The relative age and birth order effect in Japanese professional football

This study examines how the probability of becoming a professional football player depends on the birth month (relative age effect) and birth order. These two factors are random and cannot be controlled by the athlete. If these factors influence the probability of the occurrence of top athletes, they not only create inequality but also close the disciplines to potentially talented athletes, lowering the level of competition. Therefore, in this study, we statistically clarified the presence or absence of “giftedness of life” by focusing on the birth month and birth order of professional football league players in the Japan Professional Football League (J-League). Our results indicate that the probability of the occurrence of J-League players decreases significantly with increasing birth order and birth month (180 days, from April onward). Moreover, we found that second-born players with an older brother had higher estimated salaries than players without siblings. These results reveal the characteristics of excellent football players and suggest the importance and direction of improvement in talent discovery and development in sports. Based on our results, we recommend improvements in the player training system to buffer the effects of relative age effect and birth order.

The effect of birth month and seasons on athlete aggression

In this study, there were 3,335 football players from four continents from around the world formed a study universe in which the causes of athlete aggression. Also, the factors affecting athlete aggression were investigated with different variables. It has been observed that the levels of aggression of footballers are different according to the positions they play. As the number of matches that players participate in increases, aggression levels increase among the important results. A correlation was found between the ages of the footballers and their levels of aggression, but it was concluded that athletes born in December were more aggressive. Those born in January and those born in winter have shown minimal levels of aggression compared to other footballers. It has been interpreted as having higher levels of aggression, with football players born in December and winter receiving more penalties than other participants. In the continents where football players were born, the highest number of athlete aggression was observed in the participating football players from the continent of Europe, while the aggression of athletes born in the continent of Africa and Asia was found to be lower. Taking into account the data obtained from the research, it was concluded that the athlete's position, age, month, and season of birth and continent of birth are factors affecting athlete aggression.

PSXII-29 Evaluation of Barbados Blackbelly and St. Croix sheep under accelerated lambing using purebred and terminal sire mating: Lamb survival and body weight

Objectives were to evaluate lamb survival and body weight (BW) under an accelerated, pasture-lambing system. Lambs were born to Barbados Blackbelly (BB) or St. Croix dams (SC) mated within breed (purebred) or to Dorset (terminal) in single sire mating groups. Lambs were born in April (2013 and 2015), December (2013 and 2015), and August (2014 and 2016) and weaned at 9 weeks of age. Traits considered were BW at birth (BW0; n = 959), 65-d adjusted weaning BW (BW65; n = 788), and survival to weaning (n = 959). Data were analyzed with fixed effects of dam age, sex, birth type, dam breed (BB vs SC), dam mating system (purebred vs terminal), birth month-year, and significant two-way interactions and a random dam effect. Dam breed did not impact BW65 (P = 0.09). While BW0 was greater for lambs born to SC than BB dams (3.44 vs 3.23 kg; P < 0.01), survival to weaning was greater for lambs born to BB than SC dams (0.93 vs. 0.87; P = 0.02). The dam mating system x birth month-year interaction was significant for both BW traits (P ≤ 0.01). Within birth month-year, BW0 was 18 to 24% greater and BW65 was 12 to 24% greater for terminal than purebred lambs (P < 0.01). However, BW0 differences between dam mating systems were greatest for August born lambs whereas BW65 differences were greatest for April born lambs. Lamb survival was not affected by dam mating system or birth month-year (P ≥ 0.27). Using a terminal sire improved BW without affecting survival of lambs reared by landrace hair sheep dams, making this a viable management tool to increase productivity of forage-based production systems.

Antibacterial use by birth year and birth season in children 0-2 years in Norway

Introduction: Consumption of antibacterials in children follows seasonal cycles, and time to first treatment depends on birth season. The aim of this study was to describe dispensing rate, one-year periodic prevalence, and age at first prescription in children aged 0-2 years in Norway.Methods: We used data from the Norwegian prescription database and included all dispensed prescriptions on systemic antibacterials in 2008-2017 during the first three years of life to children born 2005-2014. We calculated age by subtracting birth month and birth year from date of collection of prescription. We used multiple linear regression to investigate the effect of birth season on age at first dispensed prescription.Results: We included 714 262 prescriptions to 281 888 individuals (53.1% boys). In 2016, one-year-old boys had the highest periodic prevalence (35.6%) and the highest dispense rate (545/1000 individuals), followed by one-year-old girls (32.6%, 478/1000 individuals). The lowest prevalence and dispense rate in all age groups was found towards the end of the period. Winter months had the highest proportion of dispensed prescriptions, and children born in autumn were significantly younger when collecting their first prescription. On average, boys collected their first prescription 26 days younger compared to girls.Conclusion: One-year-olds have the highest periodic prevalence and the highest dispense rate. This contrast with results from other studies on Norwegian data and is probably attributed to our use of birth month for calculation of age. Children born in autumn were younger when collecting their first prescription compared to other birth seasons. It is unknown whether this has any long-term clinical implications.