José Laerte Nörnberg

Prebióticos na nutrição de não ruminantes

Due to the increasing constraint on the use of veterinary drugs as growth promoters in nonruminants nutrition there is a need to develop alternatives in supporting the microflora of the digestive tract in their approach to control pathogenic bacteria. The prebiotics are resistant compounds to digestion in the animal digestive tract, but selectively fermentable by intestinal microflora. These compounds can beneficially affect native microbiota, immune system and intestinal mucosal improving the digestion and absorption of nutrients. However, not always the use of the prebiotics causes alterations in the biological response. There may be several factors involved that partly explain the lack of response, such as: differences in the chemical composition of the ingredients of the diet, differences in the levels (percentage) of the prebiotics used in the diet, adaptation and the selectivity of the microflora and stress factors.

Produção e composição do leite de vacas de quatro grupos genéticos submetidas a dois manejos alimentares no período de lactação

The objective of this work was to evaluate the production and composition of milk of beef cows of four genetic groups, including Charolais (C), Nellore (N), CN crossbreds daughters of C bulls, and NC crossbreds, daughters of N bulls, maintained on native pasture and submitted to different managements during pre-weaning: supplemented with rice bran (.7% of the body weight) and weaned at 42 or 63 days postpartum, or non supplemented and weaned at 63 days. The cow age varied from 3 to 12 years, being classified as: first calf, young, adult and old cows. The data were submitted to variance analysis, the statistic model included management, cow genetic group, cow age and period effects and the interactions among these factors. Lactose and fat contents were not influenced by the factors studied. There was a significant interaction between cow age and period for milk production and between management and cow age for protein content. Supplemented cows showed higher milk production (3.85 vs 3.25 L/day), total dry extract content - EST (12.18 vs 11.83%) and nonfat dry extract content - ESD (8.75 vs 8.57%). The milk production declined as the lactation period advanced, and the reduction was more accentuated in the non supplemented cows. CN crossbred cows produced more milk (4.17 L/day) than the straigthbreds, not differing from the NC crossbred (3.76 L/day). N cows showed milk production similar to the C cows, respectively, 3.16 and 3.11 L/day. However, N cows milk was of better quality, including protein (3.16 vs 2.86%), EST (12.52 vs 11.46%) and ESD (8.87 vs 8.49%). Adult cows showed higher ESD content, followed by the young cows, first calf and old cows, being 8.86; 8.62; 8.62 and 8.54%, respectively.

CARACTERÍSTICAS PRODUTIVAS E QUALITATIVAS DE HÍBRIDOS DE MILHO PARA PRODUÇÃO DE SILAGEM

O objetivo do presente trabalho foi determinar as isotermas de sorcao das espigas de milho para diversas condicoes de temperatura e umidade relativa do ar e ajustar diferentes modelos matematicos aos dados experimentais. Para obtencao do teor de agua de equilibrio higroscopico das espigas de milho foi utilizado o metodo estatico, em câmaras com temperatura controlada, contendo no seu interior dessecadores com solucoes salinas saturadas. A temperatura variou entre 10 e 50°C e a umidade relativa entre 0,11 e 0,84 (decimal). As amostras foram pesadas periodicamente, sendo o equilibrio higroscopio alcancado quando a variacao da massa das amostras foi igual ou inferior a 0,01 g. Os modelos matematicos recomendados pela ASAE foram ajustados as dados experimentais. Para a avaliacao do grau de ajuste de cada modelo considerou-se a magnitude do coeficiente de determinacao ajustado, erros medio relativo e estimado, e a verificacao do comportamento da distribuicao dos residuos. Conclui-se que a higroscopicidade da espiga de milho segue a mesma tendencia da maioria dos produtos agricolas e que os modelos de Chung-Pfost Modificado, Halsey Modificado e Oswin Modificado representam adequadamente o fenomeno.

Efeito do tamanho de partícula e da altura de colheita das plantas de milho (Zea mays L.) sobre as perdas durante o processo fermentativo e o período de utilização das silagens

This trial evaluated the effect of particle size (small: between 0.2 and 0.6 cm or large: between 1.0 and 2.0 cm) and cutting height (low cut: 15.2 cm or high cut: 38.6 cm) of the corn plant on losses and nutritional value of silages. Treatments were: T1 - small particle size with low cutting height; T2 - large particle size with low cutting height; T3 - small particle size with high cutting height; and T4 - large particle size with high cutting height. No significant interaction was observed between cutting height and particle size for the following response variables: DM loss, CP loss, and NDF loss. Significant interaction was observed between cutting height and silo stratum and between particle size and silo stratum for the variables DM loss and CP loss, respectively. The high cutting silages (38.6 cm) on the inferior stratum showed higher losses (4.91%) compared to the superior silo stratum (2.67%) and low cutting silages (15,2 cm) regardless of the silo stratum. Greater CP losses were observed on the silages with small particle size on the superior stratum (18.96%) and on the silages with large particle size on the inferior stratum (18.68%) compared to silages with small particle size on the inferior stratum (11.52%) and silages with large particle size on the superior stratum (17.54%). Silages with large particle size resulted in higher physical losses at feeding-out.

Desempenho em confinamento de novilhos 5/8 Nelore - 3/8 Charolês abatidos em diferentes estádios de desenvolvimento

The objective of the experiment was to evaluate the feedlot performance of 5/8 Nellore-3/8 Charolais steers slaughtered at 425, 467 and 510 kg. The steers presented at the beginning of the confinement average age of 660 days, live weight of 361 kg and body condition score of 2.9 points. The animals were fed with a 60:40 roughage:concentrate diet, containing 10.25% of crude protein (CP), 72.18% of total digestible nutrient (TDN) and 3.18 Mcal of digestible energy (DE)/ kg of DM. The time necessary for the animals reach the slaughter weight (P) was 30, 65 and 94 days, respectively. The daily average intake of DM, TDN, DE, CP, NDF and ADF expressed per animal, 100 kg of live weight and metabolic weight did not show a significant relationship with slaughter weight. Average daily weight gain (ADG) declined as the slaughter weight increased (ADG=4.939-0.007P), being the average values of 2.10, 1.68 and 1.56 kg, respectively, for the three slaughter weights. There was a significant relationship between slaughter weight and final body condition score (FBC=0.658+0.008P) and daily gain in BC (DGBC=-2.684+0.008P). The food conversion of the DM,TDN,DE and CP intake into weight gain, increased linearly as the slaughter weight increased (CDM=-5.644+0.025P; CTDN=-4.074+0.0187P; CDE=-17.925+0.079P; CCP=-0.578+0.003P), showing that the feed efficiency declined. However, the food conversion can be considered satisfactory, respectively, 4.75, 5.97 and 6.75 kg of DM consumed/kg of weight gain.

Systematic evaluation on the effectiveness of conjugated linoleic acid in human health

ABSTRACT The term CLA (conjugated linoleic acid) corresponds to a mixture of positional and geometric isomers of linoleic acid. Two of these isomers (9c, 11t and 10t, 12c) have biological activity. The milk and dairy products are the most abundant source of conjugated linoleic acid, which refers to a group of positional and geometric isomers of CLA (CLA 18:2 cis-9, cis-12). The following research aims to approach aspects regarding the CLA, as well as its relationship with diseases. Conjugated linoleic acids have been studied for their beneficial effects in the prevention and treatment of many diseases, including obesity, cancer, diabetes, and cardiovascular diseases. Scientific information put together the physiological properties of CLA, which serves as inputs to claim their potential as functional ingredients to be used in the prevention and control of several chronic metabolic disorders.

Características fenológicas, produtivas e qualitativas de híbridos de girassol em diferentes épocas de semeadura para produção de silagem

The objective of this study was to estimate the effect of three sowing dates: October (early), November (normal) and December (late), on the phenological, yield and qualitative traits of four sunflower hybrids: Rumbosol-91 (forage), M-734 (double purpose), C-11 (double purpose) and BRS-191 (grain) grown for silage making. A 4 x 3 factorial treatment combination (four hybrids x three sowing dates) was allocated in a randomized block design with four replications. The October sowing brought about longer cycle, higher plant height, and smaller seed head diameter and contribution due to the prevailing climatic conditions of lower temperature, insolation and photoperiod during the crop growth period. The Rumbosol-91 and BRS-191 hybrids sowed in November showed higher lodging plus stalk breaking proportion of about 49.6 and 65.7%, respectively. The BRS-191 and M-734 hybrids sowed in December showed higher biomass yields of 39.71 and 43.76 t ha-1 fresh matter and 11.31 and 11.41 t ha-1 drymatter, respectively. While the CP content increased, the NDF, ADF and ADL contents decreased from the stem, to the leaf and to the head plant fractions. The whole plant DM values ranged from 23.2% in the Rumbosol-91 hybrid sowed in November to 47.9% in the C-11 hybrid sowed in December, indicating that the hybrids have differentiated moisture retention capacity at similar physiologic maturity of the culture (R-9 phase). The CP values ranged from 7.0 to 15.7%, an evidence of the high protein content of the culture. The ADL values of the whole plant ranged among 6.5 to 12.4%, with lowest values for the M-734 hybrid sowed in December and C-11 hybrid sowed in October. The M-734 hybrid sowed in December has better relationship among phenology, yield and bromatological composition, traits required for the making of high quality silage.

Fracionamento dos carboidratos e proteínas de silagens de milho, sorgo e girassol

This work evaluates and characterizes the carbohydrates and proteins fractions of corn, sorghum and sunflower silages. The purpose was to supply composition data that make it possible to maximize use of foods and optimize animal performance. Two corn (Zea mays) hybrids, DKB-215 and DKB-344; sorghum (Sorghum bicolor) hybrids, Ambar and AG-2005; and sunflower (Helianthus annuus) hybrids, Rumbosol and M-734; were evaluated. Sunflower silage showed the lowest total carbohydrates (TC) and B2 (cellulose and hemicelluloses) values and the highest content of C (lignin and fiber associated lignin). Corn silages showed higher non-fiber carbohydrates (NFC), A+B1 (soluble sugars + starch and pectin) and TC together sorghum silage while the last one showed higher B2 due to higher stem contribution. There were differences between hybrids of sunflower for TC, when Rumbosol showed higher contents than M-734, due to the aptitude of these materials, forage and grain respectively. The sunflower silage showed higher crude protein (CP) and protein fractions. There were no differences between hybrids for CP and protein fractions values.

Composição botânica e estrutural e valor nutricional de pastagens de azevém consorciadas

The objective of this work was to evaluate the influence of species intercropped with ryegrass on the botanical and structural composition and the nutritional values of pastures in an agroecological transition system. It was evaluated ryegrass (Lolium multiflorum Lam.) intercropped with black oats (Avena strigosa Schreb.), white clover (Trifolium repens L.) and forage peanut (Arachis pintoi Krapov. & Gregory). It was used a complete random design with three treatments and three repetitions. The first grazing was done 21 days after emergence of the plants on the pastures with ryegrass and black oats and ryegrass and forage peanuts and 28 days after emergence on the pasture of ryegrass + white clover. The second grazing, on the pasture with ryegras + black oats, occurred 30 days after the first one, whereas on the other pastures, grazing occurred 37 days later. The rates of dry matter (DM) accumulation, from the beginning of period of exclusion until maximal production of dry matter were: 77.7; 75.0 and 71.3 kg/ha/day of DM for the pastures intercropped with white clover, forage peanut and black cover, respectively. Leaf/culm ratio until second grazing, was high on all pastures. Reduction on contents of crude protein according to exclusion days on ryegrass + black oat pasture is lower than on pastures of ryegrass intercropped with white clover or forage peanut.Neste trabalho objetivou-se avaliar a influencia de especies em consorcio com azevem sobre a composicao botânica e estrutural e o valor nutritivo dos pastos em um sistema de transicao agroecologica. Foi avaliada a cultura do azevem (Lolium multiflorum Lam.) consorciada com aveia-preta (Avena strigosa Schreb.), trevo-branco (Trifolium repens L.) e amendoim-forrageiro (Arachis pintoi Krapov. & Gregory). O delineamento experimental foi o inteiramente casualizado, com tres tratamentos e tres repeticoes. O primeiro pastejo foi realizado 21 dias apos a emergencia das plantas nas pastagens de azevem + aveia-preta e azevem + amendoim-forrageiro e 28 dias apos a emergencia na pastagem de azevem + trevo-branco. O segundo pastejo na pastagem de azevem + aveia-preta ocorreu 30 dias apos o primeiro pastejo, enquanto nas demais pastagens ocorreu 37 dias depois. As taxas de acumulo de materia seca (MS) do inicio do periodo de exclusao ate o pico de producao de MS foram de 77,7; 75,0 e 71,3 kg/ha/dia de MS para as pastagens consorciadas com trevo-branco, amendoim-forrageiro e aveia-preta, respectivamente. A razao folha/colmo ate o segundo pastejo foi elevada em todas as pastagens. A reducao dos teores de PB conforme os dias de exclusao no pasto de azevem + aveia-preta e menor que nos pastos de azevem consorciado com trevo-branco ou amendoim-forrageiro.

Composição química, digestibilidade e cinética de degradação ruminal das silagens de híbridos de girassol em diferentes épocas de semeadura

The objective of this trial was to estimate chemical composition, digestibility and ruminal degradation kinetics of silages from four sunflower hybrids: Rumbosol-91 (forage), M-734 (double purpose), C-11 (double purpose) and BRS-191 (grain) sowed in October (early), November (normal) and December (late). A randomized complete block design in a 4 x 3 factorial arrangement (four hybrids x three seeding dates) with three replicates was used. Dry matter values ranged from 23.2 to 43.0%, pH from 4.0 to 5.1, and NH3-N%/TN from [...]The objective of this trial was to estimate chemical composition, digestibility and ruminal degradation kinetics of silages from four sunflower hybrids: Rumbosol-91 (forage), M-734 (double purpose), C-11 (double purpose) and BRS-191 (grain) sowed in October (early), November (normal) and December (late). A randomized complete block design in a 4 x 3 factorial arrangement (four hybrids x three seeding dates) with three replicates was used. Dry matter values ranged from 23.2 to 43.0%, pH from 4.0 to 5.1, and NH3-N%/TN from 5.3 to 16.8%. Ash values increased from October to December ranging from 6.8 to 8.8%. The Rumbosol-91 showed the lowest content of EE and the highest contents of N in the cell wall, unavailable N and total carbohydrates (TC). Crude protein contents increased from October to December while the opposite was observed for TC. November sowing and the C-11 gave the lowest contents of NDF, NDFcp and ADF. The C-11 sowed in November gave the lowest ADL values. October sowing and the Rumbosol-91 gave the highest content of ADL%/NDF. The Rumbosol-91 gave higher IVDMD and IVNDFD. November sowing and the C-11 and M-734 hybrids gave the highest value of TDN. Only one degradation profile was necessary to fit DM disappearance data. The proportion of undegradable NDF (I) increased from October to December sowing, being the BRS-191 sowed in December gave the highest values. The extent (Vf1) and rate (k1) of degradation of soluble fractions of rapid digestion decreased from October to December sowing, being the Rumbosol-91 sowed in October gave the highest values. The overall nutritive value measured by chemical composition, digestibility, total digestible nutrients and ruminal degradation kinetics was better for the M-734 and C-11 hybrids sowed in November.