Effects of protected sodium butyrate (PSB) in broiler diets with reduced metabolizable energy (ME) content on production performance, intestinal histomorphometry and nutrient metabolizability were evaluated in two experiments. In one experiment, 384 one-day-old male chicks with an average weight of 44 ± 0.2 g were distributed into four treatment groups in a completely randomized design with six replications of 16 birds. The treatments consisted of i) a basal diet without reduced ME or PSB (BD); ii) BD with a 100 kcal/kg reduction in ME, without PSB; iii) BD with a 100 kcal/kg reduction in ME + 105 g/t PSB; and iv) BD with a 100 kcal/kg reduction in ME + 225 g/t PSB. Performance and carcass yield were evaluated. In the second experiment, 280 one-day-old male chicks were also distributed into four treatment groups in a completely randomized design with seven replications of 10 birds to evaluate metabolizability coefficients and intestinal development. The birds that received diet 3 had the best feed conversion ratio (FCR), final weight (FW) and weight gain (WG). Inclusion of PSB (105 and 225 g/t) in reduced-ME diets increased the metabolizability of crude protein coefficient at 35 days old. Birds that received diet 3 also had greater jejunal villus height at 21 and 35 days old. It is recommended to feed 105 g/t of PSB with a 100 kcal/kg reduction in ME until broilers were 35 days old.

Two experiments were conducted to evaluate the effect of including protected sodium butyrate (PSB) in the diets of laying hens of advanced age on productive performance and egg quality. In experiment 1, a total of 320 Dekalb White 61-week-old laying hens were distributed in a randomized block design to four treatments (0, 105, 210, and 300 g/ton of PSB) with eight replicates of 10 birds. The experiment was conducted over 112 days, divided into four periods of 28 days each. Productive performance and egg quality were evaluated. In experiment 2, a total of 58 000 Dekalb White 70-week-old laying hens were assigned to diets containing either 0 or 105 g/ton of PSB with two replicates of 14 500 birds. The experiment was conducted on a commercial poultry farm. Egg production and the percentages of broken eggs and dirty eggs were evaluated. The PSB levels did not influence the productive performance of laying hens. A quadratic effect was observed for eggshell thickness, percentage of eggshell and eggshell strength, reaching maxima at 193, 136 and 198 g/ton of PSB, respectively. A quadratic effect on yolk index reached a minimum at 181 g/ton of PSB. The percentages of dirty eggs and broken eggs were lower in laying hens fed 105 g/ton of PSB. In conclusion, the addition of PSB to the diets of old laying hens improved the eggshell quality and decreased the percentage of broken and dirty eggs.

The addition of protease to broiler diets may complement the action of endogenous enzymes and improve protein digestibility. Here, the authors evaluated the effect of adding protease to broiler diets that contained animal-based meal on bird performance, digestibility, and biometry of digestive tract organs. Four treatments, which contained animal- or plant-based meals with or without supplementary protease were compared, namely basal vegetable feed (BVF), BVF + protease (BFP), basal vegetable feed + animal byproduct meal (BFA), and BFA + protease. In the first experiment, 320 one-day-old Cobb 500® chicks were allocated to eight replicates with 10 birds per replicate. The experimental period was seven days, and nutrient metabolizability was evaluated. In the second experiment, 720 one-day-old Cobb 500® chicks were assigned to treatments in a similar manner, with six replicates and 30 birds per replicate, but the experimental period was 42 days. Significant differences (P <0.05) were observed between treatments for nutrient digestibility, weight gain, feed consumption, average final weight, food conversion, viability, and biometry of the pancreas. Treatments with animal-based meals had the highest digestibility. Birds fed these meals grew faster in the pre-starter phase and consumed less feed between 1 and 21 days. However, between 1 and 42 days old, broilers fed plant-based diets had better feed conversion, and the group that did not receive protease supplementation had a better liveability rate.

Este trabalho teve como objetivo a avaliação das características anatômicas e fisiológicas de aguapé (Eichhornia crassipes) em resposta ao estresse por arsênio. As plantas de aguapé foram cultivadas em solução nutritiva hidropônica de Hoagland em casa de vegetação sob cinco concentrações de arsênio: 0,0; 0,25; 0,5; 1,0; e 2,0 mg L-1 por período de 20 dias. As plantas demonstraram aumento na taxa fotossintética, na condutância estomática, na transpiração e na relação Ci/Ca, bem como na atividade de todas as enzimas do sistema antioxidante, com maior atividade nas folhas em relação às raízes nos tratamentos contendo arsênio. As características anatômicas das folhas das plantas sob as maiores concentrações de arsênio mostraram aumento na densidade estomática, no índice estomático e na espessura do parênquima esponjoso. A anatomia radicular não evidenciou alterações decorrentes da intoxicação por arsênio e modificações nas características do xilema e floema, porém não houve prejuízos à sua estrutura e função. Dessa forma, o estresse por intoxicação pelo arsênio, nas concentrações testadas, não é evidente nas plantas de E. crassipes, e os mecanismos de tolerância são relacionados com modificações na anatomia e fisiologia das plantas.

This work aimed to evaluate the anatomical and physiological characteristics of Eichhornia crassipes in response to arsenic stress. Plants of E. crassipes were grown in Hoagland hydroponic nutritive solution under greenhouse conditions at five arsenic levels: 0.0, 0.25, 0.50, 1.0 and 2.0 mg L-1 during 20 days. The plants showed an increase in photosynthetic rate, stomatal conductance, transpiration and Ci/Ca rate, as well as in the activity of all the enzymes in the antioxidant system, with higher activity in the leaves than in the roots, in all the treatments with arsenic. The anatomical characteristics observed on the leaves of the plants under higher arsenic levels showed an increase in stomatal density, stomatal index and spongy parenchyma thickness. Root anatomy showed no toxic evidences at any arsenic level; changes in the xylem and phloem characteristics were exhibited by the roots in the arsenic treatments, but no damage was caused to its structure and function. Thus, stress caused by arsenic intoxication at the levels tested, is not evident on E. crassipes plants, and the mechanisms of tolerance of E. crassipes are associated to anatomical and physiological changes.

A duração do estro e os intervalos início do estro-ovulação e fim do estro-ovulação após luteólise induzida ou espontânea, e os intervalos administração de prostaglandina-início do estro e administração de prostaglandina-ovulação foram avaliados em 35 vacas da raça Gir e 12 da raça Guzerá, no inverno e no verão de dois anos consecutivos. A duração do estro não diferiu (P>0,05) entre as raças Gir (12,13±0,47h) e Guzerá (12,30±0,63h) e não foi influenciada (P>0,05) pelo tipo de luteólise e pela estação do ano. Os intervalos do início e final do estro à ovulação não diferiram (P>0,05) entre as raças Gir (29,30± 0,96h e 17,28± 0,93h, respectivamente) e Guzerá (28,33± 1,26h e 16,04± 1,21h, respectivamente) e foram similares (P>0,05) entre os estros induzido e natural, e entre estações. O intervalo aplicação de prostaglandina-início do estro foi menor (P<0,05) na raça Gir (64,68± 2,41h) do que na Guzerá (73,47± 3,45h) e não diferiu (P>0,05) entre as estações. O intervalo administração de prostaglandina-ovulação foi similar (P>0,05) entre as raças Gir e Guzerá (96,62± 4,25h e 104,01± 6,51h, respectivamente). Observou-se ampla variação no intervalo prostaglandina-início do estro e alta correlação entre este e o momento de ovulação, sugerindo que as sincronizações do estro e da ovulação não foram suficientemente precisas para permitir a adoção de IA programada.

The lengths of estrus, and intervals from the beginning of estrus to ovulation and from the end of estrus to ovulation after induced or spontaneous luteolysis, and after prostaglandin application were evaluated in 35 Gir and 12 Guzera cows during the winter and summer seasons of two consecutive years. No difference in length of estrus between Gir (12.13±0.47h) and Guzera (12.30±0.63h) was observed (P>0.05). The length of estrus was not influenced (P>0.05) by induced or spontaneous luteolysis and season. No differences (P>0.05) in lengths from the beginning of estrus to ovulation and from the end of estrus to ovulation between Gir (29.30± 0.96h and 17.28± 0.93h, respectively) and Guzera (28.33± 1.26h and 16.04± 1.21h, respectively) cows, between induced and natural estrus, and between seasons were found. The prostaglandin application to beginning of estrus interval was shorter (P<0.05) in Gir breed (64.68± 2.41h) than in Guzera breed (73.47± 3.45h). The prostaglandin to ovulation interval was similar (P>0.05) between Gir and Guzera (96.62± 4.25h and 104.01± 6.51h, respectively). Large variation in the length from prostaglandin application to beginning of estrus, and high correlation between this interval and ovulation time were observed. These results suggest that the synchronization of estrus and ovulation was not sufficiently precise to adopt fixed-time AI.

O comportamento de vacas da raça Gir em estro e a concentração plasmática de progesterona foram avaliadas durante um estro induzido e o natural subseqüente, em 35 animais da raça Gir, no inverno e no verão de dois anos consecutivos. Observou-se efeito de interação entre estação e ano do experimento sobre a duração do ciclo estral. O proestro foi maior no verão (51,82± 4,77h) do que no inverno (33,43± 4,82h) e no estro natural (64,41± 4,95h) do que no induzido (20,85± 4,64h). Observou-se menor duração da atividade sexual total no estro induzido do que no natural (41,62± 4,81 vs 94,83± 4,56h no inverno, e 64,00± 4,14 vs 127,44± 4,04h no verão). A duração do estro foi similar no inverno (12,33± 0,74h) e no verão (11,82± 0,74h), e maior nas vacas sincronizadas (13,24± 0,70 vs 10,91± 0,78h). O número de montas recebidas durante o estro foi similar no inverno (28,16± 2,61) e no verão (22,98± 2,58) e maior nos animais sincronizados (29,97± 2,48 vs 21,17± 2,17). Observou-se efeito de interação entre estação e tipo de luteólise sobre o número de montas recebidas por hora em estro. O inverno não se constituiu em fator limitante à manifestação do estro, cuja duração e intensidade foram suficientes para permitir sua detecção; contudo, a sincronização dos estros interferiu com a manifestação do comportamento sexual.

The estrus behaviour and the plasma progesterone concentration were monitored during an induced and a natural subsequent estrus, in 35 Gir cows, during the winter and summer seasons of two consecutives years. The length of estrous cycle was influenced by the interaction between season and experimental year. The proestrus period was longer in the summer (51.82± 4.77h) compared to the one in the winter (33.43± 4.82h) season as far as in the natural (64.41± 4.95h) vs in the induced estrus (20.85± 4.64h). The total sexual activity was shorter in the induced than in the natural estrus (41.62± 4.81 vs 94.83± 4.56h in the winter, and 64.00± 4.14 vs 127.44± 4.04h in the summer). The length of estrus was similar between winter (12.33± 0.74h) and summer (11.82± 0.74h), and longer in the synchronized cows (13.24± 0.70 vs 10.91± 0.78h). The number of mounts accepted during the estrus was similar between winter (28.16± 2.61) and summer (22.98± 2.58), and greater in the synchronized animals (29.97± 2.48 vs 21.17± 2.17). It was observed effect of interaction between season of the year and luteolysis type on the total received mountings per hour in estrus. The winter was not a limiting factor to the estrus manifestation, once its length and intensity allowed heat detection, however, heat synchronization meddled the manifestation of sexual behaviour.