Successful calf gut development is key

This means the rumen is not yet developed and digestion of milk and colostrum occurs within the acidic environment of the abomasum (the fourth stomach chamber of the adult cow).

Throughout the rearing period, the calf’s gut needs to develop so the rumen becomes the largest and most significant site of digestion. As the rumen becomes functional, the calf begins to digest fibrous plant materials andutilise nutrients within them for growth. There is a strong link between pre-weaning growth rates and first lactation yield. Therefore, successful gut development has an impact on the overall health and performance of the adult cow.

Four factors affecting the development of a healthy rumen…

1. Colostrum intake.Calves should receive 10% of their birthweight in high-quality colostrum within the first hour of birth (e.g. a 40kg calf needs 4 litres). Colostrum provides the calf with antibodies to build up its immune system but can also help to establish a beneficial microbial community in the digestive tract.

2. Solid feed intake.Calf starter feeds stimulate papillae growthon the rumen wall (finger-like projections which provide lots of space for digestion). Calf starter also encourages the growth of rumen microbes, which begin breaking down fibrous plant materials tovolatile fatty acids (VFAs),the main source of energy for adult ruminants. Without adequate solid feed intake, the rumen will not develop appropriately, which can hinder growth and health.

3. Don’t feed antibiotic milk. When calves are fed antibiotic milk, this can disrupt the development of good bacterial populations in the gut, which can lead to long-term digestive issues. It can also hinder the development of the calf’s immune system and increase antibiotic resistance within the herd. While it may seem like a waste to throw away antibiotic milk, the cost to health and performance of calves and the future milking herd far outweighs the cost of discarding a few litres of milk.

4. Calf health.Scours can disrupt normal gut development and canhave long term effects on the ability of the animal to digest feeds properly. Therefore, it is important to ensure herd vaccination programmes are up to date, calves receive good quality colostrum quickly after birth and calf housing and feeding equipment is kept clean and hygienic.

Weaning marks the complete transition from a milk-based diet to a solid feed diet. During this period, the rumen again undergoes significant developments. The rumen continues to grow in size and its papillae become more developed, increasing the surface area for absorption of nutrients from fibrous plant materials.

Studies have shown that weaning with increased calf starter intake decreases rumen pH (Steele et al., 2015). If calves experience very low rumen pH, the gut can become leaky, which allows toxins and bacteria to be absorbed into the blood. The calf needs to get rid of these, and an inflammatory response is induced. This uses up energy which otherwise could have been used for growth.

However, we need to maximise starter intakes to reduce the post-weaning growth check and reach growth targets for breeding. There are some simple strategies to support rumen health during this time. Ensure to feed a suitable source of fibre(straw) to develop the rumen mat and encourage calves to produce saliva. Maximising saliva production in calves is important, as the calf’s saliva contains proportionally less bicarbonate (for rumen buffering) than the adult cow’s. Additionally, AcidBuf can be added to starter feeds to buffer the acids produced in the developing rumen which improves gut health and reduces inflammation in the calf’s blood.

Successful calf gut development is critical to health and growth. Consider adding AcidBuf to calf starter to help support healthy gut development. For more information on maximising calf gut health and how AcidBuf can be of benefit, please contact Trident MicroNutri on 02894 473478 or via Facebook @TridentMicroNutri.