烟酸铬对西门塔尔牛精料瘤胃降解率的影响

试验选用4头平均体重500±20kg,年龄4岁,装有永久性瘤胃瘘管的西门塔尔牛阉牛,采用4×4拉丁方试验设计,以混合精料和风干玉米秸秆为基础日粮,研究1.3倍维持水平下,日粮添加烟酸铬（0mg/d、40mg/d、80mg/d、120mg/d）对精料瘤胃降解率的影响。结果表明：日粮添加烟酸铬组DM有效降解率与对照组差异不显著（P〉0.05）,添加80mg/d烟酸铬组精料OM有效降解率、CP瘤胃有效降解率较对照组显著提高（P〈0.05）。本试验结果表明：日粮添加烟酸铬的适宜添加水平为80mg/d。     

饲粮过瘤胃胆碱添加量对泌乳早期奶牛生产性能及血液指标的影响

本试验旨在研究饲粮过瘤胃胆碱添加量对泌乳早期奶牛生产性能及血液指标的影响.试验选用4头胎次、预产期、体重、产奶量相近的健康荷斯坦牛,采用4×4拉丁方试验设计,试验处理为每头牛的饲粮中每天添加0、30、60或90 g过瘤胃胆碱(氯化胆碱含量分别为0、7.5、15.0、22.5 g).试验共分为4期,每期15 d.试验结果...     

The effects of calcium,phosphorus and zinc supplementation on reproductive performance of crossbred dairy cows in Tanzania

The effects of calcium (Ca), phosphorus (P) and zinc (Zn) supplementation on reproductive performance of grazing dairy cows was studied. Forty-eight cows in their first to third parity were allocated to eight groups of 6 animals each, based on stage of lactation and milk yield. Groups 1 (control), 2 (Ca), 3 (P) and 4 (Zn) received, respectively, no mineral supplement, 10 g Ca, 8 g P and 400 mg Zn. The rest of the groups received a combination of Ca/P, Ca/Zn, P/Zn or Ca/P/Zn. Animals were drenched daily. Ovarian activity was determined by progesterone concentrations in milk. Prepartum body condition score (BCS) measured using scale 1–5 was 2.5–3.5. Reproductive problems were observed in all groups except that supplemented with Ca. Cows supplemented with Ca, P, Ca/P, Ca/Zn and Ca/P/Zn had significantly (p < 0.05) shorter interval (30 days) from calving to resumption of oestrus as compared to control (69 days). Intervals from calving to conception and between calvings did not differ significantly between groups (p > 0.05), but were shorter in Ca-supplemented cows. Furthermore, cows in groups 2 and 3 needed an average of 2 services per conception against 3 for cows in other groups. Hence, supplementation with Ca, P and Zn of deficient dairy cows appears to improve reproductive performance.     

Effect of sorghum grain supplementation on glucose metabolism in cattle and sheep fed temperate pasture

The aim of this work was to evaluate the effect of sorghum grain supplementation on plasma glucose, insulin and glucagon concentrations, and hepatic mRNA concentrations of insulin receptor (INSR), pyruvate carboxylase (PC), and phosphoenolpyruvate carboxykinase (PCK1) mRNA and their association with nutrient intake, digestion and rumen volatile fatty acids (VFA) in cattle and sheep fed a fresh temperate pasture. Twelve Hereford × Aberdeen Angus heifers and 12 Corriedale × Milchschaf wethers in positive energy balance were assigned within each species to one of two treatments (n = 6 per treatment within specie): non‐supplemented or supplemented with sorghum grain at 15 g/kg of their body weight (BW). Supplemented cattle had greater plasma glucose concentrations, decreased plasma glucagon concentrations and tended to have greater plasma insulin and insulin‐to‐glucagon ratio than non‐supplemented ones. Hepatic expression of INSR and PC mRNA did not differ between treatments but PCK1 mRNA was less in supplemented than non‐supplemented cattle. Supplemented sheep tended to have greater plasma glucagon concentrations than non‐supplemented ones. Plasma glucose, insulin, insulin‐to‐glucagon ratio, and hepatic expression of INSR and PC mRNA did not differ between treatments, but PCK1 mRNA was less in supplemented than non‐supplemented sheep. The inclusion of sorghum grain in the diet decreased PCK1 mRNA but did not affect PC mRNA in both species; these effects were associated with changes in glucose and endocrine profiles in cattle but not in sheep. Results would suggest that sorghum grain supplementation of animals in positive energy balance (cattle and sheep) fed a fresh temperate pasture would modify hepatic metabolism to prioritize the use of propionate as a gluconeogenic precursor.     

可调式UVB自动控制系统的研制

我们在中国科学院千烟洲生态网络实验站建立了国内一个可调式UV—B辐射自动控制系统，用于模拟研究水稻对一定比例的地表UVB增强的反应。该系统能够根据阳光中UVB辐射强度的变化而自动增加和减少人工光源输出的UV—B辐射强度，介绍了该系统的原理、结构及观测与控制效果。     

Studies on the effect of dry Sundakai (solanum torvum) powder supplementation on lipid profile,glycated proteins and amino acids in non-insulin dependent diabetic patients

The effect of dry Sundakai powder supplementation (7 g providing 1.23 g of crude fibre) on glycemic control, lipidemic control, total amino acids and uronic acid was studied on 30 non-insulin dependent diabetes mellitus patients. All the patients were on hypoglycemic drugs. The above parameters were monitored at day 1, 15 and 30 days. After one month of fibre supplementation, no significant changes were observed with respect to glucose, lipid profile, glycated proteins, total amino acids and uronic acid levels in these subjects.     

Life history traits and food supplementation affect productivity in a translocated population of the endangered Hihi (Stitchbird, Notiomystis cincta)

We studied the effect of food supplementation, female age and clutch order on productivity in a translocated species. Food supplementation increased clutch size from 3.9 to 4.4 (average) eggs per nesting attempt, and more than doubled fledging and recruitment success. Supplemented females started a second clutch 9 days sooner after fledging first clutch chicks than unfed females. During second clutches, supplemented females incubated the eggs for a shorter period of time (15.2 days vs. 16.8). Older females laid larger clutches (4.6 vs. 3.7 eggs) than yearlings and incubated second clutch eggs for a shorter period (15.4 vs. 16.6 days). Females laid more eggs in first clutches (4.2 vs. 3.8 eggs), and those eggs took approximately 30% longer to lay than eggs in second clutches. The successful maintenance of hihi populations on the available islands may be dependent on the permanent provision of supplemental food at nest sites.     

冬季补饲对妊娠后期藏母羊瘤胃挥发性脂肪酸、 微生物群落结构和羔羊发育的影响

为了研究冬季补饲对妊娠期藏母羊瘤胃挥发性脂肪酸(volatile fatty acid,VFA)、微生物区系及羔羊生长发育影响.采用单因子试验设计,随机选择健康藏母羊440只,分为2组.对照组(control check,CK)为放牧饲喂,处理组(test,T)在放牧基础上,每只母羊补饲0.1 kg·d-1精料补充料,试验期为45 d(配种后106～150 d).试验结束后,从处理组和对照组中随机选择5只和6只母羊屠宰后分析瘤胃挥发性脂肪酸和细菌菌群组成.同时测定新生羔羊的生长发育指标.结果 表明:(1)处理组羔羊的体重、体高和胸围显著高于对照组(P＜0.05);(2)处理组瘤胃液总挥发性脂肪酸(Total volatile fatty acids,TVFA)、丙酸和丁酸含量显著高于对照组(P＜0.05),同时乙酸和异丁酸显著低于对照组(P＜0.05);(3)两组母羊瘤胃微生物在门和属水平上组成相似,拟杆菌门(Bacteroidetes)、厚壁菌门(Firmicutes)以及疣微菌门(Verrucomicrobia)为优势菌门;而普雷沃菌属-1(Prevotella l)、理研菌科RC9肠道群(Rikenellaceae-RC9-gut-group)、普雷沃氏菌科-UCG-001(Prevotellaceae-UCG-001)为优势菌属;(4) Alpha多样性指数中,对照组的Shannon指数显著高于处理组(P＜0.05),说明对照组瘤胃微生物多样性优于处理组;(5)瘤胃微生物功能预测发现,两组母羊瘤胃微生物主要富集于复制和修复(Replication and Repair)、碳水化合物代谢(Carbohydrate Metabolism)和信号转导(Signal Transduction).综上,妊娠后期藏母羊的冬季补饲能够为胎儿的生长发育提供必要的营养需求,同时提高母羊瘤胃液中TVFA、丙酸和丁酸含量,但在一定程度上影响了瘤胃细菌的多样性.     

Chemical and biological characteristics of a West African weaning food supplemented with compea (Vigna unguiculata)

The effects of cowpea and amino acid supplementation on the protein quality and chemical characteristics of a maize-based West African traditional weaning food were studied. Process optimization for improved nutritive value was also determined. Supplementation of the traditional weaning food with cowpea increased the lysine, tryptophan and threonine content while the sulphur-amino acids decreased with increasing levels of cowpea. Further supplementation of 70:30 maize/cowpea blends with lysine, threonine or methionine did not significantly improve (p>0.05) protein quality in terms of the biological value (BV) and net protein utilization (NPU), although significant increases in the protein scores were noted. However, considerable improvements in the BV and NPU were recorded in blends fortified with either tryptophan alone or a combination of lysine, tryptophan, methionine and threonine. Cooking whole cowpea seeds for 45 min before incorporating in the blend formulation also significantly improved (p<0.05) the protein quality of maize/cowpea blends. The BV and NPU of blends containing 30% pre-cooked cowpea increased from 52 to 76% and 50 to 71% respectively compared to pure maize porridge. The protein content increased from 10 to 14% and the utilizable proteins more than doubled. The weight increase of experimental rats fed with these blends was comparable to that of rats on casein diet. A 30% supplementation of the maize-based weaning food with cowpea therefore greatly enhances the nutritive value especially when the cowpea is pre-cooked for 45 min. Use of chemical scores alone for such blends cannot be a reliable index of blend quality.