Survey of California dairy nutritionists on extent of byproduct usage

Byproduct feedstuffs play a crucial role in California dairy rations and contribute to the sustainability of the industry, but the extent of their usage in the state has not been widely investigated. In March 2022, we sent a byproduct feeding and management survey via email to 61 dairy cattle nutritionists in California. Twenty-six completed surveys were included in the final data analysis (response rate = 46%; n = 26/61). Nutritionists reported servicing 498 dairy farms that represented approximately 936,700 milking cows. Respondents serviced mostly cows housed in San Joaquin Valley herds (87.6%), with some cows housed in Northern California (5.5%) and Southern California (6.9%) regions. Survey respondents also reported 58 byproducts that were fed on California dairies; almond hulls and whole cottonseed were the most frequently utilized byproducts. The average lactating ration byproduct inclusion rate was estimated at 40.9% on a dry matter (DM) basis. Looking ahead to the next five years, 20 nutritionists (80%) thought byproduct usage would increase in California dairy rations, with fewer anticipating decreased ( n = 3; 12%) or unchanged ( n = 2; 8%) usage.