Recent research has demonstrated that lymphocyte apoptosis sensitivity appears to be related to training status and exercise intensity. This work investigated the effect of prolonged, submaximal treadmill running on percentage (%) apoptosis, % necrosis and DNA strand breaks in lymphocytes and related these to changes in total lymphocyte and blood cortisol concentrations in well-trained runners. Venous blood samples (n = 14) were taken immediately before (PRE), immediately after (IPE) and 3 h after (3PE) 2.5 h of treadmill running at 75% of VO2 max from eight well-trained male endurance athletes (age 34.2 +/- 2.44 years) and analysed for cellular content and serum cortisol concentrations. Lymphocytes were isolated from whole blood and % apoptotic and necrotic cell were detected by flow cytometry using Annexin V-FITC and propidium iodide uptake. DNA strand breaks were measured by single-cell gel electrophoresis. Despite a significant (P < 0.001) exercise-induced increase in mean serum cortisol concentrations and reduction in lymphocyte counts, the mean % Annexin-V positive cells (13.3 +/- 6.78 in PRE, 11.3 +/- 5.51 in IPE and 12.8 +/- 6.75 in 3PE samples) were not significantly different at the three time-points (P > 0.05). Mean DNA strand breaks in the lymphocytes also did not change significantly (P > 0.05) rising from 25.7 +/- 2.16 to 26.9 +/- 1.89 and 27.1 +/- 1.38 microm in IPE and 3PE samples, respectively. The exercise-induced changes in total blood lymphocyte counts and cortisol concentrations did not result in a significant change in % apoptotic lymphocytes or DNA strand breaks in the endurance-trained athletes during this prolonged, submaximal exercise.

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ABSTRACT:The aim of the study was to evaluate egg shell quality characteristics, mineral content in the egg shell, and serum mineral concentration during the egg formation process as influenced by oviposition time and ambient temperature at the beginning and end of the laying cycle in laying hens and broiler breeders. Egg shell quality deteriorated significantly at the higher temperature and was lower in broiler breeders than in laying hens. The Ca (P = 0.047) and P (P = 0.018) contents of the egg shell were significantly higher at the higher temperature. The highest (P = 0.028) shell Ca content (352 g/kg) was in eggs laid in the morning, but the highest P (P = 0.030; 1.43 g/kg) and Mg (P = 0.001; 3.88 g/kg) contents were in eggs laid in the afternoon. Broiler breeder egg shells contained significantly more P (P = 0.004) and Mg (P = 0.001) than did those from laying hens. Serum Ca and P levels remained constant throughout the day whereas serum Mg and Zn levels decreased, the rate of decrease in Zn content being the same in all treatments, but with the amounts being greater in laying hens than broiler breeders. The results demonstrate that shell quality characteristics are more severely affected by different factors implemented in this trial compared to the shell mineral composition and especially compared to the serum mineral content.

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________________________________________________________________________________ AbstractMale broiler breeders were photostimulated at different ages (56, 77, 98, 119, 147 and 161 d) during the period of growth prior to achieving sexual maturity to observe their response to photoperiod stimulation. Birds were sampled at regular intervals to measure the average testis weight -these values responding curvilinearly to the age at photostimulation, similar to the attainment of sexual maturity observed previously in females. However, males reached sexual maturity at an earlier age than females, as measured by the start of semen production. Based on the age at first semen production, no differences in the mean age at sexual maturity (ranging from 164 to 172 d) resulted from the different ages at photostimulation. Testis weights from males on different photostimulation treatments showed that some males respond to early stimulation, but from 189 d of age some of these early photostimulated males still had an average testis weight of less than 10 g, while males photostimulated 98 d and later all had an average testis weight over 10 g. Serum testosterone concentration measured at 351 d also showed that early photostimulation resulted in two groups of birds that either responded or not. At 351 d the serum testosterone concentration was more evenly distributed in males photostimulated after 98 d, while males photostimulated before 98 d had either high or low serum testosterone concentrations. Directional asymmetry was observed in testis weights, with the left testis being bigger than the right. Other bilateral traits measured also showed directional asymmetry, an indication of developmental instability. However, the degree of relative asymmetry was not related to treatment. All males should respond to photostimulation by 98 d but some respond earlier, and these could be used by broiler breeding companies to eliminate seasonality in these birds. ________________________________________________________________________________