whereas HDL, LDL, triglyceride, GPT, and creatinine were not affected among the groups. The neem and organic acid groups had the lowest cholesterol and glutamic oxaloacetic transaminase values, respectively, compared to the others. It can be concluded that supplementing organic acid, probiotics, enzymes, and neem enhanced the growth performance, carcass quality, and blood biochemical profiles of the broilers, potentially serving as antibiotic alternatives. Mainly, the organic acid gives the best results among all the antibiotic alternatives.

Keywords: Enzyme Neem Organic aid Probiotic

Introduction

From conventional backyard farming to a contemporary, profit-driven business, Bangladesh’s poultry sector has experienced a dramatic transition. However, The introduction of growth-promoting antibiotics to the broiler diet [1], while once common, is now documented as a potential hazard to both poultry and human health [2] because of the emergence of antibiotic resistance and the presence of residues in meat. To address this concern, alternative feed additives such as organic acids [3], natural medicinal products, enzymes, and probiotics [4] have emerged as feasible opportunities. Organic acids and their salts, accepted by the European Union for use in feed, promote growth performance [5], [6] and gut health by suppressing the growth of harmful microbes like Salmonella spp., Campylobacter spp., and E. coli [7]. Probiotics, live microbial supplements, aid in establishing a healthy intestinal microbial balance in chicks [8], reduce the risk of carcass contamination during processing, and improve growth rates and feed conversion efficiency [9], [10]. Enzymes supplementary to broiler diets boost nutrient digestibility and utilization, reducing excreta output and lowering nutrient excretion, thereby improving the overall efficiency of meat production [11].

Natural medicinal products derived from herbs and spices, such as neem [12], have gained attention for their antiviral, antibacterial, antiprotozoal, antifungal, and other medicinal properties, all while lacking adverse effects. These plant-derived additives offer a natural, residue-free alternative to synthetic antibiotics, contributing to safer poultry diets [13]. The current research investigates how various substitute feed additives affect blood biochemical indicators, carcass quality, and broiler performance regarding growth. It compares different antibiotic alternatives for the production of safe broiler meat.

Materials and Methods

A total of 360 Cobb-500-day-old broiler chicks were housed in a gable-type, open-sided broiler house with 3 cm deep rice husk litter. The temperature started at 35°C and decreased by 2.5°C weekly until the fifth week. Lighting was provided by 100-watt bulbs, with 24 hours of light on the first day, then 23.5 hours of light, and 30 minutes of darkness daily. Birds were indiscriminately assigned into six treatment groups i.e., T1 = Control (Basal diet + without supplementation), T2 = Basal feed + Antibiotic, T3 = Basal feed + Organic acid (1 ml/liter water), T4 = Basal feed + Enzyme (1 ml/L water), T5 = Basal feed + Probiotic (1 g/2 L water), and T6 = Basal feed + Medicinal plant (2 ml neem extract/L water) having four replications of 15 birds in each. A homemade balanced ration, consisting of a starter (0 to 21 days) and grower (22 to 35 days), was given to the birds. Ad libitum watering and feeding were practiced. Table I presents the nutritional composition of the feed.

Nutrients Starter Grower
ME Kcal/kg 3050 3150
CP% 23.66 20.59
CF% 3.81 2.88
EE% 5.71 4.81
DM% 89.68 87.09
Lys% 1.24 1.06
Met% 0.50 0.63
Met + Cys% 1.00 0.92
Ca% 1.21 1.05
Available P% 0.45 0.42
Table I. Nutritional Composition of Feed

During the research, individual assessments of broiler chickens were conducted at 7, 14, 21, 28, and 35 days old. The disparity in weight between the final and initial measurements of the birds was employed to ascertain the body weight gain. Over the duration of the trial, the weekly feed intake and Feed Conversion Ratio (FCR) were also observed. Two broilers with equivalent body weights were pulled out from each pen after the study in order to record the parameters and quality of the meat yield. Following butchering, the carcasses underwent a streamlined dissection process and were measured. Abdominal fat, thigh, breast, drumstick, and wing were grouped together and weighed collectively. After broilers had been slaughtered, their weight was taken to determine the amount of bone formation. Each dressing parameter was noted separately, and their percentages compared to the live body weight were computed. Additionally, blood biochemical profiles were determined.

These data were subjected to analysis of variance in a completely randomized design by using the general linear models of SAS [14], and distinctions between groups were evaluated through Duncan’s Multiple Comparison Test, with a significant difference being considered at a 0.05 probability level [15].

Results and Discussion

Body Weight (BW) and Body Weight Gain (BWG)

Data in Fig. 1 and Table II indicate that there was no significant difference (P > 0.05) in body weight. (BW), and body weight gain (BWG) in the 1st, 2nd, 3rd, and 4th week among the dietary groups. During the experiment, significant differences (P < 0.05) in BW and BWG among the experimental groups were observed in the 5th week and total BWG. At the end of the study, the highest BW and BWG were found in organic acid, followed by the enzyme, antibiotic, probiotic, neem, and control group. The positive effect of organic acids on the intestinal flora is most likely the cause of better live weight and weight gain. The bactericidal impact of the organic acids may result from their interference with nutrition delivery and energy metabolism, or they may damage the integrity of microbial cell membranes [16], [17]. These findings support those of Al-Kassi and Mohssen [18], Attia et al. [19], Hossain and Nargis [20], who reported that broiler body weight, weight gain, and overall growth performance are all greatly increased by organic acid.

Fig. 1. Impact of various antibiotic alternatives on cumilative body weight of broiler chickens.

Parameter Control Antibiotic Organic acid Enzyme Probiotic Neem P value LS
1st week 103.99 ± 1.07 102.83 ± 1.59 103.79 ± 0.81 106.52 ± 1.00 106.78 ± 1.72 104.26 ± 1.90 0.31 NS
2nd week 250.74 ± 16.27 249.96 ± 16.94 255.34 ± 18.74 242.49 ± 15.98 249.99 ± 17.06 240.13 ± 17.20 0.99 NS
3rd week 266.48 ± 28.03 287.88 ± 29.94 290.37 ± 28.35 278.33 ± 27.63 263.10 ± 29.93 272.22 ± 45.29 0.98 NS
4th week 307.97 ± 35.62 323.95 ± 7.31 312.00 ± 0.24 324.10 ± 3.11 336.55 ± 21.84 329.61 ± 29.39 0.94 NS
5th week 309.61c ± 19.63 353.94abc ± 20.14 403.74a ± 14.36 367.82ab ± 20.24 344.69bc ± 10.52 345.47bc ± 10.77 0.02 *
Total BWG 1238.79c ± 6.19 1318.54ab ± 18.35 1365.39a ± 23.42 1319.27ab ± 19.66 1301.11b ± 20.82 1291.70bc ± 14.11 0.01 *
Table II. Impact of Various Antibiotic Alternatives on Body Weight Gain (Bwg) of Broiler Chickens

Feed Intake (FI)

As shown in Table III, there were no significant differences (P > 0.05) in feed intake among the dietary groups during the 1st, 2nd, 3rd, and 4th weeks and total FI. However, significant differences (P < 0.05) were observed in FI during the 5th week of age. The groups receiving organic acid, enzyme, and antibiotic had higher FI compared to the probiotic, neem, and control groups. According to reports, feed consumption is increased by dietary organic acids such as citric acid [21], [22]. By adding organic acids to drinking water, it is possible to lower the number of microorganisms in crops, water, and proventriculus, control gut microbiota, enhance feed digestion, and boost bird growth rates [23].

Parameter Control Antibiotic Organic acid Enzyme Probiotic Neem P value LS
1st week 138.00 ± 4.55 135.00 ± 4.56 135.75 ± 2.46 141.75 ± 4.68 142.75 ± 6.394 138.25 ± 7.397 0.87 NS
2nd week 380.00 ± 26.77 375.00 ± 16.58 367.50 ± 18.88 363.50 ± 14.49 353.75 ± 15.99 355.00 ± 21.02 0.91 NS
3rd week 437.50 ± 31.46 460.00 ± 23.45 441.25 ± 28.89 427.50 ± 24.28 420.00 ± 42.43 440.00 ± 65.95 0.99 NS
4th week 587.50 ± 63.03 607.50 ± 14.93 587.50 ± 23.93 625.00 ± 14.43 652.50 ± 39.24 625.00 ± 44.06 0.81 NS
5th week 610.00b ± 34.88 680.00ab ± 46.37 770.00a ± 17.79 700.00ab ± 35.36 672.50b ± 19.88 665.00b ± 15.55 0.04 *
Total 2153.00 ± 16.30 2257.50 ± 45.30 2302.00 ± 40.74 2257.75 ± 20.94 2241.50 ± 33.96 2223.25 ± 14.79 0.06 NS
Table III. Impact of Various Antibiotic Alternatives on Feed Intake of Broiler Chickens

Feed Conversion Ratio (FCR)

Fig. 2 shows significant differences (P < 0.05) in overall FCR among the supplementary groups. The organic acid group had significantly (P < 0.05) the best FCR by the end of the experiment. These results align with previous studies [20], [24]–[31], which found that all dietary-supplemented groups had better FCR than the control group.

Fig. 2. Impact of various antibiotic alternatives on feed conversion ratio of broiler chickens.

Meat Yield and Bone Development

Table IV shows no significant differences (P > 0.05) in meat yield (drumstick meat, thigh meat, wing weight, and breast meat) or bone development among the treatment groups. These findings are similar to those of Pelicano et al. [32], who found that broilers fed probiotics (B. subtilis, B. licheniformis, and S. cerevisiae) had higher leg yields.

Parameter Control Antibiotic Organic acid Enzyme Probiotic Neem P value LS
Meat yield (% in relation to body weight)
Breast meat 15.69 ± 1.80 16.28 ± 0.40 15.81 ± 2.04 14.29 ± 0.77 13.93 ± 0.47 14.03 ± 0.73 0.61 NS
Thigh meat 6.78 ± 0.22 6.59 ± 0.28 6.83 ± 0.44 6.67 ± 0.24 6.82 ± 0.26 6.75 ± 0.22 0.99 NS
Drumstick meat 5.75 ± 0.10 5.68 ± 0.08 5.64 ± 0.17 5.61 ± 0.22 5.53 ± 0.31 5.58 ± 0.15 0.97 NS
Wing meat 7.25 ± 0.20 7.63 ± 0.21 7.83 ± 0.43 7.46 ± 0.36 7.35 ± 0.15 7.91 ± 0.21 0.49 NS
Bone development (% in relation to body weight)
Thigh bone weight 1.80 ± 0.19 1.79 ± 0.11 1.81 ± 0.15 1.76 ± 0.18 1.82 ± 0.18 1.63 ± 0.07 0.95 NS
Drumstick bone weight 2.84 ± 0.10 3.07 ± 0.18 2.86 ± 0.07 2.92 ± 0.19 3.03 ± 0.14 2.87 ± 0.18 0.82 NS
Table IV. Effect of Various Antibiotic Alternatives on Meat Yield, and Bone Development of Broiler Chickens

Dressing Parameters

Table V results indicate no significant effects (P > 0.05) of treatments on head, skin, heart, abdominal fat, neck, leg, gizzard, and liver weight relative to body weight. Notably, the neem group showed numerically the highest neck weight compared to others. This contradicts the findings of Aksu et al. [33], while Islam et al. [34] reported no differences in skin, head, and giblet weights in broilers fed citric acid or acetic acid. Neck, leg, heart, abdominal fat, and gizzard weight were numerically reduced when birds were fed with organic acid supplements compared to the control group. This finding contrasts with Panda et al. [3], who found that treating with butyric acid significantly reduced abdominal fat content compared to the control or antibiotic treatment. In the current study, probiotic supplementation increased gizzard weight and decreased abdominal fat weight, while enzyme supplementation improved liver weight compared to the control group. However, Hossain et al. [35] and Islam et al. [36] found no significant differences in meat yield, bone development, and liver, heart, and gizzard weights [37] when a broiler diet was supplemented with neem and enzymes.

Parameter Control Antibiotic Organic acid Enzyme Probiotic Neem P value LS
Skin weight 3.89 ± 0.38 3.82 ± 0.16 4.20 ± 0.55 4.13 ± 0.45 3.64 ± 0.28 3.80 ± 0.12 0.87 NS
Head weight 2.76 ± 0.11 2.47 ± 0.09 2.56 ± 0.10 2.57 ± 0.10 2.58 ± 0.12 2.67 ± 0.08 0.44 NS
Neck weight 1.82 ± 0.10 1.94 ± 0.11 1.70 ± 0.09 2.08 ± 0.16 1.86 ± 0.09 2.21 ± 0.09 0.06 NS
Leg weight 4.37 ± 0.19 4.11 ± 0.18 3.84 ± 0.10 4.18 ± 0.14 4.32 ± 0.13 3.56 ± 0.41 0.12 NS
Liver weight 3.12 ± 0.21 2.92 ± 0.21 3.59 ± 0.37 3.69 ± 0.38 3.10 ± 0.28 2.76 ± 0.15 0.17 NS
Heart weight 0.71 ± 0.07 0.75 ± 0.10 0.64 ± 0.08 0.69 ± 0.05 0.68 ± 0.05 0.66 ± 0.04 0.91 NS
Abdominal fat weight 1.16 ± 0.23 0.99 ± 0.22 0.87 ± 0.05 1.17 ± 0.03 0.94 ± 0.18 0.81 ± 0.09 0.48 NS
Gizzard weight 1.80 ± 0.18 1.65 ± 0.09 1.65 ± 0.14 1.69 ± 0.07 2.01 ± 0.15 1.55 ± 0.12 0.22 NS
Table V. Impact of Various Antibiotic Alternatives on Dressing Parameters of Broiler Chickens (% in Relation to Body Weight)

Blood Biochemical Parameters

Table VI shows no significant differences (P > 0.05) in HDL, LDL, GPT, TG, and creatinine among the treatment groups. However, cholesterol and GOT varied significantly (P < 0.05) among the groups, consistent with Obikaonu et al. [38]. In contrast, Haque et al. [27] reported that probiotic Lactobacillus sporogenes supplementation lowered serum cholesterol, LDL, VLDL (very low-density lipoprotein), and triglycerides, whereas Roy et al. [24] Hossain et al. [35] observed no differences in neem supplementation.

Parameter Control Antibiotic Organic acid Enzyme Probiotic Neem P value LS
Cholesterol 149.56ab ± 4.49 142.31abc ± 4.00 150.89a ± 2.09 140.24bc ± 1.84 149.41ab ± 2.63 137.43c ± 1.53 0.02 *
HDL 67.69 ± 2.27 61.75 ± 3.82 67.81 ± 2.09 63.53 ± 2.14 65.67 ± 2.11 59.85 ± 2.33 0.20 NS
LDL 67.62 ± 2.48 67.41 ± 3.77 69.01 ± 1.06 64.24 ± 2.17 70.62 ± 1.15 63.43 ± 3.20 0.35 NS
GOT 19.83a ± 0.41 15.02b ± 1.27 14.00b ± 1.72 17.79ab ± 1.40 17.64ab ± 0.65 16.77ab ± 1.60 0.05 *
GPT 8.02 ± 0.44 8.31 ± 0.87 9.92 ± 0.71 9.04 ± 1.024 9.77 ± 1.25 10.06 ± 0.50 0.41 NS
TG 71.22 ± 3.84 65.73 ± 6.06 70.36 ± 4.45 62.32 ± 0.64 65.61 ± 1.96 70.73 ± 3.84 0.51 NS
Creatinine 1.042 ± 0.07 0.1 ± 0.11 0.87 ± 0.08 0.96 ± 0.05 0.84 ± 0.03 0.80 ± 0.06 0.17 NS
Table VI. Impact of Various Antibiotic Alternatives on Blood Biochemical Parameters of Broiler Chickens (Mg/Dl)

Conclusion

From the obtained findings, it can be concluded that supplementing organic acid, probiotics, enzymes, and neem enhanced the growth performance, carcass quality, and blood biochemical profiles of the broilers, potentially serving as antibiotic alternatives. Mainly, organic acid gives the best results out of all the antibiotic alternatives. Simultaneously, organic acid, as a suitable alternative to antibiotics, could provide a more homeostatic and healthy blood profile than others.

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