Considerable time is spent managing ‘transition’ periods in a milking animal’s life; weaning and the move to lactation being the two most recognised times.
However, experts suggest there is one transition period that is often overlooked, and that is the transition from colostrum to milk in the early days of a calf’s life.
A study by the department of animal sciences at the University of Guelph, Canada, found that giving five feeds of transition milk after colostrum resulted in longer intestinal villi and increased gut service area, when compared with just a single feed of colostrum and immediate transition to whole milk.
Researcher Michael Steele, of the University of Guelph, says the transition of the calf from colostrum to milk may be equally or even more important than other critical transitions in a dairy animal’s life.
He says: “We focus a lot on transition during weaning and of course transition to lactation, but the transition from colostrum to milk in the neonate is another highly critical juncture.”
Dr Christine Cummins, of Bonanza Calf Nutrition, says the focus on most farms is often on getting the rumen developed so calves can be weaned and given solid feed. But for the first 10-14 days of a calf’s life, the focus should be on the stomach and intestinal areas.
She says this is because a calf’s digestive system is not fully developed when they are born.
“It is still rapidly forming and must absorb key antibodies and nutrients to protect itself against infection and digest milk ingredients as it grows.
“A calf’s gut is inert and devoid of the vital enzymes and acids at birth that it needs to stimulate digestive development.”
Dr Cummins adds that colostrum and transition milk play an essential role in this process, as they are packed full of protein, fat, amino acids, immunoglobulin including lactoferrin, insulin and growth hormones – everything a calf needs to develop its own immune system and ensure the gut wall fully closes and is therefore protected within the first two weeks.
“But because of infectious diseases such as Johne’s disease and practical issues on many farms, many calves only receive one or two feeds of colostrum before going on to milk replacer,” says Dr Cummins.
She also says that a weak, underdeveloped digestive system is one of the reasons calves are susceptible to scour in the first few weeks of their life.
Transition milk key facts
■ It is the milk produced by the cow immediately after colostrum and before whole milk
■ It contains many of the same key nutrients as colostrum, delivering antibodies that calves use to line the surface of their still-developing intestine and protect them from infection
■ In turn, this aids digestive development and promotes good long-term gut health