Evaluation of slaughtering methods for turbot with respect to animal welfare and flesh quality

Experiments were carried out to characterise the composition and decomposition of 13 vegetable crop residues. There was a considerable range of composition, with 55␘f the dry matter being water-soluble in onion compared with only 15␒n wheat. The range of carbon/nitrogen ratio in the vegetable crops was narrow, between 9 and 24, compared with a C/N ratio of 58 in wheat. The decomposition of the residues could be described by the single-exponential equation Y = a be-k(t - d), where Y is the proportion of residue remaining at any thermal time day degrees above 0 °C, a is the proportion of residue remaining at the end of the experiment, b is the corresponding proportion of the degradable fraction, k is the rate constant for the decomposition process and d is a delay factor (in units of thermal time) which delays the start of the decomposition process. Y, a and b are all expressed as percentages on a weight basis and, by definition, a b must equal 100 at t = 0. The value of d is assumed to equal zero for all residues except those from leafy brassicas, for which it was set at 100. The half-life of crop residue decomposition ranged from 145 day deg for onion to over 1400 day deg for wheat. The decomposition rate constant (k) was related to the C and N contents (r = 0.84, p = 0.001), and the a parameter to the crop's lignin content (r = 0.74, p = 0.004).