Effect of negative dietary cation‐anion differences on carcass characteristics and beef tenderness of Japanese Black steers

Lowering dietary cation‐anion differences (DCAD) can enhance responsiveness to Ca‐homeostatic hormones and increase Ca availability, which might have potential to activate a Ca‐dependent protease, calpain, and to enhance postmortem myofibrillar proteolysis. In this study, we investigated the effects of DCAD manipulation on calpain activity and beef tenderness in Japanese Black cattle which are characterized by their high marbling. Thirty‐six Japanese Black steers were allotted to one of two treatments: (i) control (CON; DCAD +6.09 mEq/100 g of dry matter (DM)) or (ii) negative DCAD (NEGD; DCAD ?8.27 mEq/100 g DM) for 70 days before slaughter. Lowering DCAD decreased DM and energy intake (P < 0.01) even though it did not negatively affect the growth performance or carcass characteristics. In NEGD, urine pH was decreased by acidification caused by the negative DCAD (P < 0.01). Calpain activities tended to be improved in NEGD (P = 0.09), but Warner‐Bratzler shear force values were not affected by treatment. Although calpain activities tended to improve, lowering DCAD to ?8.27 for 70 days before slaughter was insufficient to enhance beef tenderness in Japanese Black steers.     

The effect of potassium fertilization on iron deficiency

Abstract

Preliminary experiments indicate that potassium fertilization at a rate of 270 mg K/kg soil amel.iorates Iron deficiencies in peanuts grown in an extremely calcareous soil (63% CaCO₃). Amelioration was greater with the application of KCl than with that of KNO₃ or K₂HPO₄, indicating that the cation:anion balance of roct uptake is involved. Potassium chloride application caused a 73% increase in the chlorophyll content; this value is 90% of that of the FeEDDHA treatment. Manipulation of the cation: anion balance of macronutrients may prove to be an effective means of controlling lime‐induced chlorosis.     

Antinephritis and radical scavenging activity of prenylflavonoids

Antinephritis activity of 5 prenylflavonoids similar to glabridin (1-5), isolated from Morus alba, Artocarpus communis, Glycyrrhiza uralensis and G. inflata, was evaluated in mice with glomerular disease (Masugi-nephritis). Oral administrations of artonin E (2) or licochalcone A (4) for 10 days (30 mg kg(-1) day(-1)) reduced the amount of urinary protein excretion compared to nephritic mice. ESR spectroscopy demonstrated that morusin (1) and licorisoflavan A (5) increased the radical intensity of sodium ascorbate by about two times. Morusin, licoricidin (3), licochalcone A and licorisoflavan A showed weak scavenging activity against superoxide anion radical.     

Fecal excretion of alcohols and organic anions in neonatal dairy calves

To clarify colonic fermentation during the perinatal period, 22 dairy calves less than 6 weeks old were used. They were given a milk replacer following colostrum feeding. A total 100 samples of normal feces including meconium were collected from the rectum of the calves. Fecal pH, alcohols, lactate and volatile fatty acids (VFAs) were analyzed. Higher ethanol and n -propanol concentrations were found in many fecal samples particularly in the first 2 weeks after birth, but these metabolites showed consistently lower concentrations thereafter. By contrast, higher concentrations of methanol were observed in some samples for all ages examined. Fecal VFA increased abruptly within a few days of birth, and mainly consisted of acetate and n -butyrate. During the first 2 weeks, the proportion of n -butyrate in VFAs decreased and that of propionate increased gradually. Proportions of VFAs were almost stable at 3–6 weeks of age (acetate, propionate and n -butyrate in increasing order). Higher concentrations of lactate and lower pHs were observed in the fecal samples during the first 2 weeks, and concentrations decreased thereafter. Accelerated colonic production of ethanol and n -propanol was confirmed during the early 2 weeks, in addition to organic acid fermentation as reported previously.     

Nitrogen accumulation in nodulated and non‐nodulated pea plants,grown in a sandy soil at different acidities

Abstract

The growth of nitrate‐supplied and dinitrogen‐fixing pea plants was studied in a pot experiment with a sandy soil in a pH‐H_?O range from 3.4 to 5.6. Optimum growth in both treatments occurred at pH 5.0. At low pH, N₂‐plants yielded significantly less than NO₃‐plants. Planting of nodulated seedlings did not enhance yield in comparison with sowing in inoculated soil, indicating that nodulation was not the most sensitive process in restricting yield. Comparison of the nitrogen contents of shoots of planted and sown N₂‐plants allowed the suggestion that the synthesis of nitrogenous compounds was also not limiting yield. At low pH, root growth was severely reduced in dinitrogen‐fixing plants in comparison with nitrate‐supplied plants. This difference could be explained by the influence of the form of nitrogen nutrition on the cation‐anion uptake pattern of the plant and the resulting pH‐shift in the rhizosphere. It is to be expected that in an acid soil under field conditions the indirect effect of nitrate on root growth and nodulation via increase of the pH is more extensive than its direct negative effect on nodulation.     

N-苯酰基-N-对硝基苯基硫脲荧光受体对阴离子的识别研究

利用荧光分析方法考察了荧光受体分子N-苯酰基-N-对硝基苯基硫脲与CH3COO-,HCO-3,H2PO-4 CO2-3,HSO-3,Br-,Cl-,SO2-4等阴离子的相互作用.结果显示该化合物对CO2-3具有较高的选择性识别能力,对不同阴离子的选择性从大到小依次为:CO2-3 ,HSO-3 , HCO-3 ,H2PO-4-, CH3COO- , Cl- , Br- , SO2-4.     

奶牛产乳热的发生及阴离子盐的应用

本文就影响产乳热的发生因素、防治措施及阴离子盐在预防奶牛产乳热中的应用作一介绍。     

极谱氧电极法测定抗氧化剂清除超氧自由基作用的研究

对极谱氧电极仪直接测定抗氧化剂在反应体系所放出的氧量表示抗氧化剂清除O-·　2 能力的初步研究 ,表明本法方便、快速、微量化、灵敏度高 ,可自动连续记录作用过程的变化 ,适用于测定一些抗氧化剂如黄酮化合物、VC对O-·　2 的消除作用