The present study aimed to generate baseline data on physiological and haemato-biochemical profile of local chicken, Sikhar of Mizoram. Body weight, respiration rate (RR), pulse rate (PR) and rectal temperature (RT) were recorded. Hb, TEC, PCV, MCV, MCH, MCHC, blood glucose, total protein (TP), albumin, globulin and total cholesterol (TCh) were estimated in plasma samples collected from five groups viz. 2 months, 4 months, 6 months, 8 months and 10 months old. Sikhar birds attained 217.92±7.11g of body weight at 2 months and 1134.20±69.58 g at 10 months. RR and PR declined gradually with age while RT was highest in 4 months old birds. Sikhar birds maintained stable glucose level till 8 month and declined at 10 months. Hb, TEC, TP, albumin and globulin increased while MCV and MCH declined with age. PCV and MCHC were not influenced by age. TCh fluctuated in different groups with highest value at 4 months.
Sikhar bird is one of the deshi/local type of chicken whose home tract is in different parts of Mizoram state in India. The system of rearing backyard birds is extensive. Being an indigenous bird they can thrive and produce with irregular supply of feed and water and with minimum healthcare (Padhi, 2016). This chicken is of scavenging type. As per its behavior this chicken is very alert to the social happening such as presence of any intruder in and around their presence by making immediate response to the sound or the gestures of the intruder. As perceived from local dwellers, Sikhar birds are being reared purposely for catching Red Jungle Fowl from the forest areas during the months from March to June as part of game or for table purposes as the meat of Sikhar birds are preferred to commercially available broiler meat by local people. For the purpose adult Sikhar birds are sold at higher prices as compared to other commercial birds; as high as Rs. 3000/- for every pair of a cock and a hen although their production performance is very low. Physiological responses and haemato-biochemical profile had been indicated as an index for determining the health status of different birds which were found to be influenced by breed, age, sex, nutrition, management practices, season etc. (Kang et al., 2011; Addass et al., 2012; Pandian et al., 2012; Kundu et al., 2013). No scientific studies on Sikhar birds had been carried out and no literatures are available on any account of these birds. The present investigation was therefore undertaken in order to generate normal baseline data on some physiological responses and hemato-biochemical profile.
Material and Methods
Birds and Blood Sampling
The study was carried out in Sikhar bird of Mizoram reared around the campus of College of Veterinary Sciences and Animal Husbandry, Central Agricultural University, Selesih, Aizawl, Mizoram, India. The study comprised of five different group’s viz. Group I (2 months old), Group II (4 months old), Group III (6 months old), Group IV (8 months old) and Group V (10 months old) and each groups comprised of 12 birds of either sexes. The chicks were kept with the mother till they attain 1 month of age and they were let loose to the field. The birds were reared in the backyard with infrequent supplementation with commercially available pelletted layer feeds. The body weight of each of the birds was recorded on the day of blood sampling by using a digital weighing balance with correction level to 0.1g. The respiration rate (RR), pulse rate (PR) and rectal temperature (RT) were recorded prior to blood collection. Blood sampling was done by puncturing jugular vein in Na2EDTA coated tubes for hematology and Lithium-heparin coated tubes for biochemical parameters. Cold chain was maintained during the transit of the samples from farm to laboratory.
Analysis of Samples
Hematological parameters viz. hemoglobin (Hb), Total Erythrocyte Count (TEC) and hematocrit (PCV) were analyzed by using manual method by following Wakenell (2012) immediately after collection. Plasma was separated from whole blood by centrifugation at 1500 rpm for 1 h immediately after collection of blood. All the biochemical parameters viz. blood glucose, total protein (TP), albumin (ALB), globulin, total cholesterol (TCh) were analyzed in the plasma. All the parameters were estimated by using auto blood analyser, Fuzifilm DRI-CHEM 4000i.
Data were analyzed using the SPSS software, version 17 by applying independent t-test to compare between the groups and one way ANOVA followed by Fisher’s Least Significant Difference Test for post hoc multiple comparisons to evaluate the effect of different age groups on all the parameters under the study and P< 0.05 was accepted as statistically significant.
The variation in Mean±S.E of body weight, erythrocyte picture and blood biochemical profile of Sikhar birds in five different groups are presented in Table 1.
Table 1: Effect of age on body weight, physiological response and haemato-biochemical profile of Sikhar birds in different age groups
|Group I||Group II||Group III||Group IV||Group V|
|Body weight (g)||217.92± 7.11d||484.67±21.69c||728.33±27.381b||1010. 80±67.21a||1134. 20±69.58a|
Values in the same row with different superscripts differ significantly (P<0.05)
Body Weight and Physiological Response
Body weight, RR and PR changed significantly with age (P<0.05). RR and PR declined gradually with age. The body weight increased significantly (P<0.05) from Group I through IV and V. There was a significant decrease (P<0.05) in RR from Group I to II and remained stable till Group III. The RR declined significantly (P<0.05) in Groups IV and V as compared to rest of the groups. PR of Sikhar birds was recorded highest in Group I and declined gradually to Group III and IV (P<0.05). After attaining 8 months (Group IV) PR of Sikhar became stable till they were 10 months in Group V (Table 1). RT of Sikhar birds fluctuated in different age groups. The birds in Group II had higher RT (P<0.05) than birds in Group I and IV which was however not different statistically from RT of birds in Group III and V.
In erythrocyte profile of Sikhar birds, Hb, TEC, MCV and MCH were significantly influenced by age (P<0.01) while PCV and MCHC were not. Birds in Group V had highest and Group I had the lowest Hb concentration. TEC of Sikhar birds increased gradually from Group I and II to Group III and IV which further increased to Group V (P<0.05). MCV and MCH remained high till 4 months of age and declined significantly at 6 months (P<0.05) and remained stable thereafter.
Blood glucose was stable till the age of 8 months and declined at 10 months of age (P<0.05). The TP, albumin and globulin were significantly influenced by age (P<0.01). TP increased significantly at 6 months which further increased till 10 months (P<0.05). Albumin level followed an increasing trend with age which showed significantly higher value at 10 months as compared to 2 months (P<0.05). The adult birds (Groups IV and V) had higher globulin than the young birds (Groups I, II and III). TCh was found to fluctuate with age with the highest value recorded in 4 months old birds as compared to birds of 6 and 8 months (P<0.05).
Since there is no literature available on the physiological, hematological and biochemical profile of Sikhar birds, the findings of the present investigation were compared and discussed in relation to the data available for indigenous chicken of different parts of the world. Due to its semi-domestication and scavenging nature in behavior the data obtained in the present investigation were also compared to other wild species of birds. Sikhar birds are small size indigenous birds as compared to other indigenous chicken of Nicobar (Padhi et al., 1999; Padhi et al., 2004) and Nigeria (Adedokun and Sonaiya, 2002). RR, PR and RT of Sikhar birds were in the ranges reported in other indigenous chicken of Nigeria (Isidahomen et al., 2012; Adedeji et al., 2015). RR of Sikhar birds were in lower ranges as compared to crossbred birds (Adedeji et al., 2015) which could be due to variations in body sizes as birds increased RR with increase in body weight (Isidahomen et al., 2012). PR of Sikhar birds declined gradually with age similar to various birds (Ringer et al., 1957) and attained a stable adult PR at 8 months of age. RT of Sikhar birds fluctuated between 41.02±0.13 to 41.51±0.08oC in different age groups which corresponds to the reports of Yahav (2015) that body temperature of birds could fluctuate by 2.48-2.84oC depending on prevailing metabolic phase. RT increased with increase in body weight and the observed significant increase in RT from 2 months old to 4 months old Sikhar chicken could be due to increase in body weight as reported earlier (Isidahomen et al., 2012). Samour (2006) reported body weight wise variation in clinically normal birds. Changing body temperature in response to environmental alterations save energy and is a key component of thermoregulation in birds of different sizes (Yahav, 2015). Increase in RT with increase in body weight without causing significant change in RR and PR in the present study was indicative of an adaptive physiological response of Sikhar birds.
Hb, TEC and PCV recorded in Sikhar birds were comparable to other indigenous birds of Saudi Arabia (Albokhadaim, 2012), Nigeria (Isidahomen et al., 2012) and Iran (Abdi-Hachesoo et al.,2013). Some other indigenous birds of Bangladesh (Sharmin and Myenuddin, 2004), Thailand (Simaraks et al., 2004) and Andaman and Nicobar islands (Kundu et al., 2013) had also been found to have lower ranges of Hb TEC. Lower ranges of PCV had also been reported in indigenous birds of Thailand (Simaraks et al., 2004), Nigeria (Addass et al., 2012) and Andaman and Nicobar islands (Kundu et al., 2013). Increase in Hb level of Sikhar birds with age was in agreement with previous reports in domestic fowl (Samour, 2006) and indigenous chicken of Nigeria (Addass et al., 2012). The TEC of Sikhar birds was found to increase with age as recorded in domestic fowl (Samour, 2006) while in other indigenous birds of Nigeria, TEC was found to increase till 3 months of age and fluctuate thereafter (Addass et al., 2012). Higher ranges of Hb and TEC in adult birds suggested that hemoglobin concentration and number of erythrocyte correlated with age. These changes might be because of adaptive mechanisms for better oxygen carrying capacity of blood in adults than in young ones (Ringer et al., 1957).
Among the erythrocyte indices MCV and MCH were influenced by age. Like reports of Furlan et al. (1999) MCV decreased from the young to adult Sikhar birds while MCV fluctuated with age in indigenous chicken of Saudi Arabia (Albokhadaim, 2012). MCV and MCH of Sikhar birds was found to be in higher ranges as compared to other indigenous birds of Saudi Arabia (Albokhadaim, 2012) and Andaman and Nicobar island (Kundu et al., 2013) and the values were close to MCV and MCH recorded in wild birds like Common Croowned Pigeon and Bar Headed Goose (Samour, 2006). Such findings could be an inherent characteristic of its closeness to its wild origin. Due to its semi-domestication, this type of birds might have adapted to increase MCV with corresponding increase in MCH to have normal MCHC as reported in other indigenous of Bangladesh, Thailand, Nigeria and Saudi Arabia (Sharmin and Myenuddin, 2004; Simaraks et al.,2004; Addass et al., 2012; Albokhadaim, 2012). Mizoram is elevated by 1,132 m from the sea level. At this level of elevation from the sea level, Sikhar birds had probably adapted with higher MCV and MCH.
Blood glucose, TP, albumin, globulin and TCh investigated in Sikhar birds were in the ranges reported in indigenous chicken of Thailand, Saudi Arabi, Sudan and Iran (Simaraks et al., 2004; Albokhadaim, 2012; Elagib et al., 2012; Abdi-Hachesoo et al., 2013). Similar to previous reports, Sikhar birds maintained a stable glucose level at different age groups (Bowes et al., 1989) and dropped significantly after attaining adult body weight like in broiler chicken whose blood glucose dropped at 42 days (Cafe et al., 2012). Similar observations had also been reported in farmed emu (Costa et al., 1993). TP, albumin and globulin of Sikhar birds increased with age till the birds attained adult level and became stable similar to previous reports (Bowes et al., 1989; Szabo et al., 2005). Increase in TP, albumin and globulin with age indicated gradual decline in demand for proteins for muscular growth and development as birds became matured. TCh was found to fluctuate in different age groups indicating fluctuations in metabolic activities (Szabo et al., 2005; Cafe et al., 2012) with the highest level at 4 months. Higher value of TCh in 4 months old birds could be due to growth and rapid metabolic turnover as lipid profile is strongly associated with energy metabolism. Moreover, the peak concentrations of cholesterol occurred at the time of the moulting, in the interval of 8–12 weeks (Szabo et al., 2005). It is thus highly possible that the augmented metabolism (in connection with thyroid activation and peripheral thyroid hormone metabolism) strongly influences cholesterol concentration in poultry blood serum (Szabo et al., 2005).
The present study revealed changes in physiological responses with age of Sikhar birds. Sikhar birds are small size semi wild indigenous chicken whose RR, PR, RT and haemato-biochemical parameters resembled other domesticated indigenous chicken as well as some wild birds. The influence of sex, growth, management and other nutritional factors on physiology of Sikhar birds need to be further investigated in order to improve production performance of native breeds of chickens through improvement in husbandry practices, better healthcare and supplementary feeds during lean season and also through selective breeding programmes. Improvement in production performance of native breed of chicken could be achieved with a complete knowledge on the normal physiological parameters which could be used in assessment of health status of native birds and thereby, prompt action could be taken to maintain a healthy and productive life.
The authors are thankful to Central Agricultural University, Imphal, Manipur and all staff of Department of Veterinary Physiology and Biochemistry, C.V. Sc & A.H., CAU, Selesih, Aizawl, Mizoram for providing financial support and technical assistance respectively during the course of study.