Biochemical Reference Intervals for Backyard Hens

Radiographic Measurements of Internal Organs in Rhode Island Red Hybrid Hens (Gallus gallus domesticus) and Their Evolution During Egg Formation

Backyard poultry hens are becoming very popular as pets, and thus the demand for treating the individual chicken is increasing. Few basic diagnostic techniques commonly used in small animal practice have been evaluated in this species. At the moment, there is no study in backyard hens describing radiographic measurements of internal organs contrary to psittacine birds or birds of prey. Moreover, the effect of egg laying on these measurements has not been studied in avian species even though it could affect radiographic measurements depending on the stage of egg formation. This is of particular concern in laying hens since they are able to lay on a daily basis. Thirteen adult hens and 3 juvenile Rhode Island red hybrid hens (Gallus gallus domesticus) were used to evaluate which organs can be reliably measured and to provide preliminary reference values for clinically healthy chickens. Additionally, whole body radiographs were collected every 2 hours over 24 hours in 5 adult hens to study the evolution of these measurements throughout egg formation. Organs that could be clearly delimitated on radiographs were measured, and the only organs that could be reliably measured were the heart and liver silhouettes. These measurements were significantly higher in adult compared to juvenile hens (P = 0.024). Among the different organ ratios, heart width: total liver width ratio was the only significantly different measurement and was higher in juvenile hens (P = 0.024). Hepatic silhouette measurements and ratios were found to increase over time (P < 0.02) but did not follow the progress of egg mineralization. Eggshell thickness was found to be a promising parameter to evaluate the stage of egg formation, and thus should be taken into account when trying to establish reference intervals for radiographic measurements of internal organs in laying hens.

Establishment of biochemical reference values for backyard chickens in Colorado (Gallus gallus domesticus)

BACKGROUND

Previous literature pertaining to biochemical RIs of domestic chickens has primarily focused on commercial production flocks and not backyard birds.

OBJECTIVE

We aimed to establish biochemistry RIs for privately-owned backyard chickens (Gallus gallus domesticus) using reference laboratory equipment.

METHODS

Samples were collected from 123 presumably healthy adult chickens between 2017 and 2019 from 22 different flocks in Colorado. Heparinized blood was obtained, and a biochemistry profile was evaluated, including sodium, potassium, chloride, calcium, phosphorous, uric acid, AST, CK, glucose, cholesterol, and total protein. Reference values were created according to current American Society for Veterinary Clinical Pathology recommendations.

RESULTS

Differences in measurand intervals compared with previous literature were found for sodium, calcium, total protein, potassium, phosphorus, uric acid, and glucose. Hens were found to have higher median calcium (17.9 mg/dL vs 11.2 mg/dL [P = .0001]), total protein (5.2 g/dL vs 4.8 g/dL [P = .0046]), and potassium (3.80 mEq/L vs 3.48 mEq/L [P = .0267]) concentrations, as well as lower sodium (155 mEq/L vs 158 mEq/L [P = .0046]) concentrations, calculated osmolalities (310 mOsm/kg vs 314 mOsm/kg [P = .0249]), and AST (165 U/L vs 194 U/L [P = .0121]) activities, than roosters. Seasonal variation was found between summer and winter samples for median sodium (144 mEq/L vs 148 mEq/L [P = .0008]), chloride (111.8 mEq/L vs 113.5 mEq/L [P = .0033]) concentrations, calculated osmolalities (306 mOsm/kg vs 311 mOsm/kg [P = <.0001]), and AST (185 U/L vs 159 U/L [P = .0053]) and CK (1098 U/L vs 770 U/L [P = .0007]) activities.

CONCLUSIONS

This study presents biochemical reference values for backyard chickens in Colorado that can be a basis for evaluations in similar settings.

Revisiting glucose regulation in birds - A negative model of diabetes complications

Birds naturally have blood glucose concentrations that are nearly double levels measured for mammals of similar body size and studies have shown that birds are resistant to insulin-mediated glucose uptake into tissues. While a combination of high blood glucose and insulin resistance is associated with diabetes-related pathologies in mammals, birds do not develop such complications. Moreover, studies have shown that birds are resistant to oxidative stress and protein glycation and in fact, live longer than similar-sized mammals. This review seeks to explore how birds regulate blood glucose as well as various theories that might explain their apparent resistance to insulin-mediated glucose uptake and adaptations that enable them to thrive in a state of relative hyperglycemia.

Influence of Dietary Supplementation with Boswellia serrata and Salix alba on Performance and Blood Biochemistry in Free-Range Leghorn Laying Hens

This study was conducted to evaluate the safety and the beneficial effects of dietary supplementation with Boswellia serrata (Bs) and Salix alba (Sa) in Leghorn hens during the critical pre-laying and laying phases. A total of 120 pullets, 17 weeks of age, were assigned to two groups (Control—C; Treated—T, n = 60 each). For 12 weeks, the T group received a diet supplemented with 0.3% of dry extracts of Bs (5%) and Sa (5%). The study lasted 19 weeks. Productive performance, serum analytes, H/L ratio, IgA and anti-IBV antibodies were investigated. Water intake was significantly higher, while body and egg weight was significantly lower for the T group (p < 0.05). No other differences were detected in performance parameters, serum analytes, IgA and H/L ratio excluding t0, with a significantly (p < 0.05) higher H/R ratio and higher titers of anti-IBV antibody for the T group. Overall, the data obtained in this study show that the supplementation with Bs and Sa was safe and resulted in an increase in water consumption, a decrease in egg weight, and a sedative effect in the hens. In the future, it would be interesting to test this supplement in hens reared on intensive farms.

Comparison of portable and conventional laboratory analyzers for biochemical tests in chickens

Antemortem blood biochemical and blood gas analyses are routinely used in health screening and diagnosis of disease in domestic veterinary species. These testing modalities are not routinely performed in poultry, in part, due to the distance from the diagnostic laboratory. Portable blood analyzers such as the i-STAT and VetScan (VS2) can be used to obtain results on the farm without delay, potentially offering a more practical option for poultry practitioners. We investigated the time effect on blood chemistry values and compared the results obtained using the i-STAT and VS2 with those obtained using conventional laboratory analyzers (GEM Premier 3000 and Cobas c501, respectively). We tested blood from 60 healthy chickens. Each sample was tested in triplicate using each of the portable analyzers and once using conventional analyzers. All samples were analyzed within 60 minutes of collection. The concentrations of some analytes were outside the limit of detection of the portable analyzers (i.e., bile acids). Although statistically significant differences were found for some biochemical analytes over time, the actual mean or median differences were too small to be considered of clinical importance. As observed in mammals, significant time-dependent changes in blood gas analytes were observed in whole blood samples exposed to ambient air. Correlation coefficients between portable and conventional analyzers were moderate to high for most of the analytes. For the most part, there was an agreement between the portable and conventional analyzers. We identified constant and proportional biases in the measurement of multiple analytes by both the i-STAT and VS2. Future studies are warranted to establish analyzer-specific reference intervals for poultry.

The occurrence of Salmonella, extended-spectrum β-lactamase producing Escherichia coli and carbapenem resistant non-fermenting Gram-negative bacteria in a backyard poultry flock environment

Increase in the number of small-scale backyard poultry flocks in the USA has substantially increased human-to-live poultry contact, leading to increased public health risks of the transmission of multi-drug resistant (MDR) zoonotic and food-borne bacteria. The objective of this study was to detect the occurrence of Salmonella and MDR Gram-negative bacteria (GNB) in the backyard poultry flock environment. A total of 34 backyard poultry flocks in Washington State (WA) were sampled. From each flock, one composite coop sample and three drag swabs from nest floor, waterer-feeder, and a random site with visible faecal smearing, respectively, were collected. The samples were processed for isolation of Salmonella and other fermenting and non-fermenting GNB under ceftiofur selection. Each isolate was identified to species level using MALDI-TOFF and tested for resistance against 16 antibiotics belonging to eight antibiotic classes. Salmonella serovar 1,4,[5],12:i:- was isolated from one (3%) out of 34 flocks. Additionally, a total of 133 ceftiofur resistant (Cef^R ) GNB including Escherichia coli (53), Acinetobacter spp. (45), Pseudomonas spp. (22), Achromobacter spp. (8), Bordetella trematum (1), Hafnia alvei (1), Ochrobactrum intermedium (1), Raoultella ornithinolytica (1), and Stenotrophomonas maltophilia (1) were isolated. Of these, 110 (82%) isolates displayed MDR. Each flock was found positive for the presence of one or more Cef^R GNB. Several MDR E. coli (n = 15) were identified as extended-spectrum β-lactamase (ESBL) positive. Carbapenem resistance was detected in non-fermenting GNB including Acinetobacter spp. (n = 20), Pseudomonas spp. (n = 11) and Stenotrophomonas maltophila (n = 1). ESBL positive E. coli and carbapenem resistant non-fermenting GNB are widespread in the backyard poultry flock environment in WA State. These GNB are known to cause opportunistic infections, especially in immunocompromised hosts. Better understanding of the ecology and epidemiology of these GNB in the backyard poultry flock settings is needed to identify potential risks of transmission to people in proximity.

Biochemical reference intervals for homing pigeons in China

As indicators of diseases, blood biochemical values play a crucial role in clinical practice and assessments of animals’ health condition. The rising population of homing pigeons in China has prompted needs for reliable blood biochemical reference intervals. Therefore, the aim of this study was to establish biochemical reference intervals for homing pigeons. Heparinized whole blood samples obtained from 77 clinically healthy pigeons were analyzed by Zoetis Abaxis VetScan VS2 with VetScan Avian/Reptilian Profile Plus Rotor. Reference intervals for pigeons were computed by Excel with Reference Value Advisor V2.1. The statistical analysis performed by SPSS program revealed correlations between biochemical analytes. Effects of sex and age and validity of published reference intervals were also discussed. The present results serve as a useful guide to broaden the scope of pigeon breeding industry.