Replacing maize silage with hydroponic barley forage in lactating water buffalo diet: Impact on milk yield and composition, water and energy footprint, and economics
Felicia Masucci, Francesco Serrapica, Monica Isabella Cutrignelli, Emilio Sabia, Andrea Balivo, Antonio Di Francia
Abstract
This study investigated the feasibility of integrating hydroponic barley forage (HBF) production into dairy ruminant production, focusing on its effect on milk yield and components, energy and water footprints, and economic implications. Maize silage (MSil) was used as a benchmark for comparison. The research was conducted on a water buffalo dairy farm equipped with a fully automated hydroponic system producing approximately 6,000 kg/d of HBF as fed (up 1,000 kg/d on DM basis). Thirty-three lactating water buffaloes were assigned to 3 dietary treatments based on the level of MSil or HBF in the diet: D0 (100% MSil), D50 (50% MSil and 50% HBF), and D100 (100% HBF). The feeding trial lasted 5 wk, plus a 2-wk adaptation period during which each cow underwent a weighing, BCS scoring, recording of milk yield and components, including SCC and coagulation characteristics. Based on the data obtained from the in vivo study, the water and energy footprints for the production of MSil and HBF and buffalo milk, as well as income over feed cost, were evaluated. Complete replacement of MSil with HBF resulted in a slight increase in milk yield without significant impact on milk components. The resource footprint analysis showed potential benefits associated with HBF in terms of water consumption. However, the energy footprint assessment showed that the energy ratio of HBF was less than 1 (0.88) compared with 11.89 for MSil. This affected the energy efficiency of milk yield in the 3 diets, with the D50 diet showing poorer performance due to similar milk yield compared with D0, but higher energy costs due to the inclusion of HBF. The production cost of HBF was about 4 times higher than that of farm-produced MSil, making feed costs for milk yield more expensive. Nevertheless, HBF can potentially improve income over feed costs if it increases milk yield enough to offset its higher production costs. Overall, the results suggest that the current practice of using HBF to replace high-quality feedstuffs as concentrates is likely to result in energy and economic losses.