Effect of pasteurization of colostrum on immunoglobulines absorption and blood parameters of newborn Zel male lambs

As newborn farm animals are almost lacking adequate immunoglobulins to tolerate against environmental pathogens, feeding colostrum is a pivotal action in first days of their life and finding approaches to enhance immunoglobulins absorption into neonates' blood is highly interested. Therefore, the goal of the study was to investigate the effect of controlled-heating of colostrum on immunoglobulins' absorption and some blood and immunity parameters.

Forty neonatal male Zel lambs (4.49±1.21) were divided into two groups; one group was fed with three equal meals of raw colostrum as 15% of BW during the first 36 hours of age and the other group was fed with the equal amount of heat-treated colostrum. For this purpose, a pool of colostrum was first collected from the previously lambed ewes of the herd and gently mixed. Then, half of collected colostrum was heated indirectly in water bath (bain-marie) at 63 °C for 30 minutes. Both raw and heated colostrums were stored and frozen in 2.5kg nylon packs. Immediately after birth, lambs were ear-tagged and weighed and then first blood samples were taken. The assigned colostrums then were fed to lambs by bottles. After the end of feeding colostrum, lambs were fed with milk and starter feed until d 35 of age. Fasted blood samples were taken immediately after birth (day 0) and days 5, 20 and 35 of age and the sera were frozen until serological assay of total protein, albumin and immunoglobulin G. Apparent efficiency of absorption of immunoglobulins was calculated by the respective equation. The data were statistically analyzed as a repeated measures design with a completely randomized arrangement including two treatments and 10 replicates.

The results showed that feeding the heat-treated colostrum had significant effects on serum immunoglobulins, globulins and albumin concentrations of lambs (p<0.05), where feeding the controlled-heated colostrum caused about 39.5 and 38.1% significant increases in serum immunoglobulins levels of lambs in days 5 and 15, respectively. Serum globulins level was significantly greater in lambs fed heat-treated colostrum than other group. In contrast, serum albumins level was significantly greater in lambs fed raw colostrum in days 5, 20 and 35 (p<0.05) as compared the other group. Heating the colostrum caused a marked increase (p=0.0001) in apparent efficiency of absorption of consumed colostral immunoglobulins into lambs blood (43.04 vs. 23.05%). No significant effects were observed in serum total protein concentrations of lambs in both groups.

In general, the results of the study showed that the controlled, in-direct heating of ewes' colostrum at 63 °C for 30 minutes causes an increase in immunoglobulins absorption into lambs' blood.