Using the company’s In Vitro Fermentation Model (IFM), the researchers processed over 400 dairy lactation total mixed ration (TMR) samples throughout 2014, with the bulk of those feed samples coming from US producers (85%), said the Kentucky headquartered group.
The remainder came from dairy farms in South America, Asia, Europe, Mexico, and Canada.
Dr Kamal Mjoun, research scientist at Alltech’s IFM Lab in Brookings, South Dakota, told us that, depending on the parameter, 15 to 40% of the samples had less than ideal values for a synchronized fermentation.
Feed analysis findings
“Most of the issues related to the rates of digestion of the fast (starch) and slow pools (fiber) with samples presenting either very ‘slow’ fast pool rates - indicating a lack of fermentable carbohydrate or the presence of slowly fermenting starch - or fast rates - indicating excess sugars and/or the presence of very fermentable starch. Such cases would present high acidosis risk,” he said.
The proportions of each component depends on the feedstuff employed, he said. "For example, ensiled feeds contain more organic acids; cereal grains contain starch; beet pulp, citrus pulp, soy hulls, and alfalfa contain significant amounts of pectins, while grass hay, molasses, and beet pulp contain large concentrations of sugars," said the scientist.
The type of nutrient available to rumen microbes will affect the rate of degradation of the different pools and size and will also determine the type of organic acids produced during the fermentation and therefore the energy value of the feed, he added.
“While most of the TMR analyzed had adequate fiber digestion, more than 25% of the samples contained fiber that was slowly digested, which will impact feed intake and animal performance,” said Dr Mjoun.
Improving digestibility
The IFM tool, he said, assesses the quality of mixed feeds of dairy cattle, the rate and extent of their digestibility and whether the balance between the fast energy pool and the slow energy pool is optimal to enable adequate volatile fatty acid production – a critical energy source - and microbial biomass production - a key source of digestible protein for the cow.
“The ultimate goal of the IFM is to improve digestibility of feed in dairy cattle either by speeding up fiber digestibility rates or by enhancing the extent of forage digestion and end-products of fermentation,” he said.
The technology was developed about 10 years ago and used internally for research purposes in relation to enzyme evaluation, he added.
“We started using it commercially about three years ago as a diagnostic tool to evaluate and troubleshoot dairy total mixed rations to try to achieve optimal rumen fermentation and feed use.
From the database that we accumulated during this period, we established an ‘ideal fermentation profile’ that corresponds to herds with superior lactation performance with higher milk yields and components. Analyzed samples are eventually compared against this optimal fermentation and then the strength and weaknesses of the TMR are analysed," he added.
Correcting dairy TMR deficiencies
The IFM technology relies on the incubation of feed samples within a standardized rumen fluid and a buffer system to mimic natural rumen fermentation. IFM then measures gas production, identifies ration inefficiencies and provides additional data on the nutritive value of the feed.
“Correcting dairy TMR deficiencies is not always about adding a feed additive. It can often just involve a slight formulation tweak or a change in inclusion rates.
For example, if the fast pool rate of digestion is too slow, we can conclude that either the amount of solubles - sugars or starches - is too low or they are slowly fermented. In the case of slow rates, perhaps, pull out the slower starches and replace them with steam flaked corn to speed up the process alongside adding sugars to the diet if necessary.
If the fiber digestibility rate is a limiting factor in a dairy TMR, we can suggest the possibility of feeding better quality forage. However, if such an option is not feasible we can propose the inclusion of by-products such as beet pulp or soy hulls that are rich in soluble fiber and quick to digest.
But, of course, we must always ensure there is an optimal level of effective fiber in the TMR to avoid rumen acidosis occurring,” said Dr Mjoun.
He said when none of that fine-tuning works, then the firm would look into the use of fibrolytic enzyme technology to break down the fiber in a ration. The evaluation of the fermentation profile takes into account the nutrient profile and uses wet chemistry analysis to target potential changes in the formulation, said the Alltech representative.
Beef ration evaluation
Dr Mjoun said that Alltech eventually hopes to apply the technology to the beef sector focusing first on finisher type diets.
"Currently, it is a lot easier to apply fermentation modelling to dairy diets as TMRs in that segment are narrower in their range and chemical composition.
The gauging of feed efficiency and impact of TMR adjustments on production gains is more straightforward on the dairy side as well but we expect to generate enough data on optimal fermentation parameters for beef within a two year time frame,” said the scientist.
In an interview with this publication last October, Dr Mark Lyons, global VP of Alltech, said the firm’s IFM technology has helped generate milk yield gains of 10 to 15% when employed on a number of dairy farms in the US and Canada.