Vehicle design and thermal comfort of poultry in transit

1. Four second‐generation artificial chickens (Glorias) simulated the sensible heat exchanges, H, of pullets and end‐of‐lay hens which they accompanied throughout commercial transit in different sites of the loads.

2. Data from two summer and two winter journeys on each of 5 naturally‐ and 2 fan‐ventilated vehicles were used to derive general equations to predict H and temperature lift for each vehicle.

3. From these, air movement, V, within the crates was calculated together with predicted H at ambient temperatures to compare the thermal comfort of the vehicles.

4. All naturally‐ventilated vehicles were over‐ventilated in motion, with mean V ranging from 0.9 to 2.4 m/s within the crate, and maximum V of 6.0 m/s resulting in negligible temperature lift above ambient. Poorly‐feathered hens were, consequently, extremely cold‐stressed in winter. When stationary, vehicles with a central passage that enabled the ‘stack effect’ to operate were thermally comfortable provided V was kept low. Designs stocked over die whole floor area of the vehicle were too hot.

5. Fan‐ventilated vehicles had a similar range of H whether stationary or in motion. The mean V of 1 to 2 m/s of bird‐warmed air maintained satisfactory thermal conditions most of the time.

6. For current designs of poultry vehicle stocked at commercial rates, V should normally be between 0.3 and 1.0 m/s; air temperature near pullets or broilers should be 10.15°C and near poorly‐feathered hens 22–28°C. Suitable ventilation rates are likely to be in the range 100 to 600 m³ per hour. It is strongly recommended that appropriate temperature monitoring systems be fitted on all vehicles.     

Gastrointestinal transit times in normal and reovirus-inoculated turkeys

Brilliant pigment powder was used to measure minimum gastrointestinal transit times (GTT) in control and cloned-reovirus-inoculated turkey poults. Compared with controls, inoculated poults had longer GTT at 120 hr (P less than 0.05) but not at 24 and 72 hr after receiving a single oral dose of cloned reovirus. Reovirus inoculation was associated with failure to eat following a fasting period. Feces passed by reovirus-inoculated turkeys were more fluid and less well formed than normal.     

Determination of the transit rates in different sections of the pig's intestine

An experiment was carried out using pigs weighing approximately 30 kg. The animals were fitted with two re-entrant cannulas in duodenum and ileum. During a 5 day period the passage of digesta through duodenum and ileum as well as the excretion by urine and faeces was estimated, taking an aliquot of 5% for N analysis. Transit of digesta amounted to 12.4 ... 13.2. kg/d in the duodenum and 2.7 ... 3.6 kg/d in the ileum. The appertaining N passage rates were 36.8 ... 42.4 resp. 8.7 ... 11.2 g N/d, corresponding to 108 ... 120% and 27 ... 32% of the N intake. The transit rate of duodenal digesta was highest immediately after feeding (1.4 ... 1.5 kg/h), decreased thereafter strongly, reaching a second lower maximum of 0.85 ... 1.0 kg/h 2 ... 3 h after feeding and then going down to 0.3 ... 0.4 kg/h just before the next feeding. The daily mean value was about 500 g/h. Endogenous N content of duodenal digesta varied between 10% after feeding and 50% 6 ... 12 h after feeding, with an average of 18.1%. In contrast the endogenous N content of ileal digesta was relatively constant amounting about 42% during the whole day. These findings correspond with those found by other authors using other rations and other live weights of the pigs. They refer to a clear diurnal rhythm of digesta transit and to the enormous dynamics of absorption and secretion processes in the intestinal tract of pigs during digestion.(ABSTRACT TRUNCATED AT 250 WORDS)     

Thermal stress on chickens in transit

1. An artificial chicken, ‘Gloria’, was constructed to simulate heat exchanges of poultry during transport. Tests of the instrument in a wind tunnel showed it to have insulation properties similar to that of a live bird.

2. Gloria accompanied chickens in two types of transport modules, A (enclosed) and B (open). The average temperature difference between inside and outside the loaded vehicles when stationary and in motion were 14.0 and 7.6 for Type A and 8.8 and 6.0 for Type B. Average air movement while vehicles were in motion was 0.5 m/s for Type A and 3.3 m/s for Type B.

3. Measurements of sensible heat loss from Gloria at different temperatures and wind speeds were compared with published estimates of thermoneutral heat production and thermal insulation for well and poorly feathered chickens to estimate the range of thermal stresses likely to be experienced by chickens in transit.

4. The results showed that the combination of circumstances necessary to ensure thermal comfort for birds both at rest and in motion is very rare (e.g. only between 7 and 8°C for well feathered birds in enclosed vehicles). It is, however, possible to ensure thermal comfort over a wide range of ambient air temperatures by appropriate control of air movement within the vehicle whether at rest or in motion.     

Headroom requirements for horses in transit

Horses intended for slaughter in Western Canada are frequently transported in double-deck trailers, where headroom may be restricted. Poll and withers height was estimated from type photographs of various horse breeds. The headroom required by Canadian legislation and codes of practice may not be sufficiently restrictive to protect the welfare of sport type horses when transported.     

Effects of temperature and time in transit on polymerase chain reaction detection of feline herpesvirus DNA.

The purpose of this study was to report methods currently recommended by commercial laboratories for collecting, shipping, and processing of samples for feline herpesvirus type 1 (FHV-1) testing using polymerase chain reaction (PCR) and to determine the effect of temperature and time on the ability of 1 PCR method to detect FHV-1 DNA in experimental and clinical samples. Eleven laboratories offering FHV-1 PCR were surveyed. There was notable variation in sample types and shipping conditions recommended and PCR protocols used by these laboratories. Subsequently, using a single PCR method, FHV-1 DNA was detected in samples exposed to various temperatures within the laboratory. Finally, FHV-1 PCR was performed on paired clinical samples collected from 25 cats and shipped at ambient temperatures via US Postal Service (USPS) or with an ice pack via a courier. Samples sent by USPS were exposed to significantly longer transit time and arrived at significantly higher temperature than did samples sent by courier. Despite this, all sample pairs yielded concordant results when tested for FHV-1 DNA using this PCR method. Although it may not be necessary for samples collected for detection of FHV-1 DNA using this PCR method to be shipped under the most expedient or temperature-controlled conditions, this should be verified for a variety of PCR assays and sample types.     

Variations in blood flow to and from the bovine mammary gland measured using transit time ultrasound and dye dilution.

Blood flow across the lactating bovine mammary gland was measured by two techniques. The use of transit time flow probes appeared to give flows which correlated well with dye dilution in only one of five cows, although the relative changes in flow were similar between the techniques in four of the cows. Further studies were made on the effect of posture on mammary blood flow using both techniques. The crossover of venous blood from one side of the mammary gland was also studied using the dye dilution technique, and revealed large differences between animals and also with posture. These observations suggest that particular care should be taken when sampling blood from the milk vein of cows, if a representative sample is required. Changes in blood flow with posture may be indicative of a repartitioning of flow within the body, and the physiology of such a mechanism would be of interest in itself. The control of this mechanism may be useful in modifying blood flow to the mammary gland and thus milk yield, since blood flow is related to the level of milk production.     

The effect of assembly and transit stressors on plasma fibrinogen concentration of beef calves.

Plasma fibrinogen concentration was measured in beef calves at various points within the system presently used to assemble, market and transport calves from one production point to another in order to determine the effect of the stresses encountered. A short haul of 160 km immediately after weaning did not significantly elevate fibrinogen concentration above the pretransit values. Yearling steers transported 400 km and confined in unfamiliar surroundings for 15 h did have an elevated (P less than 0.01) concentration of fibrinogen, but this increase was not significantly different from that of steers which were confined but not transported, thus confinement may be a significant portion of the stress associated with transit. The change in plasma fibrinogen concentration during assembly and transit was dependent upon the farm from which the calves originated. The magnitude of the change in fibrinogen concentration as a result of assembly and transit varied between the years studied. In one year pretransit assembly for ten days resulted in a higher fibrinogen concentration before and after transit than assembly for four days, but no difference was noted between the two groups in the second year. Bovine plasma fibrinogen concentration does increase in response to the stresses associated with assembly and transit. The stress of fasting and housing in unfamiliar surroundings also increase bovine plasma fibrinogen concentration and are present in the assembly and transit system. These two stresses may account for a majority of the stress associated with marketing and transit. The response of beef calves to the marketing and transit system varied between years.     

Esophageal transit of capsules in clinically normal cats

OBJECTIVE: To evaluate the esophageal passage of capsules in clinically normal cats and determine the incidence of prolonged transit or entrapment. ANIMALS: 12 clinically normal adult cats. PROCEDURE: Esophageal transit of barium sulfate-filled capsules was evaluated fluoroscopically. Each cat was examined 3 times (36 examinations). Esophageal transit times were classified as normal (< or = 30 seconds) or prolonged (> 30 but < or = 240 seconds). Capsules were considered entrapped when transit times were > 240 seconds. RESULTS: Transit times were normal in 10 of the 36 (27.8%) examinations, whereas times were prolonged in 7 (19.4%) examinations. Capsules became entrapped in the midcervical region of the esophagus during 19 (52.8%) examinations. Following termination of each examination, cats with entrapped capsules were fed a small amount (0.5 to 1 ounce) of food; this resulted in passage of the capsule to the stomach. CONCLUSIONS AND CLINICAL RELEVANCE: The possibility of medication-induced esophagitis should be considered when orally administering ulcerogenic drugs to cats. It is recommended that a small volume of food be given following medications to ensure complete esophageal clearance.     

Evaluation of esophageal transit of tablets and capsules in 30 cats

We have reported tablet-induced focal esophagitis and esophageal stricture formation in cats. The proposed mechanism is thought to be abnormal esophageal tablet retention resulting in focal esophagitis with subsequent stricture formation. The objective of this study was to evaluate the passage of tablets and capsules when given alone (dry swallow) and when followed by a water bolus (wet swallow) to determine if this could, in part, explain the esophageal stricture formation we have observed in cats. Fluoroscopy was used to evaluate tablet or capsule passage after administration. The percentage of dry tablet swallows that successfully passed into the stomach was 0.0% at 30 and 60 seconds, 6.7% at 90 seconds, 13.3% at 120 seconds, 26.7% at 180 and 240 seconds, and 36.7% at 300 seconds. Wet tablet swallows successfully passed 90.0% of the time at 30 seconds, 93.3% of the time at 60 seconds, and 100.0% of the time thereafter. The percentage of dry capsule swallows that successfully passed was 16.7% at each time interval. Wet capsule swallows successfully passed 96.7% of the time at 30 seconds and 100% of the time thereafter. For each time interval, wet swallows achieved significantly greater percentage passage into the stomach when compared to dry swallows (P < .05). This study shows that tablets or capsules given by dry swallow have prolonged retention in the esophagus compared to those given by wet swallow. On the basis of this study, we recommend the routine administration of a water bolus to cats receiving tablets or capsules PO to facilitate esophageal clearance. This practice may help prevent medication-associated esophagitis or stricture formation.     

Use of breath hydrogen measurement to evaluate orocecal transit time in cats before and after treatment for hyperthyroidism.

Orocecal transit time was evaluated in 13 cats diagnosed with hyperthyroidism. Transit was determined by measuring the change in breath hydrogen and methane concentrations following oral administration of a nonabsorbable carbohydrate (lactulose). Transit times before and three to four weeks after treatment of the hyperthyroidism with radioactive iodine were compared. There was a significant prolongation of transit time, as determined by a change in hydrogen concentration, following correction of the hyperthyroidism (p = 0.034). Average transit times and standard errors were 27.7 +/- 3.7 minutes before treatment and 56.5 +/- 12.1 minutes after treatment. Methane was not detected in any of the samples. Hyperthyroidism appears to be associated with an accelerated small intestinal transit time in cats.     

Clostridium perfringens epsilon toxin inhibits the gastrointestinal transit in mice

Epsilon toxin produced by Clostridium perfringens type B and D is a potent toxin that is responsible for a highly fatal enterotoxemia in sheep and goats. In vitro, epsilon toxin produces contraction of the rat ileum as the result of an indirect action, presumably mediated through the autonomic nervous system. To examine the impact of epsilon toxin in the intestinal transit, gastric emptying (GE) and gastrointestinal transit (GIT) were evaluated after intravenous and oral administration of epsilon toxin in mice. Orally administered epsilon toxin produced a delay on the GIT. Inhibition of the small intestinal transit was observed as early as 1 h after the toxin was administered orally but the effects were not observed after 1 week. Epsilon toxin also produced an inhibition in GE and a delay on the GIT when relatively high toxin concentrations were given intravenously. These results indicate that epsilon toxin administered orally or intravenously to mice transitorily inhibits the GIT. The delay in the GIT induced by epsilon toxin could be relevant in the pathogenesis of C. perfringens type B and D enterotoxemia.     

Warm weather transport of broiler chickens in Manitoba. I. Farm management factors associated with death loss in transit to slaughter

This observational study was conducted to identify flock of origin level factors associated with mortality during transport to slaughter of 1 090 733 Manitoba broiler chickens in spring and early summer. The death loss in transit was 0.346% (3778 birds). Death loss on the farm of origin during the growing phase of production and bird body weight at slaughter were associated with increased mortality in-transit. Death loss during production significantly exceeded, while crowding of growing birds was significantly less than, European proposed animal welfare standards.     

Warm weather transport of broiler chickens in Manitoba. II. Truck management factors associated with death loss in transit to slaughter

This observational study was conducted to identify the cause of death and load level factors associated with mortality in 1 090 733 Manitoba broiler chickens transported to slaughter in spring and early summer. Death loss in transit was 0.346% and accounted for 19% of the total carcass condemnation. The death loss pattern was clearly bimodal, with a low death loss in 180 of 198 shipments. Cumulative death loss during the growing phase of production was consistently associated with increased transport mortalities in load level models and when comparing high death loss with low death loss truckloads. High ambient temperature at the time of slaughter and loading density of the truck were the major factors associated with exceptional death loss.     

Study of the behaviour, digestive efficiency and gut transit times of crib-biting horses

The spontaneous behaviour and the apparent digestibility of dry matter and fibre and transit times of digesta were compared in four normal horses and four crib-biters. A technique was developed for measuring total gut transit times (TGTT) by using single-stool analysis of the passage of radio-opaque polyethylene markers. Longer TGTT were recorded in the crib-biters than in the normal horses but the orocaecal transit times did not differ. The crib-biters rested less than the normal horses.     

Methoxydextran as an indicator of gastrointestinal transit in Japanese quail

The recovery of polyethylene glycol, a substance frequently used as an indicator of the dynamics in the liquid phase of intestinal chyme, is considerably influenced by the presence of trichloroacetic acid in certain applications. The suitability of (methoxy-14C)methoxydextrane as an intestinal indicator in the Japanese quail was tested in the study. After the administration of this indicator, the bird expires less than 1% of the substance in form of 14CO2. The recovery of labelled methoxydextrane is 98 +/- 7%. The distribution of the indicator within the segments of the gastrointestinal tract does not differ significantly from the distribution of (14C)polyethylene glycol 4000, measured in the absence of trichloroacetic acid. The transit of the labelled methoxydextrane into the jejunum did not reduce the radio-chemical purity of the isotope, as compared with its original purity before administration. A slight decrease was only recorded during the measurement of the cumulative excretion of the indicator for 72 hours, but this decrease has no influence upon the suitability of methoxydextrane as an intestinal indicator. (Methoxy-14C)methoxydextrane does not interact with trichloroacetic acid, whereas when polyethylene glycol is used as an indicator, the substance precipitates from the liquid phase just at the concentration commonly used for the removal of protein from biological samples.     

Morphological and acrosomal changes of canine spermatozoa during epididymal transit

Background

During epididymal transit, functional and structural modifications leading to full maturation enable male gametes to reach, recognize and fertilize the oocytes. In dogs, little is known on the modifications of spermatozoa during the passage in the epididymis. The aim of this study was to describe the motility, morphology and acrosomal patterns of canine spermatozoa retrieved from the epididymis caput, corpus and cauda.

Results

After the dilution required for the collection of epididymal content, sperm motility was significantly higher (P <0.0001) in the cauda compared to corpus and caput.Proportions of spermatozoa with normal morphology were significantly higher in corpus (P =0.02) and cauda (P <0.0001) compared to caput. Overall morphological abnormalities of the head and neck/midpiece were similar in the three different epididymal regions. A significantly increased prevalence of tail defects, mainly represented by single bent tails, was observed in the corpus compared to caput (P <0.0001) and cauda (P =0.006).Numbers of immature sperm with cytoplasmic droplets decreased from the proximal to the distal region of the epididymis. Particularly, proximal cytoplasmic droplets were more frequently found in spermatozoa collected from the caput epididymis than in the corpus (P <0.0001) and in the cauda (P <0.0001), whereas the occurrence of distal cytoplasmic droplets was higher in the corpus than in the caput (P =0.0003) and in the cauda (P <0.05).Significantly higher proportions of spermatozoa with intact acrosomes were retrieved from the cauda epididymis than from the caput (P =0.03) and the corpus (P =0.008). This difference was mainly due to a lower proportion of spermatozoa with abnormal acrosomes (mainly swollen acrosomes) rather than with absent acrosomes.

Conclusions

Canine spermatozoa undergo several modifications in the epididymis. The acquisition of progressive motility, migration of the cytoplasmic droplet and acrosomal reshaping lead to mature spermatozoa which are then stored in the cauda epididymis. From this site, spermatozoa can be retrieved and used in assisted reproductive techniques as a valuable tool for propagating genetic traits of high value individuals that dies accidentally or undergoes orchiectomy for medical purposes. Further investigations should be also focused on the potential use of spermatozoa recovered from other epididymal regions.