ABSTRACT
Bovine coronavirus (BCoV) infections are widespread in newborn calf diarrhea, which is one of the critical problems in cattle breeding. This study aims to investigate BCoV infection in calves with diarrhea in Sanliurfa province. In this study, 94 calves with diarrhea (3 months) following clinical examination were sampled. Enzyme-linked immunosorbent assay (ELISA) was used to detect the presence of BCoV antigen. A total of 5 stool samples were found to be BCoV positive (5.32%). This result showed that BCoV was low in calves with diarrhea in Sanliurfa province. However, considering the rapid spread of the infection in cattle populations, it is thought that it may cause significant economic losses due to treatment costs and calf deaths.
ABSTRACT
This study was carried out for rapid etiological diagnosis of neonatal calf diarrhea by using immunochromatographic test kits in the Esme district of Usak. The animal material of the study consisted of 100 1-28 days old neonatal calves of different breeds and genders in the Esme district of Usak. Stool samples were taken from calves with diarrhea as a result of clinical examination. When stool samples were examined by a rapid diagnostic test, none of the disease factors sought in the study were found in 10 (10%) of 100 calves, while one or more disease factors were detected in 90 (90%) of calves. Rotavirus was detected in 27 (27%) calves, Escherichia coli 14 (14%) calves, Coronavirus in 8 (8%) calves, Clostridium perfringens in 19 (19%) calves, Cryptosporidium spp. in 17 (17%) calves, Rotavirus + Coronavirus in 2 (2%) calves, Rotavirus + Clostridium perfringens in 1 (1%) calf, Rotavirus + Cryptosporidium spp. in 1 (1%) calf, and Escherichia coli - Clostridium perfringens in 1 (1%) calf. As a result, data on the presence and distribution of enterogenous pathogens that cause diarrhea in neonatal calves in the Esme district of Usak were presented, and it was concluded that it would shed light on future studies on diarrheal calves in the Esme.
ABSTRACT
This experiment was conducted to investigate the effects of recombinant porcine Lactobacillus reuteri secreting bovine lactoferrin peptide (LFCA) on growth performance of newborn piglets and the protective effect on porcine transmissible gastroenteritis virus (TGEV)infection which caused piglet diarrhea. Experiment 1:thirty-six one-day-old newborn piglets with an average body weight of about 1.5 kg were randomly divided into 3 groups, which were pPG-LFCA/LR-CO21 group, pPG/LR-CO21 group and control group, each group with 12 piglets. Piglets in each group were orally administered recombinant porcine Lactobacillus reuteri expressing LFCA pPG-LFCA/LR-CO21, containing empty vector plasmid PPG/LR-CO21 and equal volume phosphate buffer (PBS);oral administration continued for 3 days, and the observation time after oral administration was 14 d. During the period, piglets were fed freely, and the changes of body weight and diarrhea were recorded. Experiment 2:thirty one-day-old newborn piglets with an average body weight of about 1.5 kg were randomly divided into 5 groups and given TGEV with a half tissue culture infection dose (TCID50) of 10-7.50/mL by oral administration of 1, 3, 6, 9 and 12 mL, respectively. The observation period of 7 d was set to analyze the conditions of half lethal dose. Experiment 3:another thirty-two newborn piglets with an average body weight of about 1.5 kg were selected as experimental animals and randomly divided into 4 groups, with 8 piglets in each group. The groups were pPG-LFCA/LR-CO21 group, pPG/LR-CO21 group, control group and TGEV infect group. There were 8 replicates in each group and 1 piglet in each replicate. Each head of the experimental group was orally fed ppG-LFCA/LR-CO21, pPG/LR-CO21 and equal volume of PBS at a dose of 2..1010 CFU per day for 1 consecutive week. At 8 days of age, TGEV was infected by oral administration at half lethal dose, and samples were collected after 7 days of infection. The weight change and diarrhea of each group of piglets were recorded;hematoxylin-eosin staining was used to detect the length of intestinal villi and the depth of crypts;enzyme linked immunosorbent assay (ELISA) was used to determine total serum total immunoglobulin G (IgG) and total secretory immunoglobulin A (sIgA) antibody contents. RT-qPCR was used to detect the mRNA relative expression levels of Claudin-1, Occludin, tight junction protein-1 (ZO-1), inflammatory cytokines interleukin-6 (IL-6), interleukin-8 (IL-8), interferon-P (IFN-P), tumor necrosis factor-a (TNF-a) and Toll-like receptor 2 (TLR2). The flora structure of the contents of the piglet's cecum was analyzed. After oral recombinant porcine Lactobacillusreuteri, compared with the control group, the average daily gain of newborn piglets in the pPG-LFCA/LR-CO21 group was significantly increased (P < 0.01), while the diarrhea rate was significantly decreased (P < 0.01). Compared with TGEV infection group, the average daily gain of piglets in pPG-LFCA/LR-CO21 group was increased and diarrhea rate was decreased, and the differences were significant (P < 0.05). Villus height and the ratio of villus height to crypt depth in jejunum and ileum were significantly increased (P < 0.05). The contents of total IgG and intestinal mucosal total sIgA antibody in serum of piglets were significantly increased (P < 0.05);the mRNA relative expression levels of tight junction protein-related genes Claudin-1, Occludin and ZO-1 in intestinal mucosal tissue were extremely significantly increased (P < 0.01), and the serum TNF-a content was extremely significantly decreased (P < 0.01). Serum IFN-P, IL-6, IL-8 and TLR2 contents were significantly increased (P < 0.01), and the survival rate of piglets was improved. The analysis of the bacterial diversity in the contents of the piglets' cecum showed that the proportion of normal intestinal flora of piglets decreased after TGEV infection. Compared with the TGEV infect group, the proportion of pathogenic bacteria Bacteroides in piglet's intestinal flora decreased by o
ABSTRACT
A 1:1 matched case-control study of calves under 1 month of age was carried out by weekly visits to 7 dairy farms in Mashhad, Iran. Fecal samples were collected from 112 calves with diarrhea and 112 controls matched assessed by scoring. Rotavirus and Coronavirus were isolated by antigen capture ELISA test. We found Rotavirus antigen in 29.5% in diarrheic and 17% in normal calves. We detected Coronavirus antigen in 2.7% and 1.8%, respectively. In diarrheic calves Rotavirus was most prevalent at 3rd week age whereas Coronavirus was found in very few cases by 2nd week. Excretion of Rotavirus in feces of scouring calves was greater (P < 0.03) than controls with odds ratio of 1.9 (1.05 - 3.76). We found no relationship between shedding Coronavirus in feces and diarrhea (P value =0.66) with odds ratio equals to 1.4 (0.24 -9.05). We find that Rotavirus is associated with newborn calf diarrhea in industrial dairy farms in Iran.