BACKGROUND: Heat stress declines the performance through physiologic changes of the poultry. OBJECTIVES: This experiment was conducted to evaluate the effects of different levels of L-carnitine on performance, carcass characteristics and some blood parameters of broiler chickens fed with high fat diets under heat stress. METHODS: Two hundred one-day-old broiler chicks (Ross 308) were used in a completely randomized design by four treatments and five replicates (pen) 10 birds in each replicate. The chickens of experimental treatments were fed with basal diet (control group) and the diets plus the different levels of 100, 200 and 300 mg/kg L-carnitine. The experimental diets were used during the finisher period (day 24 to 42 of age) and under heat stress (32±1ºC as cyclic from 9.00 AM to 5.00 PM). RESULTS: The results showed that the chicks fed with the highest L-carnitine had the higher weight gain during the finisher period as compared to control and the lower L-carnitine fed chicks (p<0.05). Furthermore, the feed conversion ratio of birds fed with the medium and high L-carnitine levels (100 and 300 mg) was lower than that of control birds (p<0.05). In orthogonal contrasts, L-carnitine supplementation caused the improvement in weight gain and feed conversion ratio during both the finisher and whole experimental periods (p<0.05). The consumption of highest L-carnitine decreased the abdominal fat as compared to control (p<0.05). In orthogonal contrasts, L-carnitine consumption caused the higher glucose and lower abdominal fat in comparison to control (p<0.05). CONLUSIONS: Totally, the results of recent experiment show that consumption of 300 mg/kg L-carnitine improves the performance of broiler chickens through the increase in dietary fatty acids and energy.

The objective of this study was to examine the effect of calving difficulty or dystocia on the vitality of newborn calves and its association with blood pH, the apparent efficiency of immunoglobulin G (IgG) absorption (AEA), and weight gain. A total of 45 calving events (N = 48 calves) were monitored from the first sight of fetal membranes. All calves were assessed at the time of first attaining sternal recumbency (SR), at 2 and 24 h, and at 7 and 14 d of age. Measurements included time to SR, rectal temperature, respiration and heart rate, analysis of blood gases and other blood measures, suckling response, time to standing, passive transfer of IgG, and weight gain. Calves were separated from their dam 2 h after birth and fed a commercial colostrum replacer containing 180 g of IgG by esophageal tube feeder. Calves born following dystocia had lower venous blood pH and took longer to attain SR and attempt to stand than those born unassisted. Duration of calving interacted with the number of people required to extract the calf by pulling as a significant predictor of pH at SR. No association was found between pH at SR and AEA. However, reduced AEA was found in calves that were female and in calves that did not achieve SR within 15 min of birth. A longer calving duration, being born in July or August rather than June, and a shorter time spent standing in the first 2 d of life were significantly associated with reduced weight gain to 14 d. It was concluded that factors at calving impact the physiology, vitality, and subsequent weight gain of newborn calves.

Quail closed-house system is a house that support quails’ optimumrequirements as far as temperature, relative humidity, ventilation and light are concerned. One of the four units of quail closed-house systems at the Institute of Poultry Technology, Malacca was used in this study. The objective of this project was to evaluate the performance of the quail closed-house system by comparing the condition of the house under current management condition and after the Standard Operating Procedure determined by DVS was adhered. Thehouse performance was evaluated by observing its ability to achieve an optimum temperature range of 20°C to 27°C with a relative humidity between 60% to 80% as perfect surroundings for quails. At the end of the experiments, the results showed a decline in internal temperature at almost 3°C and increasing in a relative humidity of 10% after all the specifications and procedures were followed.