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A 2-yr field study was conducted to reduce nutrient losses from Virginia dairy farms through nutritional and herd management practices. Ten collaborator herds were identified, all at state DHIA average or better for milk yield and days open. Baseline feed samples and ration information were collected for 2 mo and analyzed for phosphorus (P) and nitrogen (N). Feeds were analyzed monthly, and monthly DHIA milk yield, milk composition, milk urea N (MUN), and reproductive data were recorded. Blood and fecal samples were collected from 25 cows/herd every 3 mo to monitor P excretion and blood urea N. Nutrient balances were developed for each farm for N and P at the start of the study and following ration and management changes. Collaborator herds imported, on average, 290% more N and 320% more P onto the farm than was removed through milk, culled animals, crop sales, or manure sales. By following NRC (1989) recommendations, collaborator farms could reduce N inputs by 21% and P inputs by 45%. Minimizing P in purchased feed, purchased feeds/cow, purchased feeds/ha, and total P input could cause significant reductions in P balance for participating collaborator herds. None of the N variables tested (purchased feed, purchased feed/cow, purchased feed/ha, and total N input) provided significant reductions. / Master of Science

In this study, four experiments were conducted to investigate the effect of inclusion level of dry distillers grains plus solubles (DDGS) or modified wet distillers grains plus solubles (MWDGS) (0, 16.7, 33.3, and 50% of ration DM) on performance, carcass characteristics, feeding behaviour, nutrient balance, nutrient excretion, and enzymatic activity using whole corn grain-based finishing diets. In experiment one, there were no effects (P > 0.05) of dietary treatment on final BW, ADG, days on feed, rumen pH at slaughter, dressing %, hot carcass weight, marbling score, lean yield, and lean color. Liver abscess score was lower in steers fed DGS than steers fed the control. Visits of cattle to the feeder (VF) increased when cattle were fed up to 16.7% of DDGS or 33.3% of MWDSG. Number of meals (NM) and eating rate (ER) was greater and time per meal (TM) was lower in cattle fed MWDGS compared to those fed DDGS. Also, increasing the distillers grains plus soluble (DGS) increased daily time at feeder (TF); however, ER decreased when cattle were fed up to33.3% of DGS and after that increased. In experiment two, total tract DM, OM, and starch digestibility decreased with increasing DDGS up to 50%. Daily intake and total excretion of N, P, S, Mg, and K increased linearly with increasing level of DDGS. Nitrogen retention did not change with level of DDGS; however, P retention tended to increase and S retention increased with increasing DDGS. The digestion and retention of Se, Mg, K, and Na did not differ among the treatments. In experiment three, although the pancreatic protein concentration (mg/g) increased linearly with increasing DGS levels, pancreatic mass (g and g/kg BW) did not change. Feeding DGS increased the pancreatic concentration of α-amylase and trypsin activity (U/g) compared to the control diet. Increasing the DGS level increased pancreatic concentration of trypsin activity (U/g). In experiment four, increasing DGS linearly increased kidney weight (g). Hepatic and renal glutathione peroxidases (GPX) activity was not influenced by inclusion level or form of DGS. However, renal GPX activity per kilogram of BW was affected by the form and linear effect interaction. Increasing inclusion level of DGS linearly increased carbamoyl phosphate synthetase (CPS) activity (kU/liver, and U/kg of BW), argininosuccinate synthetase (AS) and ornithine transcarbamoylase (OTC) activity (U/g, kU/liver, and U/kg of BW).The results of these studies suggest that feeding DDGS or MWDGS up to 50% diet DM in whole corn grain-based finishing diets does not negatively affect animal performance, although animals appear to adapt by altering feeding behaviour and nutrient metabolism. However, environmental implications of manure should be considered in the feedlot. / Beef Cattle Research Council, and Ontario Ministry of Agriculture Food and Rural Affairs

To better understand the facets of nutrient utilization, a series of in vivo and in vitro studies were undertaken to elucidate the effect of supplementation on utilization of moderate-quality bermudagrass hay and to identify mechanisms to evaluate the role of rumen bacterial populations on feedstuff utilization. A digestion trial was conducted using 6 ruminally cannulated steers receiving bermudagrass hay supplemented with soybean hulls (HULLS), cracked corn (CORN), or soybean hulls and cracked corn (MIX; 75% and 25%, respectively) in a 3x3 Latin Rectangle arrangement. Additionally, ruminal fluid was continuously cultured using the BioFlo® 110 fermentation system to evaluate the in vitro fermentive parameters of ground moderate-quality bermudagrass hay either alone (HAY; 20 g DM L-1 d-1) or supplemented (7 g DM L-1 d-1) with corn (CORN), soybean hulls (SBH), or both (25:75; MIX) in a randomized complete block. Genomic DNA from continuous culture as well as from pure bacterial culture samples were sought to differentially enumerate select bacterial strains via real-time PCR using specie-specific DNA primers. The information is to be used for elucidating responses in ruminal digestibility of varying feed-types. Finally, as an alternative to PCR, bioluminescence of transformed Escherichia coli was evaluated by measuring extent of photonic emission with and without antibiotic selection over time. Evaluations were also made of photonic emission by E. coli grown in ruminal fluid with and without additional feed particles. Data seem to indicate that replacing a portion of corn with soybean hulls may successfully improved fiber digestion and improved ruminal N-utilization. Real-time PCR shows potential for evaluating ruminal bacteria where as biophotonics may need further modification before meaningful in situ evaluations of live ruminants can be employed.

Impact of precision feeding with feed management software was assessed for whole farm nutrient balance (WFNB) and feeding management from January through December 2006. Nine treatment and six control farms were selected in four regions of the Chesapeake Bay Watershed of Virginia. Herd sizes averaged 271 and 390 lactating cows for treatment and control farms while milk yield averaged 30 and 27 kg/d per lactating cow, respectively. Crop hectares grown averaged 309 and 310 ha for treatment and control farms, respectively. Treatment farms purchased and installed feed management software (TMR Tracker, Digi-Star LLC, Fort Atkinson WI) between May and October 2006 and received more frequent feed analysis and feedback. Data were collected for calendar year 2005 and 2006 to compute WFNB using software from the University of Nebraska. On treatment farms, up to five feed samples were obtained monthly from individual feedstuffs and each total mixed ration (TMR) fed to lactating cows. Control farms submitted TMR samples every 2 mo. Standard wet chemistry analysis of samples was performed. Data stored in the software were collected monthly from each treatment farm concurrent with feed sampling. Producers from each treatment farm participated in a 24-question personal interview in December 2006 addressing installation, operation, and satisfaction with the software. Daily feeding deviation of all ingredients across treatment farms averaged 173 ± 163 kg/d. This corresponded to average daily overfeeding of CP and P of 17.6 ± 17 and 0.4 ± 0.3 kg/d, respectively. Feeding deviation did not differ between feeders. Milk production was negatively associated with kg total deviation and kg CP deviation, but positively related to P deviation. Whole farm nutrient balance did not differ between treatment and control farms. All producers indicated TMR Tracker met expectations. Change made to the feeding program due to TMR Tracker was correlated (r=0.80) with perceived improvement in ration consistency. In conclusion, producers perceived feed management software as beneficial, but WFNB was not reduced after 3 to 6 mo of using feed management software; however, the large variation in daily over or under feeding indicates potential for future reductions in WFNB through reduced feeding variability. / Master of Science

Agricultural runoff is the largest source of nitrogen and phosphorus pollution entering the Chesapeake Bay, contributing 38% of nitrogen and 45% of phosphorus (USEPA, 2010). Since agricultural runoff is the number one contributing source of nitrogen and phosphorus entering the Chesapeake Bay, action needs to be taken to reduce nitrogen and phosphorus on agriculture production facilities, such as dairy farms. The impact of feed management software on whole-farm nutrient balance was studied on 18 dairy farms located in Virginia from 2006 to 2010. Nine farms began using the TMR Tracker feed management software in 2006 and were compared to 9 control farms not using feed management software. Each of the treatment farms were visited on a monthly basis to collect ration and feed ingredient samples and feed management data. Whole-farm nutrient balance was calculated using University of Nebraska software. Herd sizes and crop hectares averaged 314 and 366 for treatment and 298 and 261 for control farms. Milk production averaged 3,226 and 2,650 tonnes per year respectively. Measures of surplus (input-output) and use efficiency (input/output) for nitrogen and phosphorus were analyzed over a four year time span and did not differ between treatment and control farms whether expressed on a per farms, cow or hectare basis. Due to the large variation in feeding accuracy within farms, the use of feed management software did not influence whole-farm nutrient balance. Sources of variation that contributed to loading errors were investigated within the feed management data. Percent load deviation increased over time from 2007 to 2009 from 0.94 ± 0.53 to 2.37 ± 0.50 percent of the actual load weight. Effects of month, day of the week and time of day on percent load deviation were not significant. There was no effect of percent load deviation on milk production. No relationship was observed between percent load deviation and whole-farm nutrient balance. / Master of Science

Os estudos em microbacias hidrográficas têm mostrado que as características físicas, químicas e biológicas das águas dos córregos e riachos possuem uma estreita relação com a composição do ambiente terrestre adjacente, refletindo as condições de uso e ocupação dos solos da bacia hidrográfica por eles drenada. A microbacia do Córrego do Cancã, localizada perpendicularmente ao Rio Monjolinho, situa-se em uma maior parte no município de São Carlos (SP), e foi estudada sob uma abordagem ecossistêmica. As coletas e análises de campo foram realizadas em sete transectos do córrego, em dois períodos hidrológicos distintos: seca e chuva. A caracterização física e química da água foi realizada através da análise do pH, da condutividade elétrica, da concentração de oxigênio, da temperatura, da concentração e da carga de nutrientes. Alguns dos parâmetros analisados foram comparados aos limites estabelecidos pela CONAMA segundo a resolução nº 20/1986. O córrego do Cancã, segundo a classificação proposta pela CONAMA, é um rio de classe-2. A água do córrego é levemente ácida tendendo à neutralidade em um gradiente da nascente à foz e caracteriza-se pela baixa condutividade elétrica. A temperatura variou entre os períodos avaliados e espacialmente foi influenciada pelos horários de coleta. As concentrações de nutrientes não foram elevadas, e das formas nitrogenadas as mais abundantes foram o nitrato (na estação mais impactada) e o amônio (após o represamento), com valores mais elevados no período de seca. A maior variabilidade foi observada para o nitrogênio total, sendo as maiores concentrações registradas na estação seca. Com base no índice de estado trófico, as águas do córrego do Cancã foram classificadas como mesotróficas. A forma da microbacia é irregular e ligeiramente alongada e pouco sujeita a enchentes. A área da microbacia foi determinada como sendo de 3,075 Km2. Na análise das comunidades planctônicas foram encontrados poucos representantes, distribuídos principalmente nas estações localizadas nos trechos inicial e médio do córrego, sendo, entretanto mais abundantes na nascente. Ocorreu predominância das clorofíceas e diatomáceas entre os organismos fitoplanctônicos e de rotíferos e cladóceros no zooplâncton. A microbacia está sujeita à práticas agrícolas e atividade pecuária semi-intensiva que alteram o balanço de massa dos principais nutrientes, contribuindo para o aumento da carga de nutrientes que são carreados do sistema terrestre para o aquático particularmente no período chuvoso. / The studies peformed in small hydrographic basins have shown that the physical chemical and biological characteristics of the water in springs and streams have a close relation with the composition of adjacent terrestrial ecosystems, reflecting the uses and activities in the soils in the basin drained by them. The microbasin of Cancã stream belongs to the Monjolinho river basin and is mainly located inside the district of São Carlos (SP). In this study It has been evaluated under the ecosystemic approach. Field sampling and analysis were carried out in seven transects of the stream at two distinct hydrological periods: dry and rainy seasons. Physical and chemical analyses of water were performed by mesuring the pH, electrical conductivity, dissolved oxygen and the nutrient concentrations and loads. The parameters obtained were compared to the CONAMA limits, act nº 20/1986. The Cancã stream according to CONAMA proposed system, is classified as a class 2 water. The pH of Cancã water is slightly acid and there a tendency to the neutral from the source to the mouse. It is also characterized by low electrical conductivity. Water temperature has changed between dry and rainy periods and spatially it was influenced by the sampling timing. Nutrient concentrations are low and the main nitrogen compounds present were nitrate and ammonium, at the most impacted site, with highest values in the dry season. The highest variability was obtained for the total nitrogenvariability with higher concentrations at the dry season. Based on the trophic state index. The water of Cancã stream was classified as mesotrophic. The hydrographic microbasin has a non-regular shape, being slightly elongated and it has low vulnerability to floodings. The area of the catchment was found to be 3,071 Km2. Planktonic communities were composed by few organisms mainly occuring at the upper and middle stream streches, being most abundant at the first stretch. Clorophyceans and diatoms were the dominant groups among phytoplankton and the rotifers and cladocerans among the zooplankton. Cancã microbasin is subjected to a variety of agriculture and semi-intensive cattle enterprises that have changed major nutrient mass balances, contributing to the increase in nutrient loadings mainly via surface terrestrial runoff.

A quantidade de água consumida na produção de carne bovina influencia a visão da sociedade sobre a sustentabilidade desta produção em comparação com as outras fontes de proteína. O objetivo geral do estudo é avaliar como o tipo de dieta impacta a eficiência de uso da água e de nutrientes de bovinos em sistema de confinamento. O cálculo da pegada hídrica considerou as águas azul, verde e cinza consumidas no sistema de produção e no abate dos animais. Foram avaliados dois tipos de dietas, uma com o concentrado composto de milho e farelo de soja, e outra com a substituição total destes ingredientes por coprodutos (gérmen de milho gordo, polpa cítrica e farelo de amendoim). Não houve diferenças nas características de desempenho dos animais entre as dietas. A substituição promoveu a redução do consumo de água verde e redução nos valores de pegada hídrica total, porém aumentou os valores de água azul. A pegada hídrica total da dieta convencional foi de 2.125,54 L kg-1 carne e a da dieta com uso de coprodutos foi de 2.042,56 L kg- 1 carne. A pegada hídrica verde representou 88,45% e 88,52% para a dieta convencional e com uso de coprodutos, respectivamente. O balanço de nutrientes da dieta convencional foi de 115,13 kg de N, 13,90 kg de P e 73,69 kg de K e na dieta de coprodutos foi de 234,63 kg de N, 29,76 kg de P e 58,62 kg de K. Do ponto de vista ambiental o uso de coprodutos foi positivo, mas a análise econômica dessa intervenção nutricional se mostrou inviável aumentando os custos em 9,25%. A utilização de alimentos alternativos na dieta de bovinos de corte confinados manteve o desempenho animal e promoveu uma melhor eficiência hídrica. Estudos que relacionam a pegada hídrica com o manejo nutricional na produção animal são importantes para gestão hídrica da produção, promovendo impactos positivos na conservação dos recursos hídricos. / The amount of water consumed in beef production influences society\'s view on the sustainability of this production compared to other sources of protein. The overall objective of the study is to evaluate how the type of diet impacts the efficiency of water and nutrient use of cattle in a feedlot system. The calculation of the water footprint considered the blue, green and gray waters consumed in the system of production and the slaughter of the animals. Two types of diets were evaluated, one with corn and soybean meal concentrate, and the other with total substitution of these ingredients by co-products (corn germ, citrus pulp and peanut meal). There were no differences in the performance characteristics of the animals between the diets. The substitution promoted the reduction of green water consumption and reduction in the total water footprint values but increased the values of blue water. The total water footprint of the conventional diet was 2,125.54 L kg-1 meat and that of the diet with use of co-products was 2,042.56 L kg-1 meat. The green water footprint represented 88.45% and 88.52% for the conventional diet and with co-products, respectively. The nutrient balance of the conventional diet was 115.13 kg N, 13.90 kg P and 73.69 kg K and in the co-products, diet was 234.63 kg N, 29.76 kg P and 58.62 kg of K. From the environmental point of view, the use of co-products was positive, but the economic analysis of this nutritional intervention was not feasible, increasing expenses by 9.25%. The use of alternative foods in the diet of confined beef cattle-maintained animal performance and promoted better water efficiency. Studies that relate the water footprint to nutritional management in animal production are important for water production management, promoting positive impacts on the conservation of water resources.

In 16 sächsischen Landwirtschaftsbetrieben wurde das Stickstoff-Management umfassend analysiert. Das Projekt hatte zum Ziel, die N-Bilanzüberschüsse zu reduzieren und betriebsbezogene Maßnahmen zur optimalen N-Nutzung abzuleiten. Es geht konform mit der Vorgabe der Wasserrahmenrichtlinie, die Nährstoffeinträge in Gewässer und Grundwasser wirksam zu verringern. Bilanziert wurde mit dem in Sachsen entwickelten Programm BEFU und dem Umwelt- und Betriebsmanagementsystem REPRO. Die untersuchten Betriebe wiesen aufgrund der Standortbedingungen eine hohe Auswaschungsgefahr für N-Überschüsse auf. In den Szenariorechnungen mit REPRO zeigte sich, dass durch den Anbau von Zwischenfrüchten und einem reduzierten N-Einsatz die N-Salden und die potenzielle Nitratauswaschung deutlich reduziert werden können. Der Bericht enthält zahlreiche Vorschläge zur Optimierung des N-Managements im Betrieb und beweist das erhebliche Potenzial zur Minderung der Nitratverluste und Nitratbelastung.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / The good root development directly affects the crop production. The improvement of chemical characteristics of the sub superficial layer brings the benefit of minimizing the effects of water deficit periods to the plants. In this sense the study aimed to evaluate the effect of lime, gypsum and potassium doses on soil chemical attributes, by evaluating crops productivity under no-till. The specific objectives were to analyze: the correction of soil acidity and enhancements of soil chemical attributes in different depths, after 9 and 16 months; the foliar nutrient levels in the soybean plants; the production of soybean and wheat exposed to high doses of gypsum; and which cationic relations influenced productivity. The experiment was conducted in 2012/13, 2013 and 2013/14 in a dystrophic Red Oxisol in the city of Estrela Velha, RS, which presents a humid subtropical climate (Cfa), and average rainfall of 1678 mm year-1. The experiment was arranged in sub plots with three repetitions. The eight treatments were constituted by: two doses of lime + gypsum (0+0 and 5.5+3 Mg ha-1), combined with four doses of potassium chloride (0.0, 0.16, 0.33 and 0.66 Mg ha-1).The soil samples were collected at three times: initial characterization, 9 and 16 months after inputs application. The experimental design was sub plots with three measure repetitions in the sub plots. The data for each dependent variable (soil chemical and crop foliar parameters) were analyzed using all samples by repeated measures using ANOVA mixed linear model, by the method of restricted maximum likelihood (REML). The analyzed soil was stratified in seven depths: from the surface until 0.6 meters depth. Foliar samples were collected to analyze the effect of the treatments in the nutrition of soybean plants, and by manual harvest the productivity was evaluated for each plot. In the first study, the dose of gypsum increased the values of pH, V% and reduced the Al saturation down to 0.10m. Magnesium leaching occurred in all layers, while S was carried done to even deeper layers than the analyzed. Leaching of K was not observed, even in the treatment with the gypsum dose. The elevated doses of potassium reduced soybean productivity in average 12%. While the treatments that had lime+ gypsum presented accumulated production 5% higher. On the second study, a correlation matrix was used to indicate the linear correlations with higher R2, whereas the Ca rate and its saturation presented higher positive correlation with soybean productivity. / O bom desenvolvimento radicular das culturas afeta diretamente a produção. A melhoria química das camadas subsuperficiais traz benefícios, que em períodos de déficit hídrico, podem minimizar os efeitos causado às plantas. Nesse contexto, o trabalho buscou avaliar o efeito de doses de calcário e gesso e potássio sobre os atributos químicos, verificando a produtividade das culturas sob sistema plantio direto. Para tal, os objetivos específicos foram os de avaliar: a correção da acidez e melhoria dos atributos químicos do solo em diferentes profundidades, após 9 e 16 meses; os teores foliares de nutrientes da soja; a produção da soja e trigo expostos a alta dose de gesso; e quais relações catiônicas influenciaram na produtividade. O experimento foi conduzido nos anos agrícolas de 2012/13, 2013 e 2013/14 em um Latossolo Vermelho distrófico típico no município de Estrela Velha, RS, que apresenta clima subtropical úmido (Cfa) e precipitação média de 1678 mm ano-1. Os tratamentos foram dispostos em parcelas subdivididas com três repetições e os 8 tratamentos foram constituídos de: duas doses de calcário + gesso agrícola (0+0 e 5,5+3,0 Mg ha-1) combinadas a quatro doses de cloreto de potássio (0, 0,16, 0,33 3 0,66 Mg ha-1). As coletas de solo ocorreram em três momentos: caracterização inicial, 9 e 16 meses das aplicações dos insumos. O delineamento experimental utilizado foi o de parcelas sub divididas com três medidas repetidas na sub parcela. Os dados para cada variável dependente (parâmetros químicos do solo e foliar da cultura) foram analisados através de todas as coletas usando medidas repetidas por meio da ANOVA de modelos lineares mistos, pelo Método de Máxima Verossimilhança Restrita (REML). O solo analisado foi estratificado em sete profundidades: da superfície até 0,6 metros. Amostras foliares foram coletadas para analisar o efeito dos tratamentos na nutrição das plantas de soja e através da colheita manual avaliou-se a produtividade de cada parcela. No primeiro trabalho, a dose de gesso propiciou a elevação dos valores de pH, V% e redução da saturação por Al até 0,10 m, ocorrendo a lixiviação de Mg em todas as camadas, enquanto o S foi carreado a profundidades maiores das amostradas. Não foi percebido a lixiviação de K, mesmo no tratamento de maior dose de gesso. As elevadas doses de potássio reduziram a produtividade da soja em média de 12%, enquanto os tratamentos que receberam calcário + gesso obtiveram produção acumulada 5% superior. No segundo trabalho foi utilizada a matriz de correlação para gerar as correlações lineares com R2 mais alto, sendo o teor de Ca e sua saturação apresentou maior correlação positiva com a produtividade da soja.