a. rasooli

The quality of colostrum is affected by IgG level and microbial load.

The quality of colostrum used in feeding dairy calves and passive immunity transfer in selected dairy farms in Fars province, Iran was investigated.

A total of 75 colostrum and neonatal blood samples were collected from 11 herds. The immunological quality of colostrum was assessed using a Brix digital refractometer. The bacteriological quality was assessed by performing total plate count (TPC), total coliform count (TCC), spore-former count, fungi count, and species-specific PCR assay to detect some bacterial species.

The mean Brix of colostrum samples was 25.4% and 72% of the samples had a Brix score ≥22%. The mean serum Brix and the prevalence of failure of passive transfer (FPT) were 10% and 4%, respectively. The mean TPC, TCC, spore-former count, and fungi count were 3.6 × 105, 2.8 × 104, 3.2 × 104, and 1.1 × 104 CFU/ml, respectively. The results showed that 50, 5.9, and 4% of colostrum samples were positive for Staphylococcus spp., Salmonella spp. and Maycobacterium paratuberculosis, respectively. There was no evidence of contamination with Brucella spp., Corynebacterium bovis and Mycoplasma bovis.

Considering all colostrum quality indicators comprehensively, only 37.3% of the studied samples met the industry standard. A large number of calves were at risk of receiving poor quality colostrum, especially in terms of microbial contamination. Further researches are needed to evaluate the colostrum management and the effect of bacterial contamination of colostrum on the health of neonate calves in this region.

Probiotics may improve milk quality and the general health status of animals.

The effects of dietary Bacillus coagulans PRM101 on milk components, milk fatty acids (FA), and some health indicators of dairy cows were investigated.

The probiotic was added to the feed of 12 Holstein cows (2 g/cow: 2 × 1011 CFU/cow) for 63 days compared to a control group fed on the basal ration (n=11). Milk and blood samples were taken on days 0, 21, 42, and 63.

The yields of milk and energy corrected milk (ECM; computed from milk weight and its fat and protein content) decreased linearly and similarly (P=0.60) in both groups. The treatment cows, however, showed quadratic increases in the weights of milk (P=0.03) and ECM (P=0.04) at d42 of the study. Energy corrected milk (d42, p <0.05) and crude protein content of milk (d42, p <0.05; d63, p <0.1) were higher in the cows receiving the probiotic. The proportions of heptadecanoic (C17:0; P=0.002) and linoleic (C18:2; P=0.077) acids in milk fat (g/100 g fat) were higher in the treatment cows on d63. Milk total antioxidant capacity (TAC), malondialdehyde (MDA), and similarly, amyloid A (AA) and haptoglobin (Hp) of milk and blood were not affected. Total antioxidant capacity and MDA were negatively correlated in the control group (r=-0.669, P=0.005). Heptadecanoic acid correlated negatively with milk MDA (r=-0.611, P=0.035) and positively (r=0.591, P=0.043) with serum Hp in the treatment cows.

Dietary B. coagulans PRM101 may improve the proportions of C17:0 and C18:2 FA in milk. Some improvements in milk protein and the health status of the cows may also be anticipated.

The rabies virus infection leads to 60,000 deaths worldwide each year and is considered an economic and social hazard. Although our knowledge of the rabies virus replication and its interaction with the host cell is in its infancy, it helps us design optimal drugs and vaccines. Therefore, the aim of this study was to evaluate the changes in catalase and superoxide dismutase (SOD) enzymes, nitric oxide (NO) chemical composition and NF-κB gene activity as biomarkers of oxidative stress response in brain tissue of mice infected with street rabies virus.

In this experimental study, 16 21-day-old outbred mice were divided into two groups of healthy and experimental (n=8). After determining the titer of rabies virus, the mice in the experimental group received 0.03 ml of rabies virus with LD50 intracerebrally (IC) using Hamilton 0.25 ml syringe. To evaluate the changes of catalase, NO, and SOD enzymes, test kit and colorimetric method were used and NF-kB activity was evaluated by Real-Time PCR according to Sdha gene.

In this study, catalase activity in the brains of infected mice (0.14±0.007) was significantly reduced compared to healthy mice (control) (0.67±0.008) (p=0.01). In this experimental study, the SOD activity in the brains of infected mice (3±0.2 nmol/min/ml) was significantly reduced compared to healthy mice (control) (5.7 nmol/min/ml) (p=0.035). Evaluation of NO accumulation in the brain tissue of the infected group (9.0±0.04 mU/mg) was significantly increased compared to the healthy group (9.04±0.03 mU/mg) (p=0.025). Furthermore, the expression level of NF-κB in the brain of the mice infected with rabies virus was one tenth of the expression of this gene in the brain of healthy mice.

The results showed that rabies virus decreased the activity of catalase and SOD enzymes and increased nitric oxide. Furthermore, NF-κB expression decreased in the brain of mice infected with rabies virus, which may be due to the effect of the virus on the cellular signaling pathway.