育成生长期雄性水貂净能需要量研究

本试验旨在采用6室并联毛皮动物开放呼吸回流式呼吸测热装置研究和计算育成生长期雄性水貂生长净能(NE_g)、维持净能(NE_m)需要量,以完善我国水貂营养标准。选取健康、日龄相近的雄性短毛黑水貂24只进行呼吸测热试验,试验共设3期,每期7 d,其中适应期1 d,正常代谢3 d,绝食代谢3 d,每期3个重复,每个重复3只水貂,均放进呼吸测热装置的1个代谢室。结果表明:1)水貂正常采食时代谢能摄入量(MEI)为1 296.51 kJ/(kg BW^(0.75)·d),产热量(HP)为530.03 kJ/(kg BW^(0.75)·d),NE_g为766.92 kJ/(kg BW^(0.75)·d);绝食产热量(FHP)为414.87 kJ/(kg BW^(0.75)·d),净能(NE)需要量为1 181.79 kJ/(kg BW^(0.75)·d)。2)水貂正常采食状态下氧气(O_2)消耗量为26.60 L/(kg BW^(0.75)·d),二氧化碳(CO_2)产生量为20.51 L/(kg BW^(0.75)·d),呼吸熵(RQ)为0.78。绝食状态下O_2消耗量为20.91 L/(kg BW^(0.75)·d),CO_2产生量为15.65 L/(kg BW^(0.75)·d),RQ为0.76。3)经MEI与沉积能(RE)建立的线性回归方程推算得,NE_m为436.00 kJ/(kg BW^(0.75)·d),维持代谢能(ME_m)为518.47 kJ/(kg BW^(0.75)·d),能量转化效率(K_m)为84.09%。经MEI与HP反对数建立的线性回归方程推算得,NE_m为467.98 kJ/(kg BW^(0.75)·d),ME_m为529.00 kJ/(kg BW^(0.75)·d),K_m为88.47%。综上所述,体重为1.30~2.58 kg的育成生长期雄性水貂能量需要量为:ME_m518.00~529.00 kJ/(kg BW^(0.75)·d),NE_m414.87~467.98 kJ/(kg BW^(0.75)·d),NE_g766.92 kJ/(kg BW^(0.75)·d),NE为1 181.79 kJ/(kg BW^(0.75)·d)。

Physio-Biochemical Changes in Jujube Fruits(Zizyphus jujuba Mill. cv. Lingwuchangzao) at Mature Stage

The changes of physiological and biochemical indices in jujube fruits during the late development were investigated from 6-year-old jujube trees （Zizyphus jujuba Mill. cv. Lingwuchangzao）. The results showed that the flesh firmness decreased slowly from white-green stage to full-red stage, being significantly related with the developmental maturity of jujube fruits negatively, the correlation coefficient reached -0.980 3^＊＊. The contents of ascorbic acid and titratable acid in jujube fruits were significantly related with the developmental process of jujube fruits negatively or positively, the correlation coef- ficients were -0. 973 1^＊＊and ＋ 0. 974 6^ ＊ ＊ , respectively. The contents of soluble solids, total sugar, and sucrose increased with jujube ripening, while the relative sweetness of jujube fruits showed the same variation pattern, the correlation coefficients were 0. 996 6 ^＊ ＊ , 0. 988 0^＊＊ , and 0. 982 8 ^＊ ＊ , respectively. Before white-green stage during fruit development, the accumulation of monosaccharide was predominant in jujube fruits, following a fast accumulation of sucrose, indicating that the main component of sugars is sucrose at the crisp-ripe stage. Furthermore, the starch content of the flesh reached the peak at about thirty percentage of jujube maturity, being 51,54 mg/100 g.FW. The respiratory rates varied between 10 mg/（ kg.h） and CO2 26 mg/（ kg.h） after fruit turning red and before softening, indicating a non-climacteric respiratory type.