New UK silage trial shows inoculant increased FCM milk yields by 1.9kg/day 

A new UK-based trial undertaken at Reading University indicates that using an inoculant on grass silage can improve clamp stability, increase feedable dry matter by 29% and improve fat-corrected milk yields by 1.9 kg/day. 

Inoculant increased feedable dry matter in silage by 29%

“There were significantly higher dry matter losses in the control clamp than the treated clamp, which means there was less silage available for the cows,” he says. 

“Due to the dry matter losses, the untreated clamp shrunk considerably more than the treated clamp, equating to 29% more feedable dry matter,” explains Mr Gresham.  

Better silage increased palatability for cows

The fermentation results from the two clamps showed that the treated silage had superior lactic, acetic and propane diol acid profiles and it had 10 times less butyric acid. 

“The lower butyric acid in the treated silage indicates that clostridia, the bacteria that break down protein and cause foul-smelling silage, were effectively inhibited. This resulted in a more palatable silage, which was evident in the increased dry matter intake seen in the group of cows receiving treated silage in their ration,” he says.  

More stable silage increases energy available for cows to make milk

Aerobic stability was also improved in the treated silage. This resulted in less heating in the clamp, reducing the energy lost to the environment as heat instead of being turned into milk by the cows. This energy loss is caused by aerobic spoilage that occurs when air gets into the clamp and activates spoilage microbes, including yeasts and moulds.  

“The control clamp temperatures peaked at 34.6^oC, whereas the treated silage reached only 26.7^oC – a significant difference in energy terms.” 

“This extra 8^oC of heating in the control group is the equivalent of losing 28MJ of energy for every tonne of silage fresh weight that is unstable. This equates to 5.4kg of milk lost,” he says. 

Treated silage increased DM intakes, milk yields, fat and protein

Mr Gresham says significant improvements were also seen in cow performance when cows were fed the treated silage. 

“The well preserved and stable treated silage resulted in a significant increase in dry matter intake by 1.5 kg/day compared to the control. This correlated with an increase in fat-corrected milk of 1.9kg/day, he explains.

“A 0.1% improvement in protein and 0.19% increase in fat was seen in the milk constituents when comparing treatment and control group cows.