RED DEER — Making silage is a complex biological process that requires the right combination of bacteria, pH balance and fermentation.
Inoculants have been added for more than 50 years to curb spoilage and encourage better ensiling. Some studies show improved feed efficiency was achieved when inoculants were used, said Tim McAllister of Agriculture Canada’s Lethbridge Research Centre.
“Do they always make money? No, they don’t,” he said at the Western Dairy Seminar in Red Deer March 11-14.
The production of good quality silage requires bacteria in the inoculant to work with natural bacteria in forage.
Read Also
Farming Smarter receives financial boost from Alberta government for potato research
Farming Smarter near Lethbridge got a boost to its research equipment, thanks to the Alberta government’s increase in funding for research associations.
“When you start harvesting forage, you don’t know how many good microbes are there and how many bad microbes are there,” he said.
“You need good microbes to grow, and not all grow equally in the silage pit.”
It takes 40 days for a harvested crop to turn into silage and stabilize. The silage will keep for a long time and maintain its nutritional quality once it is covered to keep out oxygen.
McAllister said there are four generations of inoculants.
The early silage inoculants showed some improvement in lactic acid production, which lowers the pH balance and stops respiration of the harvested plants to conserve sugar, an important component of silage. The lower pH environment also prevents the growth of bad bacteria, yeasts and moulds.
However, silage sometimes spoiled faster once the pit was uncovered because it was exposed to oxygen.
The next generation of inoculants contained heterolactic bacteria, which helped inhibit growth of yeast and moulds that contributed to deterioration.
The third generation inoculants now on the market affect fibre digestibility. They provide an enzyme that breaks away the lignin so that the rumen micro-organisms can do their job during digestion. Cattle can derive more energy from the silage because of the effects of a third generation inoculant. They do not eat as much and may grow the same or better.
The fourth generation adds microbes with probiotic properties.
They have less impact on the ensiling process but may affect animal health by improving gut health and growth efficiency.
New technology allows researchers to study the process more thoroughly.
Molecular biology is unraveling some of the complexity of microbes involved in ensiling, and scientists can now determine if a bacteria or yeast that is added to the mix grows or dies.
“Ten years ago it would have been impossible to do this kind of work because the technology did not exist,” McAllister said.
It leads to further investigation into how rumen microbes change when animals move from forage to mixed forage to high grain diets.
