The effect of environmental temperature on blood volume.
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Animals↗
Biomedical subjects
J D May
Publications and source records attributed to J D May.
Radio telemeters for temperature and biopotentials.
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Animals↗
Temperature and light and broiler growth 2.
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Analysis of Variance↗
The effects of F strain Mycoplasma gallisepticum, Mycoplasma synoviae, and the dual infection in commercial layer hens over a 44-week laying cycle when challenged before beginning of lay. II. Egg size distribution.
In each of two trials, 160 commercial pullets were separated into four treatments with four replicates of 10 chickens in each treatment. Forty pullets were designated as controls and received no inoculation; 40 pullets received F strain Mycoplasma gallisepticum (FMG); an additional 40 pullets received Mycoplasma synoviae (MS); and the final 40 pullets were inoculated with both FMG and MS (dual). All inoculations occurred at 10 wk of age. Eggs from all treatments were collected daily, Monday-Thursday, and individually weighed. No significant difference was observed among the treatments for percentages of jumbo, extra-large, medium, small, peewee, or undergrade eggs. As a percentage of eggs laid for the 4 days of each week over the 44-wk laying cycle of each trial, the FMG hens laid significantly fewer large size eggs (43.2%) as compared with either controls (51.17%) or dual-infected hens (49.95%). No significant difference was found in percentage of large eggs laid by FMG hens when compared with MS hens.
Animal Husbandry↗
Effects of age at inoculation and induced molt on the recovery of Mycoplasma gallisepticum from layer chickens.
An experiment was conducted to determine the effects of age at inoculation and induced molt on the reisolation of Mycoplasma gallisepticum (MG) from commercial leghorn hens that had been eyedrop-inoculated with F strain MG at either 10 or 66 wk of age. Chickens were maintained in biological isolation units from 10 wk of age through 78 wk of age. At 70 wk of age (premolt), hens were swabbed, cultured for MG, and molted. Swabs were taken both at the end of molt (postmolt [74 wk]) and again 4 wk later (postmolt+4 [78 wk]). A significant (P < or = 0.05) decrease in MG isolations was observed in the postmolt swabs as compared with the premolt swabs of hens inoculated at either 10 or 66 wk of age. A significant (P < or = 0.05) increase in isolations was observed in the postmolt+4 swabs as compared with the postmolt swabs of hens inoculated at either 10 or 66 wk of age. For the hens inoculated at 10 wk, no significant difference was found in premolt as compared with postmolt+4 MG isolations; however, for hens inoculated at 66 wk, a significant (P < or = 0.05) decrease was observed between premolt and postmolt+4 isolations. Significantly (P < or = 0.05) fewer MG isolations were obtained from the premolt swabs of hens inoculated at 10 wk as compared with hens inoculated at 66 wk. No significant difference in MG isolations was observed in either the postmolt or postmolt+4 swabs between hens inoculated at either 10 or 66 wk.
Aging↗
The effects of ts-11 strain Mycoplasma gallisepticum vaccination in commercial layers on egg production and selected egg quality parameters.
Live Mycoplasma gallisepticum (MG) vaccines have been USDA approved and licensed for use in commercial layer chickens since 1988; however, egg production and egg quality data exist only for the F strain of MG. Information pertinent to the effects of ts-11 MG on egg and eggshell quality parameters, as well as egg size distribution, is lacking. In this study, pullets were inoculated at 10 wk of age with ts-11 strain MG and placed in biological isolation units at 10 birds/unit. Hen-day egg production, eggshell strength, Haugh unit score, pimpling incidence, and blood/meat spot incidence were monitored and recorded in each trial through a 45-wk production cycle. Further, eggs from all treatments were collected daily, Monday-Thursday, and individually weighed. Results of this study indicate that no significant difference was observed between the treatments for the parameters measured or for egg size distribution. Therefore, these data should lessen producers' concerns pertaining to the impact of ts-11 strain MG on egg production, egg and eggshell quality parameters, and egg size distribution.
Animals↗
Effect of fasting on plasma thyroid and adrenal hormone levels in turkey poults infected with Bordetella avium.
Plasma triiodothyronine (T3), thyroxine (T4), and corticosterone (CS) were measured in fasted and nonfasted control and Bordetella avium-infected poults. The stress of B. avium infection increased plasma CS, and fasting for 24 hours caused a further significant increase in CS levels. Plasma T3 was not affected by the infection, but fasting caused a significant reduction in both control and infected poults. Plasma T4 of fasted poults was increased in both control and infected groups, but infection attenuated the plasma T4 response. Total iodothyronines were increased in the control-fasted poults more than in infected-fasted poults, indicating a reduced responsiveness to stress by the thyroids of infected poults. Changes in plasma thyroid hormones and CS partially explain the decreased body weight gain and decreased body temperature after exposure to B. avium.
Animals↗
Identification of Mycoplasma gallisepticum and M. synoviae by flow cytometry.
Immunofluorescence and flow cytometric methods were examined to detect and distinguish Mycoplasma gallisepticum and M. synoviae. The procedure employed 24-hr broth cultures of each organism, direct immunofluorescence staining with either homologous or heterologous antiserum, and analyses by flow cytometry. The organisms were distinguishable on the basis of fluorescent profiles when stained with the appropriate antiserum.
Cells, Cultured↗
Effect of isolation and sanitation on the recovery of F-strain mycoplasma gallisepticum from chronically infected hens held in biological isolation units.
Two trials were conducted to determine if individual housing or improved sanitation would enable hens to clear Mycoplasma gallisepticum (MG) infection. In each of the two trials, 40 commercial leghorn hens were infected with F strain MG (F-MG) and confined in biological isolation units in two groups: 1) hens housed individually in each of eight isolation units and 2) hens housed in groups of four in each of eight other units. Each of these two groups was further subdivided into two groups: 1) non-sanitized, having the isolation unit interior cleaned but not sanitized once each 2 weeks; and 2) sanitized, having the isolator interior thoroughly cleaned and sanitized twice weekly. Choanal cleft swabs were obtained five times over a period of 16 weeks in Trial 1 and six times over 22 weeks in Trial 2. Isolates were identified as F-MG positive by agar plate fluorescent-antibody method. The incidence of isolation of F-MG did not differ significantly between individually housed and group-housed hens, except that the percentage of positive isolations was significantly lower in individually housed/sanitized hens than group-housed/sanitized hens in Trial 1. Sanitizing had no consistent beneficial effect. The results do not support the theory that hens can clear F-MG infection if isolated from other infected hens.
Animal Husbandry↗
Differentiation of two strains of Mycoplasma gallisepticum with monoclonal antibodies and flow cytometry.
Identification of infecting Mycoplasma spp. is difficult and not routine for strain. This paper describes a procedure for the rapid identification of the strain of M. gallisepticum. Monoclonal antibodies were prepared against M. gallisepticum F and M. gallisepticum S6. Aliquots of 24-hour broth cultures of these organisms were incubated briefly with either of the monoclonal antibodies. A second incubation was made with anti-mouse immunoglobulin conjugated to fluorescein isothiocyanate. Fluorescent intensity associated with the organisms was measured with a flow cytometer. The criterion for identification was a comparative increase in fluorescent intensity when the strain and monoclonal antibody were homologous. The procedure correctly differentiated the F and S6 strains of M. gallisepticum in a blind study.
Animals↗
The effect of photoperiod and nutrition on ascites incidence in broilers.
Light restriction was used to restrict growth of male broilers up to 41 days of age. Dietary energy and lysine were also investigated for their interaction with slowed growth rate. A total of 1440 male broilers was used in each of two trials. Light restriction significantly reduced body weights at 22 days (P < or = 0.05) but not at 52 days. Restricting early growth by photoperiod for the 3-to-41-day period reduced deaths due to ascites. Neither dietary energy nor lysine affected mortality from ascites. These results suggest that manipulation of photoperiod for young broilers is a useful way to limit early growth and subsequent ascites mortality.
Aging↗
Identification of mycoplasma isolates by ELISA.
An antigen-based enzyme-linked immunosorbent assay (ELISA) was developed for the rapid identification of Mycoplasma gallisepticum and Mycoplasma synoviae. Two trials were conducted to compare the ELISA with the conventional fluorescent antibody technique. In trial 1, broilers were inoculated with M. gallisepticum F, M. gallisepticum S6, and M. synoviae. In trial 2, hens were inoculated with M. gallisepticum F, M. synoviae, and a combination of the two. Swab isolates were obtained from the choanal cleft and cultures were grown in broth media with a pH indicator. The organisms were bound to 96-well plates for the ELISA or cultured on agar for the fluorescent antibody test. Monoclonal antibodies directed to M. gallisepticum F, M. gallisepticum S6, and M. synoviae were reacted with the ELISA aliquots. The ELISA test identified the mycoplasmas in these samples and was completed within 8 hr but did not identify as many isolates as the fluorescent antibody procedure. The principal advantage of this ELISA is the ability to identify the strain of mycoplasma.
Anal Canal↗
Epitope diversity of F strain Mycoplasma gallisepticum detected by flow cytometry.
A culture of F strain Mycoplasma gallisepticum (F-MG) that exhibited an epitope identified by monoclonal antibody (MAb) 6F10 was used to inoculate leghorn hens in two different trials. In Trial 1, mature hens chronically infected with F-MG were swabbed at intervals from 230 to 345 days postinoculation (PI). The F-MG isolates were tested with an agar plate fluorescent antibody (APFA) method that used a polyclonal antibody and with a flow cytometry (PC) technique that used MAb 6F10. Primary cultures of swabs taken at 258, 272, 293, 318, and 345 days PI were all identified as positive by APFA, whereas FC identified 23%-41% as positive. Subsequently, MAb 6B11 was found, which reacted positively with isolates negative to MAb 6F10. Both 6F10 and 6B11 were used in the second trial, which was designed to identify F-MG isolates that were negative to 6F10. In Trial 2, naive birds were inoculated with F-MG when they were 9 wk old and were sampled at six intervals from 13 to 154 days PI. The APFA method was used to identify primary isolation (P0) cultures, and FC was performed on P0 cultures and the same cultures after they had been passed three times (third serial passage [P3] cultures). The APFA test identified 100% of the P0 cultures as F-MG. The FC results on P0 cultures showed 34.5% as 6F10 positive and 85.1% as 6B11 positive. Results for FC on P3 cultures showed 92.3% 6F10 positive and 96.3% 6B11 positive. These results suggest that the microenvironment of the colonization site in the hen induced an epitope diversity in F-MG, as evidenced by the loss in the expression of MAb 6F10-defined epitope. Isolation of the organism from hens and propagation for several in vitro passages resulted in the re-expression of the epitope defined by MAb 6F10.
Animals↗
Various blood parameters in commercial hens acutely and chronically infected with Mycoplasma gallisepticum and Mycoplasma synoviae.
Two trials were conducted to study the effects of acute (Trial 1) and chronic (Trial 2) mycoplasma infections on differential leukocyte counts in chickens. The trials initially included either 20 (Trial 1) or 40 (Trial 2) 6-wk-old commercial leghorn chickens negative for antibodies to Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS). Chickens were inoculated with F strain MG (FMG), MS (WVU 1853), or both. One group of chickens remained uninoculated and served as a negative control for both trials. Chickens were housed in fiberglass isolation units from 6 to 10 wk (Trial 1) or 6 to 70 wk of age (Trial 2). Differential leukocyte counts were examined from 6 to 10 wk (Trial 1) or 66 to 70 wk of age (Trial 2) in all chickens. Also, in Trial 2, packed cell volumes (PCVs) and plasma protein values were examined from 66 to 70 wk of age. In the acute study (Trial 1), differential leukocyte counts revealed statistically significant differences (P < 0.05) in heterophil, lymphocyte, monocyte, eosinophil, and basophil values among treatments. In general, the differential counts of FMG- and MS-infected birds were characterized by heterophilia, lymphopenia, monocytosis, eosinopenia, and basopenia. Histopathologic examination of the spleen, liver, kidney, and bone marrow revealed a high degree of lymphoid foci within the spleen and bone marrow of all infected chickens. In the chronic study (Trial 2), no statistically significant differences (P < 0.05) were observed in differential leukocyte counts, PCV, and plasma protein values among treatments. Histopathologic examination of spleen, liver, kidney, and bone marrow did not reveal any difference among treatments.
Acute Disease↗
The effects of F strain Mycoplasma gallisepticum, Mycoplasma synoviae, and the dual infection in commercial layer hens over a 44-week laying cycle when challenged before beginning of lay. I. Egg production and selected egg quality parameters.
In each of two trials, 160 commercial pullets were separated into four treatments with four replicates of 10 chickens in each treatment. Forty pullets were designated as controls and received no inoculation; 40 other pullets received F strain Mycoplasma gallisepticum (FMG); an additional 40 pullets received Mycoplasma synoviae (MS); and the final 40 pullets were inoculated with both FMG and MS (dual). Hen-day egg production, egg weight, eggshell strength, Haugh unit score, pimpling incidence, and blood/meat spot incidence were monitored and recorded in each trial through an entire laying cycle. No significant difference was observed among the treatments for hen-day egg production, egg weight, eggshell strength, or Haugh unit scores. Significant differences were observed for pimpling incidence among controls (1.63%), Mycoplasma gallisepticum (MG)-infected (2.09%), and dual-infected hens (2.41%). A significant difference in blood/meat spot incidence was observed between MG-infected hens (0.27%) and dual-infected hens (0.45%). Histopathologic examination of the ovary and all segments of the oviduct revealed no significant differences among the treatments. These results suggest that the majority of the hen reproductive tract functions similarly in FMG-vaccinated, MS-infected, or dual-infected hens as compared with Mycoplasma-clean hens.
Animals↗