فصلنامه دامپزشکی ایران
سال بیست و یکم شماره 89 (زمستان 1404)

During the transition and peak lactation period, high-yielding dairy cows may face significant metabolic challenges, which can affect their health and productivity. These problems can be alleviated by Chromium, which is an essential trace element. This study investigated the effects of nano-chromium picolinate (Nano-Cr) and chromium picolinate (Cr) on serum concentrations of Ca, Ma, P, Iron, Copper, Zinc, Cobalt, and Selenium in Holstein dairy cows. Thirty-six cows were divided into three groups: the control group, the Nano-Cr group which received nanochromium picolinate 0.1 mg/Kg MW (metabolic weight) orally for 21 days, and the Cr group, which received chromium picolinate 0.1 mg/Kg MW orally for 21 days. The collection of blood samples took place on days 0, 7, 14, 21, and 28 and serum mineral concentrations were assessed using ICP-OES. The results demonstrated that the serum levels of ionized calcium on days 21 and 28 and magnesium on day 28, rose significantly compared to the control group. Also, the ionized calcium concentration in the blood of the nanochrome group was significantly higher than that of the Cr group on day 28. In the Cr group, a significant increase in the serum level of ionized calcium and magnesium was only noted on day 28 in comparison to the control group. The serum iron levels in the Nano-Cr group showed a significant decline on days 14, 21 and 28 compared to the control group. On day 28, the reduction in iron levels in the Cr group was also significant in comparison to the control group. Additionally, serum Zinc concentrations decreased on day 28 in both Nano-Cr and Cr groups compared to the control group. Serum concentrations of phosphorus, copper, cobalt, and selenium remained stable across all groups and time points. According to these findings, Nano-Cr has a higher bioavailability than Cr and has a positive impact on calcium and magnesium homeostasis, which is essential for preventing metabolic disorders in dairy cows. Also, the simultaneous decreases in iron and zinc concentrations emphasize the importance of monitoring supplementation closely to prevent mineral imbalances.

Dietary consumption of low crude protein (CP) diets in poultry can decrease the feed costs and environmental pollution. In addition to reducing feed costs, improved broiler welfare and environmental sustainability are the other benefits of feeding chickens with reduced CP. This experiment was performed to evaluate the effect of different levels of tryptophan in low protein diets on performance of broiler chickens.  This study was conducted using 200 one-day old male broilers of Ross 308 strain from 8 to 21 days old with 4 treatments, 5 repetitions and 10 birds per replication. Experimental treatments which were adjusted based on Brazilian tables included: 1- Control treatment, 2- Recommended level of tryptophan in the diet with 2% low protein, 3- 10% higher than the recommended level of tryptophan in the diet with 2% low protein and 4- 20% more than the recommended level of tryptophan in the diet with 2% low protein. The results showed that the treatment with 10% tryptophan increased the weight (721.8 g) of chickens. But reducing dietary protein reduced feed intake. Also, 10% tryptophan had a significant effect on glucose, triglycerides, total protein and globulin. But cholesterol and albumin were not affected by treatments. Diet with 10% tryptophan increased superoxide dismutase (171.6) and glutathione peroxidase (179.4). High dietary protein (control treatment) increased blood urea and uric acid and also increased litter nitrogen. None of the treatments had significant effect on intestinal morphology.  Totally, the results of the recent experiment improve performance and antioxidant capacity.

This cross-sectional study aimed to identify the risk factors associated with in-transit mortality, live weight loss during transportation, and slaughterhouse ccarcass ondemnations in broiler chickens processed at an industrial slaughterhouse in Shiraz, Iran. Data were collected over a one-year period from 103 flocks (123,345 birds). The results showed that poultry rearing during the cold season was significantly associated with a higher prevalence of footpad dermatitis (62.3%) compared with the warm season (45.3%); whereas slaughterhouse condemnations due to severe emaciation were more frequent in the warm season (0.11% vs 0.08%). Heavier broilers at slaughter exhibited greater weight loss during transport, a higher incidence of shoulder dislocation, and higher condemnation rates due to ascites. Longer duration from loading to slaughter (time spent in crates) was positively correlated with higher weight loss and physical injuries including shoulder dislocation, bruising, and skin lesions.  In contrast, crate stocking density and crop fill status showed limited effects on weight loss, in-transit mortality, or physical damage to the birds. These findings highlight the importance of season-specific management practices, producing broiler chickens with lower slaughter weight, optimizing transport stocking density, and minimizing pre-slaughter holding time to reduce losses and improve animal welfare. The results provide practical guidance for the poultry industry to mitigate economic losses and enhance final product quality.

Ulcerative colitis is associated with various neurological complications including peripheral neuropathy, headache, depression, anxiety, and cognitive impairments. This study aimed to evaluate the anxiolytic and anti-inflammatory effects of alpha-pinene on anxiety-like behaviors in an acetic acid-induced colitis model in male Wistar rats. Twenty-four rats were randomly assigned into four groups (n=6): control, colitis with normal saline treatment, and two colitis groups treated with alpha-pinene at doses of 50 and 100 mg/kg. Following colitis induction, anxiety-like behaviors were assessed using the open field test and elevated plus maze. Additionally, TNF-α levels in brain tissue were measured. The results of the study showed that colitis significantly increased anxiety-like behaviors and elevated TNF-α levels in the brain. Treatment with alpha-pinene at both doses markedly reduced anxiety-like behaviors and brain TNF-α levels. These findings suggest that alpha-pinene exerts notable anti-inflammatory and anxiolytic effects in the acetic acid-induced colitis model and may serve as a potential therapeutic agent to alleviate neurological complications associated with colitis.

The chicken major histocompatibility complex (MHC), known as the B-locus or serological blood group, is responsible for controlling autoimmune and resistance to viral, bacterial, and parasitic diseases. The microsatellite LEI0258, as a reliable marker for avian MHC typing, can be used to determine the identity of different populations and individual or breed characteristics in academic and applied studies. In this study, High Resolution Melting (HRM) analysis was used to determine MHC genotypes based on the LEI0258 microsatellite in Ross 308 broiler chickens. To this end, genotypes were first determined by conventional PCR and electrophoresis methods, as well as fragment analysis, and then the findings were compared and analyzed with the results of the HRM assay. From 100 samples, 5 genotypes were identified in conventional PCR and electrophoresis assays, as well as fragment analysis. These genotypes included alleles with molecular weights of 448, 385, 300, and 207 base pairs. In HRM analysis, normalized fluorescence changes versus temperature (degrees Celsius) were evaluated for five different genotypes. The results showed that the HRM method is capable of discriminating different genotypes as well as homozygous and heterozygous cases. Overall, it seems that the high-resolution melting analysis method can be applied to study the diversity of avian MHC genes. Although this technique cannot precisely identify the alleles of each chromosome, due to the co-dominant nature of MHC genes, the results are acceptable for assessing genetic composition and determining genotypes.

Escherichia coli is an important member of the Enterobacteriaceae family, that can cause disease(s) in humans and a wide range of animals, including dogs and cats. The aim of the present study was to determine the phylogenetic groups and phenotypic identification of extended-spectrum beta-lactamases (ESBL) in Escherichia coli isolates obtained from diarrheal and non-diarrheic dogs and to detect the antibiotic sensitivity profile of positive ESBL isolates. The cultivation of stool samples in selected environments and confirmation of the resulting isolates were obtained by performing additional biochemical tests. Determination of the phylogenetic groups was done in the isolates by the Claremont method using primers ChuA, YjaA, TspE4.c2, and arpA; Moreover, phenotypic identification of ESBL was approved by the combined disc method and the CLSI protocol. From one hundred and fifty stool samples, 182 Escherichia coli isolates were obtained eventually. From this number, 100 isolates were selected to determine the phylogenetic groups and phenotypic identification of ESBL-producing Escherichia coli. Phylogenetic analyses showed that Escherichia coli isolates from dogs belonged to phylogeny groups A, B1, B2, D and F, with prevalence rates of 39%, 42%, 4%, 9% and 6%, respectively. Also, the frequency of phylogenetic groups in diarrheal dogs was (42.3%) in group A, (38.5%) in B1, (9.6%) in D, (5.8%) in F, and (3.9%) in B2. In addition, in healthy dogs, the phylogeny groups were in (43.07%) in group B1, (39.26%) in A, (7.7%) in D, (6.2%) in F and (3.96%) in B2. Out of 100 Escherichia coli isolates, 31 isolates (31%) were phenotypically beta-lactamase ESBLs producers. Twelve isolates (38.7%) were related to diarrhea samples and 19 isolates (61.3%) were related to healthy dogs. The high prevalence of Escherichia coli isolates producing ESBL enzymes in Ahvaz district increases the risk of spread and transmission of ESBL-producing strains in the pet population and their transmission to the human population.

Insufficient awareness among livestock farmers about the epidemiology of parasitic diseases is one of the main obstacles to their control and prevention. Therfore, the present stuy aimed to determine the level of knowledge, attitude and practice of livestock farmers in Khuzestan province regarding parasitic diseases and drug resistance. The results of the study is given as follows: the relative frequency of awareness of the livestock farmers about the resistance of parasites to drugs 78%, good knowledge 52%, positive attitude 58% and good practice 57.3%. Farming location, duration of farming and satisfaction level had a significant relationship with knowledge. In addition, the farmer's knowledge, farming location, age and satisfaction level had a significant effect on the attitude. Also, farmer's attitude, satisfaction level, farmer's occupation and gender had a significant effect on practice. The findings of the present study showed that the level of awareness of livestock farmers of Khuzestan province about the resistance of parasites to drugs is high, but they do not have an acceptable performance in the context of rotating use of anti-parasitic drugs, consultation with a veterinarian for treatment, suitable ways to store the drug, and not using livestock’s product for a period after anthelmintic treatment. Also, this study showed that the level of knowledge, attitude and practice of livestock farmers of this province is acceptable, so that a significant percentage of livestock farmers are aware of the commonality of some parasitic diseases between humans and animals, the role of dogs in the occurrence of some of them, the quarantine of new animals entering herd, the ways of entry and the symptoms of parasitic diseases; however, a number of them are unaware of the possibility of some parasitic agents entering through mating and do not carry out spraying the place and anti-mite bath in preventing some parasitic diseases. Therefore, it is recommended that the interest of farmers to receive training through veterinarians, retraining classes on new findings of parasitic diseases and ways to prevention, control and treatment for the veterinarians of the province be taken into account.