Lighting and mortality rates in domestic fowl     

P. D. Lewis  T. R. Morris  G. C. Perry 《British poultry science》1996,37(2):295-300

1. Data from intermittent and conventional lighting trials were analysed to investigate the effect of daily illumination upon mortality during the laying period and in 49‐d‐old broilers.

2. Iiveability in laying hens was improved by the use of intermittent lighting: the degree of improvement was proportional to the reduction in daily illumination achieved by the intermittent programme.

3. The reduction in mortality with intermittent lighting in laying hens was not the result of intermittent lighting per se. Intermittent regimens which did not reduce daily illumination did not reduce mortality.

4. Mortality in both conventionally‐lit laying hens and 49‐d old‐broiler chickens increased with photoperiod.  相似文献   

Effect of constant and of changing photoperiods on age at first egg and related traits in pullets     

P. D. Lewis  G. C. Perry  T. R. Morris 《British poultry science》1996,37(5):885-894

1. The effects of constant photoperiods and of single (5 h) changes in photoperiod applied at 12 or 17 weeks of age upon age at first egg (AFE) were studied using ISA Brown and Shaver 288 pullets.

2. Birds reared from 2 d of age until after maturity on constant 10 h photoperiods matured 8 d earlier than birds reared on constant 8 h and 5 d earlier than the average for 13 or 18 h photoperiods.

3. A single increment in photoperiod from 8 to 13 h advanced AFE by 23 d (compared to 8 h constant day controls) when applied at 84 d, but by only 6 d when given at 119 d. An increase in photoperiod from 13 to 18 h advanced AFE by only 4 d, averaged across breeds and age at increase. A reduction in photoperiod from 13 to 8 h delayed AFE by 22 d when given at 84 d and by 16 d at 119 d. A similar 5 h reduction in photoperiod, but from 18 to 13 h, retarded maturity by 11 d in ISA Brown pullets, but only when given at 84 d, and delayed AFE in Shaver 288 by 12 d, but only when given at 119 d. This interaction may be partly explained by the different physiological stages reached by the two breeds when the photoperiod was changed.

4. Under constant daylengths cumulative food intake before first egg was positively correlated with photoperiod, but the early AFE for birds on 10 h photoperiods resulted in this group having the lowest cumulative food intake to first egg.

5. A 5 h increase in photoperiod at 84 d significantly reduced the food consumed to first egg, but had no effect when given at 119 d. A 5 h decrease in photoperiod generally increased the food consumed to first egg, but the effect was only significant when the daylength was reduced from 13 to 8 h at 119 d. Food intake to first egg in birds subjected to a change in photoperiod was highly correlated with AFE.

6. The data confirm that sexual development in growing pullets responds more to changes in photoperiod than to the absolute daylength, that changes made at different daylengths are not equivalent and that sensitivity changes with age.  相似文献   

British Columbia. Aspergillosis Outbreak in Stellar's jays (Cyanocitta stelleri) from central Vancouver Island          下载免费PDF全文

Machin K  Langelier KM  Lewis RJ 《The Canadian veterinary journal. La revue veterinaire canadienne》1993,34(4):247-248

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Electrochemical reduction of horse heart ferricytochrome c at chemically derivatized electrodes     

N S Lewis  M S Wrighton 《Science (New York, N.Y.)》1981,211(4485):944-947

Platinum or gold electrodes derivatized with an N,N'-dialkyl-4,4'-bipyridinium reagent can be used to reduce horse heart ferricytochrome c, whereas reduction doses does not occur at the "naked" electrodes. From 3 to 17.7 millimoles per liter, the reduction of ferricytochrome c is mass transport-limited at electrode potentials more negative than about -0.6 volt against a saturated calomel reference electrode. Data for the photoreduction of ferricytochrome c at derivatized p-type silicon photocathodes show directly that the rate of reduction is mass transport-limited. Use of derivatized electrodes may allow convenient manipulation and analysis of biological molecules that do not ordinarily respond at conventional electrodes.  相似文献   

Microbiological and histopathological features of canine acral lick dermatitis     

Shumaker AK  Angus JC  Coyner KS  Loeffler DG  Rankin SC  Lewis TP 《Veterinary dermatology》2008,19(5):288-298

The purpose of this study was to investigate microbiological and histopathological features of canine acral lick dermatitis (ALD). Microbial characteristics of ALD are poorly described in current literature. If infection is recognized, antimicrobial selection is usually empirical, based on appearance, cytology or surface culture, rather than deep tissue culture. It was hypothesized that cultures obtained from deep tissue would yield different results than predicted by surface culture and cytology, and that isolates from ALD have unpredictable susceptibility patterns showing resistance to antibiotics routinely administered for canine pyoderma. Biopsies were obtained from 31 lesions and submitted for aerobic, anaerobic and fungal culture, and histopathological evaluation. Surface aerobic culture and susceptibility and cytology were obtained for comparison in 22 dogs. Skin scrapings and dermatophyte culture were performed. Bacteria were isolated in 30 of 31 cases. Staphylococcus intermedius was isolated in 58% of deep cultures. Twenty per cent of deep isolates were methicillin-resistant Staphylococcus species. Forty-eight per cent of cases yielded organisms defined as multidrug resistant on deep culture. Only 57% and 55% of bacteria isolated from tissue culture were sensitive to amoxicillin-clavulanic acid and cefazolin, respectively. Cytology and superficial cultures did not correlate well with deep cultures. Surface culture predicted deep tissue isolates in eight of 22 cases. Microsporum gypseum was isolated from one dog. Histopathological features included acanthosis, follicular elongation, lymphoplasmacytic dermal inflammation, folliculitis, furunculosis, perihidradenitis, hidradenitis and vertical streaking fibrosis. Lesions associated with ALD warrant tissue bacterial cultures as the majority of cases yielded positive growth of bacteria differing from superficial culture and often resistant to empirical drugs.  相似文献   

Illuminance,sexual maturation,and early egg production in female broiler breeders     

Dr P.D. Lewis  R. Danisman  R.M. Gous 《British poultry science》2008,49(6):649-653

1. Broiler breeders were reared at an initial illuminance of 13, 21 or 44 lux and transferred at 20 weeks and a mean body weight of 2.06 kg to floor pens at 25, 55 or 71 lux, or to individual cages at various intensities between 3 and 138 lux.

2. Rate of sexual maturation was not significantly affected by the light intensity experienced during the rearing period, but was progressively accelerated by the provision of a brighter illuminance after 20 weeks, up to a ceiling of about 14 lux. There was no interaction between the pre- and post-20-week illuminance.

3. Cumulative egg numbers to 39 weeks were unaffected by illuminance in the rearing period, positively correlated with illuminance post 20 weeks up to an asymptote at about 8 lux, and highly correlated with age at sexual maturity. Peak rate of lay was both delayed and depressed at 3 lux.

4. It is concluded that the minimum light intensity required at bird-head height to achieve satisfactory photostimulation and an optimal peak rate of lay in broiler breeders is 10 lux, but that a higher illuminance would be prudent for broiler breeders kept in floor pen facilities to maximise nest-box usage.  相似文献   

Australian equine influenza: vaccine protection in the UK     

Bryant N  Rash A  Lewis N  Elton D  Montesso F  Ross J  Newton R  Paillot R  Watson J  Jeggo M 《The Veterinary record》2008,162(15):491-492

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Novelty causes elevated heart rate and immune changes in pigs exposed to handling, alleys, and ramps     

C.R.G. Lewis  L.E. Hulbert  J.J. McGlone   《Livestock Science》2008,116(1-3):338-341

The objective of the present research was to quantify the cardiovascular and physiological responses in pigs subjected to novel alleys and ramps. Ten test subject pigs were selected per treatment. The first (trained) group were trained to navigate a course including a ramp. Testing was daily for seven days. Once training was completed, the trained and control (naïve) groups were exposed to a fixed course, the course and ramp (both up and down) while heart rates, time, handling difficulty, and blood were collected to determine the innate responses. Heart rates of trained pigs were reduced significantly (P = 0.003) compared to naïve pigs travelling the same course. Both handling ease and handling time were significantly improved for the trained pigs (P = 0.03 and P = 0.01 respectively) compared to naïve pigs. Blood immune measures indicated reduced stress among trained pigs who had lower neutrophil numbers (P = 0.04) and lower total and average phagocytosis (P = 0.001 and P = 0.02) compared with naïve pigs. This study demonstrated that the exposure of pigs to a novel environment clearly causes a mild physiological response. Pigs are not inherently stressed by alleys and ramps, but rather novel experiences cause handling problems and a stress response and minimal training can reduce the stress experience for the pig.  相似文献   

Progressive encephalomyelopathy and cerebellar degeneration in a captive-bred snow leopard (Uncia uncia)     

Stidworthy MF  Lewis JC  Penderis J  Palmer AC 《The Veterinary record》2008,162(16):522-524

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Tibial osteotomies for cranial cruciate ligament insufficiency in dogs   总被引：2，自引：1，他引：1  

Kim SE  Pozzi A  Kowaleski MP  Lewis DD 《Veterinary surgery : VS》2008,37(2):111-125

Objective— To review the biomechanical considerations, experimental investigations, and clinical data pertaining to tibial osteotomy procedures for treatment of cranial cruciate ligament (CrCL) insufficiency in dogs.
Study Design— Literature review.
Methods— Literature search through Pub Med, Veterinary Information Network, Commonwealth Agricultural Bureau Abstracts, and conference proceedings abstracts (November 1977 to March 2007).
Results— Reported tibial osteotomy procedures attempt to eliminate sagittal instability (cranial tibial thrust) in CrCL-deficient stifles by altering the conformation of the proximal tibia. Functional stability can be achieved by decreasing the tibial plateau slope (cranial tibial closing wedge osteotomy [CTWO], tibial plateau leveling osteotomy [TPLO], combined TPLO and CTWO, proximal intraarticular osteotomy, chevron wedge osteotomy), altering the alignment of the patellar tendon (tibial tuberosity advancement), or both (triple tibial osteotomy). Clinical reports assessing the efficacy of these procedures frequently use subjective outcome measures, and the periods of follow-up evaluation are highly variable. Satisfactory results have been reported in most (>75%) dogs irrespective of the type of tibial osteotomy procedure.
Conclusions— Currently available data does not allow accurate comparisons between different tibial osteotomy procedures, or with traditional methods of stabilizing the CrCL-deficient stifle. Carefully designed long-term clinical studies and further biomechanical analyses are required to determine the optimal osteotomy technique, and whether these procedures are superior to other stabilization methods.
Clinical Relevance— Limb function in dogs with CrCL insufficiency can be improved using the currently described tibial osteotomy techniques.  相似文献