Australian abalone aquaculture is characterised by a prolonged culture period and slow and variable growth, and abalone is cultured in fluctuating water temperatures ranging between 10 and 25°C with distinct seasons. Temperature is a crucial environmental factor influencing abalone’s physiology and energetics, leading to a change in nutritional requirements. However, feeds are generally formulated to match the nutritional requirements at their optimal temperature. Hence, there is a need to optimise dietary protein levels to match temperature-specific requirements during extreme conditions (winter and summer). Given this, a growth trial evaluating five experimental feeds consisting of graded protein inclusion levels (320, 350, 380, 410, and 440 g·kg−1) was conducted on subadult hybrid abalone (Haliotis rubra × H. laevigata) at three different temperatures reflecting winter (12°C), summer (22°C), and the annual average water temperature (17°C) for 143 days. At lower water temperature (12°C), there was a marginal improvement in growth performance as dietary protein levels increased from 320 to 440 g·kg−1. However, at higher water temperatures (when the culture water temperature is above 17°C), there was a significant improvement in growth performance as dietary protein levels increased from 320 to 440 g·kg−1 as evidenced by an improved weight gain, specific growth rate, and feed conversion ratio. Furthermore, increasing dietary protein levels did not compromise the nutritional quality of the abalone tissue at all three tested temperatures. Therefore, during periods of higher water temperatures, feeding Australian hybrid abalone with a relatively high dietary protein level (410 g·kg−1) is expected to result in improved growth, shorter culture duration, and profit maximisation.
Ninety random samples of fresh poultry meat cuts represented by chicken thigh & breast, duck thigh & breast and turkey thigh & breast (15 of each) were collected from different slaughtered shops Tanta city, Gharbia government. The collected samples were analyzed for determination of thiobarbiturc acid (TBA), perioxide value (P.V.) free fatty acids (FFAs) and fractionation of fatty acids to determine their lipolytic indices for their keeping quality as well as their composition of fatty acids. The obtained results showed that mean values for duck thigh, chicken thigh and turkey thigh samples were 0.52+0.03, 0.33+0.02 and 0.15+0.01 (mg/kg) for TBA & 0.85+0.09, 0.57+0.07 and 0.33+0.04 (mgO 2 /kg) for PV, respectively. Plus, 0.69+0.07, 0.45+0.06 and 0.28+0.02 (mg %) for FFAs, respectively. Concerning breast of both duck, chicken and turkey samples, the mean values were 0.40+0.02, 0.19+0.01 and 0.12+0.01 (mg/kg) for TBA, where, 0.64+0.07, 0.41+0.05 and 0.27+0.02 (mgO 2 /kg) for PV. As well as, 0.52+0.05, 0.36+0.03 and 0.20+0.03 (mg %) for FFAs respectively. Finally, samples subjected to fractionation of fatty acids the ratio between total unsaturated fatty acids and total saturated fatty acids were 0.96, 1.23 and 1.66 for thigh of duck, chicken and turkey, respectively. While breast of duck, chicken and turkey ratios were 1.15, 1.45 and 2.23 respectively. Turkey breast meat had the highest keeping quality and nutritive value compared with the other samples.
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