Effects of adding natural additives to whole milk on performance, faecal, and blood parameters in suckling Holstein calves.

New-born calves are susceptible to disease due to an under-developed immune system, which at this stage is only supported by an inadequate intestinal microbiota. If healthy, the microbiota nevertheless protects against harmful gut micro-organisms, activates the immune system and assists in initial calf nutrition. Colostrum at this stage is crucial to allow large-molecule immunoglobulins to pass through the short-lived comparatively large pores in the intestinal wall. Effective passage is necessary to bolstering the immune system, and if not effected, mortality, diarrhoea and impaired growth occur. It, therefore, makes sense to enhance immune-competence during this vulnerable stage by giving appropriate supplements, one being natural products which have come onto the market, containing various promising substances such as organic acids, prebiotics and plant extracts.  The objective of the authors cited, was to evaluate one such commercial supplement, containing organic acids, herbal extracts and prebiotics, when added to milk. The focus was to assess how this supplement influences specific haematological and biochemical blood parameters, growth performance, mortality rate, diarrhoea duration, faecal scoring, immune system, and the overall health status of new-born calves.

A total of 40 one-day-old Holstein calves were randomly divided in two groups of 20 each and provided with five litres of colostrum each day, for three days. From the fourth day, one group (Control) received only whole milk, while the second group received whole milk containing the commercial supplement (CS) at 5g per litre. The CS contained butyric acid, mannan oligosaccharide, and the organisms: Illicium verum, Silyburn marianum, Allium satium and the cell walls of Saccharomyces cerevisiae. The calves had access to starter feed and water ad libitum.

The results showed that the CS group had a substantial increase in body weight and red blood cells during the first four weeks, while the occurrence of diarrhoea compared to the Control decreased. No marked differences between Control and CS were detected in intake of concentrate feed, feed conversion ratio, body weight gain, levels of white blood cells, haemoglobin, haematocrit, aspartate aminotransferase, phosphorus, gamma-glutamyl transferase, glucose, calcium, creatinine, cholesterol, triglycerides, faeces, or days with diarrhoea.

Because of the differences during the first four weeks, it was concluded that the commercial supplement added to milk had a positive effect on the early development of the digestive system of the calf, thereby increasing their body weight and making them more resistant to diseases during this critical period. Comment: Bearing in mind that farm conditions are less controlled than under experimental conditions, one could expect that differences between Control and CS will be more pronounced, which depending on supplement cost, should make addition of such a supplement a proposition.