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J McNab

Publications and source records attributed to J McNab.

7 recordsLinked to original sources

A dose-response study with the feed enzyme beta-mannanase in broilers provided with corn-soybean meal based diets in the absence of antibiotic growth promoters.

An experiment was designed to assess the effects of graded levels of beta-mannanase on performance and body weight uniformity of male broilers provided with diets based on corn and soybean meal and devoid of antibiotic growth promoters or coccidiostats. Four dietary treatments contained 0, 50, 80, and 110 MU of Hemicell/ ton (where 1 MU = 10(6) enzyme activity units, 100 MU/ton is manufacturer's recommendation). Each treatment contained 15 pens with 40 birds/pen. Individual bird weights were determined on d 0, 21, and 42. From 21 to 42 d of age, feed intake for the 80 MU/ton treatment was significantly greater than the 50 MU/ton treatment. beta-Mannanase inclusion at 80 or 110 MU/ton induced improvements (P < 0.05) in weight gain (3.9 to 4.8%) and feed efficiency (3.5 to 3.8%) over the control, whereas inclusion of 50 MU/ton resulted in no significant benefit. There were no significant differences between 80 or 110 MU/ton. The experiment demonstrated that dietary inclusion of beta-mannanase at approximately 50 MU/ton is not sufficient for maximum response. Inclusion at 80 MU/ ton improved broiler gains and feed conversion and increasing to 110 MU/ton resulted in no significant additional response.

Animal Feed↗

European reference method for the in vivo determination of metabolisable energy with adult cockerels: reproducibility, effect of food intake and comparison with individual laboratory methods.

1. A common reference procedure adopted by several European laboratories to determine apparent metabolisable energy corrected to zero-nitrogen balance (AMEn) is described. 2. Reproducibility has been estimated by comparing results from 4 diets measured in 7 laboratories. The standard deviations between laboratories of dry matter, gross energy, Kjeldahl nitrogen and AMEn were respectively, on average, 11.29 g/kg, 0.242 MJ/kg, 1.56 g/kg and 0.380 MJ/kg dry matter; the corresponding coefficients of variation between laboratories were 1.27, 1.29, 4.39 and 2.92%. 3. Effect of food intake was tested by comparing AMEn from birds fed either 0.90 or 0.45 of ad libitum: the amount of food intake had a negligible effect on AMEn values. Endogenous energy losses corrected (EELn) or not (EEL) to zero nitrogen balance were estimated either by regression between excreted energy and ingested energy or in fasted and glucose-fed cockerels. EELn estimated by regression was, on average, 8.7 kJ/bird/d.; it was independent of diet composition. EEL and EELn determined in fasted or glucose-fed birds were higher than those determined by regression. 4. AMEn values measured by individual laboratory procedures were very close to those obtained by the reference method, except from laboratories using a tube feeding procedure, where deviations were probably a consequence of overestimated EEL.

Analysis of Variance↗

European reference method of in vivo determination of metabolisable energy in poultry: reproducibility, effect of age, comparison with predicted values.

1. Apparent metabolisable energy corrected to zero-nitrogen retention (AMEn) was measured using the European reference procedure in 9 European laboratories. Seven pelleted diets were evaluated. AMEn was measured with adult cockerels and young birds. 2. Between-laboratory standard deviations were for dry matter (DM) 12.5 g/kg, gross energy 0.085 MJ/kg DM, Kjeldahl nitrogen 0.768 g/kg DM, AMEn (adults) 0.256 MJ/kg DM, and AMEn (young) 0.337 MJ/kg DM. Corresponding coefficients of variation between laboratories were 1.42, 0.45, 2.15, 1.88 and 2.60% respectively. 3. AMEn values of experimental diets were always significantly lower when measured with young birds. This effect was more pronounced when diets contained added fat. 4. Tallow or soyabean oil were incorporated into two basal diets at 40 g/kg inclusion rate. No significant differences were observed between AMEn values of either diet with adults or young birds, suggesting that AMEn energy values of these fats are indistinguishable at this inclusion rate. 5. Similar AMEn values were obtained in young birds by estimating nitrogen accretion, either by the difference between intake and excreta nitrogen or by measuring body weight gain. Determined AMEn values were very similar to those predicted using three different regression equations.

Age Factors↗

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Academies and Institutes↗

The impact of a helicopter emergency medical services program on potential morbidity and mortality.

INTRODUCTION: The evaluation of the effectiveness of helicopter emergency medical services is currently a major focus of air transport research, and dispatch judgment likely will play a significant role in any research aimed at measuring outcome or impact. SETTING: Two rotor-wing programs in Alberta, Canada. METHODS: A panel of experts evaluated the effectiveness of a helicopter service in Canada. Four hundred sequential patient records were examined and categorized into four risk levels. Level 1 included patients who required critical intervention. Level 2 included patients in whom a major deterioration of vital signs could be expected. Level 3 patients were those for whom transport by an advanced life support ground unit would have been adequate. Level 4 was strictly for missions in which patient transport by any other means would have been impractical, such as remote locations (these cases were double-rated). RESULTS: Risk level 1 included 98 cases (24.5%); risk level 2, 266 cases (66.5%); risk level 3, 36 cases (9%); and risk level 4, 16 cases, two of which were rated level 1, 11 rated level 2, and three rated level 3. CONCLUSION: The results indicate that in 91% of the reviewed cases, helicopter transport was appropriate, representing a reasonable and judicious use of a helicopter emergency medical service.

Air Ambulances↗