Natural and improved natural pastures on the reproductive performance of first-calf beef cows Pastagens naturais e melhoradas no desempenho reprodutivo de vacas de corte primíparas

This work evaluated the reproductive performance of first-calf cows at three years of age, submitted or not to protein supplementation at yearling on natural pastures. After calving, cows were managed on natural or improved pastures. The feeding managements were the following: on natural pastures as yearlings and during pregnancy, post-calving period and breeding season; on natural pastures with protein supplement as yearlings and only natural pasture during pregnancy, post-calving and breeding season; on natural pastures as yearlings and during pregnancy and on improved natural pastures (Lolium multiflorum L., Trifolium repens cv. Yi and Lotus corniculatus cv. São Gabriel) during the post-calving period and breeding season; on natural pastures with protein supplement at yearling, on natural pastures during pregnancy, and on improved natural pasture during post-calving period and breeding season. Cows did not differ on body weight, but from calving to the beginning of breeding season, cows on improved natural pastures presented higher weight gain than those on natural pastures (0.203 vs. 0.109 kg/day). Cows in post-calving on natural pastures lost 1.0 point of body condition score during mating, determinant of the lowest pregnancy rate and later conception in relation to cows on improved natural pasture. Pregnant cows presented higher body weight (440 vs. 413 kg) and body condition score (4.14 vs. 3.66 points) than open cows at the end of the breeding season.<br>O trabalho avaliou o desempenho reprodutivo de vacas primíparas aos três anos de idade, submetidas previamente ou não à suplementação protéica no sobreano sobre pastagens naturais. Após o parto, foram manejadas em pastagens naturais ou naturais melhoradas. Os manejos alimentares foram: em pastagem natural na recria e nos períodos de gestação, pós-parto e reprodutivo; em pastagem natural com suplemento protéico na recria e somente pastagem natural durante os períodos de gestação, pós-parto e reprodutivo; em pastagem natural durante a recria e período de gestação, em pastagem natural melhorada (Lolium multiflorum L., Trifolium repens cv. Yi e Lotus corniculatus L. cv. São Gabriel) nos períodos pós-parto e reprodutivo; em pastagem natural com suplemento protéico na recria, em pastagem natural no período de gestação e em pastagem natural melhorada nos períodos pós-parto e reprodutivo. As vacas não diferiram em peso corporal, porém do parto ao início do acasalamento vacas em pastagem natural melhorada tiveram maiores ganhos de peso do que as vacas mantidas em pastagem natural (0,230 vs 0,109 kg/dia). Vacas no pós-parto em pastagens naturais perderam 1,0 ponto de condição corporal durante o acasalamento, determinante da menor taxa de prenhez e de concepções mais tardias em relação às vacas em pastagem natural melhorada. Vacas que conceberam apresentaram maior peso (440 vs 413 kg) e condição corporal (4,14 vs 3,66 pontos) no final do acasalamento do que as vacas não prenhes

Search for top squark production in fully hadronic final states in proton-proton collisions at s =13 TeV

© 2021 CERN. for the CMS Collaboration.A search for production of the supersymmetric partners of the top quark, top squarks, is presented. The search is based on proton-proton collision events containing multiple jets, no leptons, and large transverse momentum imbalance. The data were collected with the CMS detector at the CERN LHC at a center-of-mass energy of 13 TeV, and correspond to an integrated luminosity of 137 fb-1. The targeted signal production scenarios are direct and gluino-mediated top squark production, including scenarios in which the top squark and neutralino masses are nearly degenerate. The search utilizes novel algorithms based on deep neural networks that identify hadronically decaying top quarks and W bosons, which are expected in many of the targeted signal models. No statistically significant excess of events is observed relative to the expectation from the standard model, and limits on the top squark production cross section are obtained in the context of simplified supersymmetric models for various production and decay modes. Exclusion limits as high as 1310 GeV are established at the 95% confidence level on the mass of the top squark for direct top squark production models, and as high as 2260 GeV on the mass of the gluino for gluino-mediated top squark production models. These results represent a significant improvement over the results of previous searches for supersymmetry by CMS in the same final state