The experiment compared four different space allowances for growing pigs housed on fully slatted floors. Space allowance {A m 2 ) was defined in relation to live weight (M kg) of the pigs according to the equation A = kM 067 , using values for the constant (it) of 0-024, 0-027, 0-030 and 0-034. Six replicate pens of 12 pigs were housed on each treatment in a controlled environment building. Food was given ad libitum and from 34 kg until slaughter at 85 kg pigs were individually weighed each week and the pen size was adjusted according to the appropriate equation. Increasing space allowance increased live-weight gain (844, 862, 883, 897 (s.e.d. 14-4) g/day). Differences in killing-out proportion reduced the effect on final carcass weight (63-3, 63-9, 64-1, 64-5 (s.e.d 0-82) kg). Daily food intake was unaffected by treatment but food conversion ratio was significantly poorer at the lowest space allowance (2-70, 2-56, 2-60, 2-59 (s.e.d. 0-043) kg/kg). Economic analyses of the results indicated an adverse effect on profitability of space allowance less than that defined by the equation y4(m 2 ) = 0-027 A/ 067 (kg). A minimum allowance defined by the equation A(m 2 ) = 0-030 A/ 067 is recommended in commercial practice for pigs in fully slatted housing.

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The effects of light illuminance and wavelength on the growth of male and female broiler chickens from day-old to 8 weeks of age were studied. Different coloured lights, at equal illuminance and peak wavelengths of 425, 525 and 610 nm and a broad-spectrum white light of median wavelength 560 nm had no significant effect on the growth rate or cumulative food intake of birds of either sex.The performance of male broilers was unaffected by light of different illuminances, equal to 0-7, 3-0, 15-0 and 46-5 lux. The weight gain of female broilers, adjusted for food intake, was progressively depressed at illuminances above 3 lux.There is probably no commercial advantage in using broad-spectrum white light at intensities above 3 lux.

Preweaning mortality generally accounts for 10-20% of all piglets born alive. A better understanding of the reasons for this mortality should help reduce losses.Data from 493 litters born over a period of 18 months were analysed to investigate the timing, apparent cause and predisposing factors of piglet mortality.To examine in more detail the way in which deaths occur a continuous video recording was made for the first 48 h. after farrowing for 31 litters. The way in which any deaths happened and the events leading up to them were then examined in detail.

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