Camilla Mendonça Silva

Níveis de ractopamina para suínos machos castrados em terminação e mantidos sob conforto térmico

The objective of this study was to evaluate the performance and the quantitative characteristics of barrows carcass maintained under thermoneutral environment and fed with diets containing different ractopamine levels. Forty-eight barrows were used, with initial weight of 67.0±2.7kg, distributed in a randomized blocks design with four ractopamine levels (0, 5, 10 and 20ppm) and six replicates with two animals each. The experimental period lasted 28 days. The average temperature recorded was 20.9±2.9°C, relative humidity was 86.7±7.3% and BGHI was 69.6±4.0. The final weight of the animals and feed intake were not influenced (P>0.05) by treatments. The ractopamine levels influenced (P 0.05) by treatments. It was concluded that the ractopamine optimal level of inclusion in the diet of barrows kept under thermoneutral environment is 20ppm.

Energia líquida e ractopamina para leitoas em terminação sob altas temperaturas ambientais

The objective of this paper was to assess net energy (NE) levels and ractopamine in the diet of finishing gilts maintained under high temperature environment (29.5±2.3°C). Forty gilts were used, with initial weight of 69.3±2.8kg, distributed in a randomized block design, in a factorial scheme 2x4 (0 and 20ppm of ractopamine; and 2,300; 2,424; 2,548 and 2,668kcal/kg NE kg-1 of feed), and five replications and one animal each. There was interaction (P<0.05) between NE levels and ractopamine, and the inclusion of 20ppm of ractopamine in the diets containing 2,548 and 2,668kcal reduced (P<0.05) backfat thickness and increased (P<0.05) the percentage of lean meat of carcasses. The use of ractopamine improved (P<0.05) feed gain ratio and increased (P<0.05) the amount of lean meat in carcasses. It was concluded that ractopamine at a dose of 20ppm provides benefits in performance and carcass traits of gilts under heat stress and this effect is more positive in diets containing higher energy levels (2,548 and 2,668kcal of NE kg-1).

Níveis de energia líquida e ractopamina para leitoas em terminação sob conforto térmico

This research was conducted to evaluate the net energy and ractopamine levels in the diet of finishing gilts kept under thermal comfort conditions. Forty gilts were used, with initial weight of 67.4 ± 3.4 kg, distributed in a randomized blocks design in a 2 × 4 factorial scheme composed of two levels of ractopamine, 0 and 20 ppm, combined with net energy levels of 2,300; 2,424; 2,548 and 2,668 kcal/kg of feed, with five replications, considering each animal per experimental unit. The experimental period lasted 28 days. Air temperature, relative humidity, black globe temperature, and black globe temperature and humidity index were 21.5 ± 2.8oC, 91.7 ± 6.8%, 21.7 ± 2.9oC and 70.1 ± 3.7, respectively. There was interaction between net energy levels and ractopamine, once the inclusion of 20 ppm of ractopamine in diets with 2,668 kcal of net energy/kg of feed resulted in a decrease in backfat thickness and consequently an increase in lean meat percentage and in carcass allowance index. The inclusion of 20 ppm of ractopamine caused an increased in daily weight gain, improved feed gain ratio, providing higher hot carcass weight and increasing the lean meat amount in carcasses. Diets supplemented with 20 ppm of ractopamine improve the performance and increase meat production of finishing gilts. Ractopamine is ineffective in reducing fat deposition and increasing the percentage of lean meat in the carcass of gilts fed with diets containing low concentration of energy. The level of 2,300 kcal of net energy/kg diet meets the nutritional requirement of finishing gilts under thermal comfort.

Digestibilidade de dietas suplementadas com fitase para suínos sob diferentes ambientes térmicos

We conducted a digestibility trial with the aim of evaluate phytase levels on digestibility and nutrient excretion for pigs submitted to thermoneutral conditions and heat stress. We used 24 barrows housed in metabolic cages in climatic chamber, distributed in randomized blocks in a 2x4 factorial design, two environments (23 and 31°C) and four phytase levels (0, 300, 600 and 900UF kg-1 diet), with three replicates and each experimental unit consists of one animal. It was concluded that pigs submitted to high ambient temperatures (31°C) have worse digestibility of protein, phosphorus, calcium, zinc, iron and magnesium and therefore have a higher percentage of nutrients excreted in feces when compared to pigs submitted to thermoneutral environment (23°C). Phytase supplementation did not alter the energy value of feed and the digestibility coefficient of protein, but it increases the digestibility coefficient of phosphorus, calcium and magnesium and reduces the percentage of phosphorus and calcium in the faeces of pigs. We recommend the inclusion level of 300UF kg-1 feed, regardless of the environmental thermal condition.

Duração da suplementação de ractopamina em dietas para leitoas em terminação mantidas sob alta temperatura ambiente

The study was conducted to evaluate the duration of the supplementation of ractopamine in the diet of finishing gilts maintained under high temperature environment. Forty eight females, with initial weight of 70.4±2.6kg were used. The pigs were distributed in randomized blocks design of six treatments (supplementation of ractopamine for 0, 7, 14, 21, 28 and 35 days pre-slaughter) and four replications, each experimental unit consisted of two animals. The final weight and daily feed intake were not affected (P>0.05) by treatments. The weight gain increased and the feed conversion decreased linearly (P 0.05) by duration of supplementation of ractopamine in the diet. The weights of the lungs, heart, liver, kidneys and spleen were not modified (P>0.05) by treatments. It was concluded that inclusion of 20ppm of ractopamine in the diet of finishing gilts maintained under high temperature environment during 28 days maximizes the response of daily gain and during 35 days maximizes the response to feed conversion. However, the inclusion of the additive does not alter the quantitative characteristics of carcass and does not affect the development of the viscera.

Complexo homeopático na prevenção e tratamento de diarréias em leitões lactentes

The main objective of this work was to use the cluster analysis in order to classify nonlinear growth models in relation to different quality fit evaluators when data from the following lambs genetic groups were utilized: Dorper x Morada Nova, Dorper x Rabo Largo e Dorper x Santa Ines. After the choice of the best model, it was also aimed to apply the identity model test in order to identify the most efficient genetic group. The proposed methodology was applied to data of all animals from each group regarding twelve nonlinear models, whose fit quality was measured by determination coefficient, Akaike information criterion, Bayesian information criterion, mean quadratic error of prediction, predicted determination coefficient and convergence percentual. The cluster analysis indicated the von Bertalanffy as the best model for the three data sets. The model identity tests revealed that the Dorper x Santa Ines group presented higher adult weight, therefore this group is recommend for meat production.

Estabilidade de silagens de grãos úmidos de milho e milho reidratado

This work was carried out to evaluate the fermentation characteristics and aerobic stability, regarding the conventional high moisture corn grain silage (Fortuna variety), the high moisture sweet corn grain silage and the high moisture rehydrated corn silage. Data were statistically analyzed as a 3x3 factorial arrangement in a completely randomized design, and the factors were three types of corn (Fortuna, sweet and rehydrated) and three inoculation treatments (without inoculum, bacterial inoculum and bacterial inoculum plus enzymes). The aerobic stability values were assessed, collecting the temperatures from the room dry bulb and from the silage thermometers, and the pH values, at 0, 24, 48, 72, 96, 168, 192, 216, 240 and 296 hours after aerobic exposition. Additionally, different mathematical models to estimate the mean pH values after opening were tested. Interactions were observed (P The sweet corn silage presented lowest pH values at 48 hours after opening. The pH values at 168 hours of rehydrated corn silage treated with bacterial inoculum plus enzymes was more acid. Richard’s Equation (1959) was the best tool for the pH estimation when either types of inoculants or rehydrated corn silage were considered. On the other hand, the model proposed by Morgan et al. (1975) was the best equation model to fit the data regarding either Fortuna or sweet corn silages. Normal 0 21 false false false PT-BR X-NONE X-NONE