Current feeding challenges for dairy and beef calves

In Spain, the beef fattening system is an intensive system where calves are commonly housed in partially open barns with straw bedding and 40% of the calves, mainly males, are from dairy origin (surplus calves). These calves are transported by road for long hours (up to 3-5 days) from their dairy origin farms to the rearing farm where these calves are fed low amounts of milk replacer for 6-8 weeks and concentrate and straw ad libitum in separate feeders from very young ages with a resulting concentrate to straw ratio around 90-80 to 10-20%. These calves are not castrated and slaughtered around 12 months of age. In Europe the use of hormones or growth promoters are not allowed. This dairy beef production system needs to face mainly 3 challenges and need the design of nutritional strategies to: i) reduce the incidence of BRD and the antimicrobial use of unweaned calves upon arrival, mainly focusing on the nutrition and management before arrival to the rearing farm and transportation and the recovery from the negative energy balance, the increased gut permeability, the oxidative stress, the anemia, and the drop of feed intake ii) reduce the bulls aggressive and aberrant oral non-nutritive behaviours based on the modulation of inflammation processes to reduce the incidence of DFD meat; and finally to face one of the main challenges iii) reduce the environmental impact of this dairy beef production by decreasing the methane and N emissions, and to find alternative feed ingredients with low LCA impact.

Keywords: dairy beef cattle, intake recovery, aggressive and aberrant behavior, environmental impact.