José Luis Guzmán, Francisco de la Vega, Luis Ángel Zarazaga, Anastasio Argüello and Manuel Delgado-Pertíñez
The viability of conventional goat farms, such as the native Payoya dairy goat, could be improved by switching to organic production, but product quality needs to be ensured. The present work assesses the carcass and meat quality of Payoya kids raised under conventional and organic grazing-based systems. Twenty-four kids (12 males, 12 females) were selected from each system (n = 48). The slaughter live weight (8.52 vs. 8.28 kg), cold carcass weight (4.44 vs. 4.29 kg) and farm dressing percentage (51.7 vs. 50%) of the conventionally raised kids were significantly higher than those of the organic kids. The shoulder (first category) (21.7 vs. 22.3%) and long leg (32 vs. 32.9%) percentages were lower in the conventional than in the organic kids. The percentage contribution of the intermuscular fat (10.70 vs. 8.11%) to the shoulder weight was greater in the conventional kids, while the percentages of muscle (59.7 vs. 57.2%) and bone (24.7 vs. 22.8%) were higher in the organic kids. For the chemical composition, there were only differences between the two sexes in the percentage of fat (6.64 and 7.99% on dry matter, for male and female, respectively). For rheological variables, only differences were found in the water holding capacity (% water expelled), the meat of the organic females had a higher value (17%) than that of the conventional females (14%). For the meat colour, the conventional male kids returned the highest values for C* and Hº (14.32 and 64.34, respectively). Farms following conventional grazing-based management could easily switch to organic production. Most of the meat and carcass quality variables studied were very similar across the systems.
Carlos Rodríguez, Ernesto Aranda-Escolástico, María Guinaldo, José Luis Guzmán and Sebastián Dormido
This paper proposes a new method for the analysis of continuous and periodic event-based state-feedback plus static feed-forward controllers that regulate linear time invariant systems with time delays. Measurable disturbances are used in both the control law and triggering condition to provide better disturbance attenuation. Asymptotic stability and L2-gain disturbance rejection problems are addressed by means of Lyapunov–Krasovskii functionals, leading to performance conditions that are expressed in terms of linear matrix inequalities. The proposed controller offers better disturbance rejection and a reduction in the number of transmissions with respect to other robust event-triggered controllers in the literature.