The aim of this experiment was to evaluate the effect of the duration of progestagen (P4) exposure and sexual maturity of prepubertal and pubertal heifers submitted to timed artificial insemination (TAI). A hundred and fourteen 16- month old Bradford heifers were classified, according treatment and sexual maturity, in 4 groups: PPLPG (prepubertal long exposure to P4, n=21), PPSPG (prepubertal short exposure to P4, n=19), PLPG (pubertal long exposure to P4, n=34) and PSPG (pubertal short exposure to P4, n=40). On […]

A simulation study was carried out to apply and compare an alternative mating strategy for increasing the probability of producing outstanding animals and reducing progeny variability, with other conventional strategies. Fifty populations were simulated, each containing 4,800 dams, 160 sires and 4,800 calves. For each dam and sire, a random variable from a normal distribution was generated, mimicking an index composed by several expected progeny differences (EPD). The mating strategies considered were: (1) random mating (RM); (2) positive assortative mating […]

The objectives of this study were to estimate the genetic parameters of the following categorical traits: musculature, physical structure, racial breed aspects, conformation, navel, pigmentation and sacrum, and predict breeding values, using bayesian statistics under threshold animal models, considering different ages of cattle of the Nelore breed. The information concerning visual scores were obtained from 2000 to 2005 from cattle of the Nelore breed from thirteen participant farms of the Brazilian Nelore Program. In the two-trait analyses, 500,000 rounds up […]

Yields of B. decumbens cultivar Basilisk and B. brizantha cultivars Marandu and Xaraés were evaluated under different shade levels. A completely randomized block split plot design was used, with the shade levels as plots (0, 50, 70%), and the species and cultivars as split-plots. Seeds were germinated on trays and three seedlings were transplanted to each pot. Four harvests were made on each split-plot. Prior to each harvest, plant height, number of live tiller per pot and the leaf area […]

Nitrogen (N) at 100, 200, 300, and 400 kg ha-1 was applied to Tanzania grass swards to evaluate the animal response and relationships between sward characteristics and the performance of young Nellore bulls (Bos indicus) under continuous stocking. A completely randomized experimental design was used with two replications between 11 November 2001 and 15 April 2002 when the sward heights were maintained at 60 cm by using different stocking rates. The average daily gain (ADG) (0.73 kg d-1) was not […]

The objective of this experiment was to evaluate the effects of nitrogen doses (0, 100, 200, 300, and 400 kg ha-1 year-1), with or without dolomitic lime covering application, on the potassium (K) soil content at depths varying form 0 to 5, 5 to 10, and 10 to 20 cm, and the potassium concentration in the plant. The experiment was carried out in a rhodic ferralsol with a slightly rolling relief, in a 5 × 2 factorial arrangement, in a […]

The action of different concentrations of sodium chloride, benzocaine and clove oil in the survival of fingerling and juvenile tilapia (Oreochromis niloticus),chitraladalineage, was tested during 5 hours for transportation. A total of 1350 fingerlings were used ( weight 9.74 ± 0.04 g and length 6.79 ± 0.01 cm) and 270 juveniles (average weight 29.6 ± 0.06 g and length 11.52 ± 0.01 cm). The fish were maintained without food for 24 hours in four 500L asbestos boxes with constant aeration. […]

Precision livestock involves innovative technologies to monitor the animal within its pastoral environment. Understanding ingestive behaviour is fundamental to management decisions based upon animal and vegetation monitoring. The way such information can be used is not yet clear. In precision agriculture, the governing principle has been to correct or manage variability so as to homogenise yield at maximized levels. If the same reasoning is applied in livestock production, it can foster classical mistakes in grazing management. However, if precision livestock […]

The energy value of foods as well as energy requirements of dogs and cats is currently expressed in terms of metabolizable energy (ME). The determination of ME content of foods requires experimental animals and is too expensive and time consuming to be used routinely. Consequently, different indirect methods have been proposed in order to estimate as reliably an accurately as possible the ME content of pet food. This work analyses the main approaches proposed to date to estimate the ME […]

The effects of the addition of 15% of different addictives (coffee hulls, cocoa meal and cassava meal) to green elephant grass forage, in natural matter basis (weight/weight), at the ensilage moment on the consumption of nutrients and the performance of twenty Santa Inês sheep under feedlot system were evaluated. The animals had 5.0 months of age, initial weight of 22.27 ± 3.24 kg and final weight of 28.6 ± 3.78 kg. The treatments were: T1 = elephant grass ensiled without […]