Specific Diseases of Large Animals and Man
Rebecca A. Krimins in Learning from Disease in Pets, 2020
Cattle are the other large animal species in which ‘gastric’ ulceration occurs. The forestomachs (rumen, reticulum, and omasum) precede the abomasum in ruminants. The abomasum is the equivalent of the monogastric stomach and abomasal ulceration is a distinct disease in this species. However, definitive ulcer diagnosis can be more challenging in cattle since endoscopy of the abomasum is not possible with the anatomical arrangement of the ruminant forestomachs. Clinical signs such as melena and anemia may provide a degree of suspicion of a bleeding ulcer. In contrast to the other species, ulcers in cattle perforate at a higher rate leading to either localized or generalized peritonitis. This may be due to the non-distinct clinical signs that are associated with ulcer disease in cattle and a failure to recognize the disease before significant progression. The prevalence of ulcers is reported as being up to 76% in calves and up to 20% in adult cattle at slaughter. As with the horse, pig, and humans, stress, diet, and NSAID use are involved in the pathogenesis of abomasal ulcers in cattle. A disease which crosses species such as gastric ulcer disease provides a unique comparative aspect to understanding the strong underlying causes of the disease in the different species and in man. Clearly, stress, diet, and NSAID drug use are common to each; however, at this time only the pig appears to have a strong relationship with Helicobacter infection in the pathogenesis of ulcer disease.
Pregastric Esterase
Margit Hamosh in Lingual and Gastric Lipases: Their Role in Fat Digestion, 2020
Hydrolysis of milk occurs in the abomasum (stomach) of the preruminant calf. Although pregastric esterase has been localized in the oral and pharyngeal area,20 abomasal preparations also contained lipase activity20 (Table 2). Thus, some of the lipolytic activity could be of gastric origin. The studies of Toothill et al. have provided conclusive evidence that the lipolytic activity in the abomasum originates in the oral cavity.42 Innervated pouches of the abomasum were prepared and secretions were collected from the pouches and from the abomasal contents of preruminant calves given liquid diets. No lipolytic activity was detected in pouch secretions collected 1 h after feeding, though lipolytic activity was present in abomasal contents. Pepsin and renin were, however, present in both pouch secretions and abomasal contents. While it could be argued that lipase secreted into the pouch might have been inactivated by low pH (pouch secretions had a pH of 1.2 to 1.8, whereas those of the abomasal contents were 4.2 to 5.9), studies in which substrates were introduced into the pouch at pH 5.5 to 6.3 showed no trace of activity. These studies provide, therefore, definite proof that, in ruminants, digestion of fat in the stomach is catalyzed by pregastric esterase.
Impact of Probiotics on Animal Health
Marcela Albuquerque Cavalcanti de Albuquerque, Alejandra de Moreno de LeBlanc, Jean Guy LeBlanc, Raquel Bedani in Lactic Acid Bacteria, 2020
Ruminants’ digestive tract has some peculiarities, it contains four-compartmentalized stomach chambers: the rumen, the reticulum, the omasum, and the abomasum, each one performing in different processes. Briefly, in the rumen the fibers and solid feeds are fermented by commensal microbiota. The liquids are transferred to the reticulum, also serving to the entrapment of large feed particles, which are regurgitated subsequently for a complete digestion. In the omasum the liquids are filtered and various nutrients are absorbed. Finally, the enzymatic digestion of the feed takes place in the abomasum (Hofmann 1989, Zoumpopoulou et al. 2018).
Helminths, hosts, and their microbiota: new avenues for managing gastrointestinal helminthiases in ruminants
Published in Expert Review of Anti-infective Therapy, 2020
Alba Cortés, James Rooney, Dave J. Bartley, Alasdair J. Nisbet, Cinzia Cantacessi
In particular, to the best of our knowledge, the impact of GI helminths, and specifically of abomasal nematodes, on the composition of the gut microbiota of ruminant hosts has been the subject of four studies [9,10,17,18], each targeting different host-parasite pairs, i.e. O. ostertagi in cattle [17], H. contortus in goats and sheep, respectively [9,18] and Tel. circumcincta in sheep [10]. In addition, the experimental procedures described in these studies involved different parasite doses and infection protocols, as well as varying sampling sites for whole DNA extraction and metagenome sequencing, i.e. abomasal [9,17,18] and ruminal [18] contents, and feces [10]. In these experiments, significant variations in the abundances of selected populations of gut bacteria were detected in the abomasum and rumen (cf. Table 1) of goats and sheep infected by H. contortus [9,18], as well as in fecal samples from lambs infected by Tel. circumcincta [10]; conversely, no differences in gut bacterial abundances were detected in partially immune cattle following re-infection with O. ostertagi [17]. Dissimilarities in the immune responses mounted by naïve versus partially immune animals may account for this discrepancy; however, it remains unclear whether the minimal disturbances in the gut microbial composition of partially immune cattle following re-exposure to the parasites might be associated with an acquired ability to maintain the gut homeostasis, and/or with the low worm burdens that ultimately established in these animals [17].
Effects of silymarin and mesenchymal stem cells on hematological and some biochemical changes induced by gamma radiation in albino rats
Published in International Journal of Radiation Biology, 2020
A. Z. Mahmoud, H. A. Ibrahim, M. R. El-Sawi, M. N. Habza
Ionizing radiation exposure is resulting in a great reduction in the hematological values like erythrocytes and leukocytes (El-Shanshoury et al. 2016). The current result provided evidence that irradiation exposure induced disorders in the hematological parameters as manifested by a decline in Hb content, RBCs, WBCs, platelets count, Ht%, MCV and MCH. These results are in agreement with those of Jbireal et al. (2018) and Abomasum et al. (2015). Radiation acts as a provider of apoptosis, besides affecting cell growth, proliferation, viability and migration ability of stem cells (Cho et al. 2017). According to Omaima et al. (2013) decline in the number of RBCs count may be imputed to structural modification in membrane proteins and internal peptides, as well as, internal RBCs viscosity, leading to reduce production of erythropoietin (Mohamed and Farghaly 2009) causing depletion in factors needed for erythroblast differentiation, reticulocyte release from the bone marrow and the loss of cells from the circulation by hemorrhage. The observed decrease in Hb content may be attributed also to the destruction of erythrocyte precursor in bone marrow leading to increase iron excretion. In addition, ionizing radiations possibly caused retardation in incorporation of iron with a decrease in Hb binding to erythrocyte membrane (Hussein 2008).