Ultrastructure of spermatogonia and primary spermatocytes of C57BL6J mice

The three types of spermatogonia were confirmed. Type A spermatogonia have a large nucleus and loose chromatin and are poor in endoplasmic reticulum. The second type, B spermatogonia, have rounded and smaller nuclei filled with more electron-dense nucleoplasmic material. The endoplasmic reticulum has the aspect of round or elongated cisterns that are free in the cytoplasm or close to the basement membrane. In contrast, intermediate spermatogonia present chromatin material with intermediate condensation compared with the two previous cell types. Primary spermatocytes are characterized by the presence of intercellular bridges and a synaptonemal complex. In the late pachytene stages, the synaptonemal complex was found to be enveloped by chromatin material

Footpad Dermatitis in Broilers: Differences between Strains and Gender

ABSTRACT Pododermatitis, also known as "bumblefoot", is an inflammatory lesion of the footpad. The objective of this study was to evaluate the influence of genetic strain and sex on the incidence of footpad lesions in broilers. The experiment was carried out at São Paulo State University, using 480 broilers distributed in a completely randomized experimental design in a 2X2 factorial arrangement (2 strains X2 sexes), with four replicates of 30 broilers each, totaling 16 experimental units. Feed intake, weight gain, feed conversion ratio, and livability were evaluated at 21, 35 and 42 days of age; production efficiency factor was determined at the end of the rearing period. On day 42, the footpads of 100 broilers were grossly examined and assigned a lesion score in a 1-3 scale (Almeida Paz & Martins, 2014). Three samples per score within treatment were collected for microscopic evaluation. Analysis of variance was applied and performance parameter means were compared by Tukey's test. Footpad lesion incidence was analyzed by the c2 test using SAS (version8.2). Ross(r) broilers presented higher feed intake during all evaluated periods, and higher weight gain only in the period 1 to 21 days compared with Cobb(r) broilers. On the other hand, Cobb(r) presented better feed conversion ratio in the periods of 1 to 35 and 1 to 42 days. The incidence of foot pad lesions was statistically different (p< 0.05) between strains and sexes, but there were no interactions between these factors. The lesion scores assigned were compatible with the histopathological results, showing that the higher the score, the more severe were the dermal and epidermal lesions

Ultrastructural Assessment of the Integrity of the enteric Mucosa of Commercial Turkeys Vaccinated against Coccidiosis

ABSTRACT The objective of this study was evaluated the villus integrity of commercial turkeys submitted to coccidiosis prevention methods and challenged with Eimeria field oocysts, using scanning electron microscopy. Sixty BUT 9 female commercial turkeys were distributed in a completely randomized block design split with two treatments: T1- control diet without vaccinations against coccidiosis and anticoccidial drug, and T2- vaccinated against coccidiosis (commercial vaccine). On d 21 of life, all birds of all treatments were challenged with a mixed-species containing E. meleagrimitis and E. galopavonis, via crop intubation with 1 mL of ~20,000 sporulated oocysts/bird. The size of the inoculum was determined in previous experiments. At 27 and 70 days of age, five birds per treatment were randomly removed to evaluate the intestinal integrity. Duodenum, jejunum and ileum segments were collected and processed according to routine scanning electron microscope. The enteric mucosa integrity of the commercial turkeys subjected to coccidiosis vaccination was reduced when compared to the birds of the control treatment. There was no difference in the performance results, therefore these results cannot be attributed to the vaccination as well as to the ineffectiveness against the challenge that was administered

Intestinal integrity and performance of broiler chickens fed a probiotic, a prebiotic, or an organic acid

This study aimed at evaluating the intestinal integrity, using light and scanning electron microscopy (SEM), and the performance of broiler chickens fed additives alternative to antimicrobials. A total of 1080 male chicks were distributed according to a completely randomized experimental design, with six treatments with six replicates of 30 birds each. The following treatments were evaluated: basal diet (control), basal diet supplemented with an antimicrobial, basal diet supplemented with a probiotic, basal diet supplemented with a prebiotic, basal diet with a symbiotic, and basal diet supplemented with organic acids. Weight gain, feed intake, feed conversion ratio and livability were recorded when broiler chickens were 10, 21, 35, and 42 days old. On day 42, 72 birds were individually weighed and sacrificed. In order to evaluate the morphometrics of the different intestinal wall layers, segments of the small intestine and the cecum were collected from two birds per replicate, and intestinal integrity (SEM) was evaluated in the same segments of two birds per treatment. During the starter period (1-21 days old), birds fed the alternative additives presented similar weight gain as those fed the antimicrobial product, but were not different from control birds. Feed conversion ratio of birds fed alternative additives was better than that of the control birds from one to 10 days of age, but not during the remaining rearing period, and was similar to the birds receiving the antimicrobial. The morphometric parameters of the different intestinal wall layers was not influenced by the treatments. During the total rearing period, the evaluated alternative additives did not improve intestinal integrity or broiler performance

Effects of pre-slaughter fasting on broiler welfare, meat quality, and intestinal integrity

The Brazilian Ministry of Agriculture (MAPA) regulations establish 12 hours as the maximum pre-slaughter fasting period for broilers; however, many processing plants have considered this time is not sufficient, and consequently return the birds to the farms, with consequent economic losses and welfare problems. Therefore, it is necessary to investigate the possible effects of longer pre-slaughter fasting times. The objective of the present study was to evaluate the effect of pre-slaughter fasting times longer than those established by MAPA on broiler welfare, breast meat quality, and intestinal integrity. Forty 42-d-old broilers were submitted to different pre-slaughter fasting times: group I: 6 hours, group II 9h, group III 12h, and group IV 15h. Bird welfare was assessed before slaughter. After sacrifice, intestinal samples were collected to assess their morphology and morphometrics, and the Pectoralis major muscle was analyzed for pH and color. There was no influence (p&gt;0.05) of treatments on breast muscle pH or color.There were no significant changes in intestinal morphometrics (p<0.05). Bird behavior was affected (p<0.05), suggesting that welfare was impaired as fasting time increased, but no differences in the analyzed parameters were detected between broilers fasted for 12 or 15 hours. It was concluded that the behavioral differences between birds fasted for 12 and 15 hours are not sufficient to assert that those fasted for 15 hours were in worse welfare conditions