The effect of residual nitrogen fertilization on the yield components, forage quality, and performance of beef cattle fed on Mombaça grass

The objective of this study was to evaluate the effect of residual nitrogen (N) on pastures of Mombaça grass and its impact on pasture structure and the nutritive value and performance of beef cattle. The experiment analyzed randomized blocks subdivided into plots, with three replications. The research focused on a number of pastures having received three annual doses of N (100, 200 and 300 kg ha-1) from 2015 to 2017, with no N fertilization in 2018. The results indicated that pastures under residual effect of 300 kg ha-1 of N were characterized by higher (P<0.05) rates of forage accumulation than those under the residual effect of 100 kg ha-1 N. Furthermore, this study indicated no effect (P>0.05) on the pasture nutritive value and average daily gain (0.490 kg day-1). The stocking rate was higher (P<0.05) in pastures under the residual effect of 300 kg ha-1 of N, and lower in those at 100 kg ha-1 of N, while weight gain per area followed the trend observed in the stocking rate. The results thus suggest that the suspension of N fertilization for one year after three years of sequential fertilization was responsible for an immediate loss of 50 and 55% of the productivity of plants and animals, respectively. Highlights: Fundamental nitrogen fertilization to ensure pasture productivity. The use of nitrogen fertilization has been limited by cost, due to the extension of the areas involved and the need for frequent applications. We suspended nitrogen fertilization for one year after using the same doses of nitrogen for three years in order to evaluate a possible residual effect on plant and animal production. Suspending the N fertilization of Mombaça grass for one year after three years of sequential fertilization with the same doses leaves a residual effect on the pasture structure and performance of beef cattle. The suspension of nitrogen fertilization reduces the rate of forage accumulation by an average of 50%, causing a 55% reduction in animal productivity.The objective of this study was to evaluate the effect of residual nitrogen (N) on pastures of Mombaça grass and its impact on pasture structure and the nutritive value and performance of beef cattle. The experiment analyzed randomized blocks subdivided into plots, with three replications. The research focused on a number of pastures having received three annual doses of N (100, 200 and 300 kg ha-1) from 2015 to 2017, with no N fertilization in 2018. The results indicated that pastures under residual effect of 300 kg ha-1 of N were characterized by higher (P<0.05) rates of forage accumulation than those under the residual effect of 100 kg ha-1 N. Furthermore, this study indicated no effect (P>0.05) on the pasture nutritive value and average daily gain (0.490 kg day-1). The stocking rate was higher (P<0.05) in pastures under the residual effect of 300 kg ha-1 of N, and lower in those at 100 kg ha-1 of N, while weight gain per area followed the trend observed in the stocking rate. The results thus suggest that the suspension of N fertilization for one year after three years of sequential fertilization was responsible for an immediate loss of 50 and 55% of the productivity of plants and animals, respectively. Highlights: Fundamental nitrogen fertilization to ensure pasture productivity. The use of nitrogen fertilization has been limited by cost, due to the extension of the areas involved and the need for frequent applications. We suspended nitrogen fertilization for one year after using the same doses of nitrogen for three years in order to evaluate a possible residual effect on plant and animal production. Suspending the N fertilization of Mombaça grass for one year after three years of sequential fertilization with the same doses leaves a residual effect on the pasture structure and performance of beef cattle. The suspension of nitrogen fertilization reduces the rate of forage accumulation by an average of 50%, causing a 55% reduction in animal productivity

DYNAMICS AND INTERFACE DEFOLIATION GRAZING: REVIEW

In the last five decades researchers have attempted to explain how adaptations of the morphology of the mouth and digestive tract of large ruminants interact with different food scales in the pasture ecosystem independent of the grazing method, thus understanding the dynamics of defoliation is essential in the analysis of response variations in forage production. A brief review of the literature on the factors related to the animal and plant components, influence of the grazing process and the defoliation dynamics will be presented. Grazing is the fundamental procedure that influences the dynamics and functioning of pasture ecosystems. The structural components of the tiller present in the horizontal plane of the forage canopy are likely to lead to differences in resource exploitation and impacts on vegetation, and many variables should be analyzed to fully understand the defoliation, since variations in canopy architecture are also influenced by the grazing method itself, which modifies the harvest and use of forage. In different grazing methods, it was observed that defoliation behaves in an analogous way among the methods, considering that the only variation was in the number of grazing animals, that is, changes in the stocking rate. The level of defoliation of individual tiller and its respective structural components, coupled with the grazing process, allows us to understand how the management of the pasture by adjusting the animal load influences the choices of the animals during the forage harvesting process.In the last five decades researchers have attempted to explain how adaptations of the morphology of the mouth and digestive tract of large ruminants interact with different food scales in the pasture ecosystem independent of the grazing method, thus understanding the dynamics of defoliation is essential in the analysis of response variations in forage production. A brief review of the literature on the factors related to the animal and plant components, influence of the grazing process and the defoliation dynamics will be presented. Grazing is the fundamental procedure that influences the dynamics and functioning of pasture ecosystems. The structural components of the tiller present in the horizontal plane of the forage canopy are likely to lead to differences in resource exploitation and impacts on vegetation, and many variables should be analyzed to fully understand the defoliation, since variations in canopy architecture are also influenced by the grazing method itself, which modifies the harvest and use of forage. In different grazing methods, it was observed that defoliation behaves in an analogous way among the methods, considering that the only variation was in the number of grazing animals, that is, changes in the stocking rate. The level of defoliation of individual tiller and its respective structural components, coupled with the grazing process, allows us to understand how the management of the pasture by adjusting the animal load influences the choices of the animals during the forage harvesting process

Eficácia anti-helmíntica e desempenho em rebanho de matrizes ovinas na mesorregião leste do Rio Grande do Norte

Objetivou-se avaliar a eficácia anti-helmíntica em rebanhos de matrizes ovinas na mesorregião leste do Rio Grande do Norte. Os animais foram distribuídos em cinco grupos com 12 ovelhas cada, sendo estes: cloridrato de levamisol (5mg/kg), closantel (10mg/kg), moxidectina (0,2mg/kg) e ivermectina (0,2mg/kg) e o grupo controle sem tratamento anti-helmíntico. Foram avaliadas as seguintes variáveis no dia zero e a cada sete dias após a administração dos anti-helmínticos: contagens de ovos por grama de fezes (OPG), calculado o percentual de eficácia, peso, ganho de peso, escore de condição corporal, e o grau de anemia. Observou-se diferença significativa na OPG dos animais, onde as maiores médias foram observadas no grupo tratado com ivermectina (7858,3±6880).  A ivermectina (34,7%) apresentou-se com baixa eficácia anti-helmíntica em relação a moxidectina (93,3%), closantel (89,1%) e ao levamisol (89,4%). O peso final dos animais não foi alterado pelo uso dos anti-helmínticos, com média de 39,5 kg. As matrizes tratadas com ivermectina, levamisol e o grupo controle, apresentaram-se com o escore de condição corporal concentrados nos graus 2,5 e 3. Os graus de anemia ficaram dispostos entre 2 e 4, sendo que o grupo medicado com a ivermectina foi o que apresentou animais com uma maior dispersão nesse intervalo. A moxidectina mostrou-se eficiente na redução de nematoides gastrintestinais no rebanho estudado e pode ser indicado no controle desses parasitos

Desempenho produtivo de vacas de corte cruzadas e zebuínas e seus bezerros

O objetivo do estudo foi avaliar o desempenho produtivo, produção de leite e os parâmetros da curva de lactação de vacas de corte e bezerros de três diferentes grupos genéticos no período pós-parto. Foram usadas 15 vacas paridas divididas em três grupos genéticos: cinco vacas ½Angus ½Nelore (F1), cinco ¼Angus ¼Nelore ½Tabapuã (F2) e cinco Nelore (NE). Avaliou-se a produção de leite, curva de lactação, peso corporal (PC), condição corporal (CC) e eficiência produtiva das vacas além do ganho de peso diário médio (GPDMB) e peso corporal no pós-parto e ao desmame (PCB) dos bezerros. As vacas F2 apresentaram maior PC comparado às F1 e NE que não diferiram entre si. O PCB do F2 e F1 não diferiram e, foram superiores aos NE dos 125 até 183 dias pós-parto. A CC das vacas F1 e F2 reduziu no período pós-parto, ao contrário das NE que mantiveram. Os bezerros mestiços tiveram melhor desempenho produtivo que o Nelore. A curva de lactação teve comportamento quadrático e parecido entre os grupos genéticos, assim como suas eficiências produtivas. As vacas F2 e F1 apresentaram maior produção de leite total e produção de leite diária em relação às vacas NE. Vacas mestiças, apesar das características produtivas superiores, tiveram eficiência produtiva parecida à raça Nelore, justificando o seu uso como matriz em sistemas de cruzamento com outras raças bovinas

The soil-plant interface in Megathyrsus maximus cv. Mombasa subjected to different doses of nitrogen in rotational grazing

Este trabajo tuvo como objetivo evaluar los efectos de tres dosis de nitrógeno (N) en las características morfogénicas y estructurales, la masa (MR) y la distribución de las raíces en el perfil del suelo, y la resistencia del suelo a la penetración de las pasturas de guinea Mombasa manejados con pastoreo rotacional. El diseño experimental utilizó bloques al azar con tres dosis de N (100, 200 y 300 kg ha-1) y tres repeticiones. El criterio para interrumpir el rebrote de los pastos fue la altura de 80 a 90 cm del dosel (90-95 % de intercepción de luz por el dosel). Los animales fueron retirados de los potreros cuando el dosel alcanzó el 50 % de la altura prepastoreo. Se evaluó la masa y acumulación del forraje, las características morfogénicas y estructurales del dosel, la MR y distribución en el perfil del suelo, y la resistencia del suelo a la penetración. En pastos fertilizados con 200 y 300 kg ha-1 de N, se observó la mayor aparición foliar (0.090 hojas macollo-1 día-1 y 0.081 hojas macollo-1 día-1), tasas de alargamiento (2.82 y 2.61 cm macollo-1 d-1) y mayor acumulación diaria de forraje (113.8 y 106.6 kg ha-1d-1). El uso de 300 kg ha-1 de N promovió una mayor resistencia del suelo a la penetración a 10 cm de profundidad en el pospastoreo (3.3 MPa). No se observó ningún efecto de las dosis de N en la MR (P>0.05). Por lo tanto, el control de la altura antes y después del pastoreo de los animales en los potreros ayudó a mantener la estructura del pasto y evitar el proceso de compactación del suelo.  De acuerdo con los resultados, se concluye que 200 y 300 kg ha-1 de fertilización con N es una estrategia para intensificar los pastos.This work aimed to evaluate the effects of three nitrogen (N) doses on the morphogenic and structural characteristics, root mass (RM) and distribution in the soil profile, and penetration soil resistance of Mombasa guineagrass pastures managed with rotational stocking. The experimental design used randomized blocks with three N doses (100, 200, and 300 kg ha-1) and three replicates. The criterion for interrupting the pastures’ regrowth was the height of 80 to 90 cm of the canopy (90–95 % of light interception by the canopy). The animals were removed from the paddocks when the canopy reached 50 % of the pre-grazing height. Forage mass and accumulation, canopy morphogenic and structural characteristics, RM and distribution in the soil profile, and soil resistance to penetration were evaluated. In pastures fertilized with 200 and 300 kg ha-1 of N, the highest leaf appearance  (0.090 and 0.081 leaves-1 tiller-1 d-1),  elongation rates (2.82 and 2.61 cm tiller-1 d-1) and highest daily forage accumulation (113.8 and 106.6 kg ha-1d-1) were observed. Using 300 kg ha-1 of N promoted greater soil resistance to penetration at 10 cm of depth in the post-grazing (3.3 MPa). No effect of N doses was observed for RM (P>0.05). The pre- and post-grazing height control of animals in the paddocks therefore helped to maintain the pasture structure and avoid the soil compaction process. According to the results, it is concluded that 200 and 300 kg ha-1 of N fertilization is a strategy for intensifying pastures

Relationships between body mass index, ultrasound measurements and, internal body fat depots in pelibuey sheep

The objective of this study was to evaluate the relationship between body mass index (BMI), ultrasound measurements (USM), and internal fat (IF) in hair sheep. The BMI and USM were determined 24 hours before laughter in 35 animals finished in intensive fattening. At slaughter, the IF (inner adipose tissue) was dissected, weighed, and grouped as mesenteric, omental, or perirenal fat; these three depots were summed to obtain their total weight. The relationship of the variables was evaluated through Pearson's correlation coefficient (r) using the CORR procedure and by regression models using the REG procedure of SAS ver. 9.3. The IF and BMI presented r= 0.75 (P 0.05). The regression equation between IF and BMI had a coefficient of determination (r2) of 0.67 (P <.0001). The inclusion of the subcutaneous fat thickness together with the BMI improved the r2 with a range of 0.77. The BMI and the subcutaneous fat thickness could be used to predict the weight of the internal fat in hair sheep

Efeito da dieta liquida no desempenho e custo de produção de bezerros leiteiros na fase de cria

Objetivou-se avaliar o efeito da dieta líquida no desempenho de bezerros leiteiros e nos custos operacionais da fase de cria. O experimento foi conduzido, entre os meses de novembro e dezembro de 2015. Foram utilizados 10 animais, distribuídos em delineamento inteiramente casualizado com dois tratamentos (leite integral bovino ou sucedâneo) e cinco repetições. As variáveis de desempenho avaliadas foram: peso, ganho médio diário (GMD), ganho de peso total (GPT), e medidas biométricas (altura de cernelha, comprimento corporal, perímetro torácico, largura de garupa e de peito). Os indicadores econômicos analisados foram: os custos totais com a dieta líquida, com o concentrado e os custos com a mão de obra. Foi avaliado os encargos e impostos, despesas diversas, receita bruta, custo de oportunidade, lucro operacional e lucro total. Foi observado efeito da dieta liquida para peso final, GMD e GPT, os animais que receberam leite integral tiverem GMD 38% superior. Não houve efeito de tratamento para as medidas biométricas. O item de maior participação nos custos de produção foi a dieta 75% e 70% para leite e sucedâneo, respectivamente, seguido pelo custo com mão de obra, o leite tornou o sistema mais oneroso. A receita bruta estimada foi maior para os animais que receberam leite integral (548,5 vs 353,5 US$). O balanço econômico foi negativo para ambas as dietas. Bezerros leiteiros recebendo leite bovino na fase de cria na dieta líquida, apresentam um desempenho superior aos que recebem sucedâneo. Mesmo com desempenho superior, o leite integral tornou o sistema mais oneroso

Impact of supplementation with different protein sources on the parasitological profile of ovine matrices and development of lambs

The aim was to evaluate the impact of supplementation with different protein sources from agro-industrial production on the parasitological profile of ovine matrices and the development of their offspring. The protein sources used were: soybean bran, cotton pie, babassu pie, and coconut pie. A total of 60 ovine matrices were used, with confirmed pregnancy and supplemented in the final third of gestation at 0.5% of live weight in pastures of deferred Marandu grass. The evaluations occurred from the final third of gestation and in the lactation phase until weaning. The data collected in the matrices were: counting of eggs per gram of feces (EPG) and identification of infective larvae (Faecal test), evaluation of the degree of anemia by the FAMACHA©  method, body weight (kg), and body condition score (BCS). In the lambs, the biometric measurements were taken from the 30 days of life until weaning. In Faecal test, the prevalence was 98% of Haemonchus spp. There was no effect of the protein sources for EPG (3476.0) and FAMACHA©. However, in the mats supplemented with coconut pie were observed the lowest body weights (36.9 kg) and lower BCS (2.7). Babassu, coconut and cotton cakes, and soybean meal used as a protein source in the supplementation of ovine matrices kept in deferred pastures of Marandu grass at the 0.5% level of live weight maintain the production indexes consistent with the physiology stage of the matrices even with a high endo-parasitic load

Aspects related to the importance of using predictive models in sheep production. Review

Los sistemas de producción ovina se enfrentan a numerosos desafíos, que hacen de la toma de decisiones un proceso lleno de riesgos e incertidumbres. En este sentido, la modelación es una herramienta útil, ya que permite a los tomadores de decisiones evaluar el comportamiento de las variables y sus interrelaciones, además de utilizar información previa o relacionada para predecir resultados y simular diferentes escenarios. El advenimiento de los modelos de predicción ha permitido monitorear el peso de un animal y determinar el mejor momento para su venta. Además, permite a los productores estimar los pesos de la canal y los principales cortes comercializables antes del sacrificio. Toda esta información está directamente asociada a la rentabilidad y el éxito de la actividad productiva. Por lo tanto, en vista de las diferentes aplicaciones de los modelos matemáticos en los sistemas de producción, esta revisión de la literatura examina los conceptos en los estudios de modelación y la importancia de utilizar modelos de predicción en la producción de ovinos de carne. Además, aborda la aplicación práctica de los estudios de modelación en la predicción de la ingesta de materia seca y los rasgos de la canal de ovinos de carne a través de variables correlacionadas.Sheep production systems face numerous challenges, which make decision-making a process fraught with risks and uncertainties. Modelling is a helpful tool in this respect, as it allows decision-makers to evaluate the behaviour of variables and their interrelationships, in addition to using previous or related information to predict results and simulate different scenarios. The advent of prediction models has made it possible to monitor the weight of an animal and determine the best time for its sale. Additionally, it allows producers to estimate the weights of the carcass and major marketable cuts before slaughter. All this information is directly associated with the profitability and success of the production activity. Therefore, in view of the different applications of mathematical models in production systems, this literature review examines concepts in modelling studies and the importance of using prediction models in meat sheep production. Furthermore, it addresses the practical application of modelling studies in predicting dry matter intake and carcass traits of meat sheep through correlated variables

Productive and economic performance of feedlot young Nellore bulls fed whole oilseeds

ABSTRACT The effects of diets containing oilseeds were measured to evaluate the productive and economic parameters in the finishing of young, feedlot Nellore bulls. Twenty-four young Nellore bulls were used, with an initial body weight (BW) of 311.46±0.37 kg and 24 months of age, distributed into individual stalls ( 4 × 20 m) in a completely randomized design, totaling four treatments with six repetitions per treatment. Four diets (control, based on corn and soybean meal, and three diets containing cottonseed, soybean, and sunflower) were evaluated. Feed and orts were measured daily to calculate intake and costs. The dry matter intake of the control group was higher than soybean (10.64 kg/day), cotton (9.88 kg/day), and sunflower (9.30 kg/day) treatments, respectively. The cottonseed treatment showed the highest average neutral detergent fiber intake. There was a dietary effect of diets on average daily gain, total weight gain, and final weight. The soybean treatment showed the highest performance, total gain (232.55 kg), and final weight (544.38 kg). Oilseed intake can modify the fatty acids profile in the meat, decreasing its saturated fatty acid content. Whole soybean seed favors performance, improves feed efficiency, fatty acid profile, and fat distribution in the carcass, and can reduce production costs