Resumo em Inglês:

This experiment was conducted to evaluate the protein and carbohydrate fractions, and to estimate the in situ rumen degradation kinetic parameters of Brachiaria decumbens grass silage with inclusion of rice bran. Five rice bran inclusion levels were tested: 0, 10, 20, 30 and 40% of the natural matter, distributed into a completely randomized design with five replications. The brachiaria grass was obtained at 60 days of regrowth by cutting the forage at 10 cm from the soil and ensiling it in 10-L experimental silo bags, which were opened after 40 days. The degradability profiles for DM, CP, NDF and of the feeds for each animal utilized made it possible to obtain the estimates of the parameters analyzed. The contents of total carbohydrates (TCH), fibrous carbohydrates and fraction A+B1 of the TCH decreased linearly as the rice bran levels were elevated. Fraction A of the protein was increased linearly by 0.64% for every 1% of rice bran added to the silage. For nitrogenous fractions B3 and C, there was a decrease of 0.11 and 0.40% for each 1% of rice bran added to the silage, respectively. For the rumen degradability parameters of the dry matter, fractions A and I had estimated increases of 0.54 and 0.04% for every 1% inclusion of rice bran. For the degradation rate of fraction B (c), treatments had no effect. Fractions A and I of the crude protein degradability parameters increased by 0.22 and 0.72%, respectively, with inclusion of 1% rice bran. Inclusion levels of rice bran had no effect on fraction D, on the degradation rate of fraction B (c) or lag time (L) estimated for neutral detergent fiber. Inclusion of 10 and 20% rice bran in the brachiaria grass silage improves protein and carbohydrate fractions and rumen degradation kinetic parameters of dry matter, crude protein and neutral detergent fiber.

Resumo em Inglês:

This experiment was carried out to evaluate the effects of the row spacing between corn plants on silage quality. Different spacing between corn rows (40, 60, and 80 cm) was used, but the population of plants was maintained around 65,000/ha in all treatments. Analysis of variance was carried out and means were compared by Tukey's test at 5% of probability. A reduction in row spacing provided better spatial distribution of plants, but did not alter morphological composition or dry matter production. The corn with most equidistant spatial distribution (lowest row spacing) showed an increase in lignin concentration, neutral detergent fiber, and total carbohydrates, and showed a decrease in total digestible nutrients when compared with 80 cm row spacing. However, the organic digestibility matter was not affected by the treatments. The content and quality of protein were higher for 80 cm row spacing compared with the other levels; also, protein content was reduced as the spacing between rows became smaller. The only mineral affected was calcium, which had the lowest value at higher levels of spacing. Although differences were detected for many variables, the most appropriate spacing between rows should also take into account economic and practical aspects when choosing the best plant arrangement.

Resumo em Inglês:

This study evaluated the influence of follicular fluid (FF) added to the maturation medium on the quality of bovine embryos produced in vitro. In the first experiment, oocytes were matured in media containing five different FF concentrations with different maturation times and classified according to meiotic progression and migration of cortical granules. In the second experiment, oocytes matured in the same media were fertilized at three different maturation times; thereafter, cleavage and blastocyst rates were evaluated. In the third experiment, oocytes were matured in media containing three different FF concentrations at two different maturation times, and embryo quality, inferred by the ratio of inner cell mass and trophectoderm cells compared with total cell number, was evaluated. Higher FF concentration (75 - 100% FF) slowed meiotic progression and CG migration (control - 78.13% vs. treated - 52.58% and control - 52.7% vs. treated - 11.59%, respectively, at 24 h of maturation). Also, FF at concentration of 75% or 100% had a negative influence on cleavage and blastocyst rates (control - 90.13% vs. treated - 82.64% and control - 35.73% vs. treated - 11.57%, respectively, at 24 h of maturation). The 50% FF resulted in embryos with increased inner cell mass numbers (control - 29.91 vs. treated - 35.49, at 24 h of maturation) and total cell numbers (control - 109.53 vs. treated - 120.67, at 26 h of maturation). Even though higher concentration of FF added to the maturation medium reduced embryonic development rates, in lower concentrations, FF slowed the meiotic progression and migration of CG and contributed to increases in inner cell mass number. Thus, FF added to the maturation medium enhances the number of cells in bovine embryos produced in vitro, especially for inner cell mass.

Resumo em Inglês:

The objective of the present work was to induce chromosome doubling in genotypes of Brachiaria ruziziensis with potential for production of good-quality biomass and tolerance/resistance to stress caused by aluminum and spittlebugs. Germinated seeds of B. ruziziensis were immersed in 0.1% colchicine solution for 2 or 3 hours. Ploidy level was determined by flow cytometry and confirmed by chromosome count. Fertility of the tetraploid plants was assessed through evaluation of pollen viability by staining. There was no statistical difference with regard to seedling survival and number of duplicate seedlings between the treatments. Survival rate was 8%, of which 11.45% were tetraploid genotypes. The mean viability of pollen grains from the evaluated tetraploid plants ranged from 51.75 to 55.50%. So, the tetraploids plants obtained from genotypes of a bred population of ruzigrass produce fertile pollen, in percentages that render crosses viable in genetic breeding programs.

Resumo em Inglês:

The objective of this study was to estimate the genetic, phenotypic and environmental parameters for calving interval (CI), days open (DO), number of services per conception (NSC) and conception rate (CR) in Holstein and Jersey cattle in Antioquia (Colombia). Variance and covariance component estimates were obtained by an animal model that was solved using the derivative-free restricted maximum likelihood method. The means and standard deviations for CI, DO, NSC and CR were: 430.32±77.93 days, 127.15±76.96 days, 1.58±1.03 services per conception and 79.88±28.66% in Holstein cattle, and 409.33±86.48 days, 125.62±86.09 days, 1.48±0.98 services per conception and 84.08±27.23% in Jersey cattle, respectively. The heritability estimates (standard errors) were: 0.088(0.037), 0.082(0.037), 0.040(0.025) and 0.030(0.026) in Holstein cattle and 0.072(0.098), 0.090(0.104), 0.093(0.097) and 0.147(0.117) in Jersey cattle, respectively. The results show that the genetic, phenotypic and permanent environmental correlations in the two evaluated breeds were favorable for CI × DO, CI × NSC and DO × NSC, but not for CI × CR, DO × CR and NSC × CR. Genetic and permanent environmental correlations were high in most cases in Holstein cattle, whereas in Jersey cattle they were moderate. In contrast, phenotypic correlations were very low in both breeds, except for CI × DO and NSC × CR, which were high. Overall, the genetic component found was very low (<8%) in both evaluated breeds and this implies that their selection would take long time and that a good practical management of the herd will be essential in order to improve the reproductive performance.

Resumo em Inglês:

The objective of this trial was to evaluate the bioavailability of DL-2-hydroxy-4-(methyl) butanoic acid (DL-HMBA) and a polyherbal ingredient (PHI) in relation to DL-methionine (DLM) on broilers. Nine hundred male broiler chickens of the Cobb 500 strain were fed from 22 to 42 days of age either a basal diet without industrial methionine supplementation or the basal diet supplemented with DL-HMBA at one of three levels (0.143, 0.286 and 0.429%) or DLM at one of three levels (0.093, 0.186 and 0.279%, each of which is 65% of the respective DL-HMBA level by weight) or PHI at one of the same three levels used for DLM (0.093, 0.186 and 0.279%). The weight gain, feed conversion ratio and relative weights of breast and abdominal fat were improved over that of basal diet-fed broilers by the addition of DL-HMBA and DLM to the diet. A simultaneous exponential regression analysis revealed that the relative bioavailability values for DL-HMBA and PHI were 52% and 5% of that of DLM, respectively, for weight gain, and 57% and 4%, respectively, for feed conversion ratio. Concerning breast meat yield, a simultaneous linear regression analysis (slope ratio) showed that the relative bioavailability for DL-HMBA was 65% of that of DLM. Considering all studied parameters together, the relative bioavailability values for DL-HMBA and PHI are 58% and 4.5% of that of DLM on a product basis.

Resumo em Inglês:

An experiment employing three hundred and twenty 81-week-old Lohmann LSL commercial-breed hens was conducted to compare alternative induced-molting methods with the conventional method (fasting). Induced molting lasted 28 days at most, production and quality being monitored for four periods of 28 days thereafter. A completely randomized experimental design with five treatments, eight replicates of eight birds each per plot was adopted. The following experimental treatments were applied until a loss of 26% of body weight was reached: T1 - fasting, T2 - wheat bran ad libitum, T3 - rice bran ad libitum, T4 - cracked rice ad libitum, T5 - ground alfalfa ad libitum. Birds were then fed production diet ad libitum, except for those on treatment T1 (fasting) which received 30, 60 and 100 g/bird/day and then feed ad libitum. During induced molting the birds were exposed to a natural photoperiod and at day 28 that period was increased by 30 minutes/week until reaching 16 hours of light/day. The characteristics evaluated during induced molting were: feed intake, body weight changes and laying percentage. In the post-molt period, performance (feed intake, laying percentage, egg weight, egg mass, feed conversion ratio per dozen and per egg mass and percentage of broken eggs) and egg quality (specific gravity, eggshell breaking strength, percentages of eggshell, yolk, and albumen, eggshell thickness, yolk color and Haugh unit) were evaluated. Every 28 days one egg was collected from each repetition for three consecutive days for quality assessment. The use of rice bran and wheat bran is viable as molting inducers since the birds given those treatments display performance and egg quality similar to those fasted during the induced molting and also because these ingredients promote easier handling, eliminates the need for grinding and feed-mixing equipment and, being less aggressive, provide greater bird welfare.

Resumo em Inglês:

The objective of the present study was to assess the growth performance and carcass traits of Moxotó goat kids fed different levels concentrate (supplement) (SL) on native pasture under semiarid conditions in Brazil. Thirty-two castrated kids (15.7±0.78 kg initial BW) were allocated randomly to one of the four SL (treatment groups: 0, 5, 10 and 15 g/kg BW). When the animals of treatment group 15 g/kg BW reached 25 kg BW, the animals in the other treatments groups were also slaughtered. Therefore, the animals belonging to the 0, 5, 10 and 15 g/kg of BW were finished with 18.40, 21.04, 22.94 and 25.74 kg of BW, respectively. The concentrate supplementation positively influenced the performance and the carcass traits of animals, providing higher feed intake and thus greater weight gain. The results of cold carcass yields were 405.9, 427.0, 449.1 and 462.9 g/kg of SBW for 0, 5, 10 and 15 g/kg BW, respectively. The weight of the different commercial cuts, (neck, ribs, shoulder, loin and leg) increased linearly as the SL increased; however the yields of the carcass cuts were not influenced, except for the shoulder. Overall, the distribution of non-carcass fat increased as SL increased, with the exception of mesenteric fat yield, which was not influenced. The use of concentrate supplementation to Moxotó goats under grazing conditions on native rangelands of the Brazilian semiarid improves the performance of animals and carcass yield, but does not affect the yields of commercial cuts of Moxotó growing goats.