ABSTRACT
Two 2 × 2 factorial experiments were conducted to investigate the interaction between cereal type (wheat v. barley) and exogenous enzyme supplementation (with or without) on odour and ammonia emissions (experiment 1) and growth performance (experiment 2) in grower-finisher pigs. The enzyme supplement used contained endo-1, 3 (4) - ß- glucanase (EC 3.2.1.6) and endo-1, 4 - ß-xylanase (E.C 3.2.1.8). The diets were formulated to contain similar levels of net energy (9.8 MJ/kg) and lysine (10.0 g/kg). The experimental treatments were as follows: (1) wheat-based diet, (2) wheat-based diet containing a ß-glucanase and ß-xylanase mixed enzyme supplement, (3) barley-based diet and (4) barley-based diet containing a ß-glucanase and ß-xylanase mixed enzyme supplement. In experiment 1, the diets were offered to the pigs for 23 days in sealed pens (eight pigs per pen) and this was repeated four times (n = 4). Odour and ammonia emissions were measured on days 9, 11, 14, 16, 21 and 23 of each replicate period. Odour samples were collected in 20-l Nalophan bags and analysed for odour concentration using an ECOMA Yes/No Olfactometer. Ammonia concentrations in the ventilation air were measured using Dräger tubes. In experiment 2, 220 pigs were group fed in mixed sex pens using single-space feeders (11 pigs per feeder, six boars and five gilts) (n = 5). There was a cereal × enzyme interaction in odour emission rates, ammonia emissions and selected microbial populations in the caecum and colon (P < 0.05). The addition of an enzyme supplement to the barley-based diet increased both odour and ammonia emission, however the addition of an enzyme to the wheat-based diet decreased ammonia emission rates and had no effect on odour emission. Pigs offered the unsupplemented barley-based diet had a significantly (P < 0.05) lower population of Enterobacteriaceae spp. and a higher population of Bifidobacteria spp. compared with enzyme-supplemented barley diets. However, there was no effect of enzyme supplementation in wheat-based diets. In the performance experiment, neither cereal type nor enzyme inclusion had an effect on pig performance or carcass characteristics. In conclusion, the inclusion of an enzyme mix to barley-based diets increased odour and ammonia emissions, while the addition of an enzyme mix to wheat-based diets decreased ammonia emissions.
ABSTRACT
The use of lasers has simplified, shortened, and made less traumatic many surgical procedures. It has also increased the range of conditions amenable to treatment in all of the surgical specialties. There are, however, potentially serious hazards associated with the surgical use of lasers. The most serious hazards are explosions and fire, particularly during surgery on the airway, where flammable material, i.e., the endotracheal tube, high oxygen concentrations, and the laser, which is a high energy ignition source, are in close proximity. This report deals with techniques of anesthesia delivery that minimize the risks to the patient and operating room environment consequent on laser use in the airway. Laser use elsewhere in or on the body is associated with no greater danger than the use of electrocautery and requires no special anesthetic adaptation.
