Showing papers in "Revista Brasileira De Zootecnia in 2012"

Phytogenic additives and organic acids in broiler chicken diets

Abstract: The experiment evaluated the influence of isolated or associated phytogenic additives (PA) and organic acids (OA) on nutrient digestibility, performance and carcass characteristics of broiler chickens. Two experiments were conducted in a completely randomized design with a 2 × 2 + 1 factorial arrangement of treatments (with or without PA × with or without OA + antibiotic performance enhancer and anticoccidial). In the first experiment, two metabolic tests were conducted to determine the metabolizability coefficients of the nutrients of starter and growth diets. In the second experiment, 2520 one-day-old chicks were housed in 40 experimental units to evaluate the performance and carcass characteristics. The phytogenic additives and organic acids, isolated or associated, improve the nutrient digestibility of the diet and replace the growth- promoting antibiotics. The use of organic acids isolated or associated with phytogenic additives in broiler diets improves broiler performance in comparison with free antibiotic performance enhancer at 42 days of age. Isolated or associated phytogenic additives and organic acids provided better carcass characteristics.

Creatinine excretion and relationship with body weight of Nellore cattle

Abstract: The objective of this study was to estimate the urinary creatinine excretion by the shrunk body weight (SBW). In experiment I, 32 Nellore bulls with initial body weight of 259±24.9 kg and 14±1 months-old were used. The group was divided in four animals to maintenance and twenty eight animals feeding ad libitum and separated in four groups; each group was slaughtered at different times of feedlot (42, 84, 126 and 168 days). The diet was composed of corn silage and concentrate (55:45). Before the slaughters, the total urinary collection was realized during three days. A database of creatinine excretion was collected from other five studies that had been conducted with Nellore cattle. In all the studies, the total urinary collection was realized during at least three days. At the end of each collection, the animals were weighted. Urinary creatinine excretion (UCE) was related with the shrunk body weight and it can be estimated by the equation: UCE (g/day) = 0.0345 × SBW0.9491.

Egg quality of laying hens in different conditions of storage, ages and housing densities

Abstract: The objective of this research was to evaluate the quality of eggs from Dekalb White hens under different temperatures (room temperature, 25 oC; and refrigeration, 8 oC), storage times (7, 14 and 21 days), age of birds (35, 40, 45 and 50 weeks) and housing densities (625, 500, 416.6 and 357.14 cm 2 /birds). Haugh unit (HU) values and albumen height of 1,120 eggs from 528 laying hens, randomly allocated to four groups with different population densities were evaluated. The results showed a significant effect on Haugh units, between the time and storage conditions and between the ages of laying hens and storage condition. Eggs stored in refrigeration showed less weight loss and better Haugh unit indices when compared with eggs stored at room temperature. The increased time of storage, regardless of the temperature, caused loss in their quality. According to the results of this study, based on the evaluation of the albumen height, temperature, storage time, density and age of the layers influence the values of Haugh unit.

Fiber sources in diets for newly weaned piglets

Abstract: This experiment was carried out to evaluate the effects of purified cellulose, soybean hulls and citrus pulp in the diet of weaned piglets. A total of 72 piglets (36 castrated males and 36 females) weaned at 21 days of age (BW 6.45±0.66 kg) was distributed according to a randomized block design, for evaluation of performance, transit time, diarrhea incidence and blood parameters of piglets which received diets containing different sources of fiber. The experimental diets were: control diet - diet composed of corn, soybean meal and a source of lactose; control + 1.5% purified cellulose; control + 3% soybean hull and control + 9% citrus pulp. The inclusion of purified cellulose, soybean hulls and citrus pulp in diets of weaned piglets did not affect the performance or transit time of diets in the gastrointestinal tract. However, the use of purified cellulose reduced incidence of diarrhea. The use of purified cellulose, soybean hull and citrus pulp in the diet of weaned piglets does not affect performance or gastrointestinal transit time. The addition of purified cellulose promotes a beneficial effect to control the diarrhea in weaned piglets.

Protein co-products and by-products of the biodiesel industry for ruminants feeding

Abstract: The objective of the experiment was to classify 20 protein co-products and by-products of the biodiesel industry with potential to use in ruminant feeding. The meals evaluated were: cottonseed, canudo-de-pito, crambe, sunflower, castor-oil seeds detoxified with calcium, non-detoxified castor-oil seeds and soybean; and the cakes were: cottonseed, peanut, babassu, crambe, palm oil, sunflower, licuri, macauba seeds, non-detoxified castor-oil seeds, turnip and jatropha. The samples were quantified to determine dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), neutral detergent fiber corrected for ash and protein (NDFap), non-fiber carbohydrates (NFC), acid detergent fiber corrected for ash and protein (ADFap), lignin, cutin and starch levels. The CP profile was characterized in fractions A, B1, B2, B3 and C. The in vitro dry matter digestibility (IVDMD), in vitro neutral detergent fiber digestibility (IVNDFD), rumen degradable and undegradable protein, intestinal digestibility, indigestible neutral detergent fiber and undegradable neutral detergent insoluble protein were evaluated. The OM, CP, EE, NDFap, NFC, ADFap, lignin, cutin and starch contents varied from 81.95 to 95.41%, 18.92 to 57.75%, 0.56 to 18.40%, 10.13 to 62.30%, 3.89 to 27.88%, 6.15 to 36.86%, 1.19 to 5.04%, 0 to 17.87% and 0.68 to 14.50%, respectively. The values of fractions A, B1, B2, B3 and C ranged from 5.40 to 43.31%, 0.08 to 37.63%, 16.75 to 79.39%, 1.86 to 59.15% and 0.60 to 11.47%, respectively. Concentrations of IVDMD, IVNDFD, rumen-degradable and undegradable protein, intestinal digestibility, indigestible NDF and undegradable neutral detergent insoluble protein ranged from 31.00 to 95.92%, 55.04 to 97.74%, 41.06 to 97.61%, 2.39 to 58.94, 9.27 to 94.26%, 1.05 to 40.80% and 0.29 to 2.92%, respectively. Some of these products can replace soybean meal, specially the Macauba seeds cake, cottonseed meal and peanut and turnip cakes based on digestive characteristics.

Herbal extracts in diets for broilers

Abstract: The objective of this study was to evaluate the effect of feeding herbal extracts for broilers on performance and histology of the intestinal mucosa and its effects on the profiting from the metabolizable energy of experimental diets. For so, two experiments were conducted. In experiment I, the inclusion of different herbal extracts in diets on performance and intestinal histology of broilers was evaluated, and in experiment II, the values of apparent metabolizable energy and metabolizable energy corrected by the nitrogen balance of the experimental diets were studied. Treatments consisted of: positive control diet; positive control + avilamycin; negative control; negative control + 100 ppm of a complex containing three different herbal medicines (pepper, cinnamon and oregano); negative control + 75 ppm garlic extract; negative control + 150 ppm garlic extract. In the performance experiment, which comprised the period of 1 to 40 days of age, 960 male broilers were distributed in a randomized block design, with six treatments and eight replicates, with 20 birds per experimental unit. In experiment II, the method adopted was the traditional of total excreta collection with male broiler chicks in the age of 14 to 24 days, in a completely randomized design, with six treatments and eight replicates with five birds per experimental unit. The intestinal villus height was improved with addition of the composite containing the three herbal extracts; however, crypt depth and villus/crypt ratio were not affected. The use of herbal extract in diets for broilers promotes performance similar to that with the use of antibiotics. Herbal extracts can be incorporated into diets replacing antibiotics without compromising the metabolizable energy of diets, performance or intestinal mucosa for broilers in the period of 1 to 40 days of age.

Características de carcaça e cortes comerciais de tourinhos Red Norte e Nelore terminados em confinamento

Abstract: The objective of this study was to evaluate the characteristics of carcass and weight of the commercial meat cuts from carcass of Red Norte and Nellore young bulls finished in feedlot. Forty four animals - 22 Red Norte with initial average weight of 367±30 kg and 22 Nellore at initial average weight of 361±30 kg - were used. The animals received feed ad libitum with concentrate:roughage ratio of 50:50 during 112 days, from which 28 days were for adaptation. Red Norte and Nellore animals were slaughtered at 519 and 482 kg, respectively. The subcutaneous fat thickness (FT) and longissimus muscle area (LMA) were measured between 12th and 13th ribs. Higher carcass yield of the Nellore breed was observed (57.7 vs 54.7%). However, there was no difference for weight of hot and cold carcass between the groups. Red Norte animals showed greater LMA, and hindquarter and spare ribs with higher weight and yield, and forequarter with lower weight and yielding. The Red Norte genetic group showed higher weight for cap and rump and striploin, while Nellore showed higher weight for shoulder and flatround. Nellore animals had better carcass yield, which contributes to hot carcass weight. Nevertheless, the group Red Norte have higher hindquarter yield and more weight from cuts of highest commercial value.

Structural characteristics of tiller age categories of continuously stocked marandu palisade grass swards fertilized with nitrogen

Abstract: The objective of this experiment was to evaluate the structural characteristics of young, mature and old tillers on continuously stocked marandu palisade grass maintained at 30 cm and fertilized with nitrogen. Treatments corresponded to three nitrogen application rates (150, 300 and 450 kg/ha of N) plus control (no fertilization) and were assigned to experimental units (1,200-m2 paddocks) according to a completely randomized block design, with four replications. Measurements were performed during fall/winter 2007 and summer 2008. During summer, young tillers showed longer leaves and shorter stems relative to old tillers. During fall/winter, young and old tillers showed shorter leaves, while mature and old tillers showed longer stems. Tiller age interfered with the number of leaves per tiller mainly through variations in the number of expanding and senescing leaves during both fall/winter and summer. The structural characteristics of individual tillers are affected by plant age, with nitrogen favouring the production of leaf tissue in young tillers during summer.

Digestible lysine requirement of Nile tilapia fingerlings fed arginine-tolysine-balanced diets

Abstract: This study was conducted to determine the digestible lysine requirements of Nile tilapia fingerlings. Fish (n = 300; average initial weight = 1.44 g) were distributed 15 300-L aquariums, in a completely randomized design with five treatments and three replicates, and fed extruded diets containing 11.3, 13.7, 16.1, 18.4 or 20.8 g/kg of digestible lysine. The arginine:lysine ratio was maintained at 1.3:1. All fish were fed diets containing 281 g/kg of digestible protein and 3,372 kcal digestible energy/kg, hand-fed until apparent satiation. There was no effect of the dietary lysine levels on survival rate, or protein and ash body rates. With increasing levels of lysine in the diet, a quadratic effect on weight gain, feed conversion, protein efficiency ratio, protein deposition rate, deposition rate of fat, body moisture and body lipids was observed, where the best values of the variables were estimated at 15.96, 16.4, 14.35, 15.21, 15.87, 15.21 and 16.29 g/kg of lysine, respectively. The digestible lysine requirement of Nile tilapia fingerlings is 15.21 g/kg (5.41 g/100 g of digestible protein), in diets balanced for the arginine:lysine ratio.

Effects of GnRH administration on ovulation and fertility in ewes subjected to estrous synchronization

Abstract: The objective of this study was to verify the effects of GnRH on ovulation and pregnancy of ewes subjected to a short-term synchronization of estrus. Santa Ines and crossbred Santa Ines/Dorper ewes received 60 mg MAP sponges during 6 days plus 300 IU eCG and 30 μg d-cloprostenol 24 h prior to sponge withdrawal (SW). Ewes were assigned to receive 0.9% NaCl solution (T control ; n = 32) or 25 μg GnRH (licerelin, T GnRH ; n = 34) 24 hours after SW. Each group was assigned to intrauterine insemination by laparoscopy (n = 25) or to natural mating (n = 41). Artificial insemination was performed with a single dose of fresh semen. For controlled mating, females were exposed to males 12, 24, 36 and 48 hours after SW. Ten females per treatment were subjected to transrectal ultrasound examination at 12-hour intervals (SW to 60 hours after). Estrous response (100.0% vs 95.2%), interval from SW to estrus (32.9±7.4 vs 29.8±6.9 hours), estrous length (37.4±9.0 vs 31.5±10.4 hours), pregnancy rates (57.0% vs 41.0%), ovulation rate (100.0% vs 90.0%), number of ovulations/ewe (1.1±0.3 vs 1.2±0.4), maximum follicular diameter (6.4±0.7 vs 6.1±0.6 mm), interval from SW to ovulation (59.1±3.5 vs 58.4±3.5 hours) did not differ between T control and T GnRH , respectively. Administration of GnRH 24 hours after SW does not improve ovulation or pregnancy rate in estrous synchronization in ewes.

Hemolytic activity of alternative complement pathway as an indicator of innate immunity in pacu (Piaractus mesopotamicus)

Abstract: The objective of this study was to evaluate the methodology to establish the hemolytic activity of alternative complement pathway as an indicator of the innate immunity in Brazilian fish pacu (Piaractus mesopotamicus), in addition to verifying the influence of β-glucan as an immunostimulant. Fish were fed with diets containing 0, 0.1 and 1% β-glucan, during seven days, and then inoculated with Aeromonas hydrophila. Seven days after the challenge, they were bled for serum extraction. The methodology consisted of a kinetic assay that allows calculating the required time for serum proteins of the complement to promote 50% lysis of a rabbit red blood cell suspension. The method developed in mammals was successfully applied for pacu and determined that the hemolytic activity of the proteins of the complement system (alternative pathway) increased after the pathogen challenge, but was not influenced by the β-glucan treatment.

Qualidade de carcaça, desenvolvimento regional e tecidual de cordeiros terminados em três sistemas

Abstract: The objective of this study was to evaluate the effect of finishing systems on natural pasture and gender on the carcass quality, parts and tissue development of lambs. Forty-five non-castrated males and forty-five females were distributed in a completely randomized design into three treatments: lamb with mother kept on pasture; weaned lamb kept on pasture and weaned lamb kept on pasture with supplementation (soybean hulls at 1% of body weight). The criteria for slaughter was body condition score (2.0 - 3.0). The carcass characteristics and parts composition were influenced by the sex. The finishing system with supplementation promoted greater carcass yield and longer leg length. The tissue composition was different only for the sex, with the males presenting bigger amount of muscle mass. The allometric growth of shoulder of supplemented lambs and the shoulder and leg of the lambs with mother had been precocious, while the ribs of the supplemented lambs and lambs with the mother were late and the other components had growth similar to the half-carcass. For the females, only shoulder of lambs finished with mother presented precocious growth, being isogonic for the other cuts. The finished systems evaluated demonstrated that Texel × Corrierdale lambs slaughtered with similar body condition score present similar carcass quality. The development is influenced by the termination system and sex. The quali-quantitative characteristics of the carcass were influenced by the sex. The development of the regional components of the males are influenced by the finishing system. Nevertheless, the tissu components are not influenced by the finishing system or gender.

Breeding objectives and economic values for traits of low input family-based beef cattle production system in the State of Rio Grande do Sul

Abstract: The objectives of this study were to define breeding objectives and derive economic weights for production traits in family-based beef cattle systems, assess the sensitivity of these weights to changes in market and husbandry indicators and estimate the expected genetic changes in the selection criteria proposed. Based on data from the production systems, farms revenues and expenses, obtained from interviews and meetings with producers, a bioeconomic model was derived, relating biological traits of animals with the financial result of the production system based on calf-crop, selling male calves and culling cows for finishing. Traits considered in the model as breeding goals were weaning rate, weaning weight and cow weight. The economic weights, obtained by the partial derivative of the bioeconomic model with respect to the trait in question, assessed on the average value of the remaining traits, were R$ 73.21% for weaning rate, R$ 17.07/kg for weaning weight and R$ 4.75/kg for cow weight. An index for joint selection of these three criteria would allocate 89.5% of importance to weaning rate, 6.9% for weaning weight and 3.6% for cow weight. In this way, for every R$ 100.00 of genetic gain in this index, there would be an increase of 1.4% in weaning rate, but with reduction of 0.004 kg in weaning weight and 0.665 kg in cow weight due to negative genetic association between these traits. The proposed index and the relative importance identified for the economic traits can guide the selection decisions of smallholders, both in the choice of their animals and in the acquisition of bulls, cumulatively increasing the productivity of their herds.

Frequencies and intensities of defoliation in Aruana Guineagrass swards: accumulation and morphological composition of forage

Abstract: The objective of this study was to assess the accumulation and morphological composition of forage in Aruana Guineagrass (Panicum maximum cv. Aruana) swards subjected to intermittent stocking with sheep. Experimental treatments when grazing was introduced included low (95%) and high (98%) incident light interception and low (10 cm)- and high (15 cm)-residue height and were allocated to experimental units (196 m2 fenced areas) in a completely randomized 2 × 2 factorial arrangement with three replicates. Treatments were imposed between January and May 2009. More frequent grazing cycles (95% light interception) resulted in better control of stem elongation, lower proportion of dead plant material and invasive plants, and higher proportions of leaf blades in the grazing strata, compared with less frequent grazing cycles (98% light interception). Grass managed with 95% light interception combined with 10 and 15 cm post-grazing height and grass managed at 98% light interception combined with 15 cm post-grazing height did not show differences in forage accumulation rate. These results indicate that more frequent (30 cm pre-grazing height) and less severe (15 cm post-grazing height) grazing cycles provided animals with high leaf blade mass and low stem mass forage.

Bands of respiratory rate and cloacal temperature for different broiler chicken strains

Abstract: The objective of this investigation was to estimate ideal bands of respiratory rate and cloacal temperature for broiler chicken strains during the rearing period and to evaluate the influence of time of exposure on bird physiological variables under different thermal stress conditions. The research was conducted in a climatic chamber during the six weeks of the rearing period, with Avian and Cobb strains exposed to two climatic conditions (comfort and stress), in three distinct times of exposure, in three conditions (before going to the chamber; at the end of exposure time; 30 minutes after the end of exposure), in four treatments: comfort with 60 minutes of exposure; stress with 30 minutes of exposure; stress with 60 minutes of exposure; stress with 90 minutes of exposure. Bands of respiratory rate and cloacal temperature were elaborated for both strains, for each one of the weeks of the rearing period. Strains differed, regardless of treatments and conditions adopted in the research on the third, fifth and sixth weeks of life in relation to the cloacal temperature. The Cobb strain is more tolerant to thermal stress in comparison with the Avian. There was difference for both variables between comfort and stress, but time of exposure to stress did not influence the physiological response of birds, except for cloacal temperature on the second week of life.

Effect of the ovulatory follicle diameter and progesterone concentration on the pregnancy rate of fixed-time inseminated lactating beef cows

Abstract: The objective of this study was to evaluate the influence of the ovulatory follicle diameter on the reproductive performance of lactating beef cows subjected to low progesterone fixed-time artificial insemination (FTAI) protocols. Ninety-three lactating beef cows (60-80 days postpartum) at random stages of estrous cycle were given a luteolytic dose of prostaglandin F2α (500 μg cloprostenol; PGF) twice, 11 d apart. Ten days after the second PGF treatment, cows were given 1.5 mg of estradiol benzoate im and a progesterone-releasing intravaginal device (Cue-Mate) with a single pod containing 0.78 g progesterone (Day 0). Cows received another luteolytic dose of PGF on Day 0. On Day 8, the Cue-Mate was removed. Fifty-four to 56 hours later, cows received 12.5 mg of porcine LH (pLH) i.m. and were concurrently artificially inseminated. Ultrasound examinations of the ovaries were performed on Days 10 and 17 to evaluate the diameter of ovulatory follicle and corpus luteum, respectively. Cows which presented ovulatory follicle > 19 mm resulted in larger corpus luteum than cows that had ovulatory follicle <15 mm in diameter. However, cows with ovulatory follicle between 13-15 mm had higher pregnancy rate than other categories of ovulatory follicle. Although larger ovulatory follicles result in larger corpus luteum and consequently higher progesterone production, the optimal size of ovulatory follicles (13-15 mm) may result in positive benefits on pregnancy rate for cows subjected to FTAI with low progesterone concentration protocols.

Sources of variation in milk urea nitrogen in Paraná dairy cows

Abstract: The present study was conducted to determine the relationship between milk urea nitrogen (MUN) and milk yield, fat and protein contents, breed and season effects, parity and days in milk in dairy cows from Parana State, Brazil. A total of 127,428 test-days from 16,013 dairy cows belonging to 96 herds enrolled in an official milk recording program were analyzed. Multivariate mixed model methodology was used to determine the relationship between MUN and the fixed effects and the covariable milk production. Milk urea nitrogen averaged 14.45±4.60 mg/dL. Positive and intermediate association between MUN and milk yield (r = 0.34) were found. Holstein cows showed lower MUN adjusted means than crossbred, Jersey, and Brown Swiss cows: 14.18 vs. 15.49, 16.12, and 17.62 mg/dL, respectively. First-lactation cows showed higher MUN values than second-lactation and older cows: 16.16 vs. 15.95, and 15.45 mg/dL, respectively. MUN test-days collected during the winter were higher than those collected in the other seasons. The effects of the lactation stage on MUN were significant, with the highest MUN values observed in the sixth month of lactation. High-producing dairy cows showed higher milk urea concentrations but several environmental factors may contribute to reduce this important parameter of diet utilization efficiency.

Organic and inorganic sources of zinc, copper and selenium in diets for dairy cows: intake, blood metabolic profile, milk yield and composition

Abstract: The present study was carried out with the objective of evaluating the effects of feeding dairy cows with organic or inorganic sources of zinc (Zn), copper (Cu) and selenium (Se) on blood concentrations of these minerals, blood metabolic profiles, nutrient intake and milk yield and composition. Nineteen Holstein cows were selected and randomly assigned to two groups for receiving organic (n = 9) or inorganic (n = 10) sources of Zn, Cu and Se from 60 days before the expected date of calving to 80 days of lactation. Samples of feed, orts and milk were collected for analysis. Body condition score (BCS) was determined and blood samples were collected for analysis of Zn, Cu and Se concentrations, as well as for metabolic profile. Supplying organic or inorganic sources of Zn, Cu, and Se did not affect dry matter and nutrient intake, blood metabolic profile, milk yield and composition, plasma concentration of these minerals, and BCS or change the BCS in cows from 60 days before the expected date of calving to 80 days of lactation. An effect of time was observed on all feed intake variables, plasma concentrations of Zn and Se, milk yield, milk protein content, BCS and change in BCS.

Forage yield and nitrogen nutrition dynamics of warm-season native forage genotypes under two shading levels and in full sunlight

Abstract: The successful achievement of a highly productive understorey pasture in silvopastoral systems depends on the use of well-adapted forage genotypes, showing good agronomic performance and persistence under shading and grazing. In this study, the herbage dry matter yield (DMY) and nitrogen nutrition dynamics were determined in three native warm-season grasses (Paspalum regnellii, Paspalum dilatatum and Paspalum notatum) and a forage legume (Arachis pintoi) under two shading levels compared with full sun. The experiment was conducted in the Campanha region, Bage, state of Rio Grande do Sul, Brazil, during two evaluation cycles (2008/2009 and 2009/2010). Three shade cloth levels (0%, 50% and 80% of light restriction) were applied to the forage genotypes in a split plot design, in which shading levels were the main plot and forage genotypes were the subplots, with three replications. P. regnellii showed the highest accumulated DMY (1500 and 1700 g m-2, respectively, for the first and second evaluation cycles) at all shading levels and showed no DMY decreased under the heavy shade (80%). Average DMY over the four genotypes under the 50% shade level was higher or equal compared with full sun. Influence of rainfall was observed on the DMY performance of all genotypes: the positive effect of moderate shading (50%) on P. dilatatum and P. notatum DMY was associated to a low soil water availability status. Increased shading level resulted in high nitrogen nutrition index values on grasses, in comparison with full sun. All genotypes performed well under the moderate shading level, but the DMY of both P. regnellii and P. dilatatum and the herbage N content in P. notatum and A. pintoi of all genotypes stood out, showing that those main genotypes are promising to grow in silvopastoral systems at the Campanha region in southern Brazil.

Genetic parameters for type traits in Holstein cows in Brazil

Abstract: Data from 26,558 Holstein cows in 802 herds were used to estimate genetic, residual and phenotypic parameters for 22 type traits. The model included the fixed effects of herd-year, period of classification, classifier, stage of lactation and age of cows at calving (covariate) and random genetic and residual effects. Heritability for type traits ranged from 0.10 to 0.39. The genetic variability in these traits suggested the possibility for moderate genetic gains through selection. The phenotypic correlations were moderated, mainly in the section conformation. Genetic correlations between type traits ranged from -0.44 to 0.85. High genetic correlations indicated that breeding programs could be successful without including all type traits. The selection for the final score at the expense of other traits must be performed with restraint, because in the long term, this may promote undesirable changes in some type traits.

Polyculture of Nile tilapia and shrimp at different stocking densities

Abstract: This study aimed to evaluate the productivity, growth performance and economic feasibility of polyculture of Nile tilapia Oreochromis niloticus and shrimp Litopenaeus vannamei at different stocking densities. Feed was provided based on fish requirements. The experiment was conducted at the Aquaculture facility of the Universidade Federal Rural do Semi-Arido - UFERSA, in a completely randomized design with five treatments and four replicates each. Treatments consisted of a tilapia monoculture with 2 tilapias.m-2; and polyculture with 2 tilapias.m-2 and L. vannamei at four different densities (3, 6, 9 and 12 shrimps.m-2). The initial individual biomass for fish and shrimp were 1.23±0.12 g and 0.133±0.009 g, respectively. Water quality parameters, temperature, dissolved oxygen, pH and transparency were monitored. The experiment lasted 120 days and biomass gain was evaluated every two weeks. Final biomass, survival and feed conversion rates were calculated at the end of the experiment. The economic analysis showed that polyculture systems at stocking densities of nine and twelve shrimps.m-2 resulted in higher gross revenue and operational profits of 120.9% and 97.5% respectively, with mean gross return significantly higher than the monoculture. The O. niloticus and L. vannamei polyculture in oligohaline water was shown to be technically and economically feasible. These two species can be cultured together, without competing for the same resources, because they have different trophic niche, thus increasing productivity and economic returns for the farmers.

Consumo, digestibilidade e desempenho de novilhas leiteiras alimentadas com dietas contendo torta de dendê

Abstract: The objective was to evaluate the effects of inclusion of palm kernel cake in the diet on intake, digestibility and performance of dairy heifers. Sixteen dairy Holstein-Zebu crossbred heifers with average age of 13 months and average weight of 183.4±32.5 kg were distributed to four treatments in a completely randomized design with four levels of palm kernel cake (0, 11.9, 22.9 and 34.2% from total dry matter), each one with four replicates. The intake of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), non-fibrous carbohydrates (NFC), ether extract (EE) and total digestible nutrients (TDN), and the apparent digestibility of DM, CP, NDF, NFC and EE were evaluated. There was linear reduction in DM, CP, NDF, NFC, and TDN intake. The apparent digestibility of DM and NDF reduced with the inclusion of palm kernel cake in the diet, while the apparent digestibility of CP and NFC showed quadratic effect. The inclusion of palm kernel cake in the diets resulted in linear increase in the apparent digestibility of ether extract. Weight gain decreased linearly with the inclusion of palm kernel cake in the diet, with values of 1.06, 0.99, 0.89 and 0.54 kg/day for diets containing 0, 11.9, 22, 9 or 34.2% palm kernel cake, respectively. Feed conversion was not affected by the inclusion of levels of palm kernel cake. The inclusion of palm kernel cake in the diet reduces nutrient intake and performance of dairy heifers during growth, but when used in levels up to 24.6% of the total diet, it provides weight gain compatible with growth programs aiming calving at 24 months of age.

Fermentation and aerobic stability of corn silage inoculated with Lactobacillus buchneri

Abstract: The characteristics of fermentation and aerobic stability were evaluated in corn silage inoculated with different doses of Lactobacillus buchneri. The whole corn plant (300 g/kg DM) was ensiled in quadruplicate laboratory silos (7L). L. buchneri 40788 was applied at 5×104, 1×105, 5×105 and 1×106 cfu/g of fresh forage. Silages with no additive were used as controls. After 130 d of ensiling, the silages were subjected to an aerobic stability evaluation for 12 days, in which chemical and microbiological parameters as well as the temperature of the silage were measured to determine the aerobic deterioration. The addition of L. buchneri resulted in increased acetic acid concentrations. The number of yeast colonies was low in all treated silages. The pH, lactic and propionic acid concentrations did not differ between silages. Under aerobic conditions, all the treated silages showed a low number of yeasts and a great aerobic stability. Therefore, L. buchneri is effective against yeasts and improves the aerobic stability of corn silage in laboratory silos. However, doses equal or superior to 1×105 cfu/g of fresh forage were more efficient in the control of aerobic spoilage.

Sunflower cake from biodiesel production fed to crossbred Boer kids

Abstract: The intake of the dry matter (DM), the crude protein (CP) and the metabolizable energy intake (ME) in megacalories per day (Mcal/day) were not affected by the diets In contrast, the intake of neutral detergent fiber (NDF), in g/kg BW, increased linearly An increasing linear effect was also observed for the ether extract (EE) intake, whereas a decreasing linear performance was observed for the non-fibrous carbohydrate (NFC) intake The digestibility of DM, organic matter and NFC decreased linearly with the sunflower cake inclusion, whereas the digestibility of CP, NDF, and EE were not influenced by the diets No effect was observed for the concentration of serum glucose or urea nitrogen serum No effect was observed on the urea nitrogen serum in the hours after feeding; however, including sunflower cake in the diets resulted in a quadratic performance for the serum glucose concentrations in the hours after feeding The average daily gain (ADG) had a decreasing linear effect, and the food conversions of the DM, CP, NDF, NFC and ME had increasing linear effects The feeding costs decreased with the level of sunflower cake

Crescimento do capim-tifton 85 sob doses de nitrogênio e alturas de corte

Abstract: The objective this study was to evaluate the growth rates of Tifton 85 bermudagrass under four nitrogen levels (0, 33, 66, 100, and 133 kg/ha N) and harvested at three plant heights (30, 40 and 50 cm). The experimental design was completely randomized in a split plot scheme with three replications. Nitrogen rates were set in the plots and plants heights in the subplots. For all variables, the interaction N rate × plant height was not significant. The net assimilatory rate and relative growth rate of Tifton 85 increased with increasing N rates. The leaf area ratio (LAR) decreased linearly with plant height at harvesting. In contrast, the LAR increased linearly with N rate. Linearly, the leaf weight ratio decreased with plant height at harvesting, and increased with N rate. The specific leaf area of Tifton 85 bermudagrass was influenced linear and positively only by nitrogen fertilization. The leaf area index (LAI) of Tifton 85 bermudagrass increased by about 0.05 unit for each centimeter increase in plant height at harvesting. There was a quadratic response of N in LAI of Tifton 85 bermudagrass. The increase of bermudagrass height at harvesting season decreases the participation of leaf blade in the forage. The nitrogen increases the growth rate of Tifton 85 bermudagrass. To ensure efficient harvesting of forage, the increase of N rate for Tifton 85 Bermudagrass implies a reduction in the harvest interval.

Atribuições da carne de frango relevantes ao consumidor: foco no bem-estar animal

Abstract: Objetivou-se neste trabalho estudar o comportamento dos consumidores de carne de frango em relacao ao bem-estar animal e a disposicao em pagar mais por produtos com certificacao para esse atributo de qualidade Para isso foi realizada uma pesquisa de mercado com consumidores de carne de frango da cidade de Curitiba, Parana Uma analise previa foi realizada com peritos da cadeia avicola para estruturacao do questionario Apos esta fase, 481 consumidores foram entrevistados Perguntas objetivas resultaram em informacoes gerais e imagens de produtos hipoteticos geraram informacoes sobre a atitude de compra utilizando analise conjunta e posterior simulacao de mercado Os atributos mais observados na hora da compra foram validade, preco, cor e odor O bem-estar animal inicialmente foi considerado pela minoria (3,7%) Dos entrevistados, 68,5% nao conhecem o sistema de producao, porem, depois de observar fotos dos sistemas, acreditam que o modelo semiintensivo proporciona melhor bem-estar e resulte em produtos de melhor qualidade Na analise conjunta, preco baixo, producao com melhores condicoes de bem-estar animal, carne firme e rosada e producao sem antibioticos sao, respectivamente, as caracteristicas com maiores valores de utilidade O atributo de maior importância foi o preco (34,1%), seguido do tipo de carne (24,6%), bem-estar animal (24,1%) e utilizacao de antibioticos (17,0%) Na simulacao de mercado, 70,9% dos consumidores pagariam mais por produtos que com certificacao de bem-estar animal e carne firme e rosada A baixa importância inicial do bem-estar animal para o consumidor pode estar relacionada a falta de conhecimento acerca dos sistemas produtivos, portanto o acesso a informacoes a respeito pode incentivar o pagamento por esse atributo

Apparent nutrient digestibility and mineral availability of protein-rich ingredients in extruded diets for Nile tilapia

Abstract: Apparent digestibility coefficients (ADC) of gross energy and dry matter (DM) and mineral availability were evaluated for eight protein-rich ingredients (corn gluten meal, soybean meal, cottonseed meal at 280.0 and 380.0 g/kg, poultry by-product meal, meat meal, fish meal and feather meal) in compound diets for Nile tilapia. Chromic oxide was used as inert digestibility marker. Higher ADC values of DM and energy were, respectively, 0.862 and 0.881 for corn gluten meal, 0.811 and 0.888 for poultry by-product meal; 0.729 and 0.731 for feather meal; 0.666 and 0.754 for fish meal; 0.578 and 0.642 for soybean meal; 0.476 and 0.652 for meat meal at 450.0 g/kg; 0.352 and 0.449 for cottonseed meal at 380 g/kg; and 0.251 and 0.324 for cottonseed meal at 280.0 g/kg. The highest average mineral availability was for poultry by-product meal (0.582), and the lowest calcium and phosphorus availability were recorded for cottonseed meal at 280.0 g/kg. Therefore, poultry by-product meal appears to be the best ingredient for using in Nile tilapia diets.

Technological quality of eggs in relation to the age of laying hens and Japanese quails

Abstract: This investigation was carried out to evaluate certain egg quality characteristics of ISA Brown laying hens and Japanese quails (Coturnix coturnix japonica) in relation to their age. One hundred forty-four brown-egg ISA Brown laying hens and one hundred female quails were used in the study. A total of 1,678 eggs of laying hens and 2,060 eggs of Japanese quails were used during the experiment. The eggs for technological values were collected during two consecutive days in a 4-week period when the laying hens were from 20 to 60 weeks of age and the quails were from nine to 49 weeks of age. The results show that egg weight was affected by the age of the hens and quails (overall means 61.13 g and 12.52 g, respectively). Despite frequens fluctuations, as the age of the laying hens and quails increased, the yolk index and yolk proportion increased as well, while the albumen index, eggshell strength and shell thickness decreased. The increasing age of the hens also led to a decrease in egg shape index and eggshell proportion, but these parameters increased in the quails. A significantly higher proportion of albumen was found in the hens than in the quails, but of worse quality than in the quails as expressed by Haugh units score. The egg from ISA Brown hens had a darker yolk color than those from Japanese quails (5.90 vs. 4.87 in the La Roche scale).

Association of polymorphisms in the leptin and thyroglobulin genes with meat quality and carcass traits in beef cattle

Abstract: The objective of the present study was to estimate the allelic and genotypic frequencies of the polymorphisms E2FB (AY138588.1: c.305C> T), located in the leptin gene (LEP), and TG5 (X05380.1:g.-422C>T), located in the thyroglobulin gene (TG), and evaluate the association of these polymorphisms in crossbred cattle of seven distinct genetic groups with the following traits: slaughter weight (SW), hot carcass weight (HCW), hot carcass yield (HCY), carcass fat thickness (CFT), ribeye area (REA), marbling (MARM) and shear force (SF). The animals were genotyped using the PCR-RFLP (Polymorphism Chain Reaction-Restriction Fragment Length Polymorphism) technique, using 201 products obtained from F1 Caracu × Nellore, Angus × Nellore and Valdostana × Nellore cows, mated to Canchim, Caracu and Red Angus bulls (only Caracu × Nellore cows were used with Red Angus bulls). The allelic and genotypic frequencies were compared using the Chi-squared test. Associations between the genotype of each polymorphism and the traits were analyzed using the General Linear Model (GLM) of statistical software SAS. The least squares means of genotypes of the polymorphisms were compared using Student's t test. The E2FB polymorphism in the LEP gene was associated with CFT, showing the potential for use in national programs for genetic improvement of beef cattle, through the inclusion of SNP in genotyping commercial tests. The TG5 polymorphism in the TG gene was not associated with any of the evaluated traits and was considered ineffective for selection of beef cattle in Brazilian herds.

Forage yield and nutritive value of Tanzania grass under nitrogen supplies and plant densities

Abstract: The objective of this experiment was to evaluate the nitrogen and plant density influence on the yield, forage dissection and nutritive value of Tanzania grass (Panicum maximum Jacq.). The design was of completely randomized blocks with three replications in a factorial arrangement with four nitrogen levels (0, 80, 160 or 320 kg/ha N) and three plant densities (9, 25 or 49 plants/m2). The plots were cut at 25 cm from soil level when the canopy reached 95% of light interception. The total dry matter forage yield and dry matter forage yield per harvest increased linearly with the nitrogen fertilization. The leaf and stem yield had the same response. The senesced forage yield was quadratically influenced by the nitrogen. The stems ratio in the morphologic composition was high in the high nitrogen levels and in the low plant densities. The leaf:stem ratio showed high values in this trial, but it was increased in plots without nitrogen and high plant density. The pre-grazing height was reduced with the increase in plant density. The nutritive value was favored by the nitrogen fertilization, which increased the crude protein level and reduced neutral detergent fiber and lignin. These factors increased the leaf and stem in vitro digestibility of organic matter. Nitrogen fertilization increases the forage yield of Tanzania grass under rotational grazing. After the establishment, plant density has little influence on the Tanzania grass yield and its forage dissection. The harvest with 95% light interception improves the structure and nutritive value of Tanzania grass pastures.