Effects of step-down weaning implementation time on growth performance and blood metabolites of dairy calves

• Published in: Journal of dairy science 2020-11, Vol.103 (11), p.10099-10107
• Main Authors: Mirzaei, M., Khanaki, H., Kazemi-Bonchenari, M., Khan, M.A., Khaltabadi-Farahani, A.H., Hossein-Yazdi, M., Ghaffari, M.H.
• Format: Article
• Language: English
• Subjects: Age Factors; Animal Feed - analysis; Animals; Animals, Newborn; Body Weight; Cattle - blood; Cattle - growth & development; Cattle - physiology; dairy calf; Diet - veterinary; Eating; Energy Intake; Female; Fermentation; liquid feed; Male; Milk - metabolism; Rumen - metabolism; step-up/step-down; Weaning
• ISSN: 0022-0302; 1525-3198
• DOI: 10.3168/jds.2020-18520

The current study evaluated the effects of step-down weaning implementation time on starter feed intake, growth performance, blood metabolites, and ruminal pH in dairy calves. A total of 48 Holstein dairy calves (24 male and 24 female; 3 ± 1 d old; 41.2 ± 1.8 kg of body weight) were assigned (n = 12 per treatment; 6 male and 6 female) to 4 experimental treatments in a completely randomized block design. All calves were fed 6 L/d of milk from d 3 to 10 of age, and the treatments consisted of the following: calves were offered 8 L/d of milk from d 11 to 28 of age and then 4 L/d from d 29 to 63 (Step-28; total milk offered = 326 L); calves were offered 8 L/d of milk from d 11 to 42 of age and then 4 L/d from d 43 to 63 (Step-42; total milk offered = 382 L); calves were offered 8 L/d of milk from d 11 to 56 of age and 4 L/d from d 57 to 63 (Step-56; total milk intake = 438 L); and calves were fed 8 L/d of milk from d 11 to 63 of age and abruptly weaned (control; total milk offered = 466 L). All calves were housed individually in pens and had ad libitum access to water and solid feed throughout the experiment. All calves were completely milk weaned on d 64, and their performance was measured until d 80 of age. During the experiment, the starter intake (kg/d and % of body weight) was greater in calves in the Step-28 group compared with those in the other groups. However, the total metabolizable energy intake was greater in the Step-56 calves compared with the other calves. Overall, the average daily gain (ADG), feed efficiency (ADG/dry matter intake), and ADG/total metabolizable energy intake were similar across the treatments. Circulating glucose, β-hydroxybutyrate, blood urea nitrogen, albumin, total protein, alanine aminotransferase, and aspartate aminotransferase, as well as ruminal pH, were not affected by the treatments. The implementation of step-down weaning in early life (4–6 wk of age) could stimulate solid feed intake compared with weaning at a later age with no negative effect on performance.