The aims of this study were to determine the presence and quantities of antioxidative status and oxidative stress (OS) variables in the seminal plasma and spermatozoa of bulls of varying age during cold and warm periods of the year, and to establish the correlation of these variables with semen quality parameters. The study was conducted on two groups each comprising nine Simmental bulls: one group contained younger animals (aged 2 to 4 years) and the second older animals (aged 5 to 10 years). Semen samples were collected using an artificial vagina for biochemical analysis. Seminal plasma and spermatozoa activities of total superoxide dismutase (TSOD), manganese superoxide dismutase (MnSOD), copper-zinc superoxide dismutase (CuZnSOD), catalase (CAT), selenium-dependent glutathione peroxidase, reduced glutathione and concentrations of total protein (TP), thiobarbituric acid reactive substances (TBARS) and protein carbonyl content (PCC) were determined. Several antioxidants in seminal plasma were also determined: total glutathione peroxidase (TGSH-Px), selenium-independent glutathione peroxidase (Non-SeGSH-Px), uric acid, albumins (ALB) and alkaline phosphatase (ALP). Significantly higher spermatozoa motility was observed during the cold v. warm period, and a significantly higher volume and total number of spermatozoa per ejaculate was observed in older than in younger bulls. Significantly higher values of ALP, TP and ALB were found in seminal plasma of older bulls than in younger bulls during the warm period. The seminal plasma of younger bulls showed significantly higher activities of TSOD, MnSOD, CuZnSOD, TGSH-Px and Non-SeGSH-Px. Younger bulls had significantly higher PCC concentration and activity of CAT in seminal plasma than older bulls during the cold period. Significantly higher concentrations of PCC and TBARS, and activities of TSOD, MnSOD and CuZnSOD were established in spermatozoa of the younger than in older bulls during the warm period. It could be concluded that antioxidative and OS variables differ significantly depending on bull age and time of year. Younger bulls were more sensitive to elevated ambient temperatures during the warm period, when the higher enzymatic antioxidative protection in seminal plasma and spermatozoa were insufficient to counteract the intensive oxidative processes in spermatozoa, which eventually resulted in decreased spermatozoa motility. The estimation of antioxidative and OS variables in seminal plasma and spermatozoa may have practical value for the assessment of bull semen quality.

In animal production, alternative strategies to the use of antibiotic growth promoters have stimulated research of dietary supplements to increase resistance, reduce post-weaning gut disorders and growth checks in pigs. This study was performed to determine the influence of dietary mannan oligosaccharide as a potential alternative to antibiotic growth promoters in weaned pigs on: (1) proliferation of circulating and intestinal immune cell subsets, (2) incidence and severity of diarrhoea, and (3) performance during 35 days of trial. Forty-six pigs from a commercial farm were divided into two groups comprising 23 pigs each and treated at 4 weeks of age as follows: controls received standard weaner diet, whereas diet for principals was supplemented with 0.2% of mannan oligosaccharide. The pigs were monitored/sampled on daily, weekly or monthly basis for feed efficiency, growth rate, diarrhoea severity scores, blood samples, rectal swabs and intesinal samples for bacterial isolation/counts and immunohistology/ histomorphometry analyses. The principals were heavier (P < 0.05) at 28 days and grew faster between days 7 and 28 compared to controls. Total diarrhoea score recorded in these pigs was decreased by 20.37%. Total bacterial load in jejunum was decreased in these pigs (23 × 10 7 vs. 19 × 10 8 colony forming units/ml) at day 35. Between days 28 and 35 or days 21 and 28, the principals increased in proportions of circulating CD45 + , CD4 + , CD21 + , CD8 + cells (P < 0.01), respectively. These pigs had increased (P < 0.05) the number of CD45RA + cells in interfollicular and follicular areas of ileal Payer's patches at day 35. We concluded that dietary modulation with mannan oligosaccharide resulted in stimulation of immune responses and reduced number of gut microbiota, but not necessarily promoting the growth of pigs.

The aim of this study was to determine the effects of dietary vibroactivated clinoptilolite supplementation on the intramammary microbiological findings in dairy cows, causative agents of potential intramammary infection, and their sensitivity to antibiotics. Cows (n = 78) were randomly divided into two groups: CPL-treated group that received clinoptilolite (CPL) in-feed (n = 38), i.e., 50 g natural powdered zeolite CPL, twice daily from the seventh month of pregnancy to 75 days after calving, and the control group (CON) of untreated cows (n = 40). Milk samples were taken from each cow on days 7, 25, 45, and 75 postpartum. The following causative pathogens were isolated in 86 udder quarters: Staphylococcus aureus in 5.81% of positive samples, Staphylococcus spp. 9.32%, coagulase-negative Staphylococcus (CNS) 22.09%, Streptococcus uberis 13.95%, Streptococcus agalactiae 1.16%, Streptococcus sp. 3.49%, Escherichia coli 8.13%, Enterococcus spp. 6.98%, Corynebacterium spp. 11.63%, Pasteurella sp. 10.47%, Serratia spp. 2.33%, and Arcanobacterium pyogenes, Citrobacter sp., Prototheca sp., and yeasts each in 1.16% of samples. Additionally, 3.87% of environmental microflora samples (n = 47) and 89.06% of udder samples (n = 1083) were bacteriologically negative. The most effective antibiotics were cefoperazone and amoxicillin-clavulanic acid, while cloxacillin and tetracycline were the least effective antibiotics in both groups. In the clinoptilolite supplemented (CPL) group (n = 38) of 14 cows, nine causative agents of mastitis were isolated in 27 quarters, while in the control (CON) group (n = 40) of 24 cows, 13 causative agents of mastitis were isolated in 59 quarters. Cows from the CON group had a 1.96 times higher risk of intramammary infection than cows from the CPL group during the observation period (odds ratio = 1.96, p = 0.0031; 95% CI = 1.2570–3.0770).

This study aimed to investigate the climatical impacts of air temperature, sunlight duration, and rain precipitation, in a moderate climate, on the reproductive performance of Romanov sheep in the continental part of Croatia, during two consecutive years (2019-2020).

Preweaning piglet mortality is a serious source of economic losses in pig production, with enteric diseases as the most common infectious cause of mortality. The aim of this study was to determine the efficacy of teat sanitation in lactating sows in order to reduce the piglet bacterial invasion through contaminated teats leading to outbreaks of enteric diseases. The study was carried out in a farrowing pen with 60 sows divided into three groups of 20 animals. Group 1 animals served as the control group and were left untreated. In group 2, sow teats were treated with water and in group 3 with a commercial antiseptic with potent bactericidal action. Microbiological purity of the teats was determined during 24 days of the piglet suckling period. Study results showed the bacterial count per teat to be significantly lower in both experimental groups as compared with the control group (p<0.01). Also, bacterial count was significantly lower in group 3 treated with the antiseptic than in group 2 treated with water alone (p<0.01). Accordingly, sow teat sanitation is a potential prophylactic measure during the piglet suckling period as it significantly decreased bacterial count on sow teats, thus reducing the risk of bacterial invasion of the piglet alimentary system