Welcoming the calf in Rumi-Nation!

Calf feeding: Paving the way for rumination by choosing the right proteins

By Nicolas Anglade, Category Manager Ruminants, Hamlet Protein

Weaning is the first major transition in the life of the ruminant. Indeed, the newborn calf begins its life with a strict monogastric status and must evolve in a few weeks towards a status of ruminant animal. Weaning is a fundamental validation step for the calf’s passport towards definitive maturity of its digestive system.

During this short period of about ten weeks, the weight of the calf will double! At the gastric level, this evolution resembles a revolution. The rumen, which is not functional at birth, occupies 25% of the gastric volume while the stomach (abomasum) represents 60%. At weaning, the functional rumen occupies 65% while the abomasum represents only 20%. This spectacular volumetric growth of the rumen is accompanied by the establishment of ruminal papillae structure, which exponentially increases the surface area of exchange between the rumen content and the blood system. This is fundamental for the absorption of volatile fatty acids and ammonia.

The essential dietary requirement for protein in the start-up phase is a zootechnical interspecies constant and allows young animals to ensure the fast development of essential organs as well as their muscle mass. The growing rumen, as such, requires a large amount of protein in the ruminant case. In addition, the microbial fermentation that accompanies rumen development has its own needs for protein supply to fuel the increase in its biomass.

This rapid temporal evolution of the gastric system of ruminants explains why milk feeding is essential when abomasum is predominant (first 3 weeks), but when it decreases in importance, “dry” feed – aka starter or pre-starter feed – takes over.

However, if we look at the calf feed market before weaning, we can see that the farmer's attention is mainly focused on liquid feeding and the choice of milk replacer for calves. Starter feed tends to go more unnoticed. In quantitative terms before weaning, however, both feeds provide comparable quantitative protein intake, mostly of dairy origin in the calf milk replacer (CMR) and vegetable origin in the starter feed.

Starter feed is an essential point of improvement for a successful weaning transition

The choice of proteins in calf starter feeds is crucial to properly initiate digestive function by positively activating rumen fermentation.

Trials have allowed us to gain a better understanding of what happens in the rumen of young calves around the 2nd month of life when HP 300 replaces conventional soybean meal in the starter feed, also known as iso-protein replacement (Ansia et al., 2021, University of Illinois).

Figure 1: Efficiency of microbial synthesis (microbial N, g/kg CP) as measured at the duodenum of calves fed calf starters with soybean meal (SBM) or HP 300 as main protein source. a,b: significant differences (p<0.05) )Ansia et al., 2021; AU0202).

HP 300 significantly increases the production of microbial proteins, resulting in improved rumen efficiency. The establishment of the microbial protein flow, as the main source of amino acids, is essential for the future of the young ruminant, whether it is intended to produce milk or meat.

Mind the protein bypass fraction at a young age!

The right choice of protein can also make a difference in the (post-ruminal) gut health of the calf. The same tests have shown that a significant part of the dry feed, about half, passes through the rumen without being fermented. The use of conventional soybean meal is a universal choice when it comes to protein feed. However, the anti-nutritional factors present in protein meals (anti-trypsin factors, Galacto-oligosaccharides, Beta-conglycinin) can negatively affect digestion and intestinal health in young ruminants, whose digestive and functional immaturity makes them more susceptible to dietary disturbances.

At Hamlet Protein, the enzymatic treatment of soy protein significantly reduces the level of ANF and the associated risks, making it safer to use in the diet of young animals, including starter feed.

The initiation of rumen growth and its fermentation functions is an important step to be taken in the ruminant start-up phase. The choice of protein provided by starter feeds is clearly underestimated but has a major impact on the initiation of rumination and the intestinal health of calves. This low-cost and very temporary investment will have a significant impact on the productivity and health of dairy and cattle herds.

So, make sure your calves have the right visas in their passports needed for their journey towards rumination by having Hamlet Protein in their starter feed.