Heart ventricular histology and microvasculature together with aortic histology and elastic lamellar structure: A comparison of a novel dual-purpose to a broiler chicken line

The use of dual-purpose chickens is a strategy to avoid killing one-day-old male chicks of egg laying lines. Lohmann Dual (LD) is a novel dual-purpose chicken line created by the crossbreeding of layer and broiler lines. However, many of the cardiovascular diseases of broilers are likely to be associated with intensive genetic selection for growth and feed conversion efficiency. This study aimed to compare the macroscopic and microscopic structure of the heart and the aorta of the LD chicken line with that of the broiler chicken line, Ross 308 (Ross) under typical husbandry conditions for meat production. Eighty, one-day-old male chicks of each line were housed for 5 weeks (Ross) and 9 weeks (LD). Six birds of each line were sampled weekly. Heart mass, thickness of ventricular walls, cardiomyocyte size and blood capillary density as well as aortic diameter and thickness, number of elastic lamellae and elastic fiber percentage in the aortic wall were determined. The growth patterns of the heart were the same in the two lines. Although LD chickens had a lower absolute heart mass than that of Ross chickens, the relative heart mass in both lines was similar. The cardiomyocytes of LD chickens were larger than those of Ross’s of the same body weight (BW), nevertheless both lines had similar thicknesses of their ventricular walls. The blood capillary density was greater in the LD heart than in that of the Ross heart. The aorta of LD chickens had proportionally; a greater aortic lumen radius, larger numbers of elastic lamellae and more elastic fibers than in Ross chickens. Our results suggest that the heart and aorta of the LD chickens have not been disadvantaged by their intensive genetic selection; furthermore, LD chickens have a better myocardial capillary supply and better aortic mechanical properties than those of Ross chickens

Structure and age-dependent growth of the chicken liver together with liver fat quantification: A comparison between a dual-purpose and a broiler chicken line

Rearing dual-purpose chickens is a practicable approach to avoid culling one-day-old male layer chicks. The present study examined the impact of a conventional fattening diet on the liver of a novel dual-purpose chicken line (Lohmann Dual, LD) in comparison to a broiler (Ross 308) chicken line. Age-related changes of structure and lipid content of the liver were assessed. One hundred twenty and newly hatched chicks (LD = 66, Ross = 54) were kept under the same husbandry conditions and fed a commercial diet for 5 weeks for Ross and 9 weeks for LD. Six birds of each line were examined weekly. Their body weight (BW) and liver mass were recorded. Microscopic structure and ultrastructure of the liver were investigated and the liver lipid content was measured using a pre-validated method. During the study period, liver mass increased with age, while normalized liver mass decreased. Furthermore, liver mass of Ross birds was greater than that of LD birds of the same BW. Overall, no significant differences were observed in the hepatic structure or ultrastructure between the two chicken lines. The hepatic lymphatic aggregations were without fibrous capsules and their number and area increased throughout the first week, then the values began to fluctuate with age in both chicken lines. The changes in the liver lipid content of the two chicken lines were within the normal physiological range over the term of the study. The liver lipid content correlated negatively with age and body weight in both lines. It was the highest on the first day then decreased until day 7 and thereafter did not change in both chicken lines. However, given the same body weight, the Ross chickens had a 9% greater liver lipid content than LD chickens. It is concluded that there is no apparent adverse effect of a high-energy diet on the liver of LD chickens

Intraepithelial lymphocyte numbers and histomorphological parameters in the porcine gut after Enterococcus faecium NCIMB 10415 feeding in a Salmonella Typhimurium challenge

Salmonellae are among the most widespread sources of foodborne infections and Salmonella Typhimurium, in particular, is correlated with human disease caused by the consumption of contaminated pork. Intraepithelial lymphocytes (IEL) have early contact with intestinal antigens and play an important role in the detection of pathogenic bacteria. The objective of this study was to determine whether a presumed probiotic Enterococcus faecium strain could improve histomorphological and immune system-related parameters of gut function after a Salmonella challenge in weaned pigs. In particular the morphological parameters villus length and width, crypt depth and width as well as the actual enlargement of the intestinal epithelial surface were calculated and the number of IEL was evaluated in sections of the porcine gut. Weaned piglets were challenged with Salmonella enterica serovar Typhimurium DT 104, and half of them also received Enterococcus faecium NCIMB 10415 in the diet. Animals were sacrificed at days post infection (DPI) 2 and 28. The effect of the factors “time post-infection/age” and “probiotic treatment” on jejunal morphology and IEL numbers and distribution was evaluated by light microscopy. The time post-infection had significant effects in both feeding groups. Animals sacrificed at DPI 28 had longer and wider villi, deeper and wider crypts, a higher villus enlargement factor, a higher ratio between villus and crypt enlargement factors as well as more IEL. Probiotic treatment resulted in longer villi, a higher ratio of villus surface/crypt circumference enlargement factors and significantly more IEL. The larger total number of IEL displayed by the probiotic group resulted from significantly higher numbers of IEL at the nuclear and apical levels of the intraepithelial compartment but not from the number of IEL situated at the basement membrane. The probiotic effects were only measurable 28 DPI. It is proposed that Enterococcus faecium NCIMB 10415 exerts an immune modulatory effect by increasing the numbers of intraepithelial lymphocytes

Enhancement of immunohistochemical detection of Salmonella in tissues of experimentally infected pigs

<p><em>Salmonella</em> Typhimurium is one of the main pathogens compromising porcine and human health as well as food safety, because it is a prevailing source of foodborne infections due to contaminated pork. A prominent problem in the management of this bacteriosis is the number of subclinically infected carrier pigs. As very little is known concerning the mechanisms allowing <em>Salmonella</em> to persist in pigs, the objective of this study was to develop an immunohistochemical approach for the detection of salmonellae in tissue of pigs experimentally infected with <em>Salmonella</em> Typhimurium. Samples were obtained from a challenge trial in which piglets of the German Landrace were intragastrically infected with <em>Salmonella</em> enterica serovar Typhimurium DT104 (1.4-2.1x10¹⁰ CFU). Piglets were sacrificed on days 2 and 28 post infection. Tissue samples of jejunum, ileum, colon, ileocecal mesenteric lymph nodes (<em>Lnn. ileocolici</em>), and tonsils (<em>Tonsilla veli palatini</em>) were fixed in Zamboni’s fixative and paraffin-embedded. Different immunohistochemical staining protocols were evaluated. <em>Salmonella</em> was detected in varying amounts in the tissues. Brown iron-containing pigments in the lymph nodes interfered with the identification of <em>Salmonella</em> if DAB was used as a staining reagent. Detergents like Triton X-100 or Saponin enhanced the sensitivity. It seems advisable not to use a detection system with brown staining for bacteria in an experimental setup involving intestinal damage including haemorrhage. The use of detergents appears to result in a higher sensitivity in the immunohistochemical detection of salmonellae.</p

A practicable approach to providing horses in a standing position for teaching gross anatomy and surgery

Lifelike simulation of surgical procedures as well as whole body dissections of horses in a natural standing position are superior as they show the normal topographic visceral interrelationships between organs, their ligamentous associations, vasculature and innervation. This short technical communication reports on the fixation of small-frame horses in a standing position on a mobile frame. Animals are euthanased using standard veterinary protocols and heparinised to facilitate exsanguination. All steps including the embalming procedures/ protocols, the support of the body with fabric body harnesses, and additional means to place and hold the body in an as natural position as possible are described in detail. Following these procedures, animals were dissected over a time period of three-months and exposed tissue surfaces were swabbed weekly to determine their ongoing microbial status. No adverse effects, such as aerobic and anaerobic bacteria, yeast, or mould growth were found

Gross morphology and histology of the alimentary tract of the convict cichlid Amatitlania nigrofasciata

The primary objectives of this study were to document the macroscopic and histological structure of the alimentary tract (AT) of the convict cichlid Amatitlania nigrofasciata, because there are no data available for this omnivorous freshwater fish of the family Cichlidae. The morphology of the AT of A. nigrofasciata resembles that of related species. While having morphological criteria of the AT typical of most omnivorous fishes, such as a blind sac stomach and medium length intestine, A. nigrofasciata also has some structural peculiarities: the oesophagus is lined by a uniform stratified squamous epithelial layer with interspersed goblet cells along its entire length. Additionally, it has well-developed layers of the tunica muscularis including muscle fibre bundles that ascend into its mucosal folds. Occasionally, taste buds are present. In the transitional area between oesophagus and stomach, a prominent torus-like closure device is present. The mucosa of the stomach cannot be divided into different regions according to mucosal and morphological properties. The simple pattern of intestinal loops of A. nigrofasciata has few variations, irrespective of sex, mass and length of the individual fish. The first segment of the intestine is characterized by the largest mucososerosal ratio and the most complex mucosal surface architecture. A distinction of midgut and hindgut was not possible in A. nigrofasciata due to lack of defining structural components as described for other fish species

Growth‐related micromorphological characteristics of the porcine common carotid artery

The purpose of this study was to gain knowledge about the micromorphology of the porcine common carotid artery (CCA) during the period of growth over the bodyweight range of 10–40 kg. CCA samples from German landrace pigs (DL) aged either 2 or 3 months (DL‐2 and DL‐3) were compared with samples from Göttingen minipigs (GM) aged either 18 or 40 months (GM‐18 and GM‐40) using transmitted light (phase‐contrast mode) and transmission electron microscopy. The GM‐18, GM‐40 and the DL‐3 groups had typical muscular artery histological characteristics. Contrasting to this, the 2‐month‐old DL pigs had a transitional artery type being characterized by a significantly higher proportion of elastic fibres and a significantly lower number of smooth muscle cells than did the 1 month older DL‐3. During the period of maturation, the tunica media of the CCA in GM animals thickened by 1.3× and in DL animals by 2.5× resulting in an overall increased vessel wall thickness. The cumulated thickness of the tunica interna (endothelium, stratum subendotheliale and internal elastic lamina) and the tunica media (including the external elastic lamina) of DL‐3 and GM‐40 pigs were similar to each other and comparable to that of humans. With an increasing vessel wall thickness, the luminal diameter decreased in GM by 19% and in DL by 11%. Additionally, in the older age groups, GM‐40 and DL‐3, the internal elastic lamina principally was continuous, but there were also interrupted large segments of elastic lamina separated by gaps. In addition, the principal internal elastic lamina was duplicated in several places

Influence of age at weaning and feeding regimes on the postnatal morphology of the porcine small intestine

The small intestinal mucosal epithelium is the interface between ingested nutrients and their distribution networks in the underlying vasculature and lymphatics. This review reports on the small intestinal mucosal surface changes in the piglet from birth to the time of natural weaning (> 54 days). Despite numerous publications on the morphological characteristics of the gastrointestinal tract, there is limited comparability among these due to substantial methodological differences. The comparability of the methodological designs used in this review was achieved by relativizing the data to the day of weaning. Weaning at 35 days or later had little to no effect on the intestinal mucosa. Early weaning at 28, 21, 14, 5, 3, and 1 day after birth was associated with dramatic structural changes in the mucosa. A frequent observation after early weaning was prominent villus atrophy. While the crypt epithelium responds to redress these dramatic changes, villus recovery to near preweaning status may be slow. The earlier a piglet is weaned, the greater the villus atrophy and the longer the time to recovery. A causal relationship between reduced feed intake in the first days after weaning, independent of the diet, and the morphological alterations of the intestine is apparent

Structure and age-dependant development of the turkey liver: A comparative study on a highly selected and a wild-type turkey line

In this study the macroscopic and microscopic structure of the liver of a fast growing, meat-type turkey line (British United turkeys BUT Big 6, n = 25) and a wild-type turkey line (Wild Canadian turkey, n = 48) were compared at the age of 4, 8, 12, 16, and 20 wk. Because the growth plates of long bones were still detectable in the 20-week-old wild-type turkeys, indicating immaturity, a group of 8 wild-type turkeys at the age of 24 wk was included in the original scope of the study. Over the term of the study, the body and liver weights of birds from the meat-type turkey line increased at a faster rate than those of the wild-type turkey line. However, the relative liver weight of the meat-type turkeys declined (from 2.7 to 0.9%) to a greater extent than that of the wild-type turkeys (from 2.8 to 1.9%), suggesting a mismatch in development between muscle weights and liver weights of the meat-type turkeys. Signs of high levels of fat storage in the liver were detected in both lines but were greater in the wild-type turkey line, suggesting a better feed conversion by the extreme-genotype birds i.e., meat-type birds. For the first time, this study presents morphologic data on the structure and arrangement of the lymphatic tissue within the healthy turkey liver, describing two different types of lymphatic aggregations within the liver parenchyma, i.e., aggregations with and without fibrous capsules. Despite differences during development, both adult meat-type and adult wild-type turkeys had similar numbers of lymphatic aggregations