Asian Journal of Animal and Veterinary Advances

Year: 2022 | Volume: 17 | Issue: 3 | Page No.: 91-97
DOI: 10.3923/ajava.2022.91.97

Impact of Chicken Protector, Prebiotic and Phytobiotics Feed Supplement on Layer Chicks Growth and Development

J.A. Hamidu , E.L. Dohoe, I. Seydous, A. Zakari, K.O. Donkor, E. Ofori- Kuragu, A. Osei- Adjei, G.K. Sarfo, K.A. Acheampong and A.N. Akunzule

Abstract: Background and Objective: Early maturity of layer poultry has been greatly undermined for years especially because of their purpose of production. This study was conducted to investigate the impact of chicken protector, a blend of essential oils and plant extracts acting as prebiotics and phytobiotics on layer chicks’ growth rate indicators of the early establishment of immunity. Materials and Methods: In the experiment, 50 Isa brown layer day-old chicks obtained from a local hatchery in Ghana were used. They were randomly assigned to two treatments, chicken protector and control in a Completely Randomized Design (CDR) for 21 days. The parameters that were measured included, haematological parameters, body weight, blood cholesterol levels, immunology, histological performance and gut microbial level. Results: Body weights of chicks on chicken protector and control were not significant over 3 weeks period. The total gut pathogenic bacteria load and Enterobacteria count (CFU g^–1) in control (6.65×10⁷, 6.75×10⁷) was higher than in CP groups (1.6×10⁶, 3.3×10⁷). The red blood cells, white blood cells, hematocrit and neutrophils counts were all higher in CP birds compared to control. Conclusion: The CP over the long term could reduce over-dependence on antibiotics during egg-laying and increase food safety for humans.

Keywords: early growth rate, Layer, gut development, chicken protector and histological performance

INTRODUCTION

The early maturity of layer poultry has been greatly undermined for years especially because of their purpose of production. The farmers' focus tends to be drawn more to the early growth of the broiler, to prepare the chicken for the market within a few months of production. The rate of maturation determines the reproductive maturity of the chicken. Local chickens in Ghana were found to take a longer time to reach reproductive maturity. The age at which local hens lay their first eggs is 6-7 months¹. The age of the first egg may increase when there is a delay in sexual maturity in the chicken. This delay is caused by certain environmental conditions² and stress such as heat. Poor management has been found to cause late sexual maturity in layers. For example, giving them a small amount of feed daily may result in late maturity in layers. Practicing good management such as a good feeding regime that will increase their feed intake and prevent wastage of feed to accurately determine their feed conversion ratio and, good housing and disease management of poultry are important for good sexual maturation.

Furthermore, the higher efficiency and productivity of foreign birds versus local birds are very significant. Local birds in Ghana were found to have low immunity and are of low quality leading to a high mortality rate and high importation of foreign birds^3-5. But there are disadvantages to importing exotic breeds. The cost of production is high due to recent increases in the price of day-old chicks by more than 50%. Additionally, differences in environmental conditions require optimum input to increase survival. However, farmers choose to embrace these shortcomings rather than get local chicks because of huge disadvantages that come with them, high mortality rate because of low immunity, low productivity and cost of production such as low feed conversion ratio. With increased uncertainties such as the recent outbreak of the COVID-19 pandemic and frequent occurrences of avian influenza developing countries continue to ban the importation of day-old chicks, which shifts the normal curve of supply and demand to make inputs more expensive⁶. Therefore, the main objective of this study was to increase the immunity of locally hatched chicks with prebiotics and phytobiotics feed supplements and evaluate its effect on growth performance during the first 3 weeks of growth post-hatch and identify the common pathogenic microbes during growth.

MATERIALS AND METHODS

Location of experiment: The research was conducted at the Poultry Research Unit of the Department of Animal Science, Kwame Nkrumah University of Science and Technology, Kumasi. The study started on April, 19, 2021 and got terminated on May, 10, 2021, making exactly 21 days duration. All experiments were conducted according to the Procedure for Animal Research Ethics Committee (AREC) of the Kwame Nkrumah University of Science and Technology, Kumasi-Ghana, Quality Assurance and Planning Unit (KNUST POLICY 0016) (AREC 2018).

Experimental design: Fifty Isa brown layer day-old chicks obtained from top man farms located in Kumasi, Ghana. Chicks were randomly allocated to two treatment groups, a control group (A) and a chicken protector group (B) with twenty-five chicks per treatment group in a Completely Randomized Design (CRD).

Housing and management: Birds were raised for 3 weeks in a slated poultry house. Black polythene sheets were used to cover the structure and two 100-watt tungsten light bulbs as a source of heat for brooding. Medication and vaccination were followed according to the schedule of the Ghana Veterinary Service Directorate, except that the CP group was not given any antibiotics. The birds were fed ad libitum. The chicken protector was given at a rate of 1 mL to 10 L of water.

Chick quality determination: On the first day of arrival, all the chicks were weighed and the chick length and shank length were determined. The chick length was measured by laying the chick on its back over a 30 cm ruler and the length was recorded from the tip of the beak to the longest toe after a normal stretch of the chick such that it experiences no pain. The shank length of each bird was measured from the hock joint to the posterior end of the metatarsal. The chick length and shank lengths were taken only at the day old. After the measurements, five chicks from each treatment were randomly selected and euthanized by decapitation. Blood samples were collected from the jugular veins into two test tubes with one containing EDTA in the tubes to prevent blood clotting. The dead chicks were dissected at the abdomen and the residual yolk sacs (RYS) were removed. The weight of the wet yolk sac was determined and transferred to an oven to dry at 70°C for 4 days. It was reweighed after drying the RYS to determine the dry weight.

Haematological and bacteriological parameters: The blood samples taken from the 3 chicks per treatment were analyzed for total counts of red blood cells, white blood cells, platelets, hematocrit, haemoglobin, neutrophils and lymphocytes. Additional blood was collected from 2 birds per treatment which did not contain EDTA and allowed the serum to separate from the blood after clotting. The biochemical profiles of the blood were done to assess the functionality of internal organs and disease susceptibility including creatinine, alanine transaminase (ALT), aspartate transaminase (AST), urea and total cholesterol levels. All analysis was done using a Hematological Auto Analyzer (Automated Hematology Analyzer, XK-21N^TM, Sysmex). The blood and serum biochemical analysis were performed in day-old chicks, at 7, 14 and 21 days of life.

Bacteriological parameters: At 21 days a bird from each treatment were slaughtered and a portion of the intestines removed (caecum) and placed in sterile zip lock bags for bacterial isolation and identification. Media such as Mannitol salt agar, MacConkey agar, Simmons citrate agar and Tryptone nutrient agar were prepared for the bacteria growth, identification and isolation⁴.

Statistical analysis: All the data obtained were subjected to analysis of variance using the Proc GLM procedure of SAS 9.4 (SAS Institute, 2012). The means were separated using PDIFF and means by Tukey’s test at p<0.05.

RESULTS

Physical indices: The weekly body weights of chicks, the chick length and shank length under the two treatments were not significantly different (p>0.05) as shown in Table 1. On day 1, the chicks used for control weighed 34.64 g while those used for chicken protector treatment weighed 34.52 g. On day 7, the chicks on control weighed 79.2 g while chicks on chicken protector were 83.49 g and therefore were 4.29 g heavier than those of the control. By day 14, the chicks on control weighed 3.33 g higher than the chicken protector treatment (141.71 g vs. 138.38 g). However, by 21 days of rearing, although not significantly different the chicks on chicken protector were heavier than control chicks by 14.41 g (221.72 g vs. 207.31 g) indicating some level of improved growth performance on prebiotics and photobiotic supplemented birds. The chick length and shank length of birds in the CP treatment group (19.28 and 3.72 cm) were higher compared to the in the control treatment group (18.29 and 2.83 cm), respectively. However, there was no significant difference between both treatments on chick length and shank length (Table 1).

The residual yolk sac weights were also not significantly different between the chicken protector and control treatments on days 1 (3.38 g vs. 3.44 g), day 7 (2.76 g vs. 2.56 g), day 14 (0.26 g vs. 0.24 g) and 21 (0.2 g vs. 0.18 g), respectively as shown in Table 2. While not significantly different the rate of disappearance of the residual yolk sac in control and chicken protector chicks were high (R = 0.89 and 0.88) respectively, the rate was just 1% higher in the control (y = -0.1803x+3.5429, R² = 0.89) compared to the chicken protector group (y = -0.1798x+3.5828, R² = 0.88).

Haematological and immunological indices: The results of the haematological analysis are shown in Table 3. The red blood cell count at the beginning of the study between the control (2.27×10⁶ μL^–1) and the CP (1.90×10⁶ μL^–1) on day 1, day 7 (7.77×106 μL^–1 vs. 1.04×10⁶ μL^–1), day 14 (2.48×10⁶ μL^–1 vs. 2.47×10⁶ μL^–1) and day 21 (2.25×10⁶ μL^–1 vs. 2.60×10⁶ μL^–1) were not significantly different. The white blood cell count was higher in the control (197.75×10³ μL^–1) than in the CP group (182.00×10³ μL^–1) on day 1. However, from 7 days to 21 days there was no difference in the WBC counts between the control and CP groups. The haemoglobin count was significantly higher in the control (10.05 g dL^–1) compared to the CP group (8.05 g dL^–1) on day 1, while it was higher in the CP group than in control on day 21 (9.85 g dL^–1 vs. 8.55 g dL^–1). The HGB at 7 and 14 days were not different between the treatments. The proportion of HTC was also significantly higher in the control group (36.20%) compared to the CP group (29.65%) on day 1 and lower in the control (30.93%) compared to the CP group (35.60%) on day 21. Similar to the HGB, the HCT at 7 days and 14 days was not different between the treatments. The MCV and MCH levels were not different between the treatments on any of the days of the study between the treatments. However, MCHC was higher in the CP chicks at 7 days (28.80 g dL^–1) compared to control (27.45 g dL^–1), there was no difference for 1 day, 14 days and 21 days between treatments. The platelet count, red cell distribution width standard deviation, red cell distribution width coefficient of variation, mean platelet volume and platelet large cell ratio were all not different between the treatments on any of the days of study. The week by the week number of neutrophils counts were all not significant between the treatment at days 7 and 14 except on day 1 and day 21. On day 1 the control had higher neutrophil counts and proportions (197.75, 100%) compared to the CP group (4.05, 2.25%). But by 21 days the CP group had higher counts and proportions (185.35, 100%) compared to the control (9.00, 5.05%). A significant increase in hematocrit and neutrophil counts are important indicators of immunity establishment.

Biochemical indices of chicks: Table 4, 5, 6 and 7 show the measurements of cholesterol, urea, creatinine, aspartate transaminase (AST) and alanine transaminase (ALT) in the blood of layer chicks over 21 days. On day 1 the blood cholesterol level in the chicken protector group (18.7 mmol L^–1) was numerically higher compared to the control (12.53 mmol L^–1) but not different (p = 0.2196). While not significantly different, the urea was numerically lower on day 1 in the CP chicks (5.73 μmol L^–1 vs. 6.20 μmol L^–1). The creatinine (12.33 μmol L^–1 vs. 34.33 μmol L^–1), aspartate transaminase (AST) (257.33 μmol L^–1 vs. 236 μmol L^–1) and alanine transaminase (ALT) (11.33 μmol L^–1 vs. 10.0 μmol L^–1) levels were not significantly different on day 1 between chicken protector and control groups in Table 4.

There was a significant increase in blood cholesterol level in the CP birds on day 7 compared to the control (8.97 mmol L^–1 vs. 4.57 mmol L^–1, p = 0.0023). However, there was no difference in urea (0.53 μmol L^–1 vs. 0.7 μmol L^–1), creatinine (14.33 μmol L^–1 vs. 36.33 μmol L^–1), aspartate transaminase (302 μmol L^–1 vs. 256.67 μmol L^–1) and alanine transaminase (6.67 μmol L^–1 vs. 7.33 μmol L^–1) between control and CP on day 7 in Table 5.

At day 14 the cholesterol was numerically higher in control compared to CP (2.77 mmol L^–1 vs. 2.07 mmol L^–1) chicks, other parameters, urea (0.57 mmol L^–1 vs. 0.9 mmol L^–1), creatinine (35.33 μmol L^–1 vs. 32.33 μmol L^–1), AST (298 μmol L^–1 vs. 298 μmol L^–1) and ALT (4.33 μmol L^–1 vs. 4 μmol L^–1) were all not different between control and chicken protector treatments in Table 6.

At day 21 the cholesterol level in the blood (1.80 mmol L^–1 vs. 1.65 mmol L^–1), the urea (0.3 mmol L^–1 vs. 0.15 mmol L^–1), creatinine (33.5 μmol L^–1 vs. 19.0 μmol L^–1), AST (215.5 μmol L^–1 vrs. 210.0 μmol L^–1) and ALT (4 μmol L^–1 vrs. 7 μmol L^–1) were not different between the control and chicken protector in Table 7.

Bacteriology: The control group had higher levels of bacteria load (CFU g^–1) and enterobacteria load counts (6.65×10⁷ CFU g^–1, 6.75×10⁷ CFU g^–1) as compared to the CP group (1.6×10⁶ CFU g^–1, 3.3×10⁷ CFU g^–1). The following bacteria were isolated from the gastrointestinal tract, Staphylococcus aureus, E. coli, Salmonella spp.

DISCUSSION

A total reduction in the blood variables was seen on day 7 with a significant difference being observed. Neutrophil levels increased exponentially to 100% CP group by 21 days, which, suggested that the chicks were under some kind of stress or infection caused by bacteria or fungi, causing an immune response. It must be emphasized that these CP treated chicks were not given antibiotics even when they appeared sick. In addition, there was an increased level of White Blood Cells (WBC) confirming the presence of bacteria which led to an increased level of WBC to fight against pathogens. Though there was no significant difference, the treatment group on CP kept showing an increase in the total blood component especially neutrophils in the last two weeks of the study.

On day 21, birds in the CP treatment group had increased neutrophil counts at 100% indicating the presence of stress and we assume the presence of a bacterial infection due to the inclined level of neutrophils. This may be a result of the active compounds present in the plant extract and essential oils that have a microbial effect. Monoterpenoids and sesquiterpenoids found in essential oils are known for reducing the effect of bacterial or fungal attacks⁶ and also insect repellants⁵. These may have a role to play in increasing the lymphocyte level in the CP treatment group, which in terms reduces the risk of viral infection in birds in the absence of antibiotics. Photobiotics in general is either antifungal, antiviral or antibacterial⁶.

A total reduction in the serum biochemical test was observed throughout the experiment, there was no significant difference between the two treatments except for the total cholesterol on day 1, which was even before the start of the study. Generally, the biochemical indices showed numerically lower values in the CP chicks than as seen in the control. Gopi et al.⁷ reported a low level of TC in birds infected with Eimeria suggesting that this may be due to the failure of the liver to produce cholesterol for the body. The synthesis of cholesterol is important in the production and synthesis of steroid hormones calciferol, which helps in growth and immunity⁸. Jacobs et al.⁹ also confirmed that minor illness resulted in low blood cholesterol though a much lower level was also observed in severe illnesses. Stamilla et al.¹⁰ reported that parasites play a role in lowering cholesterol when present in the body during their trophozoite stage, which may therefore be due entirely to the prebiotic effect. Additionally, Freitas et al.¹¹ reported lower values for Enterobacteriaceae and Enterococci for birds fed essential oils in combination with an organic acid. The overall effects of the treatments were positive, but they concluded that the combination of essential oils and organic acids is still challenging to be used as an antibiotic growth promoters alternative, hence the further recommendation to repeat the study over a longer period.

CONCLUSION

It has been observed in this experiment that the chicken protector has antimicrobial properties that lowered the effect of disease infection. Chicken protector even though did not affect improving body weight gain and has a higher antimicrobial effect than antibiotics and it could be due to antibiotic-resistant microbes present in the gut. The chicken protector has the potential of being used as an antibiotics growth promoters (AGP) alternative. However, it is recommended that to get maximum performance, it should be experimented with in combination with other feed additives to maximize growth and performance. While it appears to boost the immune system, further studies should be done to evaluate the full potential of chicken protectors.

SIGNIFICANCE STATEMENT

This study underscores the use of chicken protector, a prebiotic and phytobiotics feed additive an alternative to the prophylaxis use of antibiotics in the few days of layer day-old chick life. The results show that the birds given the chicken protector had higher levels of white blood cells and neutrophils, which could confirm immunity to chicks and reduce disease infection. Additionally, giving the chicken protector reduced the bacteria load and enterobacteria load counts as compared to control. This study will help researchers and industry to tailor the rearing of layer chicks in their early life by taking advantage of gut health and immune system and enhancing the competitive development of the beneficial gut microbial population that is becoming the focus of poultry nutrition in recent times among many researchers to reduce the use of antimicrobial growth promoters such as antibiotics.

ACKNOWLEDGMENT

The researchers are very much appreciative of material and logistic support from Greenflies Company Limited, Ghana, the supplier of Chicken protectors to the study. We also appreciated contributing support from the Department of Animal Science and CAN LAB, Kwame Nkrumah University of Science and Technology. We express our profound gratitude to all the field staff.

REFERENCES