Starch levels are often seen as a measure of milk potential and rumen stability in diets, thus used as a benchmark when formulating diets.
In reality, starch levels in diets do not matter, because in isolation they don't tell you a great deal. Starch is only one of four energy sources to the rumen and furthermore, the degradability of starch sources greatly influences rumen dynamics.
Rumen Health
Rumen microflora feed on all rumen degradable carbohydrates, converting them into Lactic acid, which is then converted into volatile fatty acids (VFA). These are transported across the rumen wall, leaving microflora and other parts to be washed out of the rumen and digested in the small intestine.
The type of ingredients and fibre provision dictates the rate of this process, the acid loading on the rumen and therefore, the pH in which the rumen operates. There are, however, several other factors contributing to this at a much greater level than the ration’s starch value. Many influential factors that cause acidosis or sub-acute acidosis (SARA) are environmental, such as ration sorting, feed space allocation, heat stress and feed bunk management.
Ration factors are secondary, of which starch levels paint only part of the picture. With UK diets (especially in the West), where the forage base is predominantly grass silage made from high sugar ryegrasses, lactic acid loading presents a risk to rumen health if not managed correctly. Although lactic acid is a valuable energy source to the rumen and an intermediate step in all carbohydrate fermentation, overloading can happen. Feed ingredients such as whey and molasses also provide a rapid energy source to the rumen that, along with lactic acid, is not factored into starch calculations.
The other great influence on rumen health is fibre provision. A ration with high uNDF demands a higher supply of rumen fermentable energy (often as starch), than one that has lower uNDF and higher levels of digestible NDF. This is due the digestibility of the NDF having a significant influence of the availability of carbohydrates and influencing rumen passage rate.
Production Economics
Starch sources supplied in a ration will have a significant impact on the economics of feeding a product (assuming rumen stability can be attained). This is because not all starch is equal, with some rapidly fermentable (e.g. bread) and some slower (e.g. cracked maize) - irrespective of the total amount of starch supplied by 1kg of the ingredient.
In essence, measuring starch on its own is a poor evaluation of a ration, both in terms of rumen health and yield potential. Better metrics to use include: 7hr starch rate (evaluating the starch degradation over a 7hr period) and NFC (non-forage carbohydrates), which better capture the effects of all rapidly degrading energy sources provided to the rumen and MP E production which is often a limiting factor within a ration formulation.
More importantly, the starch measure does not take into consideration fibre degradation, which can have as big an effect upon rumen function and output as any other factor. This can often be seen in practice, with herds showing evidence of acidosis but can have low starch levels (15%), and some healthy, productive herds can run with starch levels of 28%. Similarly, some herds show impressive yields at low starch levels and some struggle to reach expectations with a high starch ration. If there is as much variation on the farm as this, using starch levels to evaluate rations can be misleading and counterproductive.
Maximising profitability
In order to maximise profitability from milk production, farmers are increasingly focused on improving the efficiency of feed and animal production. One method to consider is the use of feed additives, such as RumiStar™, to optimise health and well-being.
Dairy farmers can achieve efficient milk production by investing in high-quality genetics, but this can depend on good management and high-quality rations. Evidence from trials and practical experience indicates that a reliable and cost-effective way of earning more profit per cow is through optimising feed with the right additives. This is important for farmers not only to ensure that milk production is profitable but also to ensure optimal rumen health and well-being for cows.
To get the most from a dairy cow, you must get the most from the animal’s rumen. The rumen is the engine of milk production. RumiStar™ is a product that can get you a turbocharged engine and better profits. When you feed a dairy cow, you are feeding the billions of microorganisms in its rumen. Many factors affect the performance of the rumen, get them right and you will have more productive cows with better feed efficiency.
The rumen is populated by vital microorganisms that digest the diet. Fine-tuning the rumen means maintaining these in an optimal state. This increases the energy and protein available to the cow from its feed. Sometimes the rumen needs a helping hand; for example, in order to extract a higher value from high-starchy maize.
By carrying out on-farm digestion analysis, we can evaluate the cows’ dung. By analysing digestion by muck sieving we can adjust diets accordingly, promoting good rumen efficiency and optimal rumen nutrient balance. The Nasco Three Sieve analyser is a fantastic tool to use, as it shows how well the cows are digesting the diet. Those herds with a high percentage of corn in the dung will be losing a high amount of potential energy, therefore, potential milk loss which equates to lost income.
RumiStar™ is a cutting-edge feed enzyme specifically developed for dairy cows. It increases corn starch digestion; increases energy supply and allows more milk to be produced from the same feed; greater feed efficiency and more income.
How It Works
A pure amylase (an enzyme, found in saliva and pancreatic fluid, that converts starch and glycogen into simple sugars), it releases more of the starch energy in corn based diets. This provides more starch energy to the animal and also increases forage digestion. As a result, cows make better use of their total diet and can allow increased forage use, which reduces feed costs.
Where cows are fed RumiStar™ I have seen much higher corn digestion and overall forage digestion, and rumen fill has been very consistent. Results from the UK and rest of Europe can conclude a response in milk production of an extra 1.5-1.8 kg/cow. A significant rise in efficiency and financial returns have increased.
RumiStar™ Benefits
• Better adoption and utilisation of maize based diets
• Better digestion of dietary starch and NDF
• Glucogenic effect; higher blood glucose, important link to fertility
• Better rumen health
