Watery Droppings Research Articles

Diagnostic Detection of H7N3 Low Pathogenicity Avian Influenza in a Commercial Game Bird Flock.

Low pathogenicity avian influenza (LPAI) H7N3 was diagnosed in a flock of commercially raised Japanese quail (Coturnix japonica) breeder hens. The birds were submitted with an initial complaint of a drop in egg production and watery droppings. Initial PCR testing of the flock for avian influenza (AI) was negative; however, mortality started increasing drastically, prompting further examination and the submission of more birds to the diagnostic laboratory. On antemortem examination, the birds appeared lethargic, with ruffled feathers, and had labored breathing. Gross examination revealed poor body condition, moderate dehydration, splenomegaly, ovarian regression, and airsacculitis. Several hens produced thin-shelled and shell-less eggs. Microscopically, lymphoplasmacytic encephalitis with neuronal cell necrosis, fibrinoheterophilic pneumonia, and splenic lymphoid depletion with amyloid deposition were seen. AI virus was detected in a follow-up submission and characterized as LPAI H7N3. Quail are a species of interest in the pathobiology of avian influenza viruses, underlined by the ability to serve as an amplification host.

ALLETHRIN INDUCED TOXICOPATHOLOGICAL ALTERATIONS IN ADULT MALE ALBINO RATS

This study was designed to investigate the allethrin induced toxico-pathological changes in adult male albino rats. A total of 60 adult male albino rats were divided randomly into 4 equal groups. Group A was treated as control while group B was given Allethrin @ 0.5g/kg, group C @ 1.0g/kg and group D @1.5g/kg body weight respectively, orally once at day 14 of experiment. Dullness, erected hairs, alopecia, less response towards feed and water, watery droppings, tremors, convulsions and coma were more prominent signs in treated groups. Feed intake and body weight was decreased in all treated groups. Acute mortality was seen in group C and D. The total erythrocyte and leukocyte count, hemoglobin concentration and packed cell volume (P≤0.05) was deviated from normal in all the groups treated with allethrin. Histopathologically, kidneys exhibited condensed nuclei, necrotic tubules and congested renal parenchyma. In liver, vacuolar degeneration in nucleus and cytoplasm was observed. Micro nucleated lymphocytes were also evident in group D treated with highest dose of allethrin. In conclusion, allethrin induced dose and time-dependent toxico-pathological effects in adult male albino rats were observed and presented.

Occurrence and Role of Selected RNA-Viruses as Potential Causative Agents of Watery Droppings in Pigeons.

The diseases with watery droppings (diarrhea and/or polyuria) can be considered some of the most severe health problems in domestic pigeons of various ages. Although they do not always lead to bird death, they can contribute to poor weight gains and hindered development of young pigeons and, potentially, to poor racing results in sports birds. The gastrointestinal tract disorders of pigeons may be of various etiology, but some of the causative agents are viral infections. This review article provides information collected from scientific reports on RNA-viruses belonging to the Astroviridae, Picornaviridae, and Coronaviridae families; the Avulavirinae subfamily; and the Rotavirus genus that might be implicated in such health problems. It presents a brief characterization, and possible interspecies transmission of these viruses. We believe that this review article will help clinical signs of infection, isolation methods, occurrence in pigeons and poultry, systemize and summarize knowledge on pigeon enteropathogenic viruses and raise awareness of the importance of disease control in pigeons.

Lead Levels in the Eggs of a Chicken With Lead Toxicosis

A 1.5-year-old Polish hen was presented with a history of watery droppings and poor vent tone. Results of diagnostic tests revealed blood lead at levels considered to be toxic. Chelation therapy was started with calcium ethylenediaminetetraacetate. The hen was laying eggs before, during, and after chelation therapy. Eggs were tested for the presence of lead by combining yolk and albumen together. Before chelation therapy, the level of lead in the egg tested was 14 μg. Two days after the end of chelation therapy, results of a second blood lead test revealed a drop to nontoxic levels. No lead was detected in the combined yolks and albumen of eggs collected 7-11 days after the end of chelation therapy. Four weeks after the end of chelation therapy, no lead was identified in the shells of tested eggs.

Pathogenic potentials and shedding probability of Salmonella enterica serotype Kentucky in experimentally infected backyard chicken

Objective: Salmonella is a widely-reported zoonotic bacterial pathogen and human infection is mostly attributed through direct or indirect contact with chickens. Salmonella Kentucky (S. Kentucky) is one of the motile serovars which has recently been identified from both poultry and human samples in Bangladesh. This study was conducted to assess its pathogenic potentials and shedding probability in backyard chicken. Materials and methods: We infected 22 backyard chickens orally, each with 106 cfu of Salmonella Kentuckey, which were then observed for 23 days to enlist clinical signs, gross and histo-pathological changes. Polymerase chain reaction (PCR) for Salmonella was applied on some representative samples to identify the presence of Salmonella. Results: Four chickens were sacrificed and the internal organs were examined to observe gross and microscopic tissue changes. Some reactive changes were seen in spleen during prolonged course of infection. The probability of S. Kentucky shedding was 77% (95%; CI 54-90%) on DPI 2, 41% (95%; CI 21-60%) on DPI 12 and 13% (95%; CI 3-31%) on DPI 21. The survival probability of the infected chickens was 50% (95%; CI 28-68%) on DPI 6, 32% (95%; CI 14-51%) on DPI 15 and 14% (95%; CI 3-31%) on DPI 23. Conclusion: Zoonotic S. Kentucky strain of human non-typhoidal clinical cases of gastroenteritis has potentials to produce clinical signs such as reduced feed uptake, watery or pasty fecal droppings and lesions, such as catarrhal enteritis and typhlitis.

Analysis of different toxic impacts of Fipronil on growth, hemato-biochemistry, protoplasm and reproduction in adult cockerels

Fipronil (FIP), a broad-spectrum phenylpyrazole, is extensively used across the globe to control pests and as a veterinary drug. Incorrect use of FIP leads to contamination of soil and water ultimately causes toxic effects in non-target organisms. Therefore, the present experimental study was aimed to determine the deleterious effects of sub-lethal concentrations of FIP in adult cockerels. FIP mixed in corn oil was administered orally in different groups as follows: A = control, B = 1.5 mg/kg, C = 2.5 mg/kg, D = 3.5 mg/kg and E = 4.5 mg/kg body weight for 60 d. Signs of toxicity like anemic comb, tremors, gasping and watery droppings were evident in birds exposed to higher levels. The feed intake, body weight, absolute and the relative weight of different organs were significantly (p ≤ .05) decreased in birds exposed to higher concentrations. Histomorphometric analysis of small intestine in birds exposed to higher levels of FIP showed decreased villus height and crypt depth of duodenum, jejunum and ilium. Histologically, congestion in liver, pyknosis of hepatocytes and congestion in kidneys along with necrosis of tubular epithelial cells and increased urinary spaces were observed in birds. Microscopically, seminiferous tubules exhibited necrotic nuclei of the spermatids, arrest of process of spermatogenesis and admixture of necrotic cells in testes of exposed birds. Moreover, significantly (p ≤ .05) decreased hematological parameters such as erythrocytes counts, hemoglobin concentrations and hematocrit, while increased total leukocyte counts were recorded in birds. Furthermore, significantly (p ≤ .05) increased concentrations of serum urea, creatinine, alanine aminotransferase, aspartate aminotransferase and cardiac isoenzyme (CK-MB), while reduced serum testosterone levels were recorded in birds. Results revealed significantly (p ≤ .05) increased frequency of micronuclei in erythrocyte and bone marrow cells. The findings of our study demonstrated that FIP induces deleterious impacts on multiple tissues in birds even at low doses.

Sodium arsenate and/or urea differently affect clinical attributes, hemato-biochemistry and DNA damage in intoxicated commercial layer birds

An experimental study was ascertained in birds to assess the toxicological effects of arsenic (sodium arsenate) and urea alone or in different combinations. After two weeks of acclimatization, all the birds were randomly divided into six equal groups (T0–T5) each containing 15 birds. Arsenic (A) and urea (U) was given to chickens (mg/kg body weight) daily for 39 days as follow: T1 (A10U0.5), T2 (A15U0.75), T3 (A20U1.0), T4 (A25) and T5 (U1.5). Various signs of toxicity such as depression, dullness, tremors, watery droppings, gasping, anemic comb and wattle were prominent in treated birds. Feed consumption and body weight of experimental birds treated with arsenic and urea decreased significantly. The absolute and relative weights of different visceral organs such as heart, liver, kidneys, spleen and bursa of treated birds were decreased significantly. Histologically, tissue sections of liver showed necrosis of hepatocyte, fatty degeneration and mild congestion. Microscopically, necrosis of renal tubular epithelial cells, congestion and increased urinary spaces in kidneys, mild congestion in spleen and vacuolation in bursa of Fabricius of treated birds was evident. Hematological assessment indicated significant decrease in hemoglobin, erythrocyte count, hematocrit percent and mean corpuscular hemoglobin concentrations. Results revealed significant increase in serum cardiac iso-enzyme, triglycerides, cholesterol and malondialdehyde concentration in treated birds as compared to untreated birds. A significant decrease in serum total proteins while increased concentrations of alanine aminotransferase, asparatate aminotransferase, lactate dehydrogenase, creatinine and urea was estimated in treated birds. Significantly increased frequency of micronucleus and nuclear abnormalities in erythrocytes was recorded. It was concluded that arsenic and urea in combinations even at low levels affect clinical attributes, hemato-biochemical parameters and erythrocyte morphology in layer birds.

Inclusion body hepatitis associated with an outbreak of fowl adenovirus type 2 and type 8b in broiler flocks in South Africa.

Inclusion body hepatitis is an acute disease of chickens ascribed to viruses of the genus Aviadenovirus and referred to as fowl adenovirus (FAdV). There are 12 FAdV types (FAdV1to FAdV8a and FAdV8b to FAdV11), classified into five species based on their genotype (designated FAdVA to FAdVE). A total of 218 000 chickens, 2-29 days of age, were affected over a 1-year period, all testing positive by microscopy, virus isolation and confirmation with polymerase chain reaction (PCR). Affected birds were depressed, lost body weight,were weak and had watery droppings. Pathological changes observed during necropsy indicated consistent changes in the liver, characterised by hepatomegaly, cholestasis and hepatitis. Lesions were also discernible in the spleen, kidney and gizzard wall and were characterised by splenomegaly, pinpoint haemorrhages, nephritis with haemorrhage,visceral gout and serosal ecchymosis of the gizzard wall. Histopathological lesions were most consistently observed in the liver but could also be seen in renal and splenic tissue. Virus isolation was achieved in embryonated eggs and most embryos revealed multifocalto diffuse hepatic necrosis, with a mixed cellular infiltrate of macrophages and heterophils(necro-granulomas), even in the absence of macroscopic pathology. Virus isolation results were verified by histopathology and PCR on embryonic material and further characterised by nucleotide sequence analysis. Two infectious bursal disease virus isolates were also made from the Klerksdorp flock. Nucleotide sequence analysis of the L1 hexon loop of all the FAdV isolates indicated homology (99%) with prototype strains P7-A for FAdV-2, as well as for FAdV-8b.

Clinico-hematological and tissue changes induced by butachlor in male Japanese quail (Coturnix japonica)

The present experiment was executed to determine the pathological effects induced by concurrent feeding of butachlor (chloroacetanilide herbicide) in male Japanese quail. For this purpose mature male quail about 4–5weeks of age were procured from the local market and randomly divided into six equal groups (A–F). Butachlor was mixed in corn oil and administered orally for 30days using crop tube. Four birds from each group were killed at day 10, 20 and 30 of the experiment and blood was collected with and without anticoagulant. The birds in groups (A–D) did not reveal any clinical and behavioral alterations. Clinical signs like watery droppings, dullness, ruffled feather, depression, decrease frequency of crowing, mounting with pen mates and foam production were observed. Maximum intensity of these clinical signs and behavioral alterations were observed in group F throughout the experiment. Significant lower values of erythrocytes, hematocrit percent and hemoglobin were recorded. Significantly increased numbers of erythrocytes with micronuclei, lobed and notched nuclei were observed. Histopathologically, enlarged intertubular space, fewer numbers of round spermatids, necrotic spermatids and admixture of dead spermatids were observed in testes. The results revealed significant increase in serum lactate dehydrogenase (LDH), aspartate transaminase (AST), alanine transaminase (ALT) and urea concentrations. The results of present experimental study indicated that butachlor induces hematobiochemical and testicular changes in birds.

Gross and Histopathological Evaluation of Runting Stunting Syndrome in a Broiler farm

A poultry farmer reported a case of abnormal growth among 17 to 25 days old broilers chicks in his farm to the poultry Unit, Faculty of Veterinary Medicine, University Malaysia Kelantan. The housing system was a modified closed type with a total of 130,000; 10,000 birds per house. The clinical signs observed were damp feathers which are poorly developed, stunted growth, watery droppings containing undigested feeds and unequal sizes of chicks. Post mortem examination was conducted on thirty culled chicks and the gross lesions observed were; corrugated intestines (83.3%) with some being thin and translucent with poorly digested feed within the lumen, atrophied pancreas (70.0%) and liver (66.7%), slightly atrophied thymus (33.3%), dilated proventriculus (50.3%) and enlarged gall bladder (43.3%). Histopathological evaluation of the intestine and pancreas showed lesions such a cystic dilation and degeneration of intestinal crypts, degeneration of the pancreas with vacuolation in the paranchyma and atrophy of the acinar cells. Based on the clinical signs observed, post mortem lesions and the histopathological findings, the case was diagnosed as Runting Stunting Syndrome (RSS). There is no treatment for this syndrome and it can only be prevented through good management practices

Inclusion body hepatitis (IBH) outbreak associated with fowl adenovirus type 8b in broilers

The causative agent of inclusion body hepatitis (IBH) was identified as fowl adenovirus (FAdV) type 8b, a member of the Fowl adenovirus E species, based on PCR results of adenoviral polymerase and the hexon gene in an outbreak of acute mortality that affected a broiler flock of 12,000 animals. In two waves of elevated mortality rate, a total of 264 chickens were found dead. Affected birds showed ruffled feathers, depression, watery droppings and limping. The most common pathological lesions seen on necropsy were pale, swollen and friable livers. On histological examination, acute hepatitis characterized by necrosis of hepatocytes, with large basophilic intranuclear inclusion bodies, were observed. In addition, infectious bursal disease virus and infectious bronchitis virus were detected in the same flock.

Study of potential toxic effects of acetylsalicylic acid upon short-term repeated oral administration in chickens

In avian medicine, non-steroidal anti-inflammatory drugs are used in the treatment of various musculoskeletal inflammatory disorders. Although usage of acetylsalicylic acid suggested in birds and continued to be use in the treatment of certain clinical conditions nevertheless, the studies relating to the potential toxic effects of this drug upon repeated oral administration in birds are rarely reported. Thus, a study was designed to assess the toxic effects of acetylsalicylic acid in chickens. For the purpose of the study two groups (n=10) of broiler chickens were used. Group I served as normal control and received distilled water (1.0 ml/day, p.o.) and group II received acetylsalicylic acid (10 mg/kg/day, p.o.) daily at 24 h interval for five consecutive days. Clinical signs of toxicity such as hypo activity, disinclination to move and watery droppings accompanied with blood mixed mucous observed in group II birds. These birds showed significant (P<0.01) decrease in serum total protein concentration and significant (P<0.05) decrease in the total erythrocyte count, haemoglobin concentration, per cent PCV and platelet count. Besides, gross and histopathological lesions were observed in small intestine. Thus, based on the results, it was concluded that acetylsalicylic acid (10 mg/kg) upon repeated oral administration daily for a period of five days found toxic in chickens.

Effects of feeding urea and copper sulphate in different combinations on live body weight, carcass weight, percent weight to body weight of different organs and histopathological tissue changes in broilers

The study was carried out on a total of 100 broiler chicks divided into six equal groups at day 7 of age. Birds were fed copper sulphate and urea in different combinations for up to 37 days and then the birds of all the groups were fed plan feed for one week. The general signs were an increased water intake, ruffled feathering, watery droppings along with salivation in treatment groups. These signs were mild in groups fed low level of urea, while were severe in fed higher levels of these compounds together. Mild to moderate gross changes were observed in the birds of group B, C and D, while more pronounced changes were seen in birds of group E and F. In the latter groups, the liver was pale to yellowish and fragile. Kidneys were enlarged, swollen, congested and sometimes hemorrhagic. Histologically, mild cytoplasmic vacuolation and condensation/pyknosis or disappearance of the nucleus in the cells of the liver and kidney were the salient changes observed in the treatment groups, those were severe in birds fed higher levels of the two compounds. Changes in lungs were congestion and edema. Changes in the bursa of Fabricius were mild cytoplasmic vacuolation, cell depletion and chromatolysis. The live and carcass weights were lower in broilers fed higher levels of both copper and urea than the control group. The weights of kidney and heart were higher in birds fed higher levels of both of the compounds than the control group. It can be concluded from the present study that urea above 2% and copper sulphate above 1 gm in combination cause tissue damage, especially the liver and kidneys.

Ulcerative Enteritis-Like Disease Associated with Clostridium perfringens Type A in Bobwhite Quail (Colinus virginianus)

Ulcerative enteritis-like disease due to Clostridium perfringens type A was attributed as the cause of mortality in excess of 50% in a flock of 1000, 10-to-16-wk-old bobwhite quail (Colinus virginianus). Clinical signs in these birds ranged from sudden death to listlessness, depression, watery white droppings, ruffled feathers, loss of weight, and death in a few days. Necropsy of 30 birds revealed multiple deep ulcers of the mucosa throughout the small intestine and ceca, some with perforation and subsequent coelomitis (peritonitis). The livers in some birds contained white foci of necrosis, and many birds had enlarged and congested spleens. Microscopic lesions included multifocal severe fibrinosuppurative ulcerative enteritis associated with large numbers of rod-shaped gram-positive bacteria, and necrotizing hepatitis with or without rod-shaped bacteria. Anaerobic culturing of the intestine and liver yielded pure cultures of C. perfringens. The C perfringens isolates were of genotype A and were polymerase chain reaction-positive for alpha toxin and for cpb2, the structural gene for beta2 toxin. Repeated attempts to isolate C colinum by using a specialized medium containing 8% horse plasma were not fruitful, suggesting that the enteritis and hepatitis in these birds were produced by C pefringens. Retrospective examination of records of quail submissions to the California Animal Health and Food Safety Laboratory System over 16 yr revealed at least nine quail submissions in which isolation of C. perfringens from the liver, intestine, or both was associated with ulcerative enteritis and hepatitis in quail. This is the first description of ulcerative enteritis-like disease in quail associated with C perfringens. Final conclusions await experimental reproduction of the disease.

Pathological effects of gentamicin administered intramuscularly to day-old broiler chicks

The aim of this experimental study was to investigate the pathological effects of gentamicin in birds. Broiler chicks at 1 day of age were intramuscularly administered gentamicin at dose levels varying from 0 to 180 mg/kg. Clinical signs comprising of depression, decreased feed consumption, increased water intake, loose watery droppings and reduced body weights appeared in a dose-related manner in chicks administered 30 mg/kg or higher dose levels. Mortality was 0% and 20% in chicks given 40 mg and 50 mg/kg gentamicin. It increased in a dose-related manner and was 100% in 100 mg/kg or higher dose groups. The LD50 calculated at total deaths in 5 weeks duration was 77.56 mg/kg. Kidneys and livers of chicks given 50 mg/kg or higher doses of gentamicin were congested, enlarged and had hemorrhages on the surfaces. Microscopically kidneys exhibited acute tubular necrosis. Livers showed fatty change, vacuolar degeneration, necrotic areas and cellular infiltration around portal triads. Serum total proteins and albumin decreased while creatinine and ALT increased in chicks given 20 mg/kg and higher doses. The no observable effect level (NOEL) of a single intramuscular administration of gentamicin in day-old broiler chicks was 10 mg/kg body weight.

Investigation on Infectious Bursal Disease Outbreak in Debre Zeit, Ethiopia

2 Abstract: An outbreak of infectious bursal disease affecting 20-45 days old broiler and layer chickens was investigated for the first time in Ethiopia in the months of March and April 2002. Death of chickens started at the 30 day of age and continues to the 55 day. The mortality rate of the disease in different poultry houses th th ranges from 45-50 %. The over all mortality rate was 49.89%. Broiler mortality was 56.09% while 25.08% for layer chickens. The major clinical symptoms were sudden drop in feed and water consumption, sever depression, white watery droppings and mass death. Grossly, hemorrhages in leg muscles, degeneration of the pectoral muscle, white mass (Urate deposit) in kidneys and in Cloaca were frequently observed during post mortem examination. In addition, haemorrhagic & swollen bursas filled with straw colored fluid were identified in few cases. Histopathology revealed hyperplasia of the reticulo-endothelia cells and interfollicular tissue of affected bursa of fabricius. The Agar Gel Immuno Diffusion (AGID) Test detected precipitating antibodies against Infectious Bursal disease virus in sera collected from convalescent chicken. Virus cytopathic effect was observed in chicken fibroblast cells (CFC) inoculated with bursa and spleen tissue suspension of sick chicken. Vaccination failures were encountered to Newcastle disease vaccine (Clone 30). This paper probably is the first to report the occurrence of infectious bursal disease in Ethiopia as the country has been known to be free from Infectious Bursal Disease(IBD).

Diseases of the digestive tract of psittacine birds

MEMBERS of the order Psittaciformes are prone to many infectious and husbandry-related conditions and, like many birds, they frequently mask any signs of illness until very late in the course...

Further Observations on Enterovirus Infection in Specific-Pathogen-Free Turkey Poults

To evaluate sites of enterovirus replication and to characterize the resulting lesions, twenty 4-day-old specific-pathogen-free (SPF) turkey poults were orally inoculated with an enterovirus. Twenty uninoculated SPF poults served as controls. Inoculated poults were depressed, had ruffled feathers, watery droppings, and pasted vents. Gross lesions were dilated thin-walled ceca with foamy yellow fluid. Immune electron microscopy of the gastrointestinal tract contents revealed an enterovirus with an average diameter of 23.5 nm. Immunoperoxidase and indirect immunofluorescent antibody assays revealed intracytoplasmic staining in enterocytes of the duodenum, jejunum, and ileum. This correlated with the scanning electron microscopy findings, which showed the most lesions in the jejunum and ileum. The ileum had prominent cell outlines because of rounded, distinct, bulging epithelial cells. Histopathology revealed slight shortening of villi and increased crypt depth in the intestines of inoculated poults. Our findings indicate that the small intestine is the site of turkey enterovirus replication, and the gross and microscopic changes observed are determined to result from viral damage to the enterocytes.

A Syndrome in Commercial Turkeys in California and Oregon Characterized by a Rear-Limb Necrotizing Skeletal Myopathy

A necrotizing skeletal myopathy of rear limbs was diagnosed in 17 flocks of commercial turkeys. The mean mortality attributed to the myopathy was 2.29% (range = 0.13-9.7%) over a mean period of 9.6 days (range = 6-14 days). The mean age of the birds at the time of onset was 7.4 weeks (range = 4-10.5 weeks). Clinically, birds experienced an episode of watery droppings and high-pitched crying, followed by rear-limb paresis or paralysis. Creatine kinase and aspartate aminotransferase were markedly elevated in birds with the myopathy. Grossly, a few birds had pale streaking in the muscles of the thighs and legs. Histologically, acute and subacute degeneration was present in myofibers of the legs, abdomen, thighs, back, and tail. The subacute lesion was characterized by marked sarcolemmal cell proliferation. Feed analyses ruled out selenium deficiency and the presence of mycotoxins as etiologies. Monensin was present in approved usage or only slightly elevated levels. A known potentiating antibiotic was being used concurrently with monensin in only one flock.

Excess sodium bicarbonate in the diet and its effect on Leghorn chickens.

1. A commercial 62-week-old layer flock experienced an acute drop in egg production and an increase in shell-less egg production within 2 days of consuming feed erroneously formulated to contain over 30 g/kg instead of 3 g/kg sodium bicarbonate (NaHCO3). Other symptoms included increased water consumption, diarrhoea and increased mortality associated with visceral gout. 2. An experiment was conducted to assess the responses of hens under controlled conditions. Twenty Dekalb XL Single Comb White Leghorn hens (50 weeks old) were placed in individual cages, having ad libitum access to water from trough waterers. Ten hens were fed the TEST (High NaHCO3) feed for one week (Test group), and ten hens remained on normal commercial layer ration (Control group). 3. Hens in the Test group had high water consumption and watery droppings, but egg production and mortality were not affected. Physiological evaluations indicated the Test feed caused metabolic alkalosis. Plasma sodium, urine pH and urinary sodium excretion were increased, and glomerular filtration rates were decreased in the Test group. 4. These physiological effects are consistent with known responses to excess sodium intake in domestic fowl. The reduced egg production and increased mortality caused by the Test feed under commercial conditions may be related to more severe dehydration experienced by hens in multi-bird cages supplied by cup-type watering systems.