Understanding the metabolism of lipoproteins in birds is important to enable nutritionists to design diets aimed at obtaining better meat characteristics and egg quality, and can furnish useful information for future studies. In comparison to mammals, there are a number of expressive differences in the metabolism of lipids in birds, such as the transport of dietary lipids to the liver, hepatic lipogenesis and the presence of unique lipoproteins in the blood (portomicrons). Greater differences are found in egg-laying hens during the production phase, in which lipoproteins produced in the liver, under the action of oestrogen, are used for the formation of the egg yolk. The regulation of the lipid metabolism by hormones and the participation of key enzymes associated to advances in molecular biology techniques could assist in the genetic selection of more productive birds and better quality products for consumers.

The objective of this study was to determine the chemical and energy composition of spirulina (Spirulina platensis), the nutrient metabolizability coefficients, and the values of apparent metabolizable energy (AME) and the apparent metabolizable energy corrected for nitrogen balance (AMEn) in broilers. A digestibility trial was carried out by using total excreta collection method, with 90 Cobb 500 lineage chicks, with initial weight of 256 ± 5 g at 11 days of age. Birds were allotted in metabolic cages for 10 days, distributed in a completely randomized design, with three treatments and six repetitions with five birds each. Diets consisted on a reference-ration based on corn and soybean meal and two test diets, one containing spirulina (30%) and the other one with soybean meal (30%). Spiruline was superior to soybean meal for contents of dry matter (DM), gross energy (9.60%), crude protein (26.56%), ether extract (54.45%), mineral matter (42.77%), calcium (100%) and total phosphorus (130.77%) and also for most amino acids, except lysine, glutamate, histidine and proline. Nevertheless, spiruline presented lower values of gross fiber (83.95%), acid detergent fiber (85.12%) and neutral detergent fiber (6.15). The AME and AMEn values (kcal/kg of DM) were, respectively, 2,906 and 2,502 for the spirulina and 2,646 and 2,340 for the soybean meal and AMEn of spirulina was 6.92% higher than soybean meal.

SummaryThe purpose of this systematic review was to evaluate the evidence that the injection of carbohydrate-based solutions into embryonated eggs improves broiler performance. A literature search was conducted in April 2017 using the keywords broiler, carbohydrate, in ovo, nutrition and poultry. Only papers that involved in ovo carbohydrate injections in poultry were used in this study. After specific selection criteria, 17 papers were selected. The quality scoring system of the selected studies was based on the injection methodology, use of control groups, type of solution injected, period of injection, egg and hens characteristics, number of variables analysed and the statistical design. Among papers, there was no standardised procedure in to inoculate the solutions. Nevertheless, in general, in ovo feeding of carbohydrates decreases the hatch rate, improves the hatch weight, but it does not seem to influence the post-hatch performance of broilers. The inoculation of 75 mg of glucose in the albumen seems to bring better results. Further studies are needed to improve the technical methodology of in ovo injections for commercial use. K E Y W O R D Shatchability, in ovo nutrition, incubation, performance, poultry

The aim of this study was to evaluate the effects of silicon application and administration of the phytohormone gibberellic acid on resistance of the corn plants to the fall armyworm (FAW), Spodoptera frugiperda, and their vegetative characteristics. We evaluated larval and pupal duration, survival and biomass, and adult longevity, malformation and fecundity of S. frugiperda after feeding on plant matter treated with silicon and/or gibberellic acid. The feeding preference of FAW first-instar larvae, the total leaf area consumed by the insects, and the vegetative parameters of corn plants were also evaluated. No significant differences were observed in the measured parameters of larval and pupal stages of S. frugiperda in response to silicon or gibberellic acid. In adult stage insects, the number of eggs per female was significantly reduced in insects derived from larvae fed plants treated with silicon or gibberellic acid. In a non-preference test, 48 h after release, caterpillars preferred control untreated plants and consumed less matter from plants that had received hormonal treatment (gibberellic acid). Gibberellic acid also altered the vegetative characteristics of plants, by increasing their height, shoot fresh and dry mass, and silicon content. We conclude that gibberellic acid can alter the vegetative characteristics and silicon uptake of corn plants, leading to a reduction in their consumption by S. frugiperda larvae and a decrease in female insect oviposition.

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Several researchers have developed prediction equations to estimate the metabolisable energy (ME) of energetic and protein concentrate feedstuffs used in diets for broilers. The ME is estimated by considering CP, ether extract, ash and fibre contents. However, the results obtained using traditional regression analysis methods have been inconsistent and new techniques can be used to obtain better estimate of the feedstuffs' energy value. The objective of this paper was to implement a multilayer perceptron network to estimate the nitrogen-corrected metabolisable energy (AMEn) values of the energetic and protein concentrate feeds, generally used by the poultry feed industry. The concentrate feeds were from plant origin. The dataset contains 568 experimental results, all from Brazil. This dataset was separated into two parts: one part with 454 data, which was used to train, and the other one with 114 data, which was used to evaluate the accuracy of each implemented network. The accuracy of the models was evaluated on the basis of their values of mean squared error, R 2 , mean absolute deviation, mean absolute percentage error and bias. The 7-5-3-1 model presented the highest accuracy of prediction. It was developed an Excel R AMEn calculator by using the best model, which provides a rapid and efficient way to predict the AMEn values of concentrate feedstuffs for broilers.Keywords: avian production, broilers, metabolisable energy, multilayer perceptron ImplicationsIt is difficult and expensive to estimate the nitrogencorrected metabolisable energy (AMEn) values of the feedstuffs used for broilers. The results of this study demonstrate that the implementation of multilayer perceptron networks (MLP) in a meta-analysis is suitable to estimate these energy values. Furthermore, a calculator was created on the basis of the results of the MLP, which allows an efficient way of predicting the AMEn values.

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The objective of this study was to evaluate the effect of reduced-crude protein (CP) and available phosphorus (aP) diets, added with phytase and amino acids for broilers in the growing (14 to 21 days old) and retirement (35 to 42 days) phases on nitrogen, potassium and phosphorus balance. Ninety Cobb broilers were distributed in a completely randomized design with three treatments and six replications with five and three birds per experimental unit in the growing and retirement phases, respectively. Diets were elaborated to contain reduced CP and aP levels (19 and 17% CP in the growing phase, with 0.34% aP; and 18 and 16% CP in the retirement phase, with 0.30% aP), supplemented with crystalline amino acids and 500 FTU of phytase/kg diet. These were compared to a control diet (21% CP and 0.46% aP for growing phase and 19% CP and 0.40% aP for retirement phase). The reduction of CP in four percentual units reduced the N excretion and increased the retention of this element, showing that the phytase had no influence on N balance when used the crystalline amino acids in the diets. The phytase reduced the P excretion and increased the retention ones. The potassium excretion decreased in reduced-CP diets, but this excessive reduction decreased the retention of this element, except in the retirement phase. It was concluded that the reduced-CP and aP diets, supplemented with phytase and amino acids, are efficient in reducing the pollutant power of the broilers excrements in the growing and retirement phases of production.