Herd health status and management practices on 16 Irish suckler beef farms

peer-reviewedBackground: There have been few studies published internationally which document herd health management practices in suckler beef herds and no published Irish studies. The study objective was to document herd health status and management practices on sixteen Irish suckler beef herds over a two year period (2009–2010). The farms used in the study were part of the Teagasc BETTER farm beef programme. The mean (s.d.) herd size, stocking rate and farm size was 68 cows (27.6), 2.0 LU/ha (0.3) and 64.3 (21.6) adjusted hectares, respectively. Two questionnaires were designed; 1) a farmer questionnaire to collect information on farm background and current herd health control practices and 2) a veterinary questionnaire to collect information on the extent of animal health advice given by veterinarians to their clients and identification of any on-farm herd health issues. Results: Dystocia, calf pneumonia, and calf diarrhoea, in that order, were identified as the primary herd health issues in these Irish suckler beef herds. In addition, substantial deficiencies in biosecurity practices were also identified on these farms. Conclusions: The findings of this study may serve as the focus for future research in animal health management practices in Irish suckler beef herds

Nematode control in suckler beef cattle over their first two grazing seasons using a targeted selective treatment approach

peer-reviewedBackground With concerns over the development of anthelmintic resistance in cattle nematode populations, we must re-examine our approach to nematode control in cattle. Targeted selective treatments (TST), whereby individual animals are treated instead of entire groups, are being investigated as an alternative. The study objective was to determine if anthelmintic usage could be reduced using a TST-based approach to nematode control in spring-born suckler beef cattle over their first and second grazing seasons (SGS) without affecting performance. In the first grazing season (FGS), 99 calves with an initial mean (s.d.) calf age and live weight on day 0 (June 28th 2012) of 107 (23.1) days and 160 (32.5) kg, respectively, were used. The study commenced on day 0 when calves were randomised and allocated to one of two treatments; 1), standard treatment (control) and 2), TST. Control calves were treated subcutaneously with ivermectin on days 0, 41 and 82 in the FGS. All calves were treated with ivermectin on day 124 and housed on day 133. In the SGS, only heifer calves from the FGS were used and control heifers were treated with ivermectin on day 393. Animals were weighed, blood and faecal sampled every three weeks. The TST animals were treated with ivermectin if thresholds based on a combination of plasma pepsinogen concentrations, faecal egg count and/or the presence of Dictyocaulus viviparus larvae in faeces (FGS only) were reached. Results No TST calves reached the treatment threshold criteria in the FGS. The FGS average daily live weight gain (ADG ± s.e.m.) for control and TST group calves was 0.89 ± 0.02 kg and 0.94 ± 0.02 kg day−1, respectively (P = 0.17). In the SGS, all heifers were treated with ivermectin on day 431 due to clinical signs of respiratory disease. The ADG for control and TST heifers from turnout on day 321 to day 431 was 0.90 ± 0.04 and 0.80 ± 0.04 kg day−1, respectively (P = 0.03). Conclusions Spring-born FGS suckler beef calves require minimal anthelmintic treatment to maintain performance. In contrast, clinical parasitic disease may develop in the SGS unless appropriate anthelmintic treatment is provided

Modeling the source of GW150914 with targeted numerical-relativity simulations

In fall of 2015, the two LIGO detectors measured the gravitational wave signal GW150914, which originated from a pair of merging black holes. In the final 0.2 seconds (about 8 gravitational-wave cycles) before the amplitude reached its maximum, the observed signal swept up in amplitude and frequency, from 35 Hz to 150 Hz. The theoretical gravitational-wave signal for merging black holes, as predicted by general relativity, can be computed only by full numerical relativity, because analytic approximations fail near the time of merger. Moreover, the nearly-equal masses, moderate spins, and small number of orbits of GW150914 are especially straightforward and efficient to simulate with modern numerical-relativity codes. In this paper, we report the modeling of GW150914 with numerical-relativity simulations, using black-hole masses and spins consistent with those inferred from LIGO's measurement. In particular, we employ two independent numerical-relativity codes that use completely different analytical and numerical methods to model the same merging black holes and to compute the emitted gravitational waveform; we find excellent agreement between the waveforms produced by the two independent codes. These results demonstrate the validity, impact, and potential of current and future studies using rapid-response, targeted numerical-relativity simulations for better understanding gravitational-wave observations.Comment: 11 pages, 3 figures, submitted to Classical and Quantum Gravit

Combinations of Maternal KIR and Fetal HLA-C Genes Influence the Risk of Preeclampsia and Reproductive Success

Preeclampsia is a serious complication of pregnancy in which the fetus receives an inadequate supply of blood due to failure of trophoblast invasion. There is evidence that the condition has an immunological basis. The only known polymorphic histocompatibility antigens on the fetal trophoblast are HLA-C molecules. We tested the idea that recognition of these molecules by killer immunoglobulin receptors (KIRs) on maternal decidual NK cells is a key factor in the development of preeclampsia. Striking differences were observed when these polymorphic ligand: receptor pairs were considered in combination. Mothers lacking most or all activating KIR (AA genotype) when the fetus possessed HLA-C belonging to the HLA-C2 group were at a greatly increased risk of preeclampsia. This was true even if the mother herself also had HLA-C2, indicating that neither nonself nor missing-self discrimination was operative. Thus, this interaction between maternal KIR and trophoblast appears not to have an immune function, but instead plays a physiological role related to placental development. Different human populations have a reciprocal relationship between AA frequency and HLA-C2 frequency, suggesting selection against this combination. In light of our findings, reproductive success may have been a factor in the evolution and maintenance of human HLA-C and KIR polymorphisms