Jay Johnston has an excuse if he is ever stopped for speeding on the 417 heading into Ottawa. In the coolers stashed away in his car are the partially digested contents of a cow’s rumen. Johnston, a nutritionist and president of Ritchie’s Feed and Seed, must get the digesta to his lab before the rumen bacteria start to expire.
Johnston, with the help of dairy farmer Ed Beimers from Vars, is changing the way farmers feed their livestock. The research he conducts in his lab, the only one of its kind in a commercial feed mill in Ontario, is already enabling dairy producers across Canada and the northeast United States to optimize the way that they feed their livestock. As a result of the research done at Ritchie’s, dairy farmers can expect to have healthier cows that produce more and live longer.
Just as importantly, by optimizing the quantity and quality of livestock feed, farmers can reduce environmentally harmful pollutants such as phosphorous and nitrogen that are excreted via the manure. Manure has become the focus of the Walkerton water disaster, whether rightly or wrongly, and Johnston feels Ontario is sure to introduce legislation situation similar to that now in place in Quebec, Europe, and parts of the United States to control the situation.
Studies have shown that proper diet management can maintain production but lower nitrogen excretion by 25kg per cow per 308 day lactation. In Russell County alone (including Cumberland Township) there are 195 dairy herds, averaging 50 to 55 cows per herd. That’s a lot of nitrogen. By following a nutrient management plan, farmers can reduce the amount of nitrogen excreted by their cattle, making a positive impact on the environment.
"The whole intent of nutrient management," explains Johnston, "is that if you know how nutrients are being used you can avoid overfeeding the cow. For example if you can feed more forages and less concentrates, there should be less nitrogen excreted and that is what society is going to demand."
According to Johnston, the nutrient management rules in Quebec regulate how much manure farmers can put on their fields and when they can do it. " You can’t have more cows than you have land for," says Johnston. "But if you can lower the nitrogen or phosphorous excretion rate you can have more cows."
Johnston conducts his nutrient management research with the help of five fistulated Holstein cows, which have had neoprene plugs known as cannulas inserted in their rumens. The surgery was performed by Dr. Dave Douglas of the Navan Veterinary Clinic, with the help of Dr. Ken Hartin, a retired surgeon from Agriculture Canada. In order to be able to conduct the surgery Ritchie’s had to apply for a provincial license, maintain an animal care committee and allow regular inspections of the animals being used for research.
On his regular visits to Beimer’s farm Johnston or Ed Beimers removes the lid of the cannula. Using a device adapted by Dr. Hartin (his wife still does not know where her pressure cooker went) rumen fluid is quickly removed, and a 1kg sample of rumen mat is extracted form the cow, who seems oblivious to the whole procedure.
Johnston must then rush the coolers containing the rumen fluid and mat back to his lab at Ritchie’s. There the mat and fluid are homogenized in a blender and strained through cheesecloth. The resulting mix contains bacteria, protozoa, and fungi which are then added to a preset buffer solution so as to mimic the conditions of a cow’s rumen. Samples of forages are then immersed in the mix . The flasks are then bathed in carbon dioxide and placed inside a heated fermentation chamber.
"We are trying to find out the extent and rate of digestion," explains Johnston. "This allows us to see how a cow would utilize an ingredient, and is light years ahead of standard laboratory techniques". Without these newer techniques farmers would have to use standard analyses and take their cues from production levels and general body conditioning. But these external cues cannot explain any changes that occur as a result of the diet, as they are simply too general. Was it the hay or the haylage? Was the corn silage too mature? "Digestibiltiy is really the only way to answer these questions."
Beimers, whose herd of 80 head includes about 30 lactating cows, says that since he began using rations based on digestibility five years ago his milk production has increased and feed costs have gone down "by a fair bit" as more forage and less grain is being fed. "If you are feeding her something she doesn’t need it is costing you money and not doing the cows any favours as she has to handle the excess nutrients."
One of Johnston’s clients says that as a result of using digestibility data he was able to save over $10000 on his feed bill while also increasing production.
"The point of all this research is that it offers plenty of opportunities," stresses Johnston. " We have been able to figure out how to change digestibility rates using feed enzymes. For example we recently completed a trial using 132 cows fed the enzymes and we were able to show a statistically significant milk production response and a milk protein response that would pay for most of the cost of the enzyme. The trial was set up in such a way that the only thing that was changed was the digestibility of the ration, so we were able to change production without adding scads of extra protein.
"Once you look at the results, it makes sense. You wonder why nobody has done it before in Canada. By doing it the amount of forage fed should go up and that is going to result in healthier cows."
Ritchie’s has been performing forage analyses for the past 10 years, and has recently entered into a joint venture with Agri-Foods Labs in Guelph that has exciting implications for cattle and dairy producers. In this venture, Ritchie’s will conduct the biological part of in situ starch analyses while Agri -Foods will do the chemical analyses. The in situ analysis involves putting known amounts of grains or forages right into the cow’s rumen and measuring digestion rates over set periods of time.
The benefit of doing the work on starch is that preliminary results have shown a great variance between and within corn silage hybrids, as well as between methods of grain processing. On top of all this the effects of environment on starch level and availability have proven to be large.
The digestibility tests that Johnston performs have taken much of the guesswork out of ration formulation. If, for example, a particular ration doesn’t work because of the effects of weather or hybrid selection you can now redesign the ration without resorting to a guess or using something that a neighbour has tried. "The trouble with guesses," says Johnston, "is that you have a 50 per cent chance of being wrong, and when you are talking about someone’s livelihood that is not an intelligent way to do it."
The important thing to remember about digestibility work is that research out of Michigan State University has shown that a one-per-cent increase in dietary NDF digestibility can result in a milk increase of 0.28kg/cow/day. Over a whole lactation this can result in a lot of profit, so the $125 test looks like a wise investment.
From the Archives:
AgriProfile, July 2000
