A. L. Guidoni

Influência da temperatura de incubação em ovos de matrizes de corte com diferentes idades e classificados por peso sobre os resultados de incubação

A total of 61,920 eggs from a single commercial line of broiler breeders was incubated. The effect of different incubation temperatures (T), measured by the wet bulb thermometer in degrees Celsius (oC), was evaluated with eggs classified by weight (P) from broiler breeders with different ages (I). Evaluation of the percentages of total hatched, hatchability, egg weight loss and embryo mortality was performed. A completely randomized experimental design in a factorial 3 x 4 x 5, representing, respectively, three T (28.6, 29.6 and 30.6oC), four I in weeks (34, 39, 53 and 63) and five P, with weight averages (g) of 60.0, 65.1, 66.6, 69.0, and 73.2, was used. Total embryo mortality (Metot) was lower at T 28.6oC. At 39-weeks of age, Metot was the lowest, and for P, ME had the lowest averages. There was a significant effect of factors age and egg weight and of the interactions age x egg weight, temperature x age and temperature x age x egg weight on average egg weight (Povo). For the percentage of egg weight loss up to transference (Pppeso), there was a significant effect of T, I and P. The percentages of the total hatched and hatchability were optimized with 10.3% weight loss during incubation at 28.6oC.

Efeito da restrição alimentar qualitativa sobre o ganho compensatório em frangos de corte

An experiment was conducted to determine the effects of the diet dilution on performance of broiler chickens until 42 days of age. Nutrient restriction was achieved by feeding a starter diet (CP 21.5% and ME 3,050 kcal/kg) in which the major ingredients were replaced with 25% or 50% of soybean hulls. Four treatments involved feeding the diluted diets for seven days (7-14 days of age), either continuous or split into periods with the undiluted diet (control). The treatments were: T1: control diet; T2 and T3: diluted diet (25% and 50% of soybean hulls, respectively) 7-14 days; T4 and T5: diluted diet (25% and 50% of soybean hulls, respectively) on days 7, 9, 11 and 13 alternating with T1 (on days 8, 10 and 12). The birds fed with diluted diets exhibited lower mean body weights (P<0.05) than controls. Feed conversion ratios from 0-42 days of age for restricted broilers were not different. Varying the period of nutrient restriction did not affect adversely body weight and body weight gain. There was no statistical difference in the overall mortality through 0-42 days among the dietary treatments. Compensatory growth was not observed, and this result could be associated with the pattern of growth curve exhibited by the hybrids used in this experiment.

In vitro solubility of meat and bone meal protein with different pepsin concentrations

In vitro protein digestibility of protein sources has been correlated with in vivo digestibility values. However, factors like protein origin, enzyme used and its concentration, pH and processing have been related with the significance of the correlation between the estimates. To address only the enzyme concentration factor, this paper had the objective of testing pepsin at 0.2, 0.02, 0.002 and 0.0002% using the standard AOAC (1995) procedure. Two meat and bone meals (MBM) with low and high crude protein (CP) content were used to determine the coefficient of solubility of CP in pepsin and HCl (CSCPPEPH). Centrifugation was used to establish the nitrogen (N) in the soluble phase, instead of filtration and analysis of N in the residue. The variance analysis and a non-linear asymptotic model were adjusted. The CSCPPEPH under different pepsin concentrations for the two MBM showed higher solubility discrimination with low pepsin concentration. The level of 0.0002% pepsin is better to predict the CP soluble in MBM. This finding implies the assumption that 0.2% pepsin found in the AOAC is not correct for the purpose of determining the range of solubility in high and low CP content in MBM.

Impacts of mixed farms on water quality of Pinhal river sub-basin, Santa Catarina, Brazil

Brazil is one of the largest producers of food in the world. Agriculture and livestock production are concentrated in certain regions of the country. Livestock has been perceived as a constant threat to the quantity and quality of water resources. The objective of this study was to evaluate the impact of mixed farms on superficial water quality in Pinhal River sub-basin, which is located in Con- cordia, Santa Catarina State. Eight sampling sites representing different land-uses (LU1: dairy cattle; LU2: without animals; LU3: dairy + pigs + poultry + crops; LU4: pigs + poultry + crops; LU5: dairy + pigs + poultry + crops + human; LU6: dairy + pigs + crops; LU7 and LU8: dairy + pigs) were evaluated. These sampling sites were assessed longitudinally and sampled during the summer, spring, autumn, and winter of 2006 to 2009. LU1 presented the worst water quality with high concentrations of total suspended solids (TSS) and chemical oxygen demand. In this point, cows had access to the river. The highest concentration of nitrate (NO 3 -N) was found at the estuary of the river. There were higher concentrations of TSS, NO 3 -N and NO 2 -N in wet season. At this time, intensive fertilizer application to corn fields is common. Autumn and winter presented the worst water quality with respect to nitrogen concentration. Results showed a strong relationship between the sources of pollution (e.g., cows, pigs and poultries) and water quality. Managing the use of animal manure with optimum chemical fertilizer applications along with riparian fencing may provide important mitigation options for protecting water quality of Pinhal River.

Produção e qualidade de ovos em reprodutoras de frangos de corte com horário de arraçoamento diferenciado

Four feeding schedule were investigated for broiler breeders: at 6:30 am; 50% feeding at 6:30 am and 50% at 3:30 pm (dual); at 11:00 am, and at 3:30 pm. Arbor Acres breeders were randomly assigned to 48 boxes, with 12 replicates of 27 females and three males each. The nutritional levels and management procedures were those recommended for strain. The variables studied were: total egg production, nest, clean and broken egg production, in six collections (6:30 am, 9:00 am, 11:00 am, 1:30 pm, 3:30 pm and 5:30 pm); egg weight and egg specific gravity, grouped in three collections (9:00 am, 1:30 pm and 5:30 pm). Analysis of variance was used. Means were compared using Student t test for traits and collection and polynomial regression analysis for age. The collection and feeding schedule effects were significant for all traits, except for broken eggs, in which feeding schedule was not significant. The maximum egg production was obtained at 9:00 am for feeding schedule at 6:30 am (22.78 ± 0.36%) and dual (20.26 ± 0.33%), and at 1:30 pm for feeding schedule at 11:00 am (20.35 ± 0.39%) and at 3:30 pm (19.25 ± 0.38%). Female broiler breeders under the dual and at 3:30 pm feeding schedule showed egg weight of 71.0 ± 0.3 g, which was at least equal to the other feeding schedule in any collection. The egg specific gravity for feeding schedule at 11:00 am (1.0788 ± 2) and 3:30 pm (1.0799 ± 2) were higher than the other feeding schedule. Eggs from older female broiler breeders and eggs collected in the first hours of the day were heavier and had thinner eggshell than those from younger females and eggs collected later in the day. The dual feeding schedule could be an alternative to feeding schedule at 6:30.

Performance of female broiler breeders submitted to different feeding schedules

The performance of Arbor Acres broiler breeders (1,296 females; 144 roosters) was evaluated when submitted to the following treatments (T): T1 = feeding at 6:30 a.m. (control); T2 = 50% feeding at 6:30 a.m. and 50% at 3:30 p.m. (dual feeding); T3 = feeding at 11:00 a.m.; and T4 = feeding at 3:30 p.m. Treatments were randomly distributed in 48 pens. There were 27 females and 3 males in each pen and 12 repetitions per treatment. Nutrition and management were as recommended for the commercial strain. It was evaluated age at first egg (AFE), total egg production (TEP), number of days with production above 80% (DAP80), laying peak (P), female mortality (MOR), and gross profit margin (GM) per hen. Data were submitted to analysis of variance and means were compared by Students t-Test. TEP of T1 (186.3±2.3) and T2 (186.5±1.5) were higher (p 0.10) among treatments. GM per hen was better (p<0.05) in T1 and T2 hens. Control and dual treatments were more efficient than other treatments. It was concluded that it is possible to change conventional feeding managements by the dual feeding system.

Utilização do farelo de canola em dietas para suínos em crescimento e terminação

Foram utilizados 90 suinos (dos 25,8 kg ate o abate aos 102,6 kg) para avaliar o efeito do uso do farelo de canola nas racoes. O delineamento experimental foi em blocos casualizados em esquema fatorial com cinco niveis de farelo x dois sexos e tres repeticoes. O farelo de canola foi incluido em niveis de 20, 40, 60 e 80% de substituicao do farelo de soja tendo como base a racao referencia (milho e farelo de soja) e mantendo simultaneamente as dietas experimentais isoproteicas e isoenergeticas. Parâmetros de desempenho no crescimento, terminacao e total, e de carcaca ao abate foram avaliados. Foi observado efeito de interacao entre tratamento e sexo para a conversao alimentar em todas as fases. Na terminacao e no periodo total foi observado para tratamento um efeito quadratico no consumo. Para o ganho de peso foi caracterizado efeito quadratico apenas no periodo total. Os machos castrados apresentaram maior consumo e ganho de peso em todas as fases. Apenas os tratamentos e sexo tiveram efeito sobre a carcaca sendo verificada ausencia de interacao. E recomendado o nivel de substituicao de 40% do farelo de soja da dieta referencia que proporciona alto ganho de peso e tem associada a producao de carcacas mais pesadas resultando em maior producao estimada de carne. Porem, as carcacas apresentam maior espessura de toucinho e menor porcentagem de carne.

Metabolizable energy and amino acids relationships with the soluble fractions of protein and fiber of vegetable feed ingredients

To estimate nutrient and energy digestion with animal from in vitro variables it is necessary to control factors that may interfere on digestion such as: source and concentration of digestor substance, as well as the origin and processing of test ingredients. In this study there were performed five laboratory assays, two with poultry and finally regression equations were established based on variables generated with twelve vegetable ingredients. The results showed that there is greater solubility of proteins with NaOH than with KOH. On average, both alkali produced better discrimination of soluble protein with concentration of 0.02% (range of 68.61%) in relation to a concentration of 0.2% (range of 37.97%). Considering interaction between alkali and concentration, the best discrimination on protein solubility was reached with NaOH at 0.02%. The methods of protein or fiber solubilization together with the chemical analysis showed significant results variation among ingredients and when they were used to estimate in vivo variables they produced good estimates. It was concluded that reliable digestion estimates for energy or amino acids from vegetable feed ingredients could be obtained from in vitro variables, when considering solubilities of protein and fiber with chemical analysis.

Influence of feeding time on sexual maturity and carcass composition in female broiler breeders

One thousand two hundred and ninety six Arbor Acres females and 144 males were used to study the influence of feeding time on sexual maturity and carcass composition. Treatments were: T1 = feeding at 6:30 am, T2 = 50% feeding at 6:30 am and 50% at 3:30 pm (dual), T3 = feeding at 11:00 am, T4 = feeding at 3:30 pm. Nutrition and management were as recommended to the commercial line. Variables studied were: sexual maturity at 5% production (SM), mean egg production percentage (PEP) body weight (BW), carcass composition, tibia weight (TIBW) and tibia calcium (Ca) and phosphorus (P) contents. Analysis of variance was used, and the means were compared using Students t test. T2 females reached SM at 25.92 weeks, which was earlier (p 0.10) on carcass dry matter (DM), ether extract (EE), crude protein (CP) and ash (ASH). DM, EE, TIBW, Ca and P increased (p<0.05) whereas CP and ASH decreased with age. Time of feeding influenced body weight, but not carcass composition. Hens fed twice a day had earlier sexual maturity and similar egg production compared to those fed once at 6:30 am.

Desempenho de leitões na fase de creche alimentados com rações contendo proteína concentrada de soja

The experiment was developed in order to evaluate the effects of soy protein concentrate on performance and economic viability of piglets in nursery phase. We evaluated the following treatments in pre- starter diets (25 to 37 days old), initial I (37 to 50 days age) and initial II diets (50 to 64 days old): FS with corn and Hypro soybean meal, PCS-60% with corn and usual soy protein concentrate; PCSH-2h with corn and using PCS hydrolized by protease enzyme during 2 hours; PCSH-8h with corn and using PCS hydrolized by protease enzyme during 8 hours. In the period between 25-50 days were observed differences for the daily gross income (p = 5.1%) and gross margin (p = 2.1%). Treatments PCS-60% and PCSH(2h or 8h) showed the lowest values for daily gross income and gross margin, but in both cases, the PCS-60% treatment did not differ from FS. The inclusion of PCS-60%, and PCSH(2h or 8h) in diets for piglets in total nursery phase did not affect (p > 0.05) animal performance and economic viability. In view of performance the three PCS can be considered viable proteic ingredients in diets for piglets in the nursery phase.