Economic and environmental effects of providing increased amounts of solid feed to veal calves.

Traditionally, veal calves receive most of their nutrients from milk replacer (MR). Nowadays, however, solid feed (SF; i.e., concentrates and roughages) increasingly substitutes for MR. Studies have shown that providing SF reduces different types of nonnutritive oral behaviors. The objective of this study was to assess the economic and environmental effects of substituting SF for MR in veal calf diets. With respect to environmental effects, we considered the emission of greenhouse gases and land occupation. Substitution rates were based on an experiment in which 160 calves were provided 2 mixtures of SF at 4 levels of dry matter (DM) intake. Mixtures of SF contained either 80% concentrates, 10% corn silage, and 10% straw on DM basis (C80) or 50% concentrates, 25% corn silage, and 25% straw (C50). The 4 levels of SF during the last 17 wk of the fattening period were 20, 100, 180, and 260 kg of DM SF. Additionally, provision of MR was adjusted to achieve equal rates of carcass gain. Substitution rates, representing the SF equivalent needed to substitute for 1 kg of DM MR, were 1.43 kg of DM for C80 and 1.61 kg of DM for C50. Economic effects were assessed based on prices and substitution rates of SF for MR and the possible penalty for carcass color. Environmental effects were assessed based on effects related to the production of feed ingredients, substitution rates, and changes in enteric methane emission and energy use for feed preparation. Costs of feeding SF needed to substitute for 1 kg of DM MR were €0.68 lower for C80 and €0.71 lower for C50, compared with the costs of feeding 1 kg of DM MR. When carcass color scores became too high, however, lower feeding costs were offset by lower revenues from meat. Emissions of greenhouse gases were hardly affected when SF intake was increased. In general, increased enteric methane emission were offset by lower emissions from feed production and energy use. Land occupation increased when intake of SF was increased, mostly because of the high land occupation associated with some concentrate ingredients. In conclusion, this study only showed a negative effect on land occupation when substituting SF for part of the MR in diets of veal calves. Effects on costs and greenhouse gas emissions were neutral or positive.