Estimating daily yields of cows from different milking schemes

• Published in: Livestock production science Vol. 65; no. 3; pp. 219 - 227
• Main Authors: Schaeffer, L.R., Jamrozik, J., Van Dorp, R., Kelton, D.F., Lazenby, D.W.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.08.2000
• Subjects: Daily yields; Dairy cattle; Prediction; Recording schemes; Daily yields; Recording schemes; Dairy cattle; Prediction
• ISSN: 0301-6226; 1872-6070
• DOI: 10.1016/S0301-6226(00)00153-6

A multiple regression model was used to derive equations for predicting 24 h milk, fat, and protein yields of dairy cows on either two-times or three-times-a-day milking under different testing schemes. New prediction equations were developed for 72 subclasses of days in milk, parity, and season of calving for each of 18 possible three-times-a-day testing schemes and for each of four possible two-times-a-day testing schemes. The prediction equations were compared to current official factors and found to be slightly better than the official factors. For two-times-a-day testing schemes the accuracies of 24 h fat yield predictions from one milk weight and one fat and protein determination were 0.88 for an evening milking and 0.89 for a morning milking. For three-times-a-day milkings the accuracies of 24 h fat and protein yields from two milk weights with fat and protein contents on each were 0.91–0.94 depending on which two of the three milkings were observed. If only one of three milkings were recorded, then accuracies of 24 h predicted fat and protein yields dropped to 0.80–0.82. More data from herds milking three-times-a-day are needed on all breeds.