Intensive liquid feeding of dairy calves with a medium crude protein milk replacer: effects on performance, rumen, and blood parameters

• Grant number: 17/02721-8
• Support type: Regular Research Grants - Publications - Scientific article
• Duration: April 01, 2017 - September 30, 2017
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Nutrition and Feeding
• Principal researcher: Carla Maris Machado Bittar
• Grantee: Carla Maris Machado Bittar
• Home Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

The objective of the study was to evaluate different liquid feeding systems with a medium crude protein milk replacer and their effects on performance, rumen and blood parameters. Thirty newborn Holstein calves were blocked according to birth weight and date of birth, and randomly distributed to different liquid feeding systems: i) Conventional: 4L/d; ii) Intensive: 8L/d; iii) Step-up/step-down: week 1: 4L/d; weeks 2 to 6: 8L/d, and weeks 7 and 8: 4L/d. The commercial milk replacer (12.5% solids; 20.2% crude protein (CP); 15.6% fat) was fed twice daily (07 e 17h) until calves were weaned with 8 weeks of age. Calves were individually housed in wood hutches, with free access to water and starter concentrate, and to hay only after weaning, being followed through 10 weeks of age. Milk replacer and starter intake were affected by the feeding system, presenting an inverse relationship. After weaning, starter intake and hay intake were similar among feeding systems. Total dry matter intake (DMI) was higher for animals fed according to intensive system during the liquid-feeding period as compared to the conventional system; however, the conventional feeding resulted in highest DMI after weaning. Feed efficiency were similar among liquid feeding systems before and after weaning. Average body weight and daily gain were not affected by the liquid feeding systems before or after weaning. During liquid feeding period, diarrhea occurrence was lower for calves fed conventionally; however, when calves fed the step-up/step-down program were fed lower volumes of liquid diet, diarrhea occurrence was similar to the conventional system. Plasma concentrations of ß-hydroxybutyrate were higher for calves fed conventionally, reflecting starter intake. Rumen pH, short-chain fatty acids and N-NH3 were not affected by feeding systems. Feeding higher volumes of milk replacer with medium crude protein content had no beneficial effect on performance of calves up to 10 weeks of age. (AU)