Estimation of the test to test distribution as a proxy for generation interval distribution for the Omicron variant in England

Background Early estimates from South Africa indicated that the Omicron COVID-19 variant may be both more transmissible and have greater immune escape than the previously dominant Delta variant. The rapid turnover of the latest epidemic wave in South Africa as well as initial evidence from contact tracing and household infection studies has prompted speculation that the generation time of the Omicron variant may be shorter in comparable settings than the generation time of the Delta variant. Methods We estimated daily growth rates for the Omicron and Delta variants in each UKHSA region from the 23rd of November to the 23rd of December 2021 using surveillance case counts by date of specimen and S-gene target failure status with an autoregressive model that allowed for time-varying differences in the transmission advantage of the Delta variant where the evidence supported this. By assuming a gamma distributed generation distribution we then estimated the generation time distribution and transmission advantage of the Omicron variant that would be required to explain this time varying advantage. We repeated this estimation process using two different prior estimates for the generation time of the Delta variant first based on household transmission and then based on its intrinsic generation time. Results Visualising our growth rate estimates provided initial evidence for a difference in generation time distributions. Assuming a generation time distribution for Delta with a mean of 2.5-4 days (90% credible interval) and a standard deviation of 1.9-3 days we estimated a shorter generation time distribution for Omicron with a mean of 1.5-3.2 days and a standard deviation of 1.3-4.6 days. This implied a transmission advantage for Omicron in this setting of 160%-210% compared to Delta. We found similar relative results using an estimate of the intrinsic generation time for Delta though all estimates increased in magnitude due to the longer assumed generation time. Conclusions We found that a reduction in the generation time of Omicron compared to Delta was able to explain the observed variation over time in the transmission advantage of the Omicron variant. However, this analysis cannot rule out the role of other factors such as differences in the populations the variants were mixing in, differences in immune escape between variants or bias due to using the test to test distribution as a proxy for the generation time distribution.

Growing of replacement young cattle in ООО «PskovAgroInvest»

ООО «PskovAgroInvest» pays great attention to the rearing of replacement young animals. The rate of increase in the intensity of raising heifers on the farm meets the standards and requirements of pedigree dairy cattle breeding. The farm uses stage-bystage rearing of replacement young stock, taking into account its age. A group approach to rearing young animals. Replacement heifers use natural and cultivated pastures in the summer. In recent years, the age of replacement heifers at the first insemination has noticeably decreased and approached the norm. At the same time, the live weight of animals at the first insemination increased, which in 2020 amounted to 460 kg, which opens up prospects for a further decrease in the age of the first insemination. This became possible due to an increase in the average daily growth in cultivation, which regularly increases every year and amounts to 756 g in 2020, which is 98 g, or 14.9%, more than in 2016. From table 2 it follows that in recent years, at all age periods, replacement heifers had a live weight exceeding the breed standard, which is 250 kg at 10-month-old, 290 kg at 12-month-old and 390 kg at 18-month-old age. At the same time, an increase in the average live weight of the replacement livestock is observed every year. So, in 2020, the value of the indicator was 278 kg at the age of 10 months, 331 kg at the age of 12 months, 463 kg at the age of 18 months, which is 16 kg, 54 kg and 75 kg, or 6.1%, 19, 5% and 19.3%, more than in 2016, respectively. Thus, the analyzed period allows us to conclude about the effectiveness of zootechnical work to improve the rearing of replacement heifers on the farm, but it must be continued in order to reduce the age of first insemination to 15–17 months with the optimal live weight of the livestock.

STRESS-RESISTANT OF PUREBRED AND CROSSBRED PIGS OF DIFFERENT BRED COMBINATIONS

The authors presented the results of experimental studies on the stress-resistant of pigs. The first group is a breed created in Sapphire Ltd. This breed is a breeding group (BG) in purebred breeding and their mixtures in two- and three-breed combinations with Landrace (L) and Duroc (D) boars under conditions of industrial farm technology in Siberia. Two methods assessed stress-resistant of piglets of different breed groups. The first method is “weaning crisis”. The second method is a com-parison of cortisol levels in the blood. Three-breed weanling piglets (SGxL)xD turned out to be the most stress-sensitive. Stress-resistant piglets had an effect on their growth during the rearing period. During this period, stress-resistant animals of all breed combinations had higher average daily gain than stress-sensitive animals (P < 0.001). Stress-resistant animals of the breeding group (SG) showed an average daily growth of 547.5 g during the fattening period. Also, the stress-resistant animals of the breeding group reliably surpassed the stress-sensitive pigs by 461.4 g (P < 0.01), the two-breed pigs by 455.9 g and 404.7 g and the three-breed pigs 451.8 g and 419.2 g, respectively. There was a statistically significant advantage in the indices of the average daily gain among the purebred young-sters of the breeding group (SG) (543 g) compared to the two-breed pigs (447g) and the three-breed pigs (402g), i. e., by 17.8 % and 26 % at P < 0.001. The authors found that the EAAcr/- genotype in stress-sensitive pigs was more common than EAA-/(0.71 ± 0.07 vs 0.48 ± 0.09). Stress-resistant pigs of the breeding group (SG) with EAE edg/edf blood group genotypes were characterized by increased growth intensity and reliable superiority over stress-sensitive pigs. The authors believe that these genotypes can be accepted as preliminary candidates for genetic markers of stress resistant. Blood cortisol levels appeared to be unrelated to stress-resistant compared to the “weaning crisis” method. This relationship (blood cortisol level with stress-resistant) applies to all studied breed combinations, both individually and as a whole.

METHOD TO IMPROVE THE CONSUMER QUALITY AND ENVIRONMENTAL SAFETY OF QUAIL MEAT DURING DENITRIFICATION

Phospholipids are a kind of “solvents” of cholesterol and show a hepatoprotective effect. Also, phospholipids regulate fat and carbohydrate metabolism, improve the functional activity of the liver and its detoxification function. The study aims to study the impact of different doses of phos-pholipid lecithin preparation on economically useful indicators, meat productivity, nutritional value and environmental safety of quail meat at a subtoxic dose of nitrates in their compound feed. This article presents materials that indicate the feasibility of introducing phospholipid preparation of lecithin in the amount of 1.0 % by weight of feed under the presence of a sub-toxic dose of nitrates in the compound feed quail grown for meat. This introduction of phospholipid preparation of lecithin increases the preservation of livestock, body weight gain and reduces the cost of feed per unit gain. Poultry of the 2nd experimental group had an advantage over their control counterparts in preservation rate by 4.0 % and average daily growth by 9.50 % (P<0.05). The authors observed the benefit over the control samples in the concentration of dry substances by 0.98 and 0.99 %, protein by 0.98 and 0.97 % (P<0.05) in the examples of thigh and breast muscles of the poultry of the 2nd experimental group. The value of the protein-quality index (PQI) was higher by 13,55 % (P<0,05) in the samples of white meat from poultry carcasses of the 2nd experimental group as compared with the control counterparts. Also, the examples of poultry meat of the 2nd experimental group had better sanitary and hygienic characteristics. For instance, they had 36.83 % lower nitrate content (P<0.05) and 40.91 % lower nitrites content (P<0.05). This content indicates high denitrifying properties of phospholipid lecithin.

Evaluation of the meat quality of chickens of the egg-meat direction of productivity, for promising use in organic production

Purpose: studying the features of the formation of signs of meat productivity in chickens of the egg-meat direction in the juvenile period in ontogenesis and fixing the most informative age for early assessment of meat qualities.Materials and methods. Young grew in group cells of a 3-tier cellular battery. The dynamics of growth and the development of exterior and interior indicators, characterizing meat productivity in ontogenesis in the young of the Pushkin breed of chickens, which refers to an egg-meat type on productivity through periodic (every 2 weeks) weighing and taking protections of the physique in 100 heads of young people. On 21 heads, an anatomical cutting was carried out at which the mass of the heart, liver, two parts of the stomach (muscular, iron), the sum of the muscles (femur, crus, metatisium) took into account. The development of meat forms of the physique to determine the age and individual characteristics was determined using exterior articles of industrial (the length of the body, the length of the keel, the gripping of the chest, the length of the leg, hips, plus). Prombs were taken from the entire experienced livestock, together with weighing, every 2 weeks. In order to find the most informative age for an early estimate of meat quality, which would characterize meat productivity at an older age, the correlation was calculated between the industrial over the age periods and the mass of muscles at 16 weeks.Results. The dynamics of the average daily growth of the living mass and the mass of the carved carcass in the roosters was uneven. Until 8-week age, the average daily increase increased, then began to decline until 14 weeks of age, during 16-week aged an average increase increased dramatically. The dynamics of average daily growths in the roosters of individual muscles was similar, namely, from 4 to 8-week age, high rates of average daily growth were noted, and from 8 to 14 months of age there is a decrease, and then again activation of growth. Studies have shown that the growth of the skeleton is slowed down by 14 weeks. The dynamics of the average daily growth of internal organs in the roosters in the juvenile period occurs asynchronously. The greatest intensity of the growth of the heart, liver and stomach was observed on a 8-week age. Studies have shown that the stomach is most intensively developing up to 8 weeks, then development is braked sharply.Conclusion. Based on the data obtained, it can be concluded that for the preliminary selection of chickens of the egg-meat direction of cultivation with the best genetic potential for meat productivity, it is possible at 8 weeks old, but the final rating should be carried out no earlier than 14-week age. The estimation of meat qualities in a 14-week age should be carried out on the basis of live masses and industrial, namely, the oblique length of the body, the girth plus, the length of the leg, the preliminary estimate can be done in such a precursor, as the slanting the length of the body, the length of the leg and girth plus.

Influence of mineral and organic artificial substrates on productivity of covered ground tomato under additional lighting

The article presents the results of studying the reaction of tomato plants to an artificial substrate on which they are grown with all other things being equal — lighting, nutrition, temperature, and etc. Among the studied parameters, the plants reacted to the greatest extent with an average daily growth, filling of fruits, which mainly influenced the yield of tomatoes.

Effects of Water Temperature on Growth Criteria of Fingerlings of Grass Carp, Ctenopharyngodon idella (Valenciennes, 1884)

The current experiment was conducted in the Fish Laboratory of Aquaculture Unit, College of Agriculture, University of Basrah from 28th January to 19th April 2021. Growth criteria of grass carp Ctenopharyngodon idella were investigated using four water temperatures (15, 20, 25 and 30 oC). Grass carp fingerlings (4.92 g) were brought from earthen ponds of the Aquaculture Unit in Al-Hartha Station for Agricultural Researches, North Basrah. The results indicated that the highest final weight (7.96 g) was reached by fishes at 15 0C, while the lowest final weight (7.22 g) was at 30 0C. Weight increments for fishes were 3.02, 2.97, 2.76 and 2.22 g for water temperatures of 15, 20, 25 and 30 0C, respectively. Fishes had the highest daily growth rate (0.0425 g/day) at 15 0C and the lowest (0.0312 g/day) at 30 0C. Fishes at 20 0C had the best feed conversion rate of 4.03, while fishes at 30 0C had the worst feed conversion rate of 5.29. It can be concluded that the best growth criteria were obtained from fishes at 15 0C and 20 0C, while the worst was observed at 30 0C.

Effectiveness of Bacillus subtilis (Vitafort) probiotic used for raising broiler chickens

Unbalanced nutrition as well as diseases of infectious and non-infectious etiology lead to a decrease in production and a significant loss of farm animals and birds. To mitigate these problems, various probiotic drugs (probiotics) are introduced into the diets of birds and animals for preventive purposes. The aim of the research was to study the effect of the Vitafort probiotic, containing antagonistic bacteria of the endophytic strain Bacillus subtilis B11, on the body of broiler chickens. The effect of Vitafort was assessed by measuring the live weight and average daily growth of birds. In addition, a morphological study of blood was carried out and the content of Bacillus subtilis in the small intestine was determined. It was found that the endophytic strain Bacillus subtilis B11 improved the intestinal microflora. Thus, on day 5 of its use, the number of microorganisms varied from 4.1 × 104 to 8.2 × 104 CFU/g, and on day 42 the same number varied from 4 × 108 to 5.8 × 108 CFU/g on day 42, the contents of red blood cells, haemoglobin, and white blood cells in the blood of chickens from the experimental group were higher by 6.44%, 3.44%, and 2.11%, respectively, than they were in the control group. Considering the above facts, it can be assumed that the absorption of nutrients in the intestine improved, and metabolic processes were activated due to an increase in the transport abilities of red blood cells.

EFFECT OF ADDITIONAL LEAF EXTRACT OF CIPLUKAN (Physalis angulata L) ON FEED ON THE GROWTH PERFORMANCE OF TILAPIA (Oreochromis niloticus)

The purpose of this study is to determine the effect of the effectiveness of the addition of ciplukan leaf extract (Physalis angulata L.) on feed to the growth performance of tilapia (Oreochromis niloticus). This research method uses a Complete RandomIzed Design (RAL). This study consisted of 4 treatments and 3 replays, so 12 experimental units were used. Dose treatment on P0 (feed without the addition of ciplukan leaf extract), P1 (Feed added ciplukan leaf extract with a dose of 4%), P2 (Feed added ciplukan leaf extract with a dose of 8%), and P3 (Feed added ciplukan leaf extract with a dose of 12%). This dosage treatment is based on Effendi &Hardi research (2014) with dose treatment of 4%, 8%, and 12% per 1kg of feed. the addition of ciplukan leaf extract with a concentration of 8% in feed provides absolute weight growth of (37.39±20.33), survival rate of (83.33±0.9 8), daily growth rate (1.25±0.60), and feed utilization efficiency of (4.67±0.58) and tend to be higher than other treatments.