Evaluation of total and non-fatty ether extract in feeds and cattle feces using two analytical methods

AbstractThe objective of this study was to evaluate ether extract (EE) concentrations, pigments, and wax in forages (n=14), concentrates (n=23), and cattle feces (n=100) using extraction methods recommended by Association of Official Analytical Chemists (AOAC; method 920.39) and American Oil Chemist's Society (AOCS; method Am 5-04). The EE contents were compared by adjusting a linear regression model for each sample type. For the feces and forage samples, the EE contents produced by the AOCS method were greater (P<0.05) compared to those obtained using the AOAC method. No differences between methods were observed in EE content of concentrates (P>0.05). Concentration of vegetable pigments and wax were evaluated by using analysis for variance. Vegetable pigments were lower (P<0.05) in the post-extraction residues using the AOCS method, than the AOAC method, indicating greater participation of vegetable pigments in the EE. No differences were observed between the methods in wax concentration of the post-extraction residues (P>0.05). The quantification method of the EE content that is recommended by AOCS is not suggested for analyses of forage and feces of ruminants because it possibly increases the removal of non-fatty material, mostly pigments, in comparison to the method recommended by AOAC

Supplementation levels for growing beef cattle grazing in the dry-rainy transition season.

The objective of this experiment was to study the effects of different levels of supplementation on the performance, intake, digestibility, pH and rumen ammonia concentration in growing bulls grazing Brachiaria decumbens Stapf. pasture, during the dry-rainy transition season. For evaluation of performance, intake and digestibility, it was used 25 non-castrated steers at 11 months of age and initial average body weight of 270 kg, grouped in five plots of five animals each, following a completely randomized design. Each plot received one of the following feeding treatments: mineral mixture and supplement at the proportion of 0.5, 1.0, 1.5 and 2.0 kg/animal/day, corresponding to 0.18, 0.36, 0.54 and 0.72% of the average body weight of the animals. The area designated for the animals was constituted of five 2.0-ha paddocks. For the evaluation of the pH and rumen ammonia concentration, five crossbred non-castrated steers were used, with average body weight of 240 kg, fistulated in the esophagus, rumen and abomasum, disposed in a 5 × 5 Latin square, with five treatments and five experimental periods. Animal performance behaved in a positive linear manner according to the supplementation levels, responding with an increase of more than 80% on weight gains of the animals. Intakes of total and pasture dry matter (DM), organic matter and neutral detergent fiber were not influenced by supplementation. Intakes of crude protein, nonfibrous carbohydrates, ether extract and total digestible nutrients as well as nutrient digestibility and rumen ammonia concentration showed a positive linear pattern in response to supplementation levels. Increasing levels of concentrate supplementation influence positively the performance of bulls growing on pastures during the dry-rainy transition season

Efficiency of lysine utilization by growing steers

Citation: Batista, E. D., Hussein, A. H., Detmann, E., Miesner, M. D., & Titgemeyer, E. C. (2016). Efficiency of lysine utilization by growing steers. Journal of Animal Science, 94(2), 648-655. doi:10.2527/jas2015-9716This study evaluated the efficiency of Lys utilization by growing steers. Five ruminally cannulated Holstein steers (165 +/- 8 kg) housed in metabolism crates were used in a 6 x 6 Latin square design; data from a sixth steer was excluded due to erratic feed intake. All steers were limit fed (2.46 kg DM/d), twice daily, diets low in RUP (81% soybean hulls, 8% wheat straw, 6% cane molasses, and 5% vitamins and minerals). Treatments were 0, 3, 6, 9, 12, and 15 g/d of L-Lys continuously abomasally infused. To prevent AA other than Lys from limiting performance, a mixture providing all essential AA to excess was continuously abomasally infused. Additional continuous infusions included 10 g urea/d, 200 g acetic acid/d, 200 g propionic acid/d, and 50 g butyric acid/d to the rumen and 300 g glucose/d to the abomasum. These infusions provided adequate ruminal ammonia and increased energy supply without increasing microbial protein supply. Each 6-d period included 2 d for adaptation and 4 d for total fecal and urinary collections for measuring N balance. Blood was collected on d 6 (10 h after feeding). Diet OM digestibility was not altered (P >= 0.66) by treatment and averaged 73.7%. Urinary N excretion was decreased from 32.3 to 24.3 g/d by increasing Lys supplementation to 9 g/d, with no further reduction when more than 9 g/d of Lys was supplied (linear and quadratic, P < 0.01). Changes in total urinary N excretion predominantly were due to changes in urinary urea N. Increasing Lys supply from 0 to 9 g/d increased N retention from 21.4 to 30.7 g/d, with no further increase beyond 9 g/d of Lys (linear and quadratic, P < 0.01). Break-point analysis estimated maximal N retention at 9 g/d supplemental Lys. Over the linear response surface of 0 to 9 g/d Lys, the efficiency of Lys utilization for protein deposition was 40%. Plasma urea N tended to be linearly decreased (P = 0.06) by Lys supplementation in agreement with the reduction in urinary urea N excretion. Plasma concentrations of Lys linearly increased (P < 0.001), but Leu, Ser, Val, and Tyr (P <= 0.02) were linearly reduced by Lys supplementation, likely reflecting increased uptake for protein deposition. In our model, Lys supplementation promoted significant increases in N retention and was maximized at 9 g/d supplemental Lys with an efficiency of utilization of 40%

Caracterização do padrão de desenvolvimento de gramíneas forrageiras tropicais por meio das características morfogênicas e estruturais

An experiment was carried out with the objective to evaluate growth pattern of tropical forage grass under free growth by using morphogenetic and structural characteristics with the expectation of using this study for forage grass evaluation protocol. The experimental area was established with two cultivars of Panicum maximum Jacq. (Mombaca and Aruana), a hybrid cultivar of P. maximum Jacq. and P. Infestum BRA-7102 (Massai), two cultivars of Brachiaria brizantha (A. Rich.) Stapf (Marandu and Xaraes) and Molasses grass (Melinis minutiflora Beauv.) and jaragua grass (Hyparrhenia rufa (Nees) Stapf.). The grasses were planted in 1.0-m² experimental units with 24 plants arranged in a completely randomized block design with three replications. Growth pattern of the grasses was evaluated through mass development, tiller mortality, development stage and leaf longevity. Development patterns differed significantly among groups of grasses, indicating that the same available resources can be used in different manners by grasses from the same genus and/or species.Um experimento foi conduzido com o objetivo de avaliar o padrão de desenvolvimento de gramíneas forrageiras tropicais em crescimento livre por meio das características morfogênicas e estruturais, com expectativa de uso desse estudo no protocolo de avaliação de gramíneas forrageiras. A área experimental foi estabelecida com dois cultivares de Panicum maximum Jacq. (Mombaça e Aruana), um cultivar híbrido de P. maximum Jacq. e P. infestum BRA-7102 (Massai), dois cultivares de Brachiaria brizantha (A. Rich.) Stapf (Marandu e Xaraés) e com os capins gordura (Melinis minutiflora Beauv.) e jaraguá (Hyparrhenia rufa (Nees) Stapf.). As gramíneas foram plantadas em unidades experimentais de 1,0 m² com 24 plantas arranjadas em delineamento de blocos completos casualizados com três repetições. O padrão de desenvolvimento das gramíneas foi avaliado por meio do desenvolvimento de massa, da mortalidade de perfilhos, do estádio de desenvolvimento e da longevidade foliar. Os padrões de desenvolvimento diferiram significativamente entre os grupos de gramíneas, e isso indica que os mesmos recursos disponíveis podem ser usados de maneira diferente por gramíneas de mesmo gênero e/ou espécie.CNPqFederal University of Vicosa - Departament of Animal Scienc

I don’t like interacting, but it’s necessary: a brief overview of factorial experiments in animal science

The factorial experiments are useful in animal science, as they allow us to evaluate how different causative factors affect directly the animal responses and, mostly important, how the factors can interfere with each other on that responses. The animal production is naturally an interactive process. Therefore, interactions must be an important aspect to be considered when we look at a better understanding of nutritional and metabolic aspects of animal production. In this overview, I present the most basic aspects of factorial experiments applied do animal science and some ways to avoid the most common mistakes that can be made when carrying out this kind of experiment

Relações de troca com efeito tecnológico no mercado doméstico de arroz, milho, café e soja

The objective of this work was to evaluate, by means of the exchange rate, the profitability of two products directed toward the domestic market and two export products. Other objective was to identify productivity growth compensated the decrease of prices. The geometric rates of the production, area and productivity growth were estimated. The exchange rate was estimated by the relation between the index of the inputs prices and the index of the product prices. The results show a great trend of deterioration of the exchange terms for all the analyzed products. Evidenced that these effects more was been accented for rice and maize. Such behavior associates it the fact of the rice cultures and of maize to be destined to the domestic market, its demands have been not elastic in relation to the coffee and soy cultures.Terms of exchange, Grains, Inputs, Prices, Productivity, Income, Productivity Analysis,

Nutritional requirements of energy, protein and macrominerals for maintenance and weight gain of young crossbred Nellore × Holstein bulls on pasture.

The objective of this study was to estimate requirements of energy, protein and macrominerals of young Nellore/Holstein crossbreds bulls supplemented on pastures of Brachiaria decumbens Stapf. Thirty-five young bulls, at 8.53±0.18 months of age and with initial body weight of 230.6±6.1 kg were used. Ten animals were slaughtered as reference, in different weight range, and the other animals were slaughtered at the end of the experimental period. For estimate of net energy requirements for weight, a regression equation between log of retained energy (RE) and log of empty body weight gain (EBWG) was constructed. Net requirements of Ca, P, Mg, Na and K were determined by the equation Y' = a.b.Xb-1, in which a and b represent the intercept and the coefficient of equation of prediction of macrominerals in body content, respectively. Requirements of metabolizable energy for maintenance (MEm) were obtained from retained energy in function of metabolizable energy intake (MEI). The requirements of MEm of Nellore/Holstein crossbreds young bulls on pasture was 125 kcal/EBW0.75/day. The efficiency of ME utilization for maintenance (km) of grazing Nellore/Holstein crossbred young bulls was 0.58 and 0.24 for gain. The total metabolizable protein requirements for an animal with 400 kg and with average daily gain of 1.0 kg, were 638.36 g/day. The dietetic requirements of Ca and P for an animal with 400 kg BW were 0.49 and 0.21% of DM, respectively. Daily metabolizable energy requirement for maintenance of grazing Nellore/Holstein crossbred young bulls was 11.6% greater than the values found for cattle in feedlot in Brazil (112 kcal/kg EBW0.75)

Questão agrária e desenvolvimento econômico e social nas regiões Norte e Noroeste fluminense

The research has as objective to analyze the evolution of the agrarian structure, and the behavior of the economic and social development indicators, for the North and Northwest regions of the Rio de Janeiro state. Moreover, it searchs to verify if the land distribution is an important variable in the explanation of the divergences between the degree of economic development of the cities. The results show that, for the considered regions, the differences in the agrarian structure, separately, can not explain the differences in the degree of economic and social development. The size of the population, in turn, seems to be an important variable in this process. This can be associated to the greater potential demand, what is attractive the private investments. Another reason is, possibly, the greatest politics power, due to the size of the electorate, what can influence in the destination of the public investments.Agrarian structure, Economic and social development, Royalties, Community/Rural/Urban Development,