[The functional state of calves' stomach in the first month of postnatal life]
Ilgaza, A.(Latvia Univ. of Agriculture, Jelgava (Latvia). Faculty of Veterinary Medicine. Preclinical Inst.)E-mail:[email protected] | Birgele, E.(Latvia Univ. of Agriculture, Jelgava (Latvia). Faculty of Veterinary Medicine. Preclinical Inst.)E-mail:[email protected]
The dynamics of pH in the rumen and abomasum of calves from birth till 4 weeks of age in vivo was investigated. The pH of the rumen and abomasum was measured by means of a two-electrode pH-probe inserted per os and through the fistulae. The uninterrupted pH measurements probing through the fistulae lasted on average 8 hours - 4 hours before and 4 hours after the feeding. The results of studies prove that newborn calves have a low acid reaction of rumen setting - pH 6.73+-0.12, which showed a tendency to become more alkaline in four weeks. It was stated that hydrochloric acid concentration in the abomasum of a new born calf was already high - pH 1.6+-0.21. After first feeding, the acid level in the abomasum decreased rapidly reaching pH 6.2-6.3. The acid concentration in the abomasum increased on average to pH 2.83+-0.05 after 7 hours from the first feeding, but in four weeks old calves - after 4 hours. In a newborn calf, starting from the second day of its life, the conditioned reflex to "eating time" appeared. It is well-known that secretion of gastric acid is regulated neurally by stimulation of n.vagus and humorally by activation of histamine H2 receptors in parietal cells. For stopping n.vagus, atropine sulphate (0.06 mg/kg, intravenously) was used, and for blocking humoral regulation - cimetidine (0.16 mg/kg, intravenously). The results clearly showed that atropine sulphate and especially cimetidine demonstrate blocking influence on the HCL of the abomasum life.
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