Desempenho, frequência de diarreia, produção de fezes e custos de dietas com teores crescentes de farelo de abacaxi para leitões desmamados / Performance, diarrhea frequency, feces production and costs of diets with increasing levels of pineapple byproducts in weaned piglets

Esta pesquisa objetivou avaliar dietas com teores crescentes de farelo de abacaxi na alimentação de leitões desmamados. Foram utilizados 56 leitões, no intervalo de 21 a 63 dias de idade, que receberam dietas compostas principalmente por milho, farelo de soja e produtos lácteos, com adição de farelo de abacaxi em 0%, 3,4%, 6,8% e 10,2%. Foram avaliados o desempenho zootécnico; a incidência de diarreia; as excreções nas fezes, totais e por unidade de peso vivo ganho, de matérias seca (MS), mineral (MM) e orgânica (MO), nitrogênio (N) e fósforo (P); os custos relativos ao ganho de peso dos animais e os índices de eficiência econômica e de custo. As avaliações foram efetuadas dos 21 aos 35 dias; dos 21 aos 49 dias; e dos 21 aos 63 dias de idade dos leitões. Adotou-se delineamento em blocos ao acaso, de acordo com os pesos dos animais no início do experimento, com quatro tratamentos e sete repetições. Dos 21 aos 49 dias os animais submetidos às dietas com 3,4 e 6,8% de farelo de abacaxi consumiram mais ração (P<0.05) do que os alimentados com a dieta controle, e dos 21 aos 63 dias verificou-se maior ganho de peso (P<0.05) somente dos animais que receberam a dieta com 3,4% de farelo de abacaxi em relação aos leitões controle. Dos 21 aos 63 dias os animais que receberam as dietas com farelo de abacaxi apresentaram excreções de MS, MM, MO e N superiores (P<0.05) às dos animais controle. Contudo, ao se verificarem as excreções destes componentes nas fezes por unidade de peso vivo ganho neste mesmo período, foi constatado que não houve diferença (P>0.05) entre os leitões que receberam as dietas sem farelo de abacaxi e os que consumiram a dieta com 3,4% do produto. Portanto, a inclusão do farelo de abacaxi em dietas para leitões desmamados em 3,4% é viável, por não interferir negativamente nas excreções por unidade de peso vivo ganho e nos índices de custos das dietas e por proporcionar melhor ganho de peso aos leitões em relação àqueles que não consumiram farelo de abacaxi.(AU)

This research aimed to evaluate diets with growing levels of pineapple meal in weaned piglets feeding. Fifty-six piglets, from 21 to 63 days old, were fed diets composed mainly of corn, soybean meal, and dairy products, with the addition of pineapple byproduct in 0%, 3.4%, 6.8% and 10.2%. The parameters evaluated were: growth performance; diarrhea incidence; excretion in feces, total and per unit of weight gain, of dry (DM), mineral (MM) and organic (OM) matters, nitrogen (N) and phosphorous (P); diet costs related to weight gain, index of economic efficiency and of costs. The evaluations were performed from 21 to 35 days; from 21 to 49 days; and from 21 to 63 days of age. A complete randomized block design was adopted, according to the animal's weight in the beginning of the trial, with four treatments and seven repetitions. From day 21 to 49 the animals fed diets with 3.4 and 6.8% of pineapple meal consumed more feed (P<0.05) than those fed the control diet, and from day 21 to 63 only the animals that received the diet with 3.4% of pineapple presented a higher weight gain (P<0.05) than control piglets. From day 21 to 63 animals fed diets with pineapple meal presented higher (P<0.05) excretions of DM, MM, OM, and N than the control animals. However, checking the excretions of these components in the feces per unit of live weight gain in the same period, it was found that there was no difference (P>0.05) among the piglets fed diets without pineapple meal and those who consumed the diet with 3.4% of the product. Thus, the inclusion of pineapple meal in weaned piglet's diets at 3.4% is feasible, because it did not interfere negatively on excretions per unit of live weight gain and in diet cost indices, and provided better weight gain to the animals, as compared with pigs who did not consume pineapple meal.(AU)

EPSPS variability, gene expression, and enzymatic activity in glyphosate-resistant biotypes of Digitaria insularis.

Weed resistance to herbicides is a natural phenomenon that exerts selection on individuals in a population. In Brazil, glyphosate resistance was recently detected in Digitaria insularis. The objective of this study was to elucidate mechanisms of weed resistance in this plant, including genetic variability, allelism, amino acid substitutions, gene expression, and enzymatic activity levels. Most of these have not previously been studied in this species. D. insularis DNA sequences were used to analyze genetic variability. cDNA from resistant and susceptible plants was used to identify mutations, alleles, and 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) expression, using real-time quantitative reverse transcription-polymerase chain reaction. In addition, EPSPS activity was measured. We found a decrease in genetic variability between populations related to glyphosate application. Substitutions from proline to threonine and tyrosine to cysteine led to a decrease in EPSPS affinity for the glyphosate. In addition, the EPSPS enzymatic activity was slightly higher in resistant plants, whereas EPSPS gene expression was almost identical in both biotypes, suggesting feedback regulation at different levels. To conclude, our results suggest new molecular mechanisms used by D. insularis to increase glyphosate resistance.

Implementing new northernmost records to modelling the distribution of Hypsiboas caingua (Anura: Hylidae) in South America.

New northwestern records of the striped treefrog Hypsiboas caingua (Carrizo, 1991 "1990") are presented for Brazil, extending its known geographic distribution approximately 115 km northward (linear distance) of the previous northernmost record of the species. In all new localities, individuals of H. caingua were only found in calling activity under temperatures below 18°C. The species appears to be associated with Atlantic Forest, although it had already been recorded in Cerrado. Although the scientific literature data suggests that H. caingua presents discontinuous geographical distribution, three methods of distribution modelling based on climatic data show that the species' distribution is continuous. The gap in the distribution may be related to the lack of field surveys in the regions that connect these populations, especially in colder periods. Nevertheless, factors other than climate might also be responsible for the current distribution of H. caingua, since the species was absent in well-surveyed sites situated between the areas of modeled distribution. Therefore, further studies on natural history, populations' genetic structure, and geographic distribution models implementing factors other than climate will be important to elucidate some ecological and evolutionary aspects of the distribution of H. caingua in South America.