Serum from Hassan sheep of either sex aged young ones (less than one year) and adults (more than one year) were harvested and studied in the present research work in order to establish the normal basal reference values for thirteen biochemical parameters. Study revealed that there is no significance difference between males and females in both age groups, where as the values of total bilirubin (p-value <0.017), direct bilirubin (p-value < 0.010), and cholesterol (p-value < 0.021) were significantly higher in adult sheep compared to young ones. Moreover outcome of the present study will pave the way to establish the normal basal values of wide range of biochemical parameters thereby facilitating to safeguard and augment prophylactic measures to conserve this breed of sheep in their locality.
Small ruminants such as sheep and goats play important role in the livestock subsector of the Indian agricultural economy. India ranks 3rd in sheep population, next to China and Australia and is placed 7th among the top 10 countries of the world in terms of meat and wool production, the total sheep in the country is 65.06 million numbers (http://www.nddb.org/information/stats/pop ). There are about 60 sheep breeds in India including well recognized, lesser known and some wild species (FAO, 2000). Hassan sheep is one of the well recognized sheep breed by NBAGR (National Bureau of Animal Genetic Resources) widely distributed in and around Hassan district of Karnataka lying in southern peninsular agro-ecological zone of India. Hassan sheep is small animals of white body with light brown or black spots; Ears are medium-long and drooping, 39% of the males are horned, females are usually polled. Fleece is white, extremely coarse and open. The breed is well known for its mutton and coarse wool, lambing rate is 64% and animals are highly adoptable to Indian condition, as per the 18th livestock censes number of Hassan sheep in the country is 6, 45,564. The sheep has got excellent feed conversion ratio and growth performance. The average body weight of a healthy adult male and female is 33kg and 28 kg respectively (http://www.sheepfarm.in/hassan-sheep-breed-profile). Good healthy animals are said to have good breed characteristics and specifications, in addition to optimum blood parameters. Serum biochemical parameters are known to be realistic indicators of the vital organ functions and the physiological status of animals. Hematological and serum biochemical tests are widely used for the diagnosis of serious animal diseases which can lead to economic losses in animals (Bani IZA et al., 2008). There are very limited data available on the normal biochemical parameters of this breed, considering the geographical importance of this breed and in order to undertake the prophylactic measures to safeguard this sheep breed the present work was conducted to analyze and establish the baseline value for serum biochemical parameters in healthy herd.
Materials and Methods
Identification of Breed for its Purity
Pure bred Hassan sheep flocks were identified by evaluating the sheep flocks located in and around Hassan for breed specific morphological characteristics as given by NBAGR. Only flocks where in vaccination and deworming was done on regular basis animals, no history of disease outbreak in past three years and where animals were in good health were selected Fig. 1.
Fig.1: Hassan sheep flock maintained under open paddock
Grouping of Animals
In each flock, animals were segregated into age and sex groups, in order to get reliable and detailed information on the changing biochemical parameters. The age groups were young (less than one year) and adult (more than one year) and sex groups were male and females. Only non pregnant females were considered for the study.
Collection of Blood Samples
Blood samples, each of 5-10 ml, were withdrawn from jugular vein from each animal into sterile vaccutainer containing no anticoagulant, were allowed to clot and immediately kept under 40C (ice pack box) brought to laboratory and the tubes were centrifuged at 5,000 rpm for 10-15 min and the separated serum samples were collected into separate sterile ependroff vials, stored until analysed.
Analysis of Serum Samples
All the serum samples were analyzed using automated serum analyzer from SWAMED India Pvt. Ltd available at TVCC department in the college; also the reagents and kits for analysis were procured from SWAMED India Pvt. Ltd. On the same day of blood collection, parameters like serum glucose and creatinine were analyzed later samples were preserved under -200C within 48hrs all the serum parameters were analyzed as per the manufacturer’s instruction.
Statistical Analysis of Data
The data obtained in the present study were subjected to statistical analysis by using the GraphPad Prism version 5.01 (2007), by applying z test to analyse statistically significance difference at 0.05% level of significance between gender and age groups. The values were expressed as mean ± standard error and the level of significance difference was determined at P value of 0.05.
All results were expressed as means, standard deviations (SD) and range. No significance difference was observed between males and females in both age groups, where as values of total bilirubin, direct bilirubin, and cholesterol were significantly higher in Adult sheep. The results are presented in Table1, 2 and 3.
Indian sheep breeds are distributed in the four major agro-ecological regions: the Northern temperate, North-western arid and semi-arid, Southern peninsular and Eastern (Bhatia and Arora, 2005), however present Hassan breed of sheep belongs to the southern peninsular region of India. Present study depicts that there is no significant difference noticed in young (less than 1yr) and adult sheep between their sexes.
Table 1: The serum biochemical values expressed as Mean ± SD and range of young male and female Hassan sheep aged less than one year of age
|Serial Number||Biochemical parameters||Young sheep less than one year( N=128)|
|1||Total Bilirubin ٭ mg/dl||0.09±0.02||0.08±0.02||0.08±0.03|
|4||Direct Bilirubin٭ mg/dl||0.07±0.03||0.06±0.01||0.07±0.03|
|11||Total protein gm/dl||6.68±0.2||6.85±0.16||6.75±0.21|
Table 2: The serum biochemical values expressed as Mean ± SD and range of adult male and female Hassan sheep
|Serial Number||Biochemical Parameters||Adult sheep more than one year (N=106)|
|1||Total Bilirubin ٭ mg/dl||0.13±0.01(range)||0.12±0.02||0.12±0.02|
|4||Direct Bilirubin٭ mg/dl||0.12±0.03||0.11±0.06||0.12±0.04|
|11||Total protein gm/dl||6.49±0.67||7.44±0.81||6.82±0.63|
Table 3: Comparison of biochemical values expressed as Mean ± SD between young and adult Hassan sheep
|Serial Number||Biochemical Parameters||Young||Adult||P values|
|1||Total Bilirubin ٭ mg/dl||0.08±0.03||0.12±0.02||0.017*|
|4||Direct Bilirubin٭ mg/dl||0.07±0.03||0.12±0.04||0.010*|
|11||Total protein gm/dl||6.75±0.21||6.82±0.63||>0.05|
P values of < 0.05 are statistically significant. ٭ values indicating the significant difference between the age groups
The values of serum glucose are in similarity with that of the values reported by earlier studies on mecheri sheep (P Selvaraj et al., 2004). Karim and Verma (2000) found no variation in blood glucose level for different periods in lambs of different age. Serum glucose levels showed no reproductive and seasonal rhythm in sheep, the reason for maintaining constant glucose concentration in ewe might be depended on the different carbohydrate metabolism rather than season (Yokus et al ., 2006) . In addition no significant difference was noticed in the present study and the values obtained are found to be in the normal range (Kaneko et al., 2008; Latimer et al., 2011; Merck Sharp & Dohme Corp (2009-2015).
Significant difference in the serum cholesterol level between the age group in the present study is well comparable with that of the result findings of Devendran et al., 2008 in Coimbatore sheep and P Selvarajetal, 2004 in mecheri sheep where there is significant increased level of serum cholesterol in sheep aged 1-2yrs. Also similar findings were reported in Makuei sheep of Iran by B. Eshratkhah et al., 2008. This significant difference between the age group in serum cholesterol level is mainly attributed to the requirement of cholesterol in adult sheep as a major precursor for the synthesis of several vital sex hormones like estrogen (Hamadeh et al., 1996; Parmar, R. et al., 2017), cortisols and bile pigments etc. Though the serum cholesterol values obtained in the present study are lesser than reported values by P Selvarajetal., 2004 but are fall in the normal range (Kaneko et al., 2008; Latimer et al., 2011; Merck Sharp & Dohme Corp (2009-2015). The total serum protein level in the present study is as similar to that of earlier findings (Devendran et al., 2008; Latimer et al., 2011 and Merck Sharp & Dohme Corp (2009-2015). Furthermore study on serum total protein, albumin and globulin by M. Tariq Javed et al. (2010) in Punjab sheep were also in comparable to the present study. Studies reported that the total protein and albumin in male sheep were found to be significantly higher than the female Madgyal sheep of Maharashtra (Parekar et al., 2014). However no significant difference between on either sex or young ones and adult was noticed in the present study, also the values depicted were found to be in the normal range (Kaneko et al., 2008; Merck Sharp & Dohme Corp (2009-2015). The values of major serum enzyme like SGPT is found to be similar as reported in recent studies (Das et al., 2017) in local non-descript sheep of Assam. However both SGPT and SGOT values were also found to be in the similar pattern as (Hamsa et al., 1997; Kaneko et al., 2008; Latimer et al., 2011; Merck Sharp & Dohme Corp (2009-2015); Showkat Ahmad Bhat et al., 2014; A.V. Kumar et al., 2015).
Serum creatinine levels were in similar pattern as reported with earlier studies (Kaneko et al., 2008; Latimer et al., 2011; Radostits et al., 2000; B. Eshratkhah et al., 2008). Serum urea level is found to be in the normal range as reported (Kaneko et al., 2008; Radostits et al., 2000; Latimer et al., 2011; Merck Sharp & Dohme Corp (2009-2015). Also minerals like serum calcium, sodium and potassium were also found to be in the normal range (Radostits et al., 2000; Latimer et al., 2011). The values depicted in the present study for the serum total bilirubin and direct bilirubin (conjugated bilirubin) were in comparable with that of the values reported earlier (Peter et al., 2002; Kaneko et al., 2008; Latimer et al., 2011; Merck Sharp & Dohme Corp (2009-2015; Parmar, R et al., 2017). However earlier studies have shown that hepatic excretion of bilirubin into ovine bile is limited by its concentration and the rate at which conjugated bilirubin may be transported from the hepatocyte into bile (Upson et al., 1970). Elevation in the serum Bilirubin is noticed during starvation, pregnancy etc (Kaneko et al., 2008). Though the values look in the normal range in both young ones and adults, the significant difference between them is mainly attributed to their physiological status, management systems, nutrition, hormone, climate, breed, diurnal and seasonal variation, and temperature of animals (Mbassa et al., 2003; Parmar, R et al., 2017). In the earlier studies reports indicating that there is significant difference in the serum parameters between the sex (B .Eshratkhah et al., 2008; Mabruka Saleh. Sitmo, 2014; Shumaila Kiran et al., 2012) however no such findings are noticed in the current study. In the present study though there is significant difference in the values of total cholesterol level, bilirubin and conjugated (direct) bilirubin level were reported between the age but they vary in the normal range.
The outcome of the present study will surely pave the way to establish the normal basal values of wide range of biochemical parameters thereby facilitating to safeguard and augment prophylactic measures to conserve this breed of sheep in their locality.
The authors thankfully acknowledge the financial assistance of the Karnataka Veterinary and Fisheries Sciences University, Bidar in conducting this study and also thankful to the Dean and Head of TVCC, Veterinary college Hassan, for providing necessary facility to conduct the research work.