Desempenho reprodutivo de varrões e matrizes suínas de diferentes linhagens durante as estações do ano

The industrial Brazilian pig farming despite of the constant advance in the genetic improvement, nutrition, and in handling, seasonality problems occur in the production of weaned piglet, mainly due to the stations of the year that can impact directly in the profitability. These problems can be deepen due to breed and line of decent used in Brazil are all source from tempered weather countries. To the pig farmer it's difficult to determine the relations between indoor temperature of the barns, relative humidity of the air and top thermal amplitude which can provide good reproductive rates for the boars and arrays lodged in conventional barns. The lack research to production of environmental indices of easy interpretation to pigs, which are not dependent of complicated handling machines and also which are not expensive is considered as a negative factor from the producers. the objective os this experiment is evaluate the effects of the stations of the year over the reproductive performance of the boars Agroceres PIC 425, Agroceres PIC 337 and D.B. Dambred LM 6200, and of arrays Agroceres Canborough 22, Penarlan Naima e DB90 Danbred, in addition develop an environmental index with easy interpretation and use to the pig farmers of the region of Uberlândia - MG, using the maxim temperatures, rainfall monthly accumulated and of the thermal amplitude of the barn. The features rated during the stations of the years 2013 and 2014 were the volume and spermatic quality of the boars and the mainly reproductive indexes of the arrays as the total number of piglets born alive and total number of weaned piglets/ array/ parturition. The station of the year which had the worst results in the reproductive feature of the boars and arrays was the spring. Boars from different line of decent are sensitive to the effects of stress of the heat of spring causing lowest volume, concentration and problems in the spermatic morphology (p<0,05). The spring prejudice the reproductive indexes of arrays from different line of decent (p<0,05) and the pig farmers of Uberlândia are subjected to operating losses and income evasion due to the thermal stress in the reproduction that added can reach $150.000,00 annual for each 1000 arrays lodged/year.

Desempenho agronômico do milho com diferentes fontes e doses de nitrogênio

Nitrogen (N) is one of the major nutrients nutrients absorbed in corn crops, for this reason, nitrogen based fertilizers are expensive and suffer large losses to the environment. Therefore, a diversity of fertilizers, known as special or of enhanced efficiency fertilizers, has been commercialized. The aim of this study was to evaluate the effect of different sources and levels of nitrogen fertilization in coverage, for agronomic characteristics and corn grain productivity, cultivated in the Cerrado region. The experiment was installed in 2015, in Monte Carmelo-MG. The experimental design utilized was a RCBD with four replications. The treatments consisted of five N sources (common urea, polymerized urea, urea combined with NBPT (thiophosphate N-n-butiltriamida or N-n-butiltriamida of thiophosphoric acid), organomineral combined or not with NBPT), five topdress N levels (40, 80, 120, 160 and 200 kg ha-1) and a control (no N topdressing). The evaluated parameters were: the first spike insertion height (FSIH), plant height (PH), stem diameter (DC), number of rows per spike (RS), number of grains per row (GR), spike length (SL), spike diameter (SD), prolificacy (EP), 1,000-grain weight (TGW), leaf chlorophyll index (LCI), content of foliar nutrients, dry matter in aerial part of the plant (DM) and productivity (PG). The results showed that, with the exception of stem diameter, there was no significant statistical difference between sources of nitrogen, indicating that the organomineral source is as efficient as a mineral source. Regardless of the source, the addition of N fertilizers in increasing doses promoted enhanced development of corn plants, increased chlorophyll content, stem diameter, leaf N content, crude protein and productivity. For most phytotechnical features, there was no significant statistic difference in treatments compared to control.