Biomedical subjects

S L Branton

Publications and source records attributed to S L Branton.

66 records · Page 4Linked to original sources

PubMedDate not supplied

F strain Mycoplasma gallisepticum vaccination of post-production-peak commercial Leghorns and its effect on egg and eggshell quality.

Forty-five-week-old commercial leghorns negative for antibodies to Mycoplasma gallisepticum (MG) and M. synoviae were vaccinated with high-passage F strain MG (FMG). Hens were confined in modified Horsfall-Bauer isolation units through 60 weeks of age. Egg production (% hen day) and parameters of egg and eggshell quality were monitored, including egg weight, eggshell strength, Haugh unit score, pimpling, and blood/meat spot incidence. Egg production was significantly lower (P less than 0.05) for FMG vaccinates than controls (down 5.76% and 5.80% in Trials 1 and 2, respectively). However, vaccinates and controls did not differ significantly in eggshell strength, shell thickness, pimpling, or blood/meat spot incidence. Haugh unit scores were significantly (P less than 0.05) greater for FMG vaccinates. At necropsy, all reproductive tracts appeared grossly normal. These studies suggest that high-passage FMG vaccination of post-production-peak hens does not adversely affect oviduct function.

Animals↗

PubMedDate not supplied

Cyclocoelum mutabile infection and aortic rupture in an American coot (Fulica americana).

An American coot (Fulica americana) was found dead within the enclosed research compound of the South Central Poultry Research Laboratory at Mississippi State, Mississippi. Gross and microscopic examinations revealed the bird to be in good body condition; however, blood from the beak cavity and external nares was present. Biliary congestion, hemopericardium, blood-filled air sacs, and a ruptured, ascending aorta were also noted. Nineteen trematodes (Cyclocoelum mutabile) were found within the body cavity at necropsy. Bacteriological examination revealed the presence of Escherichia coli in both the heart and liver and Pseudomonas putida in the liver only. No virus was isolated.

Animals↗

PubMedDate not supplied

Egg production, egg weight, eggshell strength, and mortality in three strains of commercial layers vaccinated with F strain Mycoplasma gallisepticum.

Three strains of commercial leghorns vaccinated at 17 to 22 weeks of age with F strain Mycoplasma gallisepticum (MG) were maintained through 117 weeks of age. The three strains differed in both mortality and percent egg production per hen housed; however, the strains did not differ in egg weight (EW), eggshell strength (ESS), or percent daily egg production. Results of this study indicate EW and ESS for F strain MG-vaccinated hens follow patterns previously reported for uninfected layers. Further, mortality may account, in part, for differences in percent egg production per hen housed between strains of F strain MG-vaccinated hens.

Animals↗

PubMedDate not supplied

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↗

PubMedDate not supplied

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↗

PubMedDate not supplied

Fatty liver-hemorrhagic syndrome observed in commercial layers fed diets containing chelated minerals.

This study was originally conducted to determine the effect of various chloride levels and consumption of chelated versus non-chelated minerals on egg production and eggshell breaking strength. However, the focus of this report changed after fatty liver-hemorrhagic syndrome (FLHS) was observed in hens that consumed diets containing chelated minerals. No FLHS was observed in hens that consumed a diet that contained non-chelated minerals. Four hundred thirty-two 35-week-old commercial laying hens were housed in individual cages in groups of nine hens each. The treatments were factorially arranged (3 x 2) such that six experimental diets differing in chloride levels and in source of minerals were fed for six 28-day laying periods. A significantly higher mortality attributed to FLHS was observed in hens that consumed the diets having chelated minerals as compared with hens that consumed the diets with non-chelated minerals. No difference in mortality was observed among the hens fed the various chloride diets.

Animal Feed↗

PubMedDate not supplied

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↗

PubMedDate not supplied

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↗

PubMedDate not supplied

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↗

PubMedDate not supplied

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↗

PubMedDate not supplied

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↗

PubMedDate not supplied

Effect of drinking water containing ammonium chloride or sodium bicarbonate on Mycoplasma gallisepticum isolation in experimentally infected broiler chickens.

In each of three trials, 150 day-old broiler chicks were eyedrop inoculated with 0.04 ml of high-passage F strain Mycoplasma gallisepticum (MG) and housed in biological isolation units at 10 chicks per unit. At 4 wk of age, 50 chickens were designated as controls and remained on tap water (pH 7.30), 50 chickens were provided tap water containing 0.63% ammonium chloride (NH4Cl, pH 6.91), and 50 chickens were provided tap water containing 1.26% sodium bicarbonate (NaHCO3, pH 8.17). Fluids were supplied for ad libitum consumption. At 5 wk of age, all chickens were swabbed from the choanal cleft for MG isolation and bled from the left cutanea ulnea vein for pH determination. As a percent of total swabs obtained, significantly fewer chickens that consumed water containing NH4Cl (38.3%) were positive for MG by culture compared with either the NaHCO3 group (61.3%) or the control group (67.6%). Nonmycoplasmal swab contamination was significantly higher for chickens that consumed water containing NH4Cl (59.7%) compared with either controls (31.8%) or NaHCO3-treated chickens (38.7%). When contaminated cultures were discarded, MG isolations from the tap water group were not significantly different from MG isolations from either the NH4Cl or NaHCO3 group. However, MG isolations from the NH4Cl group (95%) were significantly less compared with the NaHCO3 group (100%). Mortality was significantly higher in chickens that consumed water containing NaHCO3 (8.7%) compared with either controls (1.3%) or the NH4Cl-treated chickens (0.7%). Blood pH values were lower for the NH4Cl group (7.927), higher for the NaHCO3 group (8.093), and intermediate for controls (8.035). Results of this study suggest that water containing NH4Cl hinders the bacteriological recovery of MG from the choanal cleft.

Ammonium Chloride↗