Effect of Different Concentrate-roughage Ratios on Rumen Degradability of Cassava Stems and Leaves Total Mixed Ration in Goat

The rumen degradations of TMR were studied in this experiment,in which cassava stems and leaves were used as roughage and formulated with concentrate in different proportions.The purpose of this study was to formulate the available TMR for finishing goat,and provide a theoretical basis for the applications of cassava stems and leaves in goat production.Six Hainan Black goats with permanent rumen fistulas were selected,the rumen degradabilities of DM,CP,NDF and ADF of TMR with 6 different concentrate to forage ratio（2:8,3:7,4:6,5:5,6:4 and 7:3）were tested using nylon bag method.The results showed that,the DM effective degradabilities at the ratio of 4:6,5:5,6:4,7:3 were significantly higher than that of 2:8 and 3:7（P<0.05).CP effective degradabilities at the ratio of 2:8,3:7,4:6 were significantly higher than that of 5:5,6:4 and 7:3（P<0.05).The NDF effective degradation at the ratio of 5:5 was significantly higher than that in the other groups（P<0.05).The ADF degradation at the ratio of 3:7 was significantly higher than that of 4:6,5:5, 6:4 and 7:3（P<0.05).The results indicated that,the nutrient degradation in rumen were higher when the concentrate to forage（cassava stems and leaves）ratio in TMR were 3:7,4:6 and 5:5,and the recommended ratio range were 4:6 to 5:5 in production practice.     

Early interspecific dynamics,dry matter production and nitrogen use in Kernza (Thinopyrum intermedium) – alfalfa (Medicago sativa L.) mixed intercropping

ABSTRACT

The global interest in growing perennial grain crops such as intermediate wheatgrass (Thinopyrum intermedium) (Kernza) for production of food and feed is increasing. Intercropping Kernza with legumes may be a sustainable way of supplying nitrogen to soil and associated intercrop. We determined the competitive interactions between intercropped Kernza (K) and alfalfa (Medicago sativa L.) (A) under three inorganic nitrogen (N) rates N0, N1, N2 (0, 200, 400 kg ha^?1) and five species relative frequencies (SRF) (100%K:0%A, 75%K:25%A, 50%K:50%A, 25%K:75%A and 0% K:100%A) in mixed intercrops (MI) in a greenhouse pot experiment. After 11 weeks of growth. Kernza dry matter yield (DM) and N accumulated (NACC) were low, but alfalfa DM and NACC high at 0 kg N ha^?1. 200 and 400 kg N ha^?1 fertiliser application increased the competitive ability (CA) of Kernza and reduced the CA of alfalfa. SRF had large impacts on alfalfa DM, NACC and NFIX only at 0 kg N ha^?1 fertiliser, and insignificant impacts on Kernza at all N fertiliser levels, indicating that adjustment of SRF may not be an effective way to modulate the interspecific competition of Kernza. Further research on the other factors that influence the interspecific competition are warranted.     

Study on Liver-protective Effect of Chinese Herbal Compound Probiotics on Acute Liver Injury Layers

This experiment was conducted to investigate the liver-protective effect of Chinese herbal compound probiotics (CHCP) on acute liver injury layers.One hundred and eight 1 day old hens were divided into 4 groups with 3 replicates in each group and 9 layers per replicate in trial 1.The layers in model groups Ⅰ to Ⅲ were gavaged with 10% (V/V) soybean oil solution of carbon tetrachloride (SCCl₄) according to 1,2 and 4 mL/(kg·BW) at 14,28 and 35 d,respectively.The layers in control group were gavaged with 2 mL/(kg·BW) soybean oil.In trial 2,sixty 1 d layers were divided into 5 groups:Control group (soybean oil),model control group(SCCl₄)and low-dose,middle-dose and high-dose CHCP group (SCCl₄+1‰ CHCP,SCCl₄+2‰ CHCP and SCCl₄+4‰ CHCP respectively).CHCP were used by drinking water since 7 days.SCCl₄ were gavaged according to 2 mL/(kg·BW) at 14 and 28 d.The results showed as follows:The model of layers liver damage could be built by intragastric administration of 2 mL/(kg·BW) 10%(V/V) SCCl₄ at 14,28 d respectively,with the signs of hepatic steatosis,severe vacuolar degeneration,nuclear condensation and necrosis.Compared to the model control group,the serum AST levels in low,medium and high dose CHCP groups were decreased by 4.35% (P > 0.05),7.57% (P > 0.05) and 9.79% (P < 0.05),the serum ALT levels in medium and high dose CHCP groups were decreased by 34.92% (P < 0.01),36.51% (P < 0.01),the serum total bilirubin content in medium and high dose CHCP groups were decreased by 25.49% (P < 0.01),27.45% (P < 0.01).The liver cell congestion was reduced to varying degrees in different dose CHCP groups,and the liver cell had no vacuoles,arranged in neat rows,abundant cytoplasm and uniform in different dose CHCP groups.In conclusion,2‰,4‰ CHCP could reduce hepatocyte necrosis,decrease the serum activities of ALT,AST and total bilirubin levels,and had protective effect on hepatic injury induced by SCCl₄.     

三峡库区不同植被覆盖对土壤氮的影响

不同植被类型影响着土壤养分的积累、分布与循环,而土壤氮素是植被生长的重要限制性元素。通过分析宜昌点军区3种植被类型(柏树地、橘树地、菜地)覆盖下土壤氮素的变化情况,研究了不同植被对土壤氮素各形态的影响。结果表明,土壤全氮、硝态氮和微生物氮都是柏树地显著大于菜地和橘树地,而菜地和橘树地之间无显著性的差异;土壤矿化氮和微生物氮/全氮的变化顺序是柏树地橘树地菜地。说明不同植被覆盖对土壤氮有显著的影响,柏树地更有利于土壤氮的积累,氮的有效性也最高,由此认为柏树长期生长有益于土壤氮的改善。     

毛泡桐皮黄酮提取物抗氧化作用研究

以毛泡桐皮为原料,通过乙醇提取,大孔吸附树脂纯化,分别得到毛泡桐皮黄酮的粗提物和纯化物。利用油脂酸败法,测定油脂的过氧化值(POV)和诱导期(IP),计算抗氧化系数(PF)。根据抗氧化系数的大小,确定毛泡桐皮黄酮提取物抗氧化能力的大小。试验结果表明:在相同浓度下,毛泡桐皮黄酮提取物抗氧化能力的大小为:毛泡桐皮黄酮纯化物>粗提物>原粉;并且随着浓度的增加抗氧化能力逐渐增大,其存在着剂量效应关系;0.1%毛泡桐皮黄酮纯化物的抗氧化系数大于2,具有较强的抗氧化能力;0.1%毛泡桐皮黄酮纯化物的抗氧化能力与0.02%BHT的抗氧化能力相当,0.06%毛泡桐皮黄酮纯化物的抗氧化能力与0.05%维生素C的抗氧化能力相当。     

遗传算法优化超声辅助低共熔溶剂提取红枣总黄酮工艺研究

本文采用一种新型绿色溶剂提取红枣总黄酮,并对其提取工艺进行优化。通过单因素试验探究含水量、超声功率、提取时间、提取温度和料液比对红枣总黄酮得率的影响。在此基础上,采用遗传算法优化超声辅助低共熔溶剂提取红枣总黄酮工艺。结果表明：超声辅助低共熔溶剂提取红枣总黄酮最优的工艺参数为：含水量37%、超声功率167 W、提取时间30 min、提取温度54 ℃和料液比1∶26（g/mL）。在此条件下,所得红枣总黄酮得率为（29.33±0.37）mg/g。试验值和理论值的相对误差为1.24%。表明遗传算法可较好地模拟和预测不同提取条件下红枣总黄酮得率,且优化工艺参数是可行的。研究发现低共熔溶剂可作为一种新型、绿色溶剂用于高效提取红枣总黄酮。[关键词] 遗传算法|红枣|总黄酮|低共熔溶剂|工艺     

Oral administration of L-citrulline changes the concentrations of plasma hormones and biochemical profile in heat-exposed broilers

We examined the effects of oral administration of L-citrulline (L-Cit) on plasma metabolic hormones and biochemical profile in broilers. Food intake, water intake, and body temperature were also analyzed. After dual oral administration (20 mmol/head/administration) of L-Cit, broilers were exposed to a high ambient temperature (HT; 30 ± 1°C) chamber for 120 min. Oral administration of L-Cit reduced (p < .001) rectal temperature in broilers. Food intake was increased (p < .05) by heat stress, but it was reduced (p < .05) by L-Cit. Plasma levels of 3,5,3′-triiodothyronine, which initially increased (p < .0001) due to heat stress, were reduced (p < .01) by oral administration of L-Cit. Plasma insulin levels were increased by heat exposure (p < .01) and oral L-Cit (p < .05). Heat stress caused a decline (p < .05) in plasma thyroxine. Plasma lactic acid (p < .05) and non-esterified fatty acids (p < .01) were increased in L-Cit-treated heat-exposed broilers. In conclusion, our results suggest that oral L-Cit can modulate plasma concentrations of major metabolic hormones and reduces food intake in broilers.