An investigation of the safety of oral calcium formate in dairy cows using clinical, biochemical and histopathological parameters

Authors: Weston SJ, McIntyre LH
Publication: New Zealand Veterinary Journal, Volume 50, Issue 5, pp 195-198, Oct 2002
Publisher: Taylor and Francis

Animal type: Cattle, Livestock, Production animal, Ruminant
Subject Terms: Animal welfare, Biochemistry/chemistry, Minerals/elememts, Clinical pathology, Diagnostic procedures, Metabolic disease, Disease/defect, Locomotor, Nervous system/neurology, Nutrition/metabolism, Pasture/crop
Article class: Short Communication

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Abstract:
AIM: To investigate the safety of orally administered calcium formate in dairy cows fed adequate amounts of good quality pasture.
METHODS: Twelve mixed-age pasture-fed lactating dairy cows were randomly allocated to three groups (n=4 cows/ group). Group 1 served as untreated controls. Group 2 was treated orally with 400 ml of 13.4% (w/w) calcium as calcium chloride gel, four times at approximately 12-h intervals. Group 3 was treated orally with 350 ml of 11.4 % (w/w) calcium as a 48.6% aqueous suspension of calcium formate, four times at approximately 12-h intervals. Cows grazed good quality autumn ryegrass and white clover pasture throughout the trial. All cows were examined clinically each evening and a blood sample collected. Cows were slaughtered 75 h after the last treatment and viscera examined visually for lesions. Samples from the mid-fundic area of the abomasum of each cow were collected for histopathological examination. Blood samples collected preand 90-h post-first treatment were analysed for serum haptoglobin and pepsinogen concentrations.
RESULTS: No evidence of abnormality was detected by observation or clinical examination in any of the trial cows. Serum haptoglobin concentrations were basal for all groups pre-treatment and remained basal for Groups 1 and 3 post-treatment, but were elevated post-treatment for Group 2 (p=0.016). No differences in serum pepsinogen concentrations were detected between sampling times or treatment groups. One cow from Group 2 had several small (5 mm) abomasal ulcers present at necropsy. Another cow from the same group had histopathology suggestive of thrombosis and re-endothelialisation.
CONCLUSIONS: Oral administration of calcium formate (350 ml of 48.6% aqueous suspension) administered on four occasions at 12-h intervals had no adverse effects on the four cows examined, and as such is considered a safe form of calcium supplementation in adult dairy cows.
KEY WORDS: Hypocalcaemia, calcium formate, calcium chloride, cattle, haptoglobin, pepsinogen.

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