2022 March Board Book

“The science of feeding cattle is its own beast,” says Jennifer Heguy, a dairy farm advisor and county director of the UC Cooperative Extension in Modesto. “Given the fact that 60 to 70 percent of the cost of [milk] production is feed, dairy cattle nutrition is a widely studied and researched topic. A lot of data goes into formulating dairy diets and determining the precise amounts of nutrients.” While alfalfa, silage and other traditional forage crops haven’t been sidelined, they are supplemented by agricultural byproducts, secondary products from food and fiber production like almond hulls, citrus and tomato pulp, canola meal, cottonseed and distiller grains — that now constitute more than 40 percent of a California dairy cow’s diet, offering a valuable source of nutrition.

More than 90% of the state’s dairy cows are found in the San Joaquin Valley, close to millions of acres of nuts, fruits, vegetables and cotton that generate these byproducts. That means minimal processing and transportation to deliver the byproducts to dairy cows.

A recent survey by UC Davis and UC Cooperative Extension revealed that 95% of California dairy farmers surveyed use byproducts in their livestock diets and that these byproducts derive from more than 70 different crop plants as well as other food waste not utilized by consumers. “Given how many crops are grown in the Central Valley, there could be as many as 200 byproducts that get fed to California dairy cows,” says Dan Sumner, the Frank H. Buck, Jr. Distinguished Professor of Agricultural & Resource Economics at UC Davis. “They use fewer scarce resources, they’re grown nearby, they’re available year-round because many are storable, and supplementing the cow’s diet this way is also environmentally and economically beneficial for the California dairy industry.” Using byproducts enables dairy farmers to reduce their use of water, energy, fertilizer, manpower and fossil fuels needed to grow alfalfa and other traditional feedstuffs, and upcycling also reduces the need to dump these previously unused byproducts in landfills where they take up space and produce greenhouse gases. Studies have determined that if these byproducts were not available to California dairy farmers, the cost of dairy cattle diets would increase by around 20 percent, leading to a 10 percent increase in milk production costs, thus decreasing milk production and increasing the price of milk, cheese, butter, ice cream and other dairy products.