Performance and haematology of broiler strains (cobbs and arbor-acre) fed ginger (Zingiber officinale) based diet at the early phase

The research was conducted to evaluate the performance and haematology of broiler strains (Cobbs and Arbor-acre) fed ginger (Zingiber officinale) at the early phase. A total of one hundred and forty-four (144) day old chicks of mixed sexes comprising of two different strains were used for the experiment. They were randomly assigned to the three different experimental treatment groups. Treatment 1 (T1 = basal diet only); Treatment 2 (T2 = basal diet + 0.5% ginger); Treatment 3 (T3 = basal diet + 1.0% ginger). Each treatment group was replicated three (3) times in a Completely Randomized Design (CRD). Results showed that ginger inclusion caused significant (p< 0.05) increase on final weight, weight gain, daily weight gain and feed conversion ratio, as better performance was recorded with the increase in the inclusion level of ginger. Final weight, weight gain, daily weight gains and feed conversion ratio was significantly affected by strain treatment interaction at 0.5% ginger inclusion as theCobbs strain had a higher performance than the Arbor acre strain. The effect of dietary levels of ginger (Zingiber officinale) on the haematology of different strains of broiler showed that ginger inclusion significantly increased (p<0.05) all the haematological parameters evaluated except for PCV. It is observed that there were better haematological indices for Cobbs strain, and better response at 1% ginger inclusion. Inclusion of ginger (at 1%) favoured the performance and haematological indices of broiler chickens.


Introduction
Nutrition is the most expensive factor in poultry production taking approximately 70% of production budgets [1; 2]. Therefore, to reduce the cost of production, improvement in the feed efficiency would be a feasible option. The use of feed additives as growth promoters in poultry nutrition is one of the ways to accomplish this goal.
Growth promoters are commonly used to stimulate growth and protect the health of poultry [3]. Among growth promoters, the most commonly used are antibiotics. However, their use is restricted due to possible development of drug resistance in bacteria, drug residue in carcass and also alteration of natural gut micro flora [4]. Many countries tend to minimize or prohibit the use of antibiotics because of their deleterious side effects on both animals and humans. Recently, studies have become more focused on the use of naturally occurring phytobiotics to replace the chemically based feed additives [5]. Phytogenics are a group of natural growth promoters or non-antibiotic growth promoters, derived from herbs, spices or other plants, which have been reported to possess antimicrobial, anti-oxidative, antiinflammatory and immuno-modulatory properties [6]. The positive effects of herbal supplements on broiler performance, carcass quality and quality traits of meat have been demonstrated [7].
There are several naturally existing herbs (medicinal plants) which could be used in preventing the accumulation of lipids including neutral fats and cholesterol, prominent among these plants is ginger (Zingiber officinale). Ginger has gained prominence due to its wide range of properties not only in reducing lipids but, in many other ways where the utmost aim is to improve the nutritive value of the animal products (meat, milk or egg) [8].
Information obtained from haematological assay, apart from being useful for diagnostic and management purposes could equally be incorporated into breeding programs [9]. Haematological studies are of ecological and physiological interest in helping to understand the relationship of blood characteristic to the environment and so could be useful in the selection of animals that are genetically resistant to certain diseases and environmental conditions [10]. Haematological parameters are good indicators of the physiological status of animals [11], and are related to the blood and blood forming organs [12]. The examination of blood gives the opportunity to investigate the presence of several metabolites and other constituents in the body of animals and plays a vital role in the physiological, nutritional and pathological status of an organism [13].

Justification of the study
The search for natural feed additives which have no adverse effect on the performance and health of animals continues to attract the attention of researchers in developing countries, achieving this through dietary inclusion of naturally occurring herbs may be a cheap and safe way, and amenable to increased adoption by poultry farmers.

Objective of the study
The feeding trial sought to investigate the effect of graded levels of ginger inclusion on the performance and haematological indices of two broiler strains at the early phase.

Materials and methods
The experiment was carried out at the Poultry Unit of the Kogi State University Livestock Teaching and Research Farm, Anyigba, Kogi State. Anyigba is located in the derived savannah zone of Nigeria on latitude 7 o 30´N and longitude 7 o 09´E. The zone is characterized by 6-7 months of annual rainfall ranging from 1400-1500mm and day temperature range of 25 o C-35 o C with the highest temperature in March and April [14].
Fresh ginger (Zingiber officinale) was purchased, washed, peeled, chopped into smaller pieces, dried andground into powder. Ginger powder was incorporated into the experimental diet for cobbs and arbor acre at 0%, 0.5% and 1% as the various treatments respectively. The experimental basal diet was formulated with a crude protein of 23%.
A total of one hundred and forty-four (144) day old chicks of mixed sexes comprising of two different strains (Arbor acre and Cobbs) were randomly assigned to the three different experimental treatment groups. Treatment 1 (T1 = basal diet only); Treatment 2 (T2 = basal diet + 0.5% ginger); Treatment 3 (T3 = basal diet + 1.0% ginger). Each of the treatment groups per strain was replicated three (3) times with eight (8) chicks per replicate.

Management of birds
All the necessary management practices for broiler chickens, such as brooding, vaccinations, feeding, sanitation, record keeping and medication were strictly adhered to.

Data collection/ method of collection
Data collected were feed intake and efficiency, body weight gain, haematological parameters [packed cell volume (PCV), red blood cell count (RBC), white blood cell (WBC), haemoglobin, mean corpuscular haemoglobin (MCH), mean corpuscular concentration (MCHC) and platelets].The duration of the experiment was four weeks.

Statistical analysis
Data collected in the course of the experiment were subjected to Analysis of Variance (ANOVA) as appropriate for a 2x3 factorial arrangement implemented within the Completely Randomized Design (CRD) using Statistical Package for Social Sciences (SPSS version 20). Significant means were separated using LSD at 5% level of significance. Result obtained in Table 1 showed that strain had no significant influence (p>0.05) on the performance characteristics and haematological indices of the birds except for RBC that showed that the Arbor acre strain was significantly (p<0.05) higher than the Cobbs strain. However, cobbs strain showed higher numeric values for initial weight, final weight, weight difference, daily weight gain and feed conversion ratio but the Arbor acre strain showed higher values for the daily feed intake.

Results and discussion
The non-significant difference (P<0.05) in body weight gain of the strains is an indication that the genetic trait variation between strain is not significant. This is in contrast with reports by Deeb and Lamont [15] who reported that genetic differences existed among broiler strains and these differences bring about differences in their performance [16]. The genetic variation between the two strains is not significant in terms of feed consumption and their different nutrient requirement, since birds eat to satisfy their nutritional needs [17]. The higher feed intake of Arbor acre strain on the other hand though not significant (p<0.05) is an indication of a higher energy requirement as compared to the cobbs strains [18]. It is reasonable to infer that limiting their feed intake by any means therefore would drastically affect the performance Arbor acre strain with less effect on the cobbs strain which is a product of their genetic make-up [19]. The low feed consumption and the high feed conversion ratio indicates superiority of the cobbs strain to Arbor acre. [20; 21] stated that the body weight gain, feed consumed and feed conversion ratio are all affected by specific physiological demands at specific age. This determines maintenance energy requirement, feed intake, feed conversion ratio and the ultimate body weight gain. This could imply that at four (4) weeks the physiological need of the different strain of birds were basically the same.
The values for haematological indices obtained in Table 1 though significantly different (p<0.05) correspond with normal ranges reported by Oladipo et al. [22] except for the WBC. [22] reported a range of 27.67% -30.00%, 2.95 x10 6 /l -3.52 x10 6 /l, l 3.10 x10 6 /l -5.67 x10 6 /l for PCV, WBC and RBC respectively. Oguntoye [23] [24], however, [25] observed variation in haematological profile of different strains.   [26] who reported a steady increase in weight gain for birds whose diets were supplemented with ginger. [27] suggested that gingerol's anti-microbial activity promotes the performance of the intestinal flora thereby improving digestion and enhancing the utilization of energy, leading to improved growth. Weight gain shows the actual gain due the treatment effect. Obtained results show significant difference (p<0.05) across treatments with increased inclusion level of ginger root meal. Value range of 460.35±13.40 to 601.87±13.40 was obtained for weight gain. Observations were in line with [28] who reported weight differences which were significantly higher with birds on ginger supplemented diets. [29] reported higher weight gain for ginger root infusion than powder. [30] however, reported a negative trend when inclusion levels reached 3% as gastric irritation, dyspepsin, diarrhea, eructation and mortality resulted due to excessive inclusion. The daily feed intake of birds in T1 (65.97±1.13) and T2(66.15g±31.13) were similar and significantly lower that T3 (70.66g±1.3). Intake increased as the level of ginger supplementation in the diet increased. This indicates that ginger increase appetite and digestion by stimulation digestive juice such as bile, saliva, gastric, pancreatic and intestinal secretion [33]. Value recorded in this research was in line with reports of [34]. [35; 36] however, reported that ginger powder had no significant effect on the intake of the birds. [37] work on the proven effects of phytobiotic feed additives in different poultry species, indicated a reduced feed intake, and improved feed conversion ratio for all species of birds.
Birds fed diets with ginger root meal had a significantly better (p<0.05) feed conversion ratio than those on the control diet. Invariably birds with higher feed conversion ratio had higher final body weight gain. Similar, observations were made by [38], in their study on weaned rabbits, they noted that these herbs addictive may have controlled and limited the growth and colonization of numerous pathogenic and non-pathogenic species of bacteria in the GIT leading to improved conversion of feed to meat. [39] also suggested that ginger supplementation enhances the activity of pancreatic enzymes and provides an environment for better absorption of nutrients.   [23]. According to [40], packed cell volume is involved in the transport of oxygen and absorbed nutrients. Increased packed cell volume shows better transportation and thus results in an increased primary and secondary polycythemia. PCV beyond the normal range is an indicator of toxic factors which could have adverse effect on the formation of blood [41].There was significant difference (p<0.05) for haemoglobin, observed result showed T3 (10.50 g/dl) being significantly higher than the rest treatment means. Value range of haemoglobin observed was 9.43g/dl-10.50 g/dl. White blood cell value though significantly different (p<0.05) among treatment means, did not follow a particular order. Diet T3 had the highest value of 232.82, while T2 (206.15) had the least value. The range observed WBC (206.15 -232.82), falls within the range for normal birds [42]. The major functions of the white blood cell and its differentials are to fight infections, defend the body by phagocytocis against invasion by foreign organisms and to produce or at least transport and distribute antibodies in immune response. Thus, animals with low white blood cells are exposed to high risk of disease infection, while those with high counts are capable of generating antibodies in the process of phagocytosis and have high degree of resistance to diseases [43] and enhance adaptability to local environmental and disease prevalent conditions [44].
Values for red blood cell showed significant difference (p<0.05) across treatments with the highest observed in T3 which was not significantly different from T2, but was significantly different from T1. RBC was 3.150 -4.167 x10 6 /l. This shows that birds fed ginger 1.0% had more red blood cells, which could imply that ginger have some innate quality to stimulate the production of red blood cells through vitamin synthesis. According to [40], red blood cell is involved in the transport of oxygen and carbon dioxide in the body. Thus, a reduced red blood cell count implies a reduction in the level of oxygen that would be carried to the tissues as well as the level of carbon dioxide returned to the lungs [40]. This implies that factors that promote the build-up of red blood cells should be encouraged.    Table 4 shows that treatment and strain interaction had significant (p<0.05) effect on performance parameters, except initial weight. Observed results show T3S1 (645.33±18.98), T3S2 (637.33±18.98) and T2S1 (619.33±18.98) being significantly higher as compared to the other treatment for final weight. The interaction of increasing inclusion of ginger with strain tends to significantly increase (p<0.05) the final weight of the birds with higher inclusion of ginger irrespective of the bird strain. This is in contrast to report by [46] who reported the significant variation (p<0.05) induced by strain effect in compensatory growth. Weight gain significantly varied (p<0.05) due to diet and strain. Results obtained show significant higher value with increase in ginger inclusion in the diet for both strain.
A similar trend was obtained for daily weight gains. Values of result obtained were significantly increased (p<0.05) with increase in the inclusion level of ginger in the diet. Improvement in body weight gain of broiler chicks fed ginger might be due to the active components present in the ginger which stimulated digestive enzymes and improved overall digestion and thus led to increased body weight gain. It has been established that ginger in diet stimulated lactic acid bacteria and decreases pathogenic bacteria such as coliform and Escherichia coli and thus improved absorption of nutrients leading to better weight gain of the birds [46]. The results are consistent with those of [47]. Results indicate that less feed was consumed by the Cobbs strain compared to their Arbor acre counterpart. However, intake increased with the increasing inclusion level of ginger. This observation is in agreement with those of different workers who had earlier reported that ginger powder in broiler diet had a significant positive effect on feed consumption [5].
It was observed that 0.5% and 1% level of ginger inclusion significantly improved FCR which was more obvious in the Cobbs strain; thereby bringing about an increase in weight per unit of feed consumed. This further implies that a significant variation (p<0.05) is observed for treatment effect and not strain. Result obtained is in line with the report of [37]. The Authors worked on the effects of phytobiotic feed additives on different poultry species, and observed increased weight gain with significant reduction in feed intake, and improved feed conversion ratio when broilers were fed ginger diets as against the control diet. Table 5 shows the interaction effect of strain and feed/treatment on the haematological indices of broiler chicken. There was significant difference (p<0.05) for strain effect and feed (ginger inclusion) on all the parameters evaluated except for the PCV. The trend of the result showed Cobbs strain had higher values for Hb and RBC. Birds showed significant increase (p<0.05) across treatment with increasing inclusion level of ginger for the parameters evaluated. Similar trends were observed with Arbor-acre which showed increased values for WBC, MCV, MCH, MCHC, neutrophils and lymphocyte as the inclusion level of ginger increased. Observed value of 9.38g/dl-10.90g/dl for haemoglobin in this study falls within the normal range for healthy chicken according to [42]. The haemoglobin count in this experiment indicates high efficiency of oxygen transportation, cellular metabolism and effective tissue respiration [48]. This corresponds with the report of [49], who opined that haemoglobin has the physiological function of transporting oxygen to tissues of the animal for oxidation of ingested food so as to release energy for the other body functions as well as transport carbon dioxide out of the body of animals.WBC ranged from 186. 30 -234.00. An increase in the WBC count suggests a severe microbial infection. This high WBC count may indicate disease presence, protective mechanism and provision of rapid and potent defense against infectious agents. However, the high percentage of the WBC may be associated with the ability of the strain of the broilers with the help of the feed (ginger) to perform well under very stressful conditions. The essential oil and oleoresin of Zingiber officinale exhibits significant antioxidant and antimicrobial activities [50]. 6-Dehydroshogaol, 6-shogaol and 1-dehydro-6-gingerdione have been shown to be potent inhibitors of free radicals [51], this could explain the build-up of the white blood cell [45]. RBC is are very important in the transportation of oxygen from the lungs to the tissues and carbon(iv)oxide from the cell and tissues to the lungs for excretion. Though low, was adequate for the proper functioning of the birds [52]. Results showed that Hb, PCV and RBC were within the normal ranges for healthy birds. This may indicate proper synthesis of vitamin and optimal functioning of the bone marrow of the birds, in addition to significant effect of ginger on the haemoglobin and red blood cell, since haemoglobin functions as a carrier of oxygen to target organs by forming oxy-haemoglobin, a situation which indicates that the birds were not anaemic nor lacked oxygen [53].MCH and MCHC values found to be within normal ranges may indicate that feed formulation and compounding was well done without a negative interaction between energy and protein balance in the diet [45]. Neutrophils and lymphocytes showed significant difference (p<0.05) with Arbor Acre interaction, T3S1 having significantly higher values (p<0.05) (5.67) for neutrophil while Cobbs interaction T2S2 (97.91) had the highest significant value for lymphocyte. This implies the ability for healing of injuries, higher resistance or recovery to foot pad dermatitis and quick clotting of wounds increased with the increase of the inclusion levels of ginger in the diet as there was no allergic reaction to the treatment offered. [54] reported that apart from genotype, age, and sex, differences in haematological indices may be caused by nutrition.

Conclusion
From the result obtained, strain showed no significant effect (p>0.05) on the early performance and haematological indices of birds except for RBC, however, values of performance parameters obtained were significantly affected (p<0.05) by the inclusion of ginger, as a consistent increase on the final weight, weight gain, daily feed intake and feed efficiency was observed with increase in the inclusion level of ginger in the diets of the broilers. Interaction effect of both strain and ginger showed significant effect (p<0.05) indicating the Cobbs strain as a better performer than Arbor acre. Haematological values of birds administered ginger at various level of inclusion showed better utilization of the experimental diets than control. Optimum haematological performance is achieved at an inclusion level of 1% in the diets of broilers. This tends to prove that the inclusion of ginger rhizome at 1% in the diets of the birds improved the health of the broilers. Thus for selection and effective utilization of feed, Cobbs strain at 1% inclusion of ginger would stimulate an excellent haematological profile for optimum performance than Arbor acre. Based on the findings of this research, it is recommended that ginger be added at an inclusion level of 1% to diets of broiler for improved performance characteristics; also, the Cobbs strain should be used instead of the Arbor acre strain for better performance.

Disclosure of conflict of interest
The authors: Iyaode Iyekeji Ifelayo, Oyewole Benjamin Osigbodi, Adesola Mercy Adetola and Anjorin, Grace Oluwabunmi hereby declare that there is no conflict of interest.

Statement of ethical approval
The research was conducted in accordance with the ethical standard of the Institution.