COMPARISON OF SOME BLOOD PARAMETERS , SERUM VITAMIN E AND MINERAL CONCENTRATIONS OF ARABIAN AND ENGLISH THOROUGHBRED RACE HORSES

The aim of this study was to determine some blood parameters, serum vitamin E and mineral concentrations of Arabian and English thoroughbred racehorses fed the same diets. The diet was formulated to provide 2.31 Mcal DE/kg, and 10.96% crude protein. Total protein, lactate, calcium, phosphorus, potassium, copper, cobalt and zinc were determined in serum obtained from 40 Arabian and 40 English healthy racing thoroughbred horses aged 2-3. The copper, cobalt and zinc concentrations were determined by atomic absorption, vitamin E by HPLC and the other biochemical parameters by a spectrophotometer. Mean values were 6.77 and 6.86 g/dl for total protein, 1.88 and 2.16 mg/dl for lactate, 13.18 and 12.80 mg/dl for calcium, 4.35 and 4.39 mmol/l for phosphorus, 2.64 and 3.14 mmol/l for potassium, 129 and 166 g/dl for copper, 36 and 44 g/dl for cobalt and, 160 and 58 g/dl for zinc in Arabian and English horses, respectively, and Mean serum vitamin E levels were 2.65 and 2.81 g/ml, respectively. This study did not demonstrate a significant effect of breed on serum total protein, lactate, calcium, phosphorus, copper, cobalt and vitamin E. However, breed may have an effect on potassium and zinc concentration in Arabian and English thoroughbred racehorses (p<0.05).

Serum copper, cobalt and zinc analysis were done according to Elmer Š4¹ using atomic absorption (model 2380, Perkin-Elmer Cooperation).Feed analyses of copper, cobalt and zinc were performed according to Osborn and Voogt Š18¹.
Serum samples were analyzed for a-tocopherol using HPLC with a fluorescence detector according to the method of Hidiroglou Š15¹.All samples were analyzed in duplicate.

Statistical analysis / Statisti~ka analiza
Results are presented as means with their standard errors (Table 2).All data were compared by means of Student's t test by using SPSS Š19¹ program.
Mean serum concentrations of total protein, lactate, calcium, phosphorus, potassium, copper, cobalt, zinc and vitamin E are presented in Table 2. Total protein values were similar in both Arabian and English horses.Lactate concentrations were higher in English horses but the difference was not significant.Similarly, serum concentrations of calcium and phosphorus and vitamin E were not statistically different between two breeds.

Results / Rezultati ispitivanja
were 2.64 and 3.14 mmol/l for Arabian and English horses, respectively.The mean copper and cobalt concentrations of serum from both breeds were not found to be significantly different whereas zinc concentrations of Arabian horses were higher than those for English horses.Mean values were 160 and 58 mg/dl for Arabian and English horses, respectively, and the difference was statistically significant (p<0.05)(Table 2).
All proteins and proteids in blood serum are called "total protein value".Acute phase proteins can be affected by disease states such as acute inflammatory disease burnt, blood losses, trauma.It was reported that in the case of chronic inflammatory diseases, nephritic syndrome, chronic hepatopathy like liver cirrhosis, chronic enteropathy, malign tumour and dehydration this value could be changed Š12¹.In the study of Kraft Š15¹ this value was reported between 55-75 g/l and 5.5-7.5 g/dl, respectively.Orsini and Divers Š17¹ found the value between 5.2-7.9g/dl.Harris Š9¹ measured this value at 58.2 ± 3.4 g/l before the race, 71.8 ± 8.36 g/l at speed of 12 m/min and 70.3 ± 9.36 g/l at the end of the race.Tyler-McGowen et al.Š21¹ divided horses into two groups.The first group was control and the other one was a highly training (exercised) group.They measured the total protein value at 1, 15 and 32 weeks and they found the values 68.0 ± 1.0 g/l and 63.0 ± 2.0 g/l and 69.0 ± 2.2 g/l in control group and 68.0 ± 0.8 g/l, 63 ± 1.2 and 67.0 ± 1.2 g/l in exercised group, respectively.Heigl Š12¹ reported this value between 5.8-8.0 g/dl.Our results support any of these reports discussed above and proved those horses, which were used in this study, had no sign of pathological disorders and our results could also prove that breed might not have an effect on total protein value.
Serum lactate concentration increases depending on exercise and has an effect on race performance and during the exercise, as a result of glycolysis, breaked down glucose glycogen into lactic acid; large quantities of energy can be supplied.If the oxygen supply of the body is not enough, two pyruvat ions, which are the last product of glycolytic reaction, and hydrogen ions are reacted to produce lactic acid Š22¹.According to our observations values related to breed in serum lactate concentrations were not reported previously and our results showed that breed might not have an effect on serum lactate concentrations.It might be useful to indicate here reported lactate concentrations previously; Kraft Š15¹ reported a maximum lactate concentration in horses of 9 mg/dl (0.999 mmol/l), Orsini and Divers Š17¹ between 10-16 mg/dl.Harris and Snow Š10¹ indicated that arterial lactate concentration ranged between 0.1-2.4mg/dl (0.208-0.266 mmol /l) venous lactate concentrations between 1.0-1.36mg/dl (0.111-0.150 mmol/l).Evans and Lorraine Š5¹ used two different methods in their work and they observed that blood lactate concentration between 1.5 ± 0 mmol/l and 11.3 ± 9.6 mmol/l, and Discussion / Diskusija plasma lactate concentration was between 3.3 ± 1.7 mmol/l and 20.7 ± 6.6 mmol/l depending on effort in exercise band.
Calcium is a component of bone and teeth and also plays an important role in muscle contraction, coagulation, enzyme and cellular defence system and secretion of some hormones.Total calcium concentration was found between 8.0-13.6 mg/dl by Kraft Š15¹.This value was around 11.2-13.6mg/dl in the study of Orsini and Divers Š17¹.Haclechner Š8¹ reported that calcium concentration in horses was between 2.5-3.3 mmol/l (10.0-13.22mg/dl).In our case, this value was around 13.18 ± 0.32 mg/dl (3.28 ± 0.08 mmol/l) in Arabian horses and 12.80 ± 0.21 mg/dl (3.19 ± 0.05 mmol/l) in English horses as in normal range and no breed difference was found in calcium concentration in serum.
Levels of phosphorus, which is a component of bone and teeth and involved in most of the reactions in the body as a source of energy and also the main component of nucleic acids, important as a buffer in blood and cell and the main element of enzyme and proteins, were between 2.5-4.5 mg/dl in horses in the study of Kraft Š15¹, between 3.61-5.6mg/dl in the study of Orsini and Divers Š17¹.Haclechner Š8¹ reported that the value of phosphorus concentration ranged between 2.2-6.6 mg/dl (0.71-2.13 mmol/l) in 95% of the horses and he claimed those numbers need to be taken as reference numbers.Our results are similar with those of these researchers and as discussed previously, no reported values are available for horse breeds for phosphorus concentration in serum.
Potassium is the main element of intracellular fluid, and plays a role in providing membrane potential, regulation of acid-alkali balance and enzyme activation.The values reported by Kraft Š15¹ were 2.5-4.5 mmol/l (9.77-17.59mg/dl).Orsini and Divers Š17¹ and Haclechner Š8¹ reported the values 2.4-4.7 mmol/l (9.38-18.38 mg/dl) and 2.2-4.8mmol/l (8.60-18.77mg/dl), respectively.In the study of Harris and Snow Š10¹ effects of excessive exercise were observed.During the exercise, plasma potassium concentration was relatively increased, and at the end of the exercise this value reached a peak.Potassium concentration in some horses was around 10 mmol/l.In another work by these authors Š11¹ in warming period, potassium concentration returned to the normal range.In our work, potassium concentration in Arabian horses was 2.64 ± 0.61 mmol/l, and in English horses 3.14 ± 0.75 mmol/l.This difference was statistically significant (p<0.05).
The results of the present study suggest that breed has no effect on serum vitamin E level since similar values were observed in both English and Arabian horses (Table 2).
After an examination of blood samples from Arabian and English horses it was found that Arabian horses had a higher mean value of zinc than English horses (Table 2).No significant breed-related difference was observed in plasma cobalt and copper levels (Table 2).Despite no data being available on breed differences in trace element content of the body or plasma of horses, some researchers attribute the differences in results to the genotype of horses.For ex-ample, when draught cross Quarter horses or Quarter horse yearlings were fed diets containing 7.6 to 15.1 mg copper/kg DM, 22.5 to 52.7 mg manganese/kg DM and 25 to 52.2 zinc mg/kg DM Š3¹, the increase of trace element intake caused no significant differences in copper, manganese and zinc concentrations in liver, kidney and plasma.Grace et al.Š7¹ also concluded that the reported differences in the trace element content of the body between the various horse studies and their study with horses do not appear to be related to varying cobalt, manganese, iron and zinc intakes and could be explained by genotypic differences.However, genotypic differences reported in most cases and also in trace element concentrations.For example, Scottish Blackface ewes were less efficient in absorbing copper than Welsh Mountain ewes Š23¹.In our work, we did not observe differences in absorbing copper and cobalt in horses but differences were observed in absorbing zinc (Table 2), and therefore English horses had lower serum zinc concentration when both breeds are fed diets of identical zinc concentrations.On the other hand, Stark et al.Š20¹ reported differences in zinc concentration between horses and they attributed this difference in zinc plasma levels to the location of housing.Our observations do not agree with this explanation since the same housing system and feed was used in our study.