key: cord-0842484-cffcypn0
authors: JUDSON, G. J.; GIFFORD, K. E.
title: HAEMATOLOGICAL VALUES IN VITAMIN B(12) RESPONSIVE CALVES
date: 2008-03-10
journal: Aust Vet J
DOI: 10.1111/j.1751-0813.1979.tb00387.x
sha: 2c0e49a9a47731c205b0c1fde30c455162918355
doc_id: 842484
cord_uid: cffcypn0

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We have recently investigated haematological values in calves responding to vitamin B,, supplementation. The investigation was carried out near Robe, South Australia with Hereford calves depastured on calcareous sands supporting largely strawberry clover and lucerne. I n May-June 1978 the calves, aged between 1 and 12 weeks, were stratified by bodyweight within sex and allocated at random to treatment groups. One group of calves the 'BIZ' group, received subcutaneous injections of vitamin BIZ* at approximately 6weekly intervals. In a second group of calves, the 'COP' group each calf received by mouth two log cobalt pellets t when introduced to the trial and a third group, the 'Nil' group, were not treated. All calves grazed as one herd and were weighed ~ * 2 mg hydroxocobalamin/50 k g hodyweighi: 'Cohalex', V R Lahorarories, t ICI Ausrralia Lid, Melbourne. Vicioria. Wales. and given anthelmintic $ at 6-weekly intervals. Subcutaneous injections of copper b were given to all calves when introduced into the trial and then at 6, 13 and 32 weeks after the trial had commenced: serum copper of the calves, monitored at 6weekly intervals, was maintained in the normal range of 8 to 22 unmol/l.

Blood samples for haematology were taken into EDTA and values determined using a Coulter S blood cell counterll. The haematocrit values obtained by this method were checked manually using a micro-haematocrit centrifuge. When the values did not agree, the manual value was substituted to establish the true red blood cell count. This procedure was undertaken because the more microcytic cells may have fallen Ausrralian Veterinary Journal, Vol. 5 5 , October, 1979 below the threshold for the red cell count and be missed, thus resulting in a falsely low red cell count and haematocrit value. The Coulter cell size estimations may be considered valid since there are obtained by pulse height analysis independent o f red cell count or blood dilution.

Bodyweights of the calves in each experimental group were similar until the 26th week of the experiment when the 'Nil' group calves were significantly less (P<0.05) than the calves in the 'Bi,' and 'COP' groups. At the 32nd week of the trial, the bodyweights of the 'BI2' calves were heavier than the bodyweights of the 'COP' calves which in turn were heavier than the 'Nil'calves. 'Nil' calves were then given subcutaneous injection of vitamin B , , to prevent bodyweight losses and at the 38th week of the trial the 'Nil' calves were similar in bodyweight to the 'COP' calves but both groups were less than the bodyweight of 'Bi,' calves (Table 1) .

Differences in bodyweights of calves were associated with differences in haematological values (Table 1 ). At 32 weeks the 'Nil' calves had a greater number of red cells but of smaller size, than calves from the 'B,2' group. A reduction in red cell numbers concomitant with an increase in cell size was observed in the 'Nil' calves by the 38th week of the trial, about 6 weeks after giving the 'Nil' calves single subcutaneous injections of vitamin B,? (5 mg hydroxocobalamin/calf). No response in haemoglobin concentration in red blood cells was observed with vitamin B,, supplementation. These findings appear to be at variance to those of Filmer (1933) and Neal and Ahmann (1937) who reported that cobalt-deficiency in cattle was associated with microcytic hypochromic anaemia.

Red cell size and numbers of red cells in the 'COP' calves were similar to those observed in the 'Nil' calves (Table 1) suggesting that the cobalt pellets in young calves may not be com-Ausrralian Vererinary Journal, Vol. 55, October, 1979 pletely effective in preventing the onset of vitamin B,, deficiency. It is of interest to note however, that the haematological values of the 'COP' calves approximated to those of the 'Bi2' calves at the 38th week of the trial. The altered haematological values may be related to an improvement in the vitamin B,, status of the 'COP' calves over the last 6 weeks of the trial although the effect of other factors such as age cannot be excluded. Schalm et a/ (1975) in summarising haematological values of cattle reported that red blood cells initially decrease in size over the first 3 to 4 months of life of the calf and then gradually increase in parallel with a gradual decrease in red cell numbers.

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Veterinary Hematology