Whole-plant Corn Silage Quality Treated with Mixed Acids and its Effect on Sheep Growth Performance

In order to explore different concentrations of mixed acids in improving quality of whole-plant corn silage and their effects on growth performance of Dorper×Han F1 sheep.4 levels of 45% formic acid,45% propionic acid and 10% sodium propionate were mixed,and 0(control),0.3%,0.6% and 1% were added to 4 groups of ripening period whole-plant corn.The results showed that compared with control group,the experimental groups could significantly decrease the proportion of AA/PA in silage (P<0.05);0.3% and 0.6% groups had the better effects.Based on the result of CNCPS,0.6% group significantly improved the PB₃ component (P<0.05),reduced the CC component (P>0.05),and improved the quality of silage.Compared with control group,the experimental groups effectively inhibited the mold and yeast reproduction,improved the aerobic stability of silage.The feeding trial results showed that ADG and F/G of sheep in experimental groups were better than control group,and F/G of both 0.6% and 1% groups were significantly better than that in control group (P<0.05).In conclusion,treatment of mixed acids could improve the quality of whole-plant corn silage,and silage treated with 0.6% levels of mixed acids could significantly improve the growth performance of Dorper×Han F1 sheep.     

Ecological implications of motor oil pollution: Earthworm survival and soil health

The nontarget effects of fresh and used motor oil were studied in a soil test system involving such criteria as earthworm survival, response of soil dehydrogenase and urease, and nitrification. When earthworms were exposed to motor oil-contaminated soil for 4 weeks, the observed median lethal concentrations (LC₅₀) were 40.33 and 3.88 g kg⁻¹ soil for fresh and used oil, respectively. Only fresh motor oil application increased earthworms' body weight even at the higher dose of 19 g kg⁻¹ soil. Gas chromatography/mass spectrometry revealed that used motor oil contained more of aromatic hydrocarbons and heavy metals than fresh oil. This disparity in the chemical composition might be the factor responsible for the significant toxicity of used motor oil towards earthworms. Activities of soil dehydrogenase and urease were significantly enhanced in presence of both the motor oils, while there was a significant inhibition in nitrification by the used motor oil even at a low concentration of 0.2 g kg⁻¹ soil. This study clearly demonstrated that earthworm survival and nitrification could serve as suitable indices to assess motor oil pollution in soil.     

青藏高原东北部3种野豌豆植物学特性及资源储量

采用野外定点法、最小样方法和统计学方法对生长于青藏高原东北部的3种野豌豆属植物的植物学特性、生态环境、群落数量特征及资源储量进行研究。结果显示,救荒野豌豆、山野豌豆和三齿萼野豌豆的植物学特性、生态环境和群落数量特征具有一定差异,3种野豌豆在青海省的资源总储量分别为0.46×10~6、0.23×10~6、0.27×10~6 kg,表明3种野豌豆属植物的资源总量在青海省并不高,应对其进行有效的引种驯化,实现人工繁育和增加资源储量,这既可保护青海省甚至青藏高原的生态环境,也可对其资源进行有效地保护和合理开发利用。     

Comparison of dietary essential amino acid requirements determined from group‐housed versus individually‐housed juvenile bluegill,Lepomis macrochirus

Two 60‐day experiments were conducted sequentially to determine (i) lysine requirement of juvenile bluegill, Lepomis macrochirus based on the dose–response method, (ii) requirements for other essential amino acids (EAAs) using whole‐body amino acid profile and (iii) whether differences in growth rates of group‐housed versus individually‐housed bluegills lead to different lysine requirement levels because of the presence and absence, respectively, of social hierarchies. Seven, semi‐purified, experimental diets (isonitrogenous, isocaloric) were prepared to contain graded levels of digestible lysine (10–31 g kg⁻¹). Experiment‐1 involved group‐housed bluegills (approximately 27 g, n = 10 fish/chamber, 4 chambers/diet) whereas experiment‐2 involved individually‐housed bluegills (approximately 30 g, n = 1 fish/chamber, 14 chambers/diet). Fish were fed twice daily to apparent satiation. Bluegill growth responses in both experiments generally improved (P < 0.05, anova ) with increasing dietary lysine levels from 10 to 16 g kg⁻¹, and then levelled off with further increase in lysine level (P > 0.05). Optimal dietary lysine level (digestible basis) was estimated to be 15 g kg⁻¹ based on broken‐line regression analyses of relative growth rate and feed conversion ratio with no differences being observed between the two rearing methods. Determined dietary requirement levels for other EAAs ranged from 2.4 g kg⁻¹ (tryptophan) to 15.3 g kg⁻¹ (leucine).     

不同配比南极磷虾粉饲料对网箱养殖俄罗斯鲟生长及氟累积的影响

配制南极磷虾粉替代饲料中鱼粉比例分别为0%、10%、20%、30%的4组饲料饲喂俄罗斯鲟(Acipenser gueldenstaedtii)200 d后,分析南极磷虾粉替代部分鱼粉对网箱养殖俄罗斯鲟生长和鱼体组织氟残留的影响。结果表明:(1)随着南极磷虾粉替代比例的升高,俄罗斯鲟的末重、增重、特定生长率、蛋白质效率先上升后下降,饲料系数先降低后升高,10%组显著高于对照组和其它试验组(P0.05);(2)实验结束时,俄罗斯鲟肌肉、肝脏和鱼鳔的氟浓度低于检测限,但鳃、皮、脊骨和背骨呈现剂量浓度效应,各试验组较对照组显著升高(P0.05)。综上所述,在本实验条件下,在俄罗斯鲟饲料中加入10%比例的南极磷虾粉时获得最佳生长效果和较低的组织氟累积。     

Comparative morphology of the digestive system of 19 species of Southern African myomorph rodents in relation to diet and evolution

Trends in digestive system-morphology have been examined in 19 species of Southern African myomorph rodents. Structure was related to function, diet, and evolution. Characters related to an ancestral proteinaceous diet, and specialized characters associated with herbivory, were recognized. All stomachs were of the unilocular hemiglandular type with increasing degrees of cornification of the corpus, although the stomach of Saccostomus compestris approached the bilocular discoglandular condition. Those of Thallomys paedulcus and Mystromys albicaudatus were highly modified in containing numerous papillae in the corpus, possibly associated with gastric fermentation. The most complex caeca, of the herbivorous Otomyids, possessed numerous haustra and internal papillae probably associated with caecal microbial fermentation.     

Vitamin and mineral supplementation and rate of gain during the first trimester of gestation affect concentrations of amino acids in maternal serum and allantoic fluid of beef heifers

The objective of this study was to evaluate the effects of feeding vitamin and mineral (VTM) supplement and (or) rate of gain (GAIN) during early gestation on amino acid (AA) concentrations in allantoic fluid (ALF) and amniotic fluid (AMF) and maternal serum. Seventy-two crossbred Angus heifers (initial BW = 359.5 ± 7.1 kg) were randomly assigned to one of four treatments in a 2 × 2 factorial arrangement with main effects of VTM supplement (VTM or NoVTM) and rate of gain (GAIN; low gain [LG], 0.28 kg/d, vs. moderate gain [MG], 0.79 kg/d). The VTM treatment (113 g•heifer⁻¹•d⁻¹, provided macro and trace minerals and vitamins A, D, and E to meet 110% of the requirements specified by the NASEM in Nutrient requirements of beef cattle. Washington, DC: The National Academies Press. doi:10.17226/19014, 2016) was initiated 71 to 148 d before artificial insemination (AI). To complete the factorial arrangement of treatments, at breeding heifers were either maintained on the basal diet (LG), or received MG diet which was implemented by adding a protein/energy supplement to the LG diet. Thirty-five gestating heifers with female fetuses were ovariohysterectomized on d 83 of gestation and maternal serum, ALF, and AMF were collected. Samples were analyzed for concentrations of neutral AA: Ala, Asn, Cys, Gln, Gly, Ile, Leu, Met, Phe, Pro, Ser, Thr, Trp, Tyr, and Val; cationic AA: Arg, His, and Lys; and anionic AA: Asp and Glu. In serum, a VTM × GAIN interaction (P = 0.02) was observed for Glu, with greater concentrations for VTM-LG than VTM-MG. Concentrations of serum Cys, Met, and Trp were greater (P ≤ 0.03) for MG than LG. In ALF, concentrations of Glu were affected by a VTM × GAIN interaction, where VTM-MG was greater (P < 0.01) than all other treatments. Further, ALF from VTM had increased (P ≤ 0.05) concentrations of His, Asp, and 12 of the 14 neutral AA; whereas GAIN affected concentrations of Arg, Cys, and Asp, with greater concentrations (P ≤ 0.05) in MG heifers. In AMF, AA concentrations were not affected (P ≥ 0.10) by VTM, GAIN, or their interaction. In conclusion, increased concentrations of AA in maternal serum and ALF of beef heifers were observed at d 83 of gestation in response to VTM supplementation and rate of gain of 0.79 kg/d, which raises important questions regarding the mechanisms responsible for AA uptake and balance between the maternal circulation and fetal fluid compartments.     

Nutritional significance of amino acids,vitamins and minerals as nutraceuticals in poultry production and health – a comprehensive review

Nutraceuticals have gained immense importance in poultry science recently considering the nutritional and beneficial health effects of their constituents. Besides providing nutritional requirements to birds, nutraceuticals have beneficial pharmacological effects, for example, they help in establishing normal physiological health status, prevent diseases and thereby improve production performance. Nutraceuticals include amino acids, vitamins, minerals, enzymes, etc. which are important for preventing oxidative stress, regulating the immune response and maintaining normal physiological, biochemical and homeostatic mechanisms. Nutraceuticals help in supplying nutrients in balanced amounts for supporting the optimal growth performance in modern poultry flocks, and as a dietary supplement can reduce the use of antibiotics. The application of antibiotic growth enhancers in poultry leads to the propagation of antibiotic-resistant microbes and drug residues; therefore, they have been restricted in many countries. Thus, there is a demand for natural feed additives that lead to the same growth enhancement without affecting the health. Nutraceuticals substances have an essential role in the development of the animals’ normal physiological functions and in protecting them against infectious diseases. In this review, the uses of amino acids, vitamins and minerals as well as their mode of action in growth promotion and elevation of immune system are discussed.     

犬慢性肾衰竭进程中肠道菌群代谢物短链脂肪酸水平的变化及其对肾功能的影响

本研究旨在评估短链脂肪酸在慢性肾衰竭患犬和健康犬中的水平,探究短链脂肪酸变化的原因及其对肾功能的影响。选取22例轻度慢性肾衰患犬（M-CRF组）、29例重度慢性肾衰患犬（S-CRF组）和26例健康对照犬（HC组）,用16S rDNA测序技术分析肠道菌群多样性,气相色谱法检测粪中短链脂肪酸浓度。通过粪菌移植和补充丁酸钠给5/6肾摘除犬,观察肠道菌群及丁酸钠对肾功能影响。结果显示：1）S-CRF组肠道菌群多样性指标观察物种数及Simpson指数低于HC组（P<0.05）,PCoA分析显示,S-CRF组肠道菌群与M-CRF、HC组有差异。2）LEfSe分析显示,S-CRF组和HC组间大量差异菌群,拟杆菌科、拟杆菌属及假单胞菌科等7个菌种富集于S-CRF组,普氏杆菌科、梭菌科、普氏杆菌属及普拉梭菌属等11个菌种富集于HC组。CCA分析发现富集于S-CRF组菌种丰度与肾功能指标呈正相关。3）S-CRF组粪中乙酸、丙酸及丁酸浓度均显著低于HC组和M-CRF组,M-CRF组丁酸浓度显著低于HC组（P<0.05）,且丁酸浓度与血中胱抑素C（Cys-c）、肌酐（Cr）及尿素氮（BUN）等肾功能指标呈负相关（r值分别为-0.451、-0.583和-0.514,P<0.01）。4）与慢性肾衰模型组（5/6 Nx组）比较,慢性肾衰犬给与丁酸钠8周后,血清Cr和BUN显著降低（P<0.05）;粪菌移植8周后,血清Cr和BUN显著升高（P<0.05）,丁酸钠可回调血清Cr和BUN水平。综上表明,慢性肾衰竭患犬肠道菌群多样性降低,菌群结构及丰度改变,粪中短链脂肪酸浓度降低,这些变化可加剧肾功能障碍。为犬慢性肾衰竭的防治提供新的理论依据。     

子午岭黑山羊与辽宁绒山羊产肉性能、肉品质、肌肉营养成分和脂肪酸含量比较

1990年,甘肃省庆阳市开始引入辽宁绒山羊对子午岭黑山羊进行杂交改良,但目前尚不清楚2个品种在脂肪酸含量、肌肉营养成分等方面的差异,影响了杂交改良效果。试验旨在分析两个绒山羊品种的产肉性能、肉品质、肌肉营养成分和脂肪酸含量差异,为绒山羊的杂交改良提供理论依据。本研究选取相同饲养管理条件下、9月龄的子午岭黑山羊和辽宁绒山羊公羊各5只,测定其屠宰性能以及背最长肌、前腿肌和后腿肌处的肉品质、脂肪酸含量和肌肉营养成分。结果表明：子午岭黑山羊的胴体重、屠宰率、净肉重、净肉率、眼肌面积、GR值、剪切力和滴水损失低于辽宁绒山羊（P<0.05）,但其肌肉的平均亮度值、色度值、pH₁和pH₂₄高于辽宁绒山羊（P<0.01）。营养成分测定结果表明,子午岭黑山羊肌肉的水分和粗灰分含量高于辽宁绒山羊（P<0.05）,但肌内脂肪和粗蛋白含量低于辽宁绒山羊。在2个山羊品种的肌肉中均检测到11 种饱和脂肪酸（SFA,以棕榈酸和硬脂酸为主）、10种多不饱和脂肪酸（PUFA,以亚油酸和顺-11,14-二十碳二烯酸为主）和6种单不饱和脂肪酸（MUFA,以油酸为主）,子午岭黑山羊肉中的SFA、PUFA、n-3 PUFA、n-6 PUFA含量和PUFA/SFA值均高于辽宁绒山羊（P<0.01）,但MUFA含量低于辽宁绒山羊（P<0.01）。结果表明,辽宁绒山羊有更高的产肉力,但子午岭黑山羊肌肉品质和营养成分更佳,脂肪酸组成和含量更符合人类健康膳食标准。