A new study by researchers in Iran has shown that replacing traditional barley grain feed with potato processing by-products, such as heated potato slice waste (HPSW) and French fries waste (FFW), can improve milk production, and efficiency of lactating dairy cows.
The study examined the effects of feeding Holstein dairy cows a diet that replaced barley grain with these potato co-products.
Twenty-four cows were divided into three groups, each receiving a different feed: a control group with a standard barley-based diet, a second group with HPSW, and a third group with FFW. The potato co-products used in this study are leftovers from the production of frozen French fries. These include heated slices and fried bits that are typically discarded during processing.
By incorporating these co-products into the cows’ diet, the researchers aimed to evaluate their impact on the cows’ dry matter intake, milk production, and overall feed efficiency.
The findings revealed several important benefits. Cows that were fed HPSW and FFW produced more energy-corrected milk (42.9 and 43.9 kg/day, respectively) compared to the control group (40.6 kg/day).
Positive environmental outcomes
Feed efficiency also improved, meaning the cows produced more milk for the same amount of food intake.
Additionally, the study found that the inclusion of potato co-products resulted in lower milk urea nitrogen levels and a reduced ratio of urine nitrogen to intake nitrogen. This suggests that the cows were able to utilize dietary protein more effectively, leading to less nitrogen waste excreted in their urine—a positive environmental outcome.
Another key result was the improved physical properties of the cows’ diet. The inclusion of potato co-products increased the physically effective neutral detergent fiber (peNDF), which plays a crucial role in promoting healthy digestion and rumination in dairy cows. The cows fed these potato-rich diets had longer rumination times, indicating that their digestive health benefited from the fiber content in the potato co-products.
Energy sources
The researchers said their work illustrates how such co-products can be used as promising energy sources in the diets of lactating dairy cows.
They concluded that the inclusion of fried and cooked potato co-products improved dietary physical properties, energy-corrected milk yield, feed efficiency, and nitrogen utilization in lactating Holstein dairy cows. while supporting more sustainable agricultural practices.
Source: Animal Feed Science and Technology
Title: Fried and cooked potato co-products improve diet physical properties and milk production in Holstein lactating dairy cows
Authors: S Mohammed Sadq, F Fatehi