Monensin controlled-release intraruminal capsule for control of bloat in pastured dairy cows

Monensin, a polyether ionophore antibiotic, is potentially an important agent for bloat relief in dairy cows grazing temperate legume-based pasture. A series of studies was undertaken to determine the effect of monensin, when delivered continuously in the rumen of lactating dairy cows by means of controlled-release capsules (monensin CRC). Such devices release approximately 300 mg/head/day for 100 d. A short-term pilot study made at Ruakura, New Zealand, tested monensin CRC in cows selected for high susceptibility to bloat and grazing lucerne (Medicago sativa) or red clover (Trifolium pratense). Treatment significantly reduced the incidence of bloat, while milk yield and protein yield were increased. There was no effect on fat yield. Following the pilot study, 6 large-scale field experiments involving a total of 368 lactating dairy cows, were made in Australia and New Zealand to confirm the effectiveness of monensin CRC for bloat control and to measure the effect of such treatment on milk production and composition. A severe bloat problem occurred in 2 experiments, mild bloat occurred in 2 others, while no visual signs of bloat were observed in the remaining 2 experiments. Bloat was significantly (P less than 0.05) reduced by monensin CRC treatment when data was pooled over the 4 experiments in which bloat occurred. Daily milk yield was increased in all experiments from a mean of 17.7 in untreated groups to 18.8 kg/head/day (P less than 0.05) in monensin CRC-treated cows. Protein percentage was not affected by treatment, while there was a decrease from 4.29 to 4.10% fat, although total fat yield was not affected.(ABSTRACT TRUNCATED AT 250 WORDS)     

Turloughs - Ireland’s unique wetland habitat

Turloughs are karst wetland ecosystems that are virtually unique to Ireland. Flooding annually in autumn through springs and fissures in the underlying limestone and draining in the springtime, often through the same fissures or swallow-holes, they have been described as ‘temporal ecotones’. Over 300 have been documented. They are priority habitats in the EU Habitats Directive and support a variety of wet grassland and fen type vegetation. Though the vegetation has been recorded and mapped for over 80 turloughs, records for invertebrates are more sporadic. Characteristic species include some aquatic species-often benefiting from the absence of fish-, and many wetland terrestrial species, including carabid beetles that are rare on a European scale. Due to their shallow nature and the full vegetation cover of the basin, turloughs can host internationally significant numbers of visiting winter wildfowl, particularly whooper swans. The variety of plant and invertebrate communities between turloughs is primarily due to different hydrogeomorphological characteristics, but also depends on the range of grazing practices on turloughs. Since these often vary within a turlough basin, this helps maintain within-turlough biodiversity. The main threat to turloughs in the past was drainage, but pollution by nutrients is also now potentially detrimental. However, a more recent and important threat may be the cessation of farming within turloughs. As potentially threatened wetlands of European importance, turloughs require a full inventory of their biodiversity and the factors affecting it. The collation here of all literature concerning turloughs will provide a basis for an integrated approach to future research on turloughs that is essential for a full understanding of these complex ecosystems.     

Genes lost and genes found: evolution of bacterial pathogenesis and symbiosis

Traditionally, evolutionary biologists have viewed mutations within individual genes as the major source of phenotypic variation leading to adaptation through natural selection, and ultimately generating diversity among species. Although such processes must contribute to the initial development of gene functions and their subsequent fine-tuning, changes in genome repertoire, occurring through gene acquisition and deletion, are the major events underlying the emergence and evolution of bacterial pathogens and symbionts. Furthermore, pathogens and symbionts depend on similar mechanisms for interacting with hosts and show parallel trends in genome evolution.     

Three-dimensional polarimetric imaging of coronal mass ejections

We present three-dimensional reconstructions of coronal mass ejections (CMEs), which were obtained through polarization analysis of single-view images recorded with the use of the Large Angle and Spectrometric Coronagraph (LASCO) C2 coronagraph on board the Solar and Heliospheric Observatory (SOHO) spacecraft. Analysis of a loop-like CME shows a complex three-dimensional structure centered at 40 degrees from the plane of the sky, moving radially at 250 kilometers/second. Reconstruction of two halo CMEs suggests that these events are expanding loop arcades.     

A description and evaluation of the physical and financial characteristics of dairy farms operating on soil types classified as poorly drained and associated with high rainfall

The physical and financial performance data used for analysis were obtained over a 6‐year period (2010–2015), from two different databases including a nationally representative data set of dairy farmers and a detailed data set of seven individual farms. Initial analysis indicated significant variations across soil type and region, across a wide range of physical and financial parameters. Further detailed analysis was completed using a group of seven farms participating in a Heavy Soils Programme (HSP), which were compared to different cohorts of the nationally representative database (National Farm Survey [NFS]), ranked on net profit per ha. The HSP farms utilized larger quantities of grass DM per ha per year than the median of the NFS farms, at similar grazing season lengths, but were using lower levels of purchased feed. Economic analysis indicated the HSP farmers achieved significantly lower net profits per hectare to the NFS median group but significantly higher net profits per kg of fat and protein. The HSP farms also achieved significantly greater overall net farm income per year (€83,788), when compared to the median nationally (€67,898), over the 6‐year period (excluding owned land and labour). The mean return on assets ascertained by the HSP farmers was also significantly greater, at 5.75% per year compared to 3.49% achieved by the median of NFS farms. In conclusion, this study has indicated that efficient dairy businesses operating on poorly drained soils can be as profitable as those across all ranges of soil types.     

Evaluating evaporation from field crops using airborne radiometry and ground-based meteorological data

Summary Airborne measurements of reflected solar and emitted thermal radiation were combined with ground-based measurements of incoming solar radiation, air temperature, windspeed, and vapor pressure to calculate instantaneous evaporation (LE) rates using a form of the Penman equation. Estimates of evaporation over cotton, wheat, and alfalfa fields were obtained on 5 days during a one-year period. A Bowen ratio apparatus, employed simultaneously, provided ground-based measurements of evaporation. Comparison of the airborne and ground techniques showed good agreement, with the greatest difference being about 12% for the instantaneous values. Estimates of daily (24 h) evaporation were made from the instantaneous data. On three of the five days, the difference between the two techniques was less than 8%, with the greatest difference being 25%. The results demonstrate that airborne remote sensing techniques can be used to obtain spatially distributed values of evaporation over agricultural fields.     

Quantitative analysis of production traits in saltwater crocodiles (Crocodylus porosus): II. age at slaughter

Crocodile morphometric (head, snout‐vent and total length) measurements were recorded at three stages during the production chain: hatching, inventory [average age (±SE) is 265.1 ± 0.4 days] and slaughter (average age is 1037.8 ± 0.4 days). Crocodile skins are used for the manufacture of exclusive leather products, with the most common‐sized skin sold having 35–45 cm in belly width. One of the breeding objectives for inclusion into a multitrait genetic improvement programme for saltwater crocodiles is the time taken for a juvenile to reach this size or age at slaughter. A multivariate restricted maximum likelihood analysis provided (co)variance components for estimating the first published genetic parameter estimates for these traits. Heritability (±SE) estimates for the traits hatchling snout‐vent length, inventory head length and age at slaughter were 0.60 (0.15), 0.59 (0.12) and 0.40 (0.10) respectively. There were strong negative genetic (?0.81 ± 0.08) and phenotypic (?0.82 ± 0.02) correlations between age at slaughter and inventory head length.     

A MUCOSAL DISEASE VIRUS AS A CAUSE OF ABORTION HAIRY BIRTH COAT AND UNTHRIFTINESS IN SHEEP

A condition resembling border disease has been transmitted by the inoculation of pregnant ewes with material from affected lambs. Forty-nine merino ewes, mated to merino rams 7 to 87 days previously, were inoculated with an homogenate of brain, spinal cord and spleen from affected lambs. Mummified foetuses, abortions and stillbirths were observed, and lambs with hairy birth coats were born to ewes inoculated between days 12 to 70 of gestation. A mucosal disease virus (MDV), present in the original material, was recovered from the aborted foetuses and lambs. Attempts to induce passive protection using bovine anti-serum to the C24V strain of MDV were not successful. The condition was also transmitted by inoculation of pregnant ewes with a cell culture supernatant prepared from tissue cultures that had been inoculated with an organ homogenate pool. MDV was present in the supernatant and was recovered from aborted foetuses and lambs. It is suggested that a condition in sheep in Australia resembling border disease is due to the infection of the pregnant ewe by a mucosal disease virus.     

The Effects of the Periodical Use of In-feed Chlortetracycline on the Reproductive Performance of Gilts and Sows of a Commercial Pig Farm with a History of Clinical and Subclinical Viral and Bacterial Infections

The objective of this study was to assess the effects of in‐feed chlortetracycline (CTC) as a measure of preventing or minimizing infectious problems of reproductive failure in gilts and sows. In a farm of 400 Large White × Landrace gilts and sows with a clinical history of porcine respiratory and reproductive syndrome (PRRS) virus, the animals were treated with CTC. Treatment consisted of 10 g CTC sow/day for 15 days every 3 months. It improved the health status of sows by decreasing post‐farrowing clinical mastitis and vaginal discharges, abortions, return‐to‐oestrus and irregular return‐to‐oestrus rates. These beneficial effects had a positive impact on the performance of the litter. More piglets were born live and weaned. These positive effects improved with repeated use of CTC. The serological evidence of PRRS virus, Leptospira spp. and Chlamydia spp. and the subsequent beneficial use of the antimicrobial agent indicate that reproductive failure, possibly resulting from the bacterial agents can be controlled with in‐feed use of broad spectrum antimicrobials.