不同营养结构的饲料对中国林蛙蝌蚪生长发育的影响

研究 4组不同营养结构的饲料对中国林蛙蝌蚪生长发育的影响。结果表明 ,Ⅰ组饲料所喂养的蝌蚪生长速度快 ,完成变态的时间最短 ( 34 4d) ;Ⅲ组饲料喂养的蝌蚪变态后的幼蛙体重最大、身体最长 (分别为 0 31 7g、1 45cm) ;Ⅳ组饲料喂养的蝌蚪生长最慢 ,完成变态所需的时间最长 ( 39 2d) ,变态后的幼蛙体重最小 ( 0 2 5 4 g) ;各组中蝌蚪的成活率和变态率差异不显著 (P >0 0 5 )。     

pH值对东北林蛙卵的孵化率及蝌蚪生长发育的影响

为探索水域pH值对东北林蛙(Rana dybowskii)卵孵化和蝌蚪生长发育的影响,在水温21~23℃的实验室条件下,采用单因子试验方法,研究了水环境不同pH值对东北林蛙卵的孵化率、蝌蚪的日增重、变态率及变态幼蛙初始重的影响。结果表明,受精卵对pH值的适应范围为4~11,孵化率较高的pH值范围为7~9;pH值为6,7,8,9组中的蝌蚪成活率分别为47.95%、48.98%、35.64%和43.64%。在pH值为5.5,6.5,7.5组中,林蛙蝌蚪的变态率分别为94.00%、93.00%和82.00%;变态幼蛙初始重分别为(267.33±46.97)mg、(278.67±37.67)mg和(260.67±35.52)mg。     

抗菌肽对镇海林蛙蝌蚪生长发育的影响

本试验旨在探讨饲料中添加不同浓度抗菌肽对镇海林蛙(Rana zhenhaiensis)蝌蚪生长发育的影响。选取镇海林蛙蝌蚪(Gosner 26~27期)500只,随机分为5个组,每组5个重复,每个重复20尾。各组分别喂添加0、1、2、4和8 mg/g抗菌肽的试验饲料。试验至镇海林蛙蝌蚪全部完全变态结束。结果表明:1)抗菌肽浓度与镇海林蛙蝌蚪的发育历期呈显著的负相关(P0.001),与镇海林蛙蝌蚪的体长相关性不显著(P=0.324);2)镇海林蛙蝌蚪的变态率平均值为94.6%,组间差异不显著(P=0.549),与抗菌肽浓度的相关性不显著(P=0.434);3)抗菌肽浓度与镇海林蛙蝌蚪的变态时间及体长、体重均呈显著正相关(P0.001);4)抗菌肽浓度与镇海林蛙变态幼蛙的跳跃距离相关性不显著(P=0.578);5)抗菌肽浓度与镇海林蛙变态幼蛙大腿肌肉的超氧化物歧化酶活性呈显著负相关(P0.001)。由此可见,抗菌肽的添加降低了镇海林蛙的发育速度,延长了变态时间,同时增加了变态个体的大小,从而提高了幼蛙的适合度。     

东北林蛙(Rana dybowskii)蝌蚪生长发育理想光照强度的研究

为探索不同光照强度对林蛙蝌蚪生长发育的影响,选择120只18日龄的东北林蛙蝌蚪进行试验。将试验动物分为6组,每组20只。光照强度分别为30,500,1 000,2 300,3 600,4 900 lx,每天光照时间12 h,其他饲养和环境条件相同。定期测量体重、体长、尾长及完全变态时间等指标。结果表明:光照强度对蝌蚪生长发育的影响明显。在蝌蚪变态之前,各组间蝌蚪的体长、尾长都有相应的差异,在光照强度为3 600 lx下喂养的蝌蚪增加最为明显。各组间蝌蚪体重随着时间的延长呈先增加后减少。在光照3 600 lx下,蝌蚪体重始终高于其他组。在变态过程中,蝌蚪后肢芽长出日龄、前腿长出日龄、完全变态时间随着光照强度的增加而缩短。在光照强度为3 600 lx、4 900 lx时,蝌蚪变态所用时间无差异且均小于其他组。在光照强度为3 600 lx、4 900 lx下,蝌蚪的变态率最高。因此,光照强度影响林蛙蝌蚪的生长发育,光照强度设为3 600 lx是林蛙蝌蚪生长发育及变态的最佳光照强度。     

饲料对东北林蛙蝌蚪生长发育影响的研究

2008年3月29日～5月26日,在佳木斯市某东北林蛙养殖场,采用2组饲料饲喂东北林蛙蝌蚪,蝌蚪分为A组和B组。结果表明：饲喂T_1组饲料的蝌蚪41期和46期时的体重、体长和尾长明显大于饲喂T_2组饲料的蝌蚪;各组蝌蚪的成活率均在95%以上,各组蝌蚪完成变态的时间差异不显著;T_2组饲料的利用率要低于T_1组。     

中国林蛙的生态习性

1两栖性林蛙是典型的水陆两栖性动物,在其生长发育过程中,蝌蚪期和冬眠期在水中生活,而变态后的幼、成蛙的活动期在陆地生活,两栖生活的时间分别为6个月左右。林蛙每年春天完成冬眠和生殖休眠以后,沿着溪流沟谷附近的潮湿植物带上山,开始完全的陆地生活。林蛙喜栖在林内郁敝度大、枯枝落叶     

青蛙不同时期的饲养管理要点

青蛙的生长发育比较迅速,只要能保证充足的饵料并管理有方,在正常情况下,从小蝌蚪变态的幼蛙,经过人工精心饲养70～80天,个体重一般可达100克左右。此时雄蛙已会开始鸣叫求偶,再饲养10～20天,即可捕捉上市出售。青蛙养殖池分为产卵池、蝌蚪池和成蛙池。     

几种生态因素对人工养殖中国林蛙的影响

为了提高中国林蛙个体生长速度和雌性比例及林蛙的群体产量,试验研究了温度对中国林蛙卵孵化率、成活率、变态率及林蛙性别的影响,盐度对中国林蛙的影响,pH值对中国林蛙变态蝌蚪的影响,光照对蝌蚪的影响。结果表明:蝌蚪最适生长发育温度为18～24℃,可利用光照调节水温,在15～25℃条件下中国林蛙蝌蚪的变态率最高,蛙卵孵化水温在13～18℃之间变雌率可达70%,变态蝌蚪饲养池水体pH值应控制在6.5～8.5,盐度控制在2 g/L以下,蝌蚪养殖水环境Ca2+、Mg2+质量浓度及Ca2++Mg2+总质量浓度应分别控制在20～50 mg/L、20～80 mg/L、50～150 mg/L。     

甘肃部分地区中国林蛙秋季种群结构的研究

研究了甘肃中西部地区中国林蛙的秋季种群结构及生长率特点。结果表明:中国林蛙生长率在三地区间差别不明显,蝌蚪期营养状态决定了变态幼蛙的体型,也影响成蛙的体型大小。甘肃中西部大部分地区中国林蛙种群衰退之势明显。     

中国林蛙蝌蚪期饲料配方的研究

为研究一种适合林蛙蝌蚪生长的饲料配方,试验选用林蛙蝌蚪受精卵共800只,分为4个大组,每大组设两个重复,共8个小组,分别饲养在8个水盆中,每盆100只。试验对比研究了蛋白质含量分别为37.765%、31.628%、23.535%及11.562%的4种饲料。试验结果表明,饲喂蛋白质含量为23.535%的一组蝌蚪重量最大,体长最长,发育的也最为良好。同时通过试验分析证明,从蝌蚪发育到变态前的饲料应以植物性饲料为主并适当的加入部分动物性饲料,这样才有利于蝌蚪的生长发育。此外,还提出用传统方法配制蝌蚪饲料的不足及解决的办法。     

Interrelationships between dietary lysine, sex, and porcine somatotropin administration on growth performance and protein deposition in pigs between 80 and 120 kg live weight

Sixty male and 60 female crossbred pigs were allocated to an experiment to investigate the effects of porcine somatotropin (pST) administration (0 or 6 mg/d) and dietary lysine content on growth performance, tissue deposition, and carcass characteristics over the live weight range of 80 to 120 kg. Pigs receiving pST were given diets containing 6.9, 7.8, 8.8, 9.7, 10.6, or 11.5 g lysine/kg, whereas control pigs received diets containing 4.8, 5.8, 6.9, 7.8, 8.8 or 9.7 g lysine/kg. These dietary levels ranged from 0.40 to 0.70 g available lysine/MJ of DE for pST-treated pigs and from 0.28 to 0.58 g available lysine/MJ of DE for control pigs. Pigs were individually housed in pens, and there were five replicates of each treatment. All diets contained 14.5 MJ of DE/kg and were offered for ad libitum consumption to pigs between 80 and 120 kg live weight. Growth rate increased exponentially and food conversion ratio (FCR) decreased exponentially with increasing levels of lysine. In addition, there was a significant sex x pST interaction such that pST reduced the sex difference in FCR. Growth rate was faster in boars than in gilts and was increased by pST at the higher levels of dietary lysine. Similarly, FCR was lower for boars than for gilts and was decreased by pST at the higher dietary lysine levels. The optimum growth rate and FCR were defined as the lysine level at which growth rate and FCR were 95% and 105%, respectively, of the lysine plateau. The optimum growth rate and FCR were achieved at similar dietary lysine contents and were approximately 0.35 and 0.52 g available lysine/MJ of DE for control and pST-treated pigs, respectively. Protein deposition in the carcass increased exponentially with increasing dietary lysine level, was higher in boars than in gilts, and was increased by pST at the higher dietary lysine contents. Sex had no effect on dietary lysine required to maximize protein deposition. The dietary lysine contents required to ensure 95% of plateau protein deposition of 104 and 153 g/d were 0.39 and 0.55 g available lysine/MJ of DE for control and pST-treated pigs, respectively. The increase in lysine requirement with pST seems to be commensurate with the increase in protein deposition.     

Interaction of dietary protein content and exogenous porcine growth hormone administration on protein and lipid accretion rates in growing pigs

Sixty-six intact male pigs were used to investigate the relationships between exogenous porcine growth (pGH) administration (0, excipient-treated, and .09 mg recombinant pGH.kg-1.d-1) and dietary protein content (8.3, 11.4, 14.5, 17.6, 20.7 and 23.8%) on protein and lipid accretion rates over the live weight range of 30 to 60 kg. Feed intakes were restricted (1.84 kg.pig-1.d-1) and pGH was administered daily by i.m. injection. Rate of protein deposition increased with increasing dietary protein up to 17.6 and 20.7%, respectively, for control and pGH-treated pigs; both growth and protein deposition were enhanced by pGH on the four higher protein diets but remained unaffected by pGH administration to pigs given the two lowest protein diets. Plasma IGF-I concentration was elevated by pGH administration in pigs given the four higher protein diets but unaffected by pGH with the two lowest protein diets. Rate of fat deposition was depressed on all dietary protein treatments by pGH administration; carcass fat content of control and pGH-treated pigs declined with each increase in dietary protein up to 17.6 and 23.8%, respectively. The results demonstrate that pGH acts independently on protein and lipid metabolism.     

日本沼虾的蛋氨酸需求量

通过研究饲料中不同蛋氨酸水平对日本沼虾(Macrobrachium nipponense)生长、饲料效率、全虾体组成、肌肉氨基酸组成和肝胰脏消化酶活性的影响,确定了日本沼虾的适宜蛋氨酸需求量。以酪蛋白、明胶、鱼粉、小麦面筋粉和晶体氨基酸为蛋白源配制了6组蛋白质水平为36.07%、能量为18.09 kJ/g的等氮等能的半纯和饲料,各组蛋氨酸实际含量分别为0.38%、0.47%、0.56%、0.64%、0.75%和0.88%。以初始体质量为0.30 g的日本沼虾为试验对象,每组设4个重复,每个重复50尾虾,养殖在规格为0.6 m×0.6 m×0.6 m的网箱中,试验期56 d。结果表明:当饲料中蛋氨酸水平由0.38%升高至0.88%时,日本沼虾的增重率、特定生长率和饲料效率均显著升高(P0.05);饲料蛋氨酸水平为0.64%时,三者均达到最大值;随着饲料中蛋氨酸水平进一步升高,三者均呈下降趋势。当饲料蛋氨酸水平为0.64%时,全虾粗蛋白含量最高,显著高于0.38%组(P0.05)。饲料蛋氨酸水平对全虾的水分、灰分、脂肪和肌肉的氨基酸组成均无显著影响(P0.05)。饲料中蛋氨酸水平显著影响日本沼虾肝胰脏蛋白酶的活性(P0.05),但对脂肪酶和淀粉酶活性均无显著影响(P0.05)。以增重率为评价指标进行一元二次回归分析,得出日本沼虾的蛋氨酸需求量为0.70%,占饲料蛋白的1.94%。     

Effect of dietary ascorbic acid supplementation level on productivity,mortality, and carcass characteristics of Venda chickens

Two experiments were carried out to determine the effect of dietary ascorbic acid supplementation levels on productivity, carcass characteristics, and mortality of indigenous Venda chickens. The first experiment determined the effect of dietary ascorbic acid supplementation levels on productivity and mortality rate of 175 unsexed Venda chickens between 1 and 6 weeks old. The second experiment determined the effect of dietary ascorbic acid supplementation levels on productivity, carcass characteristics, and mortality rate of 140 female Venda chickens between 8 and 13 weeks old. A completely randomized design was used in both experiments. Supplementation of grower diets with ascorbic acid ranged from 0 to 2,000 mg per kg DM feed in both experiments. Levels of ascorbic acid supplementation for optimum feed intake, feed conversion ratio, growth rate, live weight, and breast meat yield were determined using a quadratic equation. The optimal dietary ascorbic acid supplementation levels for feed conversion ratio, growth rate, and live weight of Venda chickens during the starter phase were 1,050, 1,301, and 1,500 mg/kg DM feed, while, at the grower phase, the optimal supplementation levels for feed conversion ratio, growth rate, live weight, and breast meat yield were 1,000, 1,250, 1,482, and 769 mg/kg DM feed, respectively. Results indicate that different levels of ascorbic acid supplementation optimized feed conversion ratio, growth rate, and live weight of Venda chickens at each growth phase. However, levels of ascorbic acid supplementation for optimum feed conversion ratio, growth rate, and live weight were higher than that for breast meat yield. These findings have implications on ration formulation for Venda chickens.     

Synchrony of nutrient supply to the rumen and dietary energy source and their effects on the growth and metabolism of lambs

The objective of the current series of experiments was to assess the effects of dietary synchrony of OM and N supply to the rumen, achieved by altering the sequence of feeding individual ingredients and in diets with different energy sources, on the metabolism and performance of growing lambs. In Exp. 1, the in situ degradability coefficients of OM and N were determined for five feed ingredients and subsequently was used to formulate two diets, based either on barley or sugar beet pulp, to have a similar predicted nutrient content. Within each diet, specific ingredients were shifted between the 0900 and 1600 feeding to provide either a synchronous, intermediate, or asynchronous supply of OM and N to the rumen. In Exp. 2, these diets were fed at a restricted level to 48 growing lambs with an initial live weight of 25.1 +/- 4.22 kg and a slaughter weight of 41.4 +/- 1.94 kg. There was no significant effect of dietary treatment on live weight gain or feed conversion efficiency. Lambs fed the synchronous diets deposited more kidney knob and channel fat than lambs on the asynchronous or intermediate diets (P < 0.05), whereas lambs fed the barley-based diets deposited more carcass (P < 0.05) and noncarcass (P < 0.001) fat than lambs on the sugar beet-based diets. Lambs fed the asynchronous diets retained less energy over the course of the experiment than lambs on the intermediate or synchronous diets (P < 0.05), and had a lower energy efficiency (0.079, 0.097, and 0.093 MJ retained/ MJ of intake, respectively, P < 0.05). Lambs fed the barley-based diets retained more energy than lambs on the sugar beet-based (P < 0.001) and had a higher energy balance (0.095 vs. 0.084 MJ retained/MJ intake, respectively; P < 0.01). Plasma ammonia concentrations mirrored ruminal ammonia concentrations on the barley-based diets, but not sugar beet-based diets. In Exp. 3, lambs fed the sugar beet-based diets had a higher digestibility of OM and NDF (P < 0.001). By contrast, lambs on the barley-based diets had a higher level of purine derivative excretion and microbial N production (P < 0.001). The results indicate that neither dietary synchrony nor energy source significantly influenced growth rate. However, both the asynchronous and sugar beet pulp-based diets resulted in a lower efficiency of dietary energy use, and the avoidance of asynchronous patterns of nutrient release within the rumen can improve energy efficiency in growing lambs.     

铜水平对幼兔早期生长及毛皮的影响

选４０日龄断乳幼兔２４只（公母各半），按二元配置法随机分成４组进行试验。在基础日粮含铜１４．２１ｍｇ／ｋｇ基础上，添加硫酸铜（ＣｕＳＯ４·５Ｈ２Ｏ）使其铜水平分别为２４．２１、４４．２１、６４．２１ｍｇ／ｋｇ。结果表明：各组日增重效果差异不显著（Ｐ＞０．０５），饲料报酬提高不明显（Ｐ＞０．０５）；不同水平铜对兔毛生长有影响（ｒ＝０．８８６），与兔皮的厚度呈负相关（ｒ＝－０．５２６）；兔毛和兔粪中含铜量随日粮铜水平提高而增大，相关系数分别为０．９０４和０．９９２。     

Intake of Essential Fatty Acids by Growing-Finishing Pigs Kept on Smallholdings in Central Vietnam

The intake of linoleic acid (LA) and alpha-linolenic acid (ALA) in relation to average daily weight gain (ADG) was studied in growing-finishing pigs kept on smallholdings in Central Vietnam. Groups of three piglets each were assigned randomly to 12 farms, where they were fed on local feedstuffs according to the farmer's choice but were given a restricted amount of dry matter according to a preset feeding regimen. On arrival at the farms, the pigs weighed 10.4 +/- 0.9 kg (mean +/- SD, n = 36) and at 130 days of age they weighed 45.4 +/- 9.6 kg. Dietary LA concentration ranged from 1.34 to 2.41 g/MJ metabolizable energy (ME) and ALA from 0.06 to 0.33 g/MJ ME. On a farm level, dietary LA and ALA concentrations were significantly correlated with their concentrations in adipose tissue, both correlation coefficients being 0.63. Dietary protein concentration and protein:energy ratio were significantly correlated with ADG, the correlation coefficients being 0.68 and 0.64. For individual piglets there were significant correlations between either LA or ALA in adipose tissue and ADG, the correlation coefficients being 0.37 and 0.45. Dietary protein concentration or protein:energy ratio was correlated with the dietary contents of LA and ALA. It is uncertain whether LA and ALA intake had a causal relationship with ADG. Since dietary LA levels were above the LA requirement, LA intake may not have limited growth. It is suggested tentatively that, through enhanced disease resistance, supplementation with ALA of the diets on the farms studied might have a positive influence on ADG.