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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Animal Genomics and Improvement Laboratory » Research » Publications at this Location » Publication #414250
Research Project: Increasing Accuracy of Genomic Prediction, Developing Algorithms, Selecting Markers, and Evaluating New Traits to Improve Dairy Cattle

Location: Animal Genomics and Improvement Laboratory

Title: Transforming the tradition of discrete milk yield correction factors: A continuous 1-step DeLorenzo-Wiggans method

Author
item WU, XIAO-LIN - Council On Dairy Cattle Breeding
item CAPUTO, MALIA - Council On Dairy Cattle Breeding
item WIGGANS, GEORGE - Council On Dairy Cattle Breeding
item NORMAN, H - Council On Dairy Cattle Breeding
item Miles, Asha
item Van Tassell, Curtis
item Baldwin, Ransom
item SCHUTZ, MICHAEL - University Of Minnesota
item BURCHARD, JAVIER - Council On Dairy Cattle Breeding
item DURR, JOAO - Council On Dairy Cattle Breeding

Submitted to: Journal of Dairy Science Communications
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/18/2024
Publication Date: 1/8/2025
Citation: Wu, X., Caputo, M.J., Wiggans, G.R., Norman, H.D., Miles, A.M., Van Tassell, C.P., Baldwin, R.L., Schutz, M.M., Burchard, J., Durr, J.W. 2025. Transforming the tradition of discrete milk yield correction factors: A continuous 1-step DeLorenzo-Wiggans method. Journal of Dairy Science Communications. 6(1):84-89. https://doi.org/10.3168/jdsc.2024-0583.
DOI: https://doi.org/10.3168/jdsc.2024-0583

Interpretive Summary: Dairy farmers who want to estimate how much milk a cow is giving participates in milk testing where cows are sampled a few times throughout their lactation and then their total milk yield is estimated. A number of methods of estimation exist, a very popular one is called the DeLorenzo-Wiggans method which involves two-steps for calculating multiplicative correction factors. In this study, the model is revamped replacing those two steps with a single global regression which is more computationally efficient and considers interactions between covariates not previously possible in a two-step method. We found this new method to result in more precise estimates of yields.

Technical Abstract: Over the past decades, various methods have been proposed to estimate daily milk yields from partial yields. Many of these divide milking interval time to varied classes, postulating constant yield factors within classes that vary between classes. However, these traditional methods, though widely used, are computationally ineffective and introduce biases. Recently, we have introduced the concept of continuous yield factors, which can enhance daily milk yield estimations. This study explored strategies to integrate continuous yield factors into established methods, as demonstrated by the DeLorenzo and Wiggans (D-W) method, widely used in the United States. The traditional D-W method follows a two-step process: it initially calculates discrete yield factors for segmented milking interval classes (MIC), then refined through a follow-up smoothing step. The renovated method, also referred to as the polynomial-interaction regression model, utilizes all available data in a single step, exhibiting greater computability efficiency and higher estimation accuracy.