Xylitol, polyol molasses and glucose in the diet of newborn calves: II. Content of antimicrobial factors in blood and saliva, bacteria in faeces and health status

The concentrations of various antimicrobial factors in the saliva and plasma of newborn calves with special reference to possible effects of a diet supplemented with different sugar alcohols were studied. Eighteen calves were assigned alternately at birth to three groups, each comprising six animals. All calves were fed a pooled colostrum diet for the first four days, thereafter whole milk plus milk replacer. Concentrates and hay were given ad libitum. The diets of the different groups were supplemented with the following test substrates: xylitol, polyol molasses or glucose(control). The daily doses of each substrate were progressively increased from 0.5 to 1.0 g/kg of live weight for the last four weeks. Plasma and saliva samples were taken from all calves before colostrum feeding (day 0) and on days 1, 2, 4, 7, 21 and 35 after birth. The following factors were determined quantitatively: lactoferrin (LF), lactoperoxidase (LP), lysozyme (LZM) and immunoglobulins IgG1, lgG2, IgM and IgA (only in plasma). Further determinations included weekly counts of total aerobic bacteria, aerobic haemolytic bacteria, coliforms, lactobacilli and clostridia in faeces. Salivary LF increased from the average 0 day level of 3.6—17.0 /µg/ml in the different groups to a maximum of 38.7—55.6 µg/ml within one week, and declining thereafter slowly in all groups. LF was not found in the saliva of all calves at birth but was consistently present later on. No LF was detected in plasma. Salivary LP increased from the average 0 day level of 56.3—86.6 /µg/ml in the different groups to a maximum of 228—296 /µg/ml within three weeks and declined markedly by day 35. LP was found in all saliva samples, but the plasma concentrations were very low and not always detectable. Salivary LZM was high at birth compared to the plasma level (average 0.8—2.1 /µg/ml vs. 0.3—0.5µg/ml in the different groups)