Accurate detection of SARS-CoV-2 might be a challenge in the molecular biology laboratory for RT-PCR final results

The challenges we experience professionally always teach us to retreat, to document ourselves, to learn, to become better and to succeed in asserting ourselves in the fields we have trained and perfected throughout several years. This also happened in the pandemic times with Covid19, when we had to document RT-PCR techniques in order to be able to detect at the molecular level the SARS-CoV-2 virus responsible for disturbing the world worldwide. Thus, in the molecular biology laboratory, analysts must make very important decisions about the final result of the RT-PCR test to determine – given several analytical criteria – whether the result is negative, positive or equivocal. There are situations where the RT-PCR equipment does not detect all the genes responsible for a clearly positive result, or when the cycle threshold (Ct) is higher than specified in the reagent insert kit, and then it is the analyst's duty to decide what is the final result of molecular test. This paper brings to the fore the involvement, duty and the art of researchers and specialists who must assume the final result of the RT-PCR test in the detection of the SARS-CoV-2 virus responsible for the global pandemic of Covid-19

Effects of Pair versus Individual Housing on Romanian Simmental x Limousine Crossbreed Calves Behaviour

The aim of the study was to assess the effects of housing method on Romanian Simmental x Limousine (RS x L) crossbred calves behaviour. To investigate these effects 12 RS x L calves were separated from damns within the first hour after birth and were housed either individually (n=6) or in pair (n=3 pairs) on straw bedded pens. The inactive standing, habitat exploring and playing behaviours were recorded on days 15, 30, 45 and 60 after birth. Individually housed calves spent more time (P≤0.016) standing inactive (means ±SEM) 5.16±0.47 bouts / day compared to pair housed calves (3.12±0.57 bouts / day). In gregarious animals, presence of a partner reduces stress and fear due to the social isolation. The pair housed calves spent significantly less time (P≤0.039) to explore the habitat (3.5±0.56 bouts / day) compared to individually housed calves, which resulted in higher frequency of exploration bouts (5.83±0.79 bouts / day). Also, paired calves spent more time (P≤0.001) in social contact, playing with the partner (4.16±0.7 bouts / day) compared with individually housed calves (0.16±0.06 bouts / day). These results indicate that housing calves in pairs generated benefits for calves such as better welfare condition, social opportunities and expression of desired behaviours patterns

Influence of Electrical Conductivity, Days in Milk and Parity on Milk Production and Chemical Composition

The aim of study was to assess milk production and chemical composition during the first 100 days of lactation, under the influence of electrical conductivity, parity and days in milk. Study was conducted at Research and Development Station for Bovine Arad, on 66 Romanian Spotted cows (20 primiparous, 46 multiparous). Significantly higher values (p≤0.017) of electrical conductivity were recorded for primiparous (10.15±0.09 mS/cm) compared with multiparous (8.79±0.15 mS/cm). During the first 30 DIM electrical conductivity was higher (9.7±0.12 mS/cm) than for 31 to 60 DIM (9.04±0.12 mS/cm; p≤0.001) and for 61 to 100 DIM (8.17±0.11 mS/cm, p≤0.001). Multifactorial regression model applied highlights significant influence of month of calving (p≤0.001) and DIM (p≤0.034) on the electrical conductivity, while parity had no influence (p>0.36). Medium and negative correlations were calculated between electrical conductivity and some chemical components (fat R=-0.15, protein R=-0.13), while to milk production correlation was positive (R=0.12). No significant correlations were obtained according to lactose content (R=-0.013). Dynamics of milk production and chemical composition have been significantly influenced by month of calving (p≤0.001), DIM (p≤0.001) and parity (p≤0.002). This study found no significant influence of milk electrical conductivity on milk production or chemical composition (p>0.59)