Veterinarski arhiv 68 6

VETERINARSKI ARHIV 68 (6), 205-212, 1998

ISSN 0372-5480
Printed in Croatia

Clinical experimental studies on acute rumen acidosis in buffaloes (Bubalus bubalis L.). V. Influence on several blood and rumen biochemical parameters

Yordan Nikolov*

Department of Internal Diseases and Clinical Toxicology,
Faculty of Veterinary Medicine, Trachia University, Stara Zagora, Bulgaria

* Contact address:
Prof. Dr. Yordan Nikolov,
Department of Internal Diseases and Clinical Toxicology, Faculty of Veterinary Medicine, Trachia University, 6000 Stara Zagora, Bulgaria,
Phone: 359 42 531 00; Fax: 359 42 395 46

Nikolov, Y.: Clinical experimental studies on acute rumen acidosis in buffaloes (Bubalus bubalis L.). V. Influence on several blood and rumen biochemical parameters. Vet. arhiv 68, 205-212, 1998.

ABSTRACT

Experiments were carried out on two groups of buffalo (Bubalus bubalis L.) calves (experimental and control) in order to evaluate changes in the biochemistry of blood (lactate, blood sugar, ammonia, urea nitrogen, bilirubin, pyruvate) and rumen content (lactate and pH). The acute lactic acidosis was provoked with the per os administration of 20 ml/kg body mass beet molasses, containing 540 g saccharose. Before treatment (at hours -48, -24 and 0) as well as after the treatment (at hours 2, 4, 6, 8, 12, 24, 48, and 72) blood and rumen content samples were taken. An increase in the values of almost all studied parameters was observed, corresponding to the severity of acidosis between post-treatment at hours 8 and 24, but by hour 72 they returned to initial values. The amount of lactate in blood reached 10.1ą0.4 mmol/l, and in rumen liquid 30.1ą1.4 mmol/l. Blood sugar increased, reaching 6.49ą0.4 mmol/l at hour 24, when pyruvate concentrations were 162.4ą8.4 mmol/l; ammonia levels 13.6ą0.6 mmol/l, and blood urea nitrogen 12.1ą0.8 mmol/l. Total bilirubin increased to 6.1ą0.3 mmol/l post-treatment at hour 8. The rumen and blood serum biochemical disorders were overcome by buffaloes and evaluated parameters returned to the normal range 72 hours after the treatment with molasses.

Key words: buffalo calves, Bubalus bubalis L., rumen acidosis, blood serum, rumen liquid, blood sugar, lactate, pyruvate, bilirubin, ammonia

Introduction

The influence of severe lacto-acidosis in ruminants upon several biochemical blood parameters has been subject to studies in cattle and buffaloes (NAURIYAL, 1978), and in sheep and goats (GANTER, 1993; LAL, 1992). In experimentally provoked acute lactic acidosis in buffaloes, an impaired rumen motility, impaired rumen biochemistry, and deviations in some clinical and blood parameters were reported (NIKOLOV, 1996; NIKOLOV, 1996a; NIKOLOV, 1996b).

The present study continues the investigations on the changes in the buffalo's organism in severe rumen metabolic disorders resulting from the ingestion of excessive amounts of easily digestible carbohydrates, and their impact on several blood and rumen parameters.

Materials and methods

The experimental studies were performed on 10 buffalo calves (Bubalus bubalis L.) divided into two groups: experimental (6) and control (4). Groups were of equal mean body mass (140 kg), age (4 months) and breed. Housing and feeding were also uniform.

The clinical status of all animals was followed daily for two weeks according to routine clinical diagnostic methods. Before the start of the experiment, both experimental and control animals received a daily ration consisting of 1.5 kg concentrate (forage for fattening of calves), 1.5 kg hay and 10 kg maize silage split into two feeds (morning and evening) and with water ad libitum.

For three consequent days prior to the experiment (at hours -48, -24 and 0) blood was sampled from v. jugularis for determination of the following blood serum biochemical parameters: blood sugar, pyruvate, lactate, ammonia, urea nitrogen and bilirubin. Concurrently, rumen samples were taken simultaneously for determination of lactate concentrations and pH.

Acute ruminal acidosis was provoked with a per os administration of a single dose of beet molasses of 20 ml/kg body mass, containing 540 g saccharose, through a gastric tube, immediately after the morning feeding. Pyruvate and lactate concentrations were estimated using the methods of IBRISHIMOV and LALOV (1987) and CARACACHOV (1980). Blood sugar, urea nitrogen, bilirubin and ammonia levels were estimated with an automated analyser REFLOTRON-MANUAL (Germany). Ruminal pH was determined with a pH-meter AP-17 (Hungary), and lactate from rumen fluid was analysed as described by IBRISHIMOV and LALOV (1987).

Blood (external jugular vein) and rumen content samples were obtained at hours 2, 4, 6, 8, 12, 24, 48, and 72 after the treatment of the experimental group of buffalo calves for determination of the fore-mentioned parameters. Simultaneously, blood was also obtained from the control group.

All results were statistically processed using the Student-Fisher test.

Results

Results from the biochemical analysis concerning changes in serum and rumen lactate in buffaloes with severe lacto-acidosis showed that both serum and rumen lactate levels in experimental and control animals before the experiment (at hours -48, -24 and 0) ranged within the physiological range (3.9ą0.1 mmol/l in serum, and 16.1ą1.2 mmol/l in rumen content; Fig. 1).

Fig. 1. Changes in lactic acid levels in blood serum and rumen liquor of buffalo calves with acute rumen acidosis (20 ml/kg body mass molasses)

After treatment of the experimental group with 20 ml/kg body mass molasses, that biochemical parameter increased progressively in parallel with the severity of disease. Peak levels were observed between hours 8 and 24 - 30.1ą1.4 mmol/l in rumen content (P<0.05) and 10.1ą0.4 mmol/l in blood serum (P<0.05). Afterwards, the amount of lactate decreased and at hour 72 was close to initial levels. In control animals, serum and rumen lactate varied within physiological limits during the whole experimental period (Fig. 1).

The pH of rumen content was normal (7.1ą0.2) in both experimental and control animals prior to the experiment (at hours -48, -24, 0). Similar values were observed in control animals during the period of the study (Fig. 2). However, rumen pH values in the experimental group decreased significantly as early as post-treatment at hour 4, reaching 4.8ą0.3 and 5.0ą0.2 respectively (P<0.05) between hours 8 and 24.

Fig. 2. Changes in pH levels of rumen liquor of buffalo calves with acute lactic acidosis (20 ml/kg body mass molasses)

The amount of ammonia and urea nitrogen in buffaloes before the experiment was normal (7.5ą0.1 mmol/l and 6.3ą0.2 mmol/l). After the treatment of experimental animals with 20 ml/kg body mass of molasses those parameters increased, reaching 13.6ą0.6 mmol/l for ammonia and 12.1ą0.8 mmol/l for urea nitrogen at about hour 24 (P<0.01; Fig. 3).

Fig. 3. Changes in ammonia and urea nitrogen levels in blood serum of buffalo calves with acute rumen acidosis (20 ml/kg body mass molasses)

Total serum bilirubin concentrations were about 3.9ą0.1 ľmol/l prior to the start of the study. In controls, those values remained unchanged up to hour 72 (Fig. 4). Between post-treatment at hours 6 and 48, bilirubin levels increased significantly in experimental animals (P<0.05), with peak levels being reached at hour 8 (6.1ą0.3 ľmol/l; Fig. 4). At about hour 72, total bilirubin concentrations were similar to initial ones.

Fig. 4. Changes in blood sugar and bilirubin levels in blood serum of buffalo calves with acute rumen acidosis (20 ml/kg body mass molasses)

Blood sugar levels (Fig. 4) and pyruvate concentrations (Fig. 5) were physiological before the experiment, 3.44-3.88 mmol/l and 95.5-104.5 mmol/l respectively. During the development of acute rumen acidosis those values increased, reaching a maximum at hour 24, 6.49ą0.4 mmol/l (P<0.001) and 162.3ą8.4 mmol/l (P<0.01). At about hour 72 the experimental group of buffalo calves overcame the pathological process and the estimated serum biochemical parameters returned to normal.

Fig. 5. Changes in pyruvate levels in blood serum of buffalo calves with acute rumen acidosis (20 ml/kg body mass molasses)

Discussion

Fermentation of the large amount of easily digestible carbohydrates (molasses) occurred rapidly, thus impairing the ratio between the volatile fatty acids (acetic, propionic and butyric). Lactate and propionate were formed in a greater amount simultaneously with a decrease in acetate and butyrate concentrations. This led to change in the microbial population in the rumen. The count of gram-positive organisms increased, and later, different strains of lactobacilli (NIKOLOV, 1996a; NIKOLOV, 1996b; NIKOLOV, 1998; LAL, 1992; RAUNDHAWA, 1987) were dominant. The changes in the microbial species inhabiting the rumen were accompanied by a change in the type of fermentation, becoming a lactic fermentation. This had an impact on the pH values of rumen liquid, which decreased in proportion to the increased amount of lactate. Our results on decreased rumen pH and the increased serum and rumen lactate concentrations further evidenced those suggestions.

In the background of those changes in the rumen, histidine decarboxylased to histamine and, as according to some authors (ROSENBERGER, 1963; SLANINA, 1968), several endotoxins were formed, further aggravating the pathological process.

The lactic acid that was normally metabolised to propionate in rumen was unable to undergo such a transformation due, on the one hand, to its excessive amount, and because of the decreased count of bacteria-using lactate on the other. It was therefore resorbed in an unchanged state. Passing into blood, lactate concentrations increased and influenced blood pH (ANGELOV and NIKOLOV, 1995) while the organism made an attempt to neutralise that effect by increasing its buffer capacity - enhanced salivation, increased amount of ammonia in rumen. As a result of the morphological and functional disorders of liver, ammonia could not be detoxicated entirely through the ornithine cycle and turn into urea, a fact which explains the increased blood ammonia levels (NIKOLOV and GROZEVA, 1993).

The parenchymatous dystrophic changes in kidneys caused a retention of urea in blood, and liver disorders are a factor in an increase in the quantity of total bilirubin (NIKOLOV and GROZEVA, 1993; GANTER, 1993; IVANOV, 1995; LAL, 1992). The toxic metabolites resorbed in blood from the rumen impaired all parenchymal tissues (liver, heart, brain etc.) and led to particularly impaired carbohydrate, detoxication, protein, lipid, etc., liver functions (NIKOLOV and GROZEVA, 1993; NAURIYAL, 1978; RAUNDHAWA, 1987). After the ingestion of large (toxic) amounts of easily digestible carbohydrates in buffalo's rumen, the cycle of transformation of glucose to pyruvate became impaired - more pyruvate was formed and then, more lactate (RAUNDHAWA, 1987). This led to an increase in blood sugar concentrations. The increased serum pyruvate levels were probably due to vitamin B₁ deficiency, due to the fact that thiamine served as a coenzyme in the process of decarboxylation in the cycle of Krebs. After post-treatment at hour 72, the estimated parameters were similar to physiological limits.

Conclusions

1. The amount of lactate in rumen liquid and blood increased in proportion to the severity of lacto-acidosis, with peaks between hours 8 and 24. Rumen pH decreased 4 hours after the treatment of buffaloes with molasses, remaining under the normal limit up to hour 72.

2. The buffer compensatory mechanism in the animal organism was manifested by an increase in the values of ammonia, while impaired parenchymal organs (liver and kidneys) led to increased blood sugar, bilirubin and urea nitrogen concentrations in blood.

3. The buffaloes overcame the impaired rumen biochemistry and all estimated parameters returned to normal 72 hours after the administration of molasses.

References

ANGELOV, G., Y. NIKOLOV (1995): Dinamic of the acidic-alkali balance of an experimental rumen acidosis in buffaloes (Bubalus bubalis L.). Vet. med. 2, 155-158.

CARACACHOV, K. (1980): Clinical laboratory. Medicina. Sofia.

GANTER, M. (1993): Experimental investigations about the pathogenesis of rumen acidosis in sheep. J. Vet. Med. A 40, 731-740.

IBRISHIMOV, N., CH. LALOV (1987): Clinical and laboratory investigations in veterinary medicine. Sofia.

IVANOV, V. (1995): Pathological physiology. Agropress. Sofia.

LAL, S. B. (1992): Biopathological studies in experimentally induced ruminal acidosis in goat. Ind. J. Anim. Sci. 62, 200-204.

NAURIYAL, D. C. (1978): Pathological changes due to rumen lactic acidosis in buffaloes and cattle. Zbl. Vet. Med. A 25, 383-392.

NIKOLOV, Y. (1996): Clinical experimental studies on acute rumen acidosis in buffaloes (Bubalus bubalis L.). I. Influence of acute rumen acidosis on ruminal function. Vet. arhiv 66, 147-154.

NIKOLOV, Y. (1996a): Clinical experimental studies on acute rumen acidosis in buffaloes (Bubalus bubalis L.). II. Influence of acute rumen acidosis on biochemistry of rumen liquor. Vet. Sci. 4, 17-20.

NIKOLOV, Y. (1996b): Clinical experimental studies in acute rumen acidosis in buffaloes (Bubalus bubalis L.). III. Influence of experimental acute rumen acidosis on some clinical and hematological parameters. Vet. Sci. 5, 31-34.

NIKOLOV, Y. (1998): Clinical experimental studies in acute rumen acidosis in buffaloes (Bubalus bubalis L.). IV. Influence of acidosis on blood, rumen liquid and urine electrolytes. Vet. arhiv 68, 1-9.

NIKOLOV, Y., N. GROZEVA (1993): Comparative clinical-morphological and ultrastructural investigations in the case of acute rumen acidosis in the ruminants. Vet. Sci. 4, 17-22.

RAUNDHAWA, S. S. (1987): Evidence of toxic factors in the rumen liquor of healty and acidotic buffalo calves. Acta Vet. 56, 455-464.

ROSENBERGER, G. (1963): Die Indigestionen des Rindes in neuer Sicht. Vet. Med. Nachrichten, 2/3, 112-125.

SLANINA, L. (1968): Experimentale ovplyvnenie alkalickej reservy krvney plasmy u prezuvavcov niektoromi bachrovymi metabolitmi. Vet. Med. 13, 143-145.

Received: 25 June 1998
Accepted: 26 October 1998

Nikolov, Y.: Klinicka pokusna istrazivanja akutne acidoze buraga u bivola (Bubalus bubalis L.). V. Utjecaj na nekoliko biokemijskih pokazatelja krvi i buragovog sadrzaja. Vet. arhiv 68, 205-212, 1998.

SAZETAK

Pokusi su izvedeni na dvije skupine (pokusnoj i kontrolnoj) bivolske (Bubalus bubalis L.) teladi da bi se odredile biokemijske promjene u krvi (laktat, krvni secer, amonijak, dusik iz mokracevine, bilirubin, piruvat) i u sadrzaju buraga (laktat i pH). Akutna mljecna acidoza buraga izazvana je per os davanjem melase od secerne repe u kolicini od 20 ml/kg tjelesne mase s ukupnim sadrzajem od 540 g saharoze. Prije davanja (-48, -24 i 0 sati), kao i nakon davanja melase (2, 4, 6, 8, 12, 24, 48 i 72 sata) uzimani su uzorci krvi i buragovog sadrzaja. Vrijednosti skoro svih promatranih pokazatelja porasle su sukladno s jacinom acidoze od 8 do 24 sata nakon davanja melase, ali su se do 72 sata vratile na pocetne vrijednosti. Visina laktata u krvi dosegla je 10.1ą0.4 mmol/l, a u buragovom sadrzaju 31.1ą1.4 mmol/l. Krvni secer je porasao i dosegao 6.49ą0.4 mmol/l u 24. satu, kada je i koncentracija piruvata bila 162.4ą8.4 mmol/l, amonijaka 13.6ą0.6 mmol/l, i mokracevinskog dusika u krvi 12.1ą0.8 mmol/l. Ukupni bilirubin porastao je u 8. satu nakon davanja melase na 6.1ą0.3 mmol/l. Svi biokemijski pokazatelji u buragu i krvi bivola vratili su se u fizioloske granice 72 sata nakon davanja melase.

Kljucne rijeci: telad bivola, Bubalus bubalis L., acidoza buraga, krvni serum, buragov sadrzaj, krvni secer, laktat, piruvat, bilirubin, amonijak

Back