It is only a tiny part of your milking plant, and it can sometimes be very unobtrusively placed, but it is critical to the ability of your milking plant to function correctly.
These terms seem to be used interchangeably.
There are many different variables that affect the consumption of calf starter, which is essential for the development of the rumen.
The lining of the rumen is composed of finger-like projections called papillae.
These papillae increase the surface area of the rumen for absorption of nutrients.
The term ‘rumen development’ reflects the number and length of these papillae, along with the microbes present in the rumen to help fermentation.
Traditionally, it was thought that feeding roughage (fibre) to calves promoted their rumen development.
Research shows that it is actually calf starter that stimulates papillae growth by production of volatile fatty acids, such as butyrate.
High fibre diets result in production of acetate, which does not promote papillae development.
Therefore, to obtain high levels of butyrate, a rapidly fermentable, high-quality calf starter must be fed.
Factors such as the milk feeding program, availability of water, texture and palatability of the calf starter, birth weight, genetics and gender of the calf can all affect starter consumption.
Alongside these factors, environmental considerations such as housing and management also influence consumption of starter.
The milk feeding program will affect starter intake which will depend on the frequency of feeding, volume fed and nature of the liquid feed.
High volume feeding can have a negative impact on starter consumption and calves should be gradually stepped-down from a high volume diet to allow starter consumption to increase.
The percentage of protein and fat in the milk diet will also affect starter intake and there should be consideration of any milk replacer used, alone or in conjunction with a fortified milk feeding plan, to allow starter consumption targets to be reached prior to weaning.
Ad lib fresh water should be available from birth as the development of rumen microbes requires an aqueous environment.
Provision of water also helps promote the consumption of dry feed.
There are certain physical factors of the calf starter which will affect the palatability and rate at which it is consumed.
Calf starters are usually classified as texturised (coarse or fine) or pelleted.
Research has shown that calves fed texturised starters begin rumination at an earlier age, develop longer rumen papillae and have improved growth in the post-weaning period compared to calves fed pelleted starters.
However, many calves are successfully reared on pelleted starters provided the pellet is of good quality (not too hard and not too soft).
Intake will be adversely affected by any starter that separates into a finely ground mixture.
Regardless of the choice of starter, the product should be free from dust and mould and contain a minimum crude protein of 18%.
Palatability and intake can be improved by the addition of molasses to the formula and should typically be 5-8% of the mixture.
Many calf starters contain an additive such as monensin (Rumensin, Elanco) or lasalocid (Bovatec, Zoetis).
These additives can help feed conversion efficiency in the developing rumen and also act as a coccidiostat to help prevent coccidiosis.
It is recommended that the level of these additives are checked with the manufacturer as they will differ amongst products.
Housing and management can affect intake of calf starter with calves housed indoors consuming less than those reared outdoors.
However, this research showed that there was no difference in average daily gain between the indoor and outdoor reared calves, with indoor reared calves using their feed more efficiently.
If there is going to be a change in the brand of calf starter between the pre-weaning and post-weaning periods, gradually introduce the post-weaning diet two weeks prior to weaning.
This will allow calves to adapt to the new diet prior to the stress of weaning and will reduce the risk of disease and poor growth in the post-weaning period.