Rearing calves outdoors with and without calf jackets compared with indoor housing on calf health and live-weight performance

peer-reviewedThe objective of this study was to compare the effects of rearing calves outdoors, with and without all-weather calf jackets, with calves reared indoors on calf immunity and animal performance. In February 1999, male Holstein calves (mean (s.e.) weight 55 (1.90) kg) were randomly assigned to one of three treatments (n=30 per treatment): 1) outdoors with jacket, (J; mean age 19 (s.e. 2.0) days); 2) outdoors without jacket (NJ; mean age 19 (s.e. 1.8) days), and 3) indoors on straw (I; mean age 19 (s.e. 1.0) days). Calves received an individual allowance of 25 kg of milk replacer dry matter during the first 42 days with ad libitum access to a concentrate ration from day 0 to 63. The jackets were removed from the calves on day 42. Live-weight gain from day 0 to day 63 of the study was not significantly different between treatments (J, 0.79; NJ, 0.80; I, 0.80 kg). Sixty percent of the J calves and 53% of the NJ calves required four or more antibiotic treatments for respiratory disease while corresponding treatments were required for 97% of the I calves. The incidence of diarrhoea was significantly higher in both outdoor treatments compared to the I treatment. There was no significant difference in white blood cell counts or in serum immunoglobulin concentrations between treatments on days 0, 21, 42 and 63 or in in vitro interferon-γ production on day 63. It is concluded that using calf jackets on calves reared outdoors had no beneficial effect on calf performance or immune status. The incidence of respiratory disease was higher and diarrhoea incidence was lower in calves reared indoors compared with calves reared outdoors. There was no significant difference in incidences of diarrhoea and respiratory disease between the two outdoor treatments

Scoping a public health impact assessment of aquaculture with particular reference to tilapia in the UK

Background. The paper explores shaping public health impact assessment tools for tilapia, a novel emergent aquaculture sector in the UK. This Research Council’s UK Rural Economy and Land Use project embraces technical, public health, and marketing perspectives scoping tools to assess possible impacts of the activity. Globally, aquaculture produced over 65 million tonnes of food in 2008 and will grow significantly requiring apposite global public health impact assessment tools.<p></p> Methods. Quantitative and qualitative methods incorporated data from a tridisciplinary literature. Holistic tools scoped tilapia farming impact assessments. Laboratory-based tilapia production generated data on impacts in UK and Thailand along with 11 UK focus groups involving 90 consumers, 30 interviews and site visits, 9 visits to UK tilapia growers and 2 in The Netherlands.<p></p> Results. The feasibility, challenges, strengths, and weaknesses of creating a tilapia Public Health Impact Assessment are analysed. Occupational and environmental health benefits and risks attached to tilapia production were identified.<p></p> Conclusions. Scoping public health impacts of tilapia production is possible at different levels and forms for producers, retailers, consumers, civil society and governmental bodies that may contribute to complex and interrelated public health assessments of aquaculture projects. Our assessment framework constitutes an innovatory perspective in the field

The shape and dynamics of a heliotropic dusty ringlet in the Cassini Division

The so-called "Charming Ringlet" (R/2006 S3) is a low-optical-depth, dusty ringlet located in the Laplace gap in the Cassini Division. This ringlet is particularly interesting because its radial position varies systematically with longitude relative to the Sun in such a way that the ringlet's geometric center appears to be displaced away from Saturn's center in a direction roughly toward the Sun. In other words, the ringlet is always found at greater distances from the planet's center at longitudes near the sub-solar longitude than it is at longitudes near Saturn's shadow. This "heliotropic" behavior indicates that the dynamics of the particles in this ring are being influenced by solar radiation pressure. In order to investigate this phenomenon, which has been predicted theoretically but has never been observed this clearly, we analyze multiple image sequences of this ringlet obtained by Cassini in order to constrain its shape and orientation. These data can be fit reasonably well with a model in which both the eccentricity and the inclination of the ringlet have "forced" components (that maintain a fixed orientation relative to the Sun) as well as "free" components (that drift around the planet at steady rates determined by Saturn's oblateness). While the magnitude of the forced eccentricity is roughly consistent with theoretical expectations for radiation pressure acting on 10-to-100-micron-wide icy grains, the existence of significant free eccentricities and inclinations poses a significant challenge for models of low-optical-depth dusty rings.Comment: 31 pages, 6 figures, accepted for publication in Icarus. Slight edits made to match various proof correction

Horseshoe-based Bayesian nonparametric estimation of effective population size trajectories

Phylodynamics is an area of population genetics that uses genetic sequence data to estimate past population dynamics. Modern state-of-the-art Bayesian nonparametric methods for recovering population size trajectories of unknown form use either change-point models or Gaussian process priors. Change-point models suffer from computational issues when the number of change-points is unknown and needs to be estimated. Gaussian process-based methods lack local adaptivity and cannot accurately recover trajectories that exhibit features such as abrupt changes in trend or varying levels of smoothness. We propose a novel, locally-adaptive approach to Bayesian nonparametric phylodynamic inference that has the flexibility to accommodate a large class of functional behaviors. Local adaptivity results from modeling the log-transformed effective population size a priori as a horseshoe Markov random field, a recently proposed statistical model that blends together the best properties of the change-point and Gaussian process modeling paradigms. We use simulated data to assess model performance, and find that our proposed method results in reduced bias and increased precision when compared to contemporary methods. We also use our models to reconstruct past changes in genetic diversity of human hepatitis C virus in Egypt and to estimate population size changes of ancient and modern steppe bison. These analyses show that our new method captures features of the population size trajectories that were missed by the state-of-the-art methods.Comment: 36 pages, including supplementary informatio

Interactions between Nuclear Polyhedrosis Virus and Three Larval Parasitoids of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae)

Interactions between a Helicoverpa nuclear polyhedrosis virus (NPV) and three larval parasitoids of H. armigera were recorded in laboratory studies. the parasitoids Microplitis demolitor, Cotesia kazak and Hyposoter didymator required a time advantage of at least 3 d at 25°C before the host was exposed to NPV to ensure successful completion of development. Helicoverpa larvae parasitised by C. kazak died from NPV after the parasitoids emerged from the host, and thus could provide a source of virus inoculum for secondary spread of the disease. On the other hand, as the interval between parasitisation and host exposure to NPV increased, the proportion of hosts parasitised by M. demolitor which died from NPV after emergence of the parasitoid decreased. It was also shown that as the time interval between host parasitisation by M. demolitor and exposure to virus increased, higher virus doses were required to kill parasitised hosts than were required for nonparasitised hosts of the same age

Effect of Host Plant on Parasitism of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) by Hyposoter didymator Thunberg (Hymenoptera: Ichneumonidae) and Cotesia kazak (Telenga) (Hymenoptera: Braconidae)

The effect of host plant on parasitism of second-instar Helicoverpa armigera by two introduced larval parasitoids, Hyposoter didymator and Cotesia kazak, was investigated in glasshouse experiments. Parasitism was lowest on chickpea (5.4% for H. didymator and 11.8% for C. kazak). Higher levels of parasitism (50.1-85.0% for H. didymator and 25.7-55.3% for C. kazak) were recorded on sorghum, sunflower, cotton, soybean and pigeonpea. This suggests that the parasitoids should be released against Helicoverpa spp. infestations on the major summer crops—sorghum, sunflower, cotton and soybean—rather than against the first spring generation infesting chickpea. Sorghum and sunflower are preferred release crops because parasitism levels are high and disruption by insecticide sprays is less likely

Understanding the Observed Evolution of the Galaxy Luminosity Function from z=6-10 in the Context of Hierarchical Structure Formation

Recent observations of the Lyman-break galaxy (LBG) luminosity function (LF) from z~6-10 show a steep decline in abundance with increasing redshift. However, the LF is a convolution of the mass function of dark matter halos (HMF)--which also declines sharply over this redshift range--and the galaxy-formation physics that maps halo mass to galaxy luminosity. We consider the strong observed evolution in the LF from z~6-10 in this context and determine whether it can be explained solely by the behavior of the HMF. From z~6-8, we find a residual change in the physics of galaxy formation corresponding to a ~0.5 dex increase in the average luminosity of a halo of fixed mass. On the other hand, our analysis of recent LF measurements at z~10 shows that the paucity of detected galaxies is consistent with almost no change in the average luminosity at fixed halo mass from z~8. The LF slope also constrains the variation about this mean such that the luminosity of galaxies hosted by halos of the same mass are all within about an order-of-magnitude of each other. We show that these results are well-described by a simple model of galaxy formation in which cold-flow accretion is balanced by star formation and momentum-driven outflows. If galaxy formation proceeds in halos with masses down to 10^8 Msun, then such a model predicts that LBGs at z~10 should be able to maintain an ionized intergalactic medium as long as the ratio of the clumping factor to the ionizing escape fraction is C/f_esc < 10.Comment: 15 pages, 2 figures; results unchanged; accepted by JCA

Intensive management in grasslands causes diffuse water pollution at the farm scale

Arable land use is generally assumed to be the largest contributor to agricultural diffuse pollution. This study adds to the growing evidence that conventional temperate intensively managed lowland grasslands contribute significantly to soil erosion and diffuse pollution rates. This is the first grassland study to monitor hydrological characteristics and multiple pollutant fluxes (suspended sediment [SS] and the macronutrients: total oxidized nitrogen-N [TONN], total phosphorus [TP], and total carbon [TC]) at high temporal resolution (monitoring up to every 15 min) over 1 yr. Monitoring was conducted across three fields (6.5-7.5 ha) on the North Wyke Farm Platform, UK. The estimated annual erosion rates (up to 527.4 kg ha-1), TP losses (up to 0.9 kg ha-1), and TC losses (up to 179 kg ha-1) were similar to or exceeded the losses reported for other grassland, mixed land-use, and arable sites. Annual yields of TONN (up to 3 kg ha-1) were less than arable land-use fluxes and earlier grassland N studies, an important result as the study site is situated within a Nitrate Vulnerable Zone. The high-resolution monitoring allowed detailed "system's functioning" understanding of hydrological processes, mobilization- transport pathways of individual pollutants, and the changes of the relative importance of diffuse pollutants through flow conditions and time. Suspended sediment and TP concentrations frequently exceeded water quality guidelines recommended by the European Freshwater Fisheries Directive (25 mg L-1) and the European Water Framework Directive (0.04 mg soluble reactive P L-1), suggesting that intensively managed grasslands pose a significant threat to receiving surface waters. Such sediment and nutrient losses from intensively managed grasslands should be acknowledged in land management guidelines and advice for future compliance with surface water quality standards.NERC-Case PhD awardUK Biotechnology and Biological Sciences Research Counci

The welfare of animals transported from Ireland to Spain AND The Physiological haematological and immunological responses of 9-month old bulls (250kg) to transport at two stocking densities (0.85m2 and 1.27m2 /250kg animal) on a 12-hour journey by road.

End of Project ReportFifty-two weanling continental x beef heifers (mean liveweight 269kg) were transported from Ireland to France on a roll-on roll-off ferry (RO-RO), and onwards by road for 3-hours to a French lairage, rested for 24 hours at a staging post and taken by road on an 18-hour journey through France to a feedlot in Spain. Animals transported to France lost 7.6 % of their bodyweight, and gained 3.3 % of their bodyweight by time of arrival in Spain and recovered to pre-transport liveweight values by day 6. Although there was some evidence that transport affected physiological and immunological variables, there was no evidence to suggest that it adversely affected the health or the performance of the animals post transport. Creatine kinase activities were increased but values were still within normal acceptable ranges. Increases in non-esterified fatty acids, beta-hydroxybutyrate and urea concentrations suggested that the animals' normal pattern of feeding was disrupted during transport. Increases in albumin, total plasma protein and osmolality would indicate slight dehydration during transit. However, albumin concentrations returned to control levels by day 38 of the study. While haematocrit values were decreased, they are within the range of normal referenced data (24 - 48%). Similarly, changes in the RBC numbers and haemoglobin were within the normal blood referenced ranges ((RBC; 5.0 – 10.0 x106 /ml) and (haemoglobin 8-14 g%)(Schalm, 1961)). The only time at which white blood counts increased above the upper limit of 12, was 12 hours after arrival at the French lairage. The aspartate transaminase concentrations for the transported animals at arrival in France and Spain were not significantly different from their pre-transport concentrations but were increased at day 11 when compared with baseline levels. Concanavalin-A induced interferon-g levels were lower on arrival in the Spanish feedlot and on Day 11 of the study, when compared with pre-transport baseline levels. Compared with pre-transport levels, keyhole limpet haemocyanin-induced interferon-g levels for the transported animals were significantly decreased on the day of arrival in France, with no significant difference on the day of arrival in Spain or on day 11 of the study. Interferon-g is produced by activated T lymphocytes and natural killer cells in response to antigen. The percentage (%) of lymphocytes decreased and the % neutrophils increased post-transport indicating a shift in the population of these blood cells relative to pre-transport baseline values. There was no significant change in plasma cortisol concentrations in transported animals at arrival in France and in Spain. On Day 11, the plasma cortisol concentrations of transported animals were significantly higher than control animals. There were significantly higher glucose concentrations on arrival in France, and in samples taken at 12 and 24 hours post-arrival in France, on arrival in Spain, and on days 7 and 11 compared with control levels. Transported animals had significantly higher glucose levels at sample 2 on the day of arrival in France compared with their pre-transport values. Transported animals had significantly higher fibrinogen levels at arrival in France compared with their pre-transport baseline concentrations. Inflammation resulting from stress can cause the release of acute phase proteins such as haptoglobin and fibrinogen, and acute phase proteins in cattle have been associated with immunosuppression, however, much higher levels have been reported in inflammatory conditions. Transported animals had significantly higher non-esterified fatty acid (NEFA) levels on arrival in France and Spain and on day 11 compared with their pre-transport baseline concentrations. Control animals had significantly higher levels on day 5 compared with their pre-transport baseline NEFA concentrations. However, all levels were within the normal acceptable ranges. The study concluded that transport had no adverse effect on animal welfare based on the physiological, immunological and haematological measurements made