Physical activity, diet and gene-environment interactions in relation to body mass index and waist circumference: the Swedish young male twins study

OBJECTIVE: The aim of the present study was to examine the relationships between genetic susceptibility to obesity, physical activity (PA), dietary fibre, sugar and fat intakes and 4-year changes in body mass index (BMI) and attained waist circumference (WC) in a cohort of 287 monozygotic and 189 dizygotic young adult male twin pairs. Increased knowledge about interactions between genes and environment may provide insight into why some individuals are more prone to obesity than others. DESIGN: Information about PA, BMI, dietary habits, WC and potential confounders was collected by questionnaire in 1998 and 2002. The cohort data were analysed by mixed linear models. RESULTS: Twins with low PA attained larger WC than twins with high PA (difference 2.5 cm; 95% confidence interval (CI) 1.3, 3.6). The twins with the lowest fibre intake were found to have attained the highest WC and to have increased most in BMI (difference between highest and lowest fibre intakes: 1.6 cm, 95% CI 0.4, 2.9 and 0.45 kg m(-2), 95% CI 0.15, 0.76, respectively). Furthermore, our results suggested the presence of interactions so that twins with genetic susceptibility to obesity were more prone to have larger WC if sedentary than twins without genetic susceptibility. CONCLUSION: PA and a diet rich in fibre may be protective against weight gain among younger adult men. An interaction between PA, genes and attained WC is a novel finding which needs confirmation by other studies.     

Factors affecting piglet mortality in loose farrowing systems on commercial farms

Crating sows in farrowing systems greatly restricts their normal behaviour (e.g. movement, nest-building, leaving the nest site for defecation), which is usually justified by the assumption that piglet mortality is higher with loose-housed sows. Based on experiments showing that this is not the case, farrowing crates were banned in Switzerland in 1997, with a 10-year transitional period. Since then, many farms have introduced loose farrowing systems, enabling an analysis of risk factors for piglet mortality in crateless farrowing systems based on a large sample size. Data from a Swiss sow recording scheme (UFA2000) were analysed using generalised linear mixed-effects models with an underlying Poisson distribution. Average total piglet mortality for the years 2002 and 2003 on 99 farms (N = 12457 litters) with loose farrowing systems amounted to 1.36 liveborn piglets per litter. The number of crushed piglets was 0.64 piglets per litter, whereas the number of piglets that died for other reasons was 0.72 piglets per litter.Herd size, pen size, possibility of confinement of the sow, presence of piglet protection bars and year of data collection did not significantly influence total piglet losses, losses due to crushing and losses due to reasons other than crushing. With greater litter size at birth, significantly more losses occurred due to all reasons (total, crushed, others). Total piglet mortality and losses for reasons other than crushing were significantly higher in older sows. Losses were therefore mainly attributable to sow-related characteristics rather than to the design of the farrowing pen.     

Fecundity and water flow influence the dynamics of Atlantic salmon

Populations are retained at reduced levels by resource competition and environmental stochasticity. In the Norwegian River Imsa, the relationship between fecundity of Atlantic salmon (Salmo salar) spawners and number of smolts per unit river area was investigated for cohorts spawned from 1976 to 2011. Annual number of smolts produced per unit area was best described by a multiplicative model and increased with the fecundity of the females as proxy for number of eggs deposited and the minimum water flow in August towards the end of the first growth season. Mean monthly water temperature, or water flow in any other month during the first year, had no significant effect on number of smolts produced. At sea, there was an almost linear relationship between number of emigrating smolts and returning adults, possibly because population abundance of Atlantic salmon is low relative to the carrying capacity in the ocean. Thus, both number of eggs spawned and minimum water flow in late summer influenced population abundance in the present river.     

水稻秸秆直接还田技术配套机具研究进展

分析了东北一熟区、水旱轮作稻区、双季稻区三大稻区的水稻秸秆直接还田配套机具的研究进展,从水稻收获、耕整地两个作业环节指出各区域实施秸秆还田过程中存在的技术难点及待解决问题。目前,长江中下游地区的水稻秸秆直接还田配套机具已经基本满足农艺要求;东北一熟区的秸秆直接还田仍存在很多问题,由于秸秆韧性强、秸秆量大,造成秸秆粉碎抛撒不均匀问题,导致后期整地困难及春季泡田搅浆后秸秆漂浮严重问题,仍是亟需解决的技术难题;南方双季稻及西南稻区由于地势限制导致的机收水平低问题,也同样限制了水稻秸秆直接还田技术的发展。在此基础上,提出了我国水稻秸秆直接还田技术配套机具发展建议,以期为下一步研究解决稻田秸秆还田关键机具问题提供参考。     

Dermatophytosis in three colony-born spotted hyenas

An adult female hyena and her two 4-month-old cubs were found to have multifocal areas of alopecia and dermatitis. Dermatophyte culture of hair and skin samples collected from the lesions yielded Trichophyton mentagrophytes. None of 10 other animals in the colony that were tested were found to have dermatophytes. Lesions were treated twice, at 3-week intervals, with thorough cleansing with chlorhexidine scrub followed by topical application of antifungal agents. Lesions resolved, and dermatophyte culture of samples collected 6 weeks after the initiation of treatment did not yield growth.     

Fetal responses to different methods of electrocution of pregnant sows

The fetal stress responses in sows euthanized by electrical current during their second and last trimester of pregnancy (G1 and G2) were evaluated. Three methods of euthanasia of pregnant sows generally applicable to cases of epizootic or emergency slaughter were investigated: 1. conventional application of electrical current to the head and heart (HH); 2. application of electrical current to the head, heart and the uterus (HHU); 3. application of electrical current to the head, heart and from the upper body to the vagina (HHV). Fetuses were delivered by cesarean section at intervals of 3 to 4 minutes and remained attached to the sow by the umbilical cord. Fetal vitality, reflexes, heart rate, blood pressure, rectal body temperature, intracardial arteriovenous pCO2, pH and lactic acid were monitored for a period of 30 minutes. No method was found to kill the fetal pigs immediately. In fetuses at G1 there were no significant differences between the HH and HHU and HHV methods. Fetuses at G2 showed a significantly faster decrease in heart rate and blood pressure as well as a shorter period of time for the absence of fetal body movements and reflexes for the HHT method, compared to the other methods. Since it is not yet known to what extent the fetal pig experiences pain and suffering, the prolonged process of dying for the in utero fetus due to hypoxia which includes struggling and gasps is inconsistent with criteria for humane euthanasia and animal welfare.     

ISApl1, a novel insertion element of Actinobacillus pleuropneumoniae, prevents ApxIV-based serological detection of serotype 7 strain AP76

Actinobacillus pleuropneumoniae, a gram-negative rod of the Pasteurellaceae family, causes pleuropneumonia in pigs. Establishing A. pleuropneumoniae free herds is difficult due to the occurrence of persistently infected animals. The ApxIV toxin is expressed by A. pleuropneumoniae in vivo and an ELISA based on the toxin is used to detect infection and to differentiate between infected and vaccinated animals. In this study, we have identified a 1070bp insertion element of the IS30 family, designated ISApl1, in the A. pleuropneumoniae serotype 7 strain AP76. ISApl1 contains a 924bp ORF encoding a transposase, which is flanked by 27bp inverted repeats showing six mismatches. We investigated the occurrence of ISApl1 in other A. pleuropneumoniae strains, and its possible interference with virulence associated factors. Four insertion sites were identified in AP76: within the apxIVA toxin ORF, within a putative autotransporter adhesin ORF, upstream of a capsular polysaccharide biosynthesis gene cluster, and downstream of a beta-lactamase gene. ISApl1 is also present in some serotype 7 field isolates, but not in reference or field strains of other serotypes. In A. pleuropneumoniae AP76, the transposase gene is transcribed in vitro. The insertion in the apxIVA toxin gene remains stable after animal passage. Since this insertion should disrupt toxin expression, we tested 7 pigs infected with AP76 at day 21 post-infection. All were negative in the ApxIV ELISA but four out of seven were positive in an ApxII toxin ELISA. These results show that insertion elements can affect the detection of A. pleuropneumoniae infected animals.