生长肥育猪营养需求模式试验

本试验设置三个营养水平验证20～35kg、35～60kg和60～90kg三个阶段杜×大×长肉猪的营养需求.试验结果表明,三个阶段各组的采食量无显著差异(p＞0.05).三个阶段高能组和中能组的日增重极显著(p＜0.01)或显著(p＜0.05)高于低能组,饲料转化率均极显著(p＜0.01)或显著(p＜0.05)优于低能组.在20～35kg阶段,高能组和中能组的日增重差异不显著(p＞0.05),但料重比的差异极显著(p＜0.01).在35～60kg阶段,高能组和中能组的日增重和料重比差异均不显著(p＞0.05).在60～90kg阶段,高能组和中能组的日增重和料重比差异均显著(p＜0.05).同时,用超声波测膘仪测量了猪的膘厚和眼肌深度,推算出胴体无脂瘦肉日增重.在20～60kg阶段,高能组和中能组极显著高于低能组(p＜0.01),高能组显著高于中能组(p＜0.05).在60～90kg阶段,高能组和中能组极显著高于低能组(p＜0.01),高能组和中能组差异不显著(p＞0.05).在20～90kg整个试验过程,高能组和中能组极显著高于低能组(p＜0.01),高能组和中能组差异不显著(p＞0.05).试验的结果显示NRC(1998)模型估测值基本符合我国瘦肉型肉猪生长需要,具有一定的实用价值,但对能量的估测值偏高,以本试验中能组的13.6MJ／kg比较符合我国的生产实际.     

The vitamin A requirement of fattening cairina

In two experiments with 420 male cairina (Cairina moschata domestica L.) semisynthetic rations were used with vitamin A supplements between 0 and 10,000IU per kg feed. Clinical deficiency symptoms, such as coordination disturbances or horny growths at the oesophagus glands, could be prevented in the starter period up to 3rd week with 500IU vitamin A and in the fattening period between the 4th and 10th/11th weeks with a 250IU vitamin A supplement per kg feed. Cairina achieved an optimal fattening performance under the conditions tested with 1,000 IU in the starter period and with 500 IU vitamin A supplement in the fattening period. Under consideration of the vitamin A storage in the liver and a safety supplement of 4000 IU vitamin A per kg start feed (0-3 weeks) and 2,000 IU vitamin A per kg fattening feed (4-11 weeks) is suggested as requirement norm and mixed feed supplement.     

Assessment of the minimum protein requirement of adult ponies

The aim of the present study was to determine the minimum protein requirement in adult ponies. Literature data from nitrogen-balance trials in adult ponies were used. In addition, nitrogen balance was measured in three mature ponies that were fed a low- and a high-protein diet according to a cross-over design. On the low-protein ration, which provided 1.1 g digestible crude protein (DCP)/kg(0.75) day, plasma albumin and total protein concentrations were non-significantly decreased by about 6% and group-mean nitrogen balance was negative. Using data from the present experiment and from six other studies, the sum of endogenous faecal and urinary nitrogen losses was calculated to be 166 +/- 37 mg/kg(0.75) day (mean +/- SE, n = 13). Subsequently, a minimum protein requirement of 1.7 g DCP/kg(0.75) day was calculated. The value for minimum protein requirement has low precision, which should be taken into account when setting the protein allowance of adult ponies.     

The vitamin A requirement and the vitamin A status of growing cattle. 1. Studies of calves

Five experiments with 18 to 36 male calves each of the black and white dairy cattle breed (age: 14-21 days, initial live weight: approximately 45 kg per animal) were carried out in order to investigate the influence of various vitamin A supply (0-80,000 IU per 100 kg LW and day) on dry matter intake and weight gain as well as the vitamin A status of liver and blood plasma over 84 days. The calves consumed a diet free of carotene and vitamin A consisting of milk replacer, concentrate and chopped wheat straw. The calves were fed in three experiments for a longer time in order to observe the further vitamin A depletion. Nine animals consumed an unsupplemented ration, nine other one got 10,000 IU vitamin A per 100 kg LW and day. Biopsies of liver and plasma samples were taken from 4 animals per group every four weeks. The various vitamin A supplementation did not significantly influence the dry matter intake (Mean: 1.67; 1.48 to 1.80 kg DM per animal and day) and the weight gain of calves (Mean: 702, 599 to 770 g per animal and day). First vitamin A deficiency symptoms (reduced feed intake, decreased weight gain, diarrhoea etc.) were observed in animals of unsupplemented group after 100 days of experiments. After 84 days the vitamin A concentration of liver of animals of unsupplemented groups decreased to 1.3-32.2% compared with the begin of experiments (60.6-155.7 mumol/kg fresh matter). Up to 51% of initial concentration were found when 10,000 IU vitamin A per 100 kg LW and day were fed. About 25,000 IU vitamin A per 100 kg LW and day were required in order to keep the initial level of vitamin A concentration of liver. The plasma vitamin A concentration is unsuitable for estimation of vitamin A status of calves. The concentration of vitamin A of liver and plasma amounted to 114 mumol per kg and 0.25 mumol per litre at the begin of experiments. The vitamin A concentration of liver of unsupplemented group decreased to 20 mumol per kg, that of plasma increased to 0.28 mumol per 1 at the end. A strong vitamin A deficiency (liver concentration: less than 10 mumol/kg) may cause a decrease of vitamin A concentration of blood.     

不同淀粉源日粮添加苹果酸盐对生长育肥羊消化率及代谢的影响

文章旨在研究不同淀粉源日粮(小麦或大麦-木薯型)添加苹果酸盐对生长育肥羊生长性能、消化率及代谢的影响。试验选择平均体重(13.12±0.54)kg的肉羊32只,随机分为4组,每组8个重复,每个重复1只。试验日粮采用2×2因子设计,即2种淀粉来源日粮,小麦型或大麦-木薯型,添加0或2 g/kg苹果酸盐,试验共进行21 d。结果 :日粮添加苹果酸盐显著提高了中性洗涤纤维和苹果酸的摄入量(P <0.05);日粮淀粉类型和添加苹果酸盐对干物质、有机物、粗蛋白质、淀粉和苹果酸的摄入量具有显著交互作用(P <0.05)。日粮添加苹果酸盐显著降低了干物质、有机物的表观消化系数(P <0.05);大麦型-木薯型日粮较小麦型日粮显著提高了干物质和有机物的表观消化系数(P <0.05)。与小麦型日粮相比,大麦型-木薯型日粮显著降低了尿中能量含量(P <0.05);小麦型日粮较大麦型-木薯型日粮日粮显著提高了尿氮含量(P <0.05);日粮淀粉类型和苹果酸盐对氮摄入量、粪氮、可消化氮及氮沉积量的影响有显著交互作用(P <0.05)。结论 :小麦或大麦-木薯型日粮对生长育肥羊的日增重和料重比无显著影响,日粮添加苹果酸盐降低了干物质和有机物的表观消化率。日粮淀粉类型和苹果酸对氮摄入量和氮沉积量的影响具有显著交互效应。     

The vitamin A requirement and the vitamin A status of growing cattle. 2. Studies of fattening cattle

Three long time individual feeding experiments (greater than 258 days) with 48 beef cattle each (dairy breed and beef breed, 50% each) were carried out in order to measure the influence of various vitamin A supply (0, 2,500, 5,000 and 10,000 IU vitamin A per 100 kg body weight and day) on fattening and slaughtering performance, vitamin A concentration of liver and serum as well as carotene concentration of serum. The bulls consumed corn silage (experiments 1 and 2; 9.4 and 18.3 mg carotene per kg dry matter) or NaOH-treated and pelleted straw (experiment 3; no carotene). The roughages were supplemented with 2 (exp. 1 and 2) and 3 kg (exp. 3) concentrate per day. The vitamin A supply of corn silage diet did not significantly influence the dry matter intake (exp. 1: means: 6.95; 6.91 to 7.05; exp. 2: means: 6.54; 6.53 to 6.54 kg dry matter per animal and day) and the daily weight gain of bulls (exp. 1: means: 1076; 1028 to 1157; exp. 2: means: 1058; 1041 to 1057 g per animal). The bulls consumed 8.87 kg dry matter per day, the daily weight gain amounted to 1030 g per animal and day in experiment 3. The bulls of unsupplemented group reduced feed intake and weight gain after 150 days, an additional vitamin A supply was necessary. At the end of experiments 1 and 2 the liver vitamin A concentration of unsupplemented groups amounted to 38.8 and 65.9 mumol/kg, it increased after vitamin A supply (up to 153.4 mumol/kg). Feeding of pelleted straw effected a liver vitamin A concentration lower than 10 mumol/kg except the group supplemented with 10,000 IU vitamin A per 100 kg body weight and day (35.7 mumol per kg fresh matter of liver). The vitamin A concentration of blood is unsuitable for evaluation of vitamin A status of cattle. The carotene content of feeds and level of vitamin A supply determined the carotene concentration of blood. Recommendations for a suitable vitamin A supply of ration of growing cattle were given depending on body weight and type of diet.     

Bioavailability of vitamin E compounds in lambs.

A study was carried out to assess the bioavailabilities of several forms of vitamin E in lambs. A total of 40 lambs was allotted to eight dietary groups of five each and supplemented or not daily for 60 d with equimolar amounts of different vitamin E compounds as follows: 1) control, no supplemental vitamin E, 2) DL-alpha-tocopheryl acetate, 3) D-alpha-tocopheryl acetate, 4), D-alpha-tocopheryl succinate, 5) D-alpha-tocopheryl polyethylene glycol 1,000 succinate (TPGS), 6) DL-alpha-tocopheryl nicotinate, 7) DL-alpha-tocopheryl nicotinate+ TPGS, or 8) D-alpha-tocopheryl acetate + TPGS. During these 60 d, serum alpha-tocopherol concentrations in the control lambs remained constant and lower (P less than .05) than in lambs that received all treatments. Various indices of bioavailability, including Cmax-C(i) (concentration maximum-concentration initial), Ct-C(i) (concentration terminal-concentration initial), areas under the serum concentrations profiles, and pooled increment were higher (P less than .05) with D-alpha-tocopheryl acetate+ TPGS than in the other groups, suggesting a synergism between these forms. No such effect was observed between nicotinate and TPGS. For the TPGS, a water-soluble form of vitamin E, the indices of bioavailability were lower (P less than .05) than for the other groups. D-alpha-tocopheryl acetate resulted in a bioavailability that outranked all the other forms of vitamin E, except those of D-alpha-tocopheryl acetate + TPGS. A slightly higher bioavailability index was observed for D-alpha-tocopheryl succinate than for DL-alpha-tocopheryl nicotinate.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of vitamin A supplementation on postnatal adipose tissue development of lambs

Vitamin A (retinoic acid) is known to be an adipogenic factor influencing both in vitro and in vivo cell development. This study aimed to determine its effect on lamb adipose tissue development during the early phase of postnatal development until 100 d of age. Male lambs (n = 24) of the Rasa Aragonesa breed were used. At birth, lambs were assigned to 1 of 2 experimental groups: 1) the control (C) group, which received feed without vitamin A supplementation, and 2) the vitamin A (V) group, which received a supplement of 500,000 IU/animal twice per week from birth to slaughter. The effect of vitamin A supplementation was studied at 16.8 +/- 0.35 kg of BW (58 +/- 0.7 d of age) and at 27.8 +/- 0.78 kg of BW (101 +/- 6.5 d of age). The variables of lamb growth, carcass, LM area, and lipid content were analyzed. To study adipose tissue development, the amount of adipose tissue accumulated, the size and number of adipocytes, and lipogenic enzyme activities (glycerol 3-phosphate dehydrogenase, fatty acid synthase, and glucose 6-phosphate dehydrogenase) of the omental, perirenal, and s.c. depots were quantified. Results showed that vitamin A supplementation had no influence on growth, carcass variables, LM area, and lipid content during lamb growth but that the number of adipocytes in the perirenal depot was 30% greater in lambs of the V group (P < 0.05) and that these lambs had smaller adipocytes in the omental and perirenal depots (P = 0.06) at 28 kg of BW (101 d of age). These results suggest that the intake of this level of vitamin A during the whole period of growth of the lambs influenced the processes of hyperplasia and hypertrophy in the different adipose depots, depending on their degree of maturity.     

Effect of vitamin D supplementation during pregnancy on the vitamin D status of ewes and their lambs

Pregnant ewes were injected intramuscularly with 300,000 iu of vitamin D3 in a water miscible vehicle either 10, seven or four weeks before the expected lambing date and the effects on plasma concentrations of 25-hydroxyvitamin D3 were monitored. The concentrations increased quickly and remained high at parturition but at no time were they outside the normal physiological range. The concentrations in the plasma of the newborn lambs were higher than in uninjected controls and were well correlated with the concentrations in their mothers. Dosing pregnant ewes with 300,000 iu of vitamin D3 in a rapidly available form, approximately two months before lambing, provided a safe means of increasing the vitamin D status of the ewe and the newborn lamb by preventing the seasonally low concentrations of 25-hydroxyvitamin D3.     

Vitamin A requirement of growing swine. 2. Effect of the vitamin A supply on the vitamin A concentrations in the liver and plasma of piglets and fattening swine

In 9 experiments the vitamin A content of the livers of 64 newborn (still births and deaths up to 48 h p.p.) and 69 weaned piglets, 122 growers and 110 fattening pigs was investigated after slaughtering or autopsy. Liver samples were taken from 78 growers by means of biopsy after latarotomy. A fluorometric analysis of the plasma vitamin A level was made. At the time of birth the vitamin A content of the piglet livers was less than 100 IU/g and did not show any differences between the experiments. At the time of weaning, however, the livers of piglets from large-scale production showed a three times higher content (175 IU/g liver) in comparison to those from traditional production. Highly significant linear relations were established between the vitamin A content of the feed and the liver. According to these, a liver content of vitamin A of approximately equal to 30 IU/g is ensured by approximately equal to 2,000 IU in weaning piglets and by approximately equal to 800 IU vitamin A/kg feed in fattening pigs. The vitamin A activity of the beta-carotene in weaners was ascertained as less than 100 IU/mg. The plasma vitamin A level indicated the vitamin A status only in the range of deficient supply. A different plasma content could not be detected between 1,000 and 4,000 IU vitamin A/kg feed. According to this, a semilogarithmic relation was calculated according to the model of a saturation curve between the vitamin A content of the plasma and the liver. The threshold value for the decrease of the plasma level under 45 IU vitamin A/dl is 35 IU/g liver. Due to the low definiteness measure (B = 0.52) the relation cannot be applied to the individual animal. A contamination of 1,000 mg nitrite/kg feed had a low, and in the course of the experiment decreasing, influence on the vitamin A content of plasma and liver.     

欧亚鲈幼鱼饲料中维生素C适宜含量的研究

选用初始体质量为(7.46±0.29)g的欧亚鲈幼鱼为试验对象,投喂6种不同水平的维生素C(0、50、100、200、400和800 mg/kg)的试验饲料,饲养8周,探讨欧亚鲈幼鱼饲料维生素C的适宜含量。结果表明,饲料中维生素C添加量从0.0升高到100 mg/kg时,鱼体增重率呈上升趋势,添加量为100 mg/kg显著高于对照组(P<0.05),但添加量继续增大,对鱼体增重率无显著变化(P>0.05);经折线模型分析表明,欧亚鲈鱼种达到最大生长时,饲料中的维生素C的最低添加量为93.58 mg/kg。欧亚鲈肝脏中维生素C含量随着饲料中维生素C(0～200 mg/kg)的增加而显著升高(P<0.05),但添加量继续升高,则肝脏中维生素C达到饱和状态,经折线分析表明,肝脏中维生素C达到饱和时,饲料中的维生素C的最低添加量为149.27 mg/kg。急性胁迫前,各组血糖之间无显著差异(P>0.05),急性胁迫后,血糖升高峰值最低和恢复最快的是饲料中维生素C为400～800 mg/kg。在本试验条件下,欧亚鲈幼鱼达到最大生长、肝脏维生素C饱和及抗拥挤胁迫的维生素C适宜添加量分别为93.58、149.27 mg/kg和400 mg/kg。     

The optimal vitamin B 6 requirement of early weaned piglets

In a two-period rearing trial (1st to 24th and 24th to 45th experimental day) using 72 early-weaned piglets, the optimal vitamin-B6 requirement was determined on the basis of different performance criteria and biochemical parameters. In the corresponding live weight ranges of 3.5 to 10 kg and 10 to 21 kg, the animals allotted in 6 groups were ad lib. fed a prestarter and starter feed, respectively containing 0.5, 1.2, 2.0, 2.8, 3.5 and 6.6 mg vitamin B6 per kg dry matter. For adequate feed intake and weight development, a dietary vitamin B6 content of 2.0 mg/kg and 1.2 mg/kg proved necessary for the 1st and 2nd part of the experiment, respectively. An optimal intermediary metabolic situation and thus an optimum vitamin B6 requirement covering, which was derived from the renal xanthurenic acid excretion and the SGOT activity, was attained only at a vitamin B6 supply level of 3.5 and 2.8 mg/kg for the 1st and 2nd experimental periods, respectively. This corresponds to an average vitamin B6 requirement per animal and day of 0.8 mg for the weight range 3.5 to 10 kg, and of 1.9 mg for the weight range 10 to 21 kg.     

A re-evaluation of the phylogeny of Old World Treefrogs

No consensus has yet been reached concerning Old World treefrog systematics. Competing hypotheses are based on differing and sometimes conflicting methodologies. I use cladistic methodology to reanalyse the data from the two most important recent studies. Two monophyletic groups result; Rhacophoridae and Hyperoliidae. Seven subfamilies are recognized; six are monophyletic (Hyperoliidae: Hyperoliinae, Kassininae, Leptopelinae, Tachycneminae; Rhacophoridae: Buergeriinae, Mantellinae), while the Rhacophorinae are polyphyletic. The taxonomic changes from the standard Amphibian Species of the World (Frost 1985) proposed are: Acanthixalus is removed from the Leptopelinae and placed in the Hyperoliinae. Tachycnemis is removed from the Hyperoliinae and placed in its own subfamily, Tachycneminae. Opisthothylax is removed from the Hyperoliinae and placed in the Kassininae. Afrixalus and Kassinula are removed from the Kassininae and placed in the Hyperoliinae. Aglyptodactylus is removed from the Rhacophorinae and placed in the Mantellinae. Buergeria is placed in the subfamily Buergeriinae. The Mantellinae, previously in the Ranidae, is demonstrated to be a subfamily within the Rhacophoridae. The biogeography of the group is interpreted in terms of a simplified area cladogram. The most parsimonius vicariance hypothesis proposes that the stock leading to the Hyperoliidae and Rhacophoridae existed before Pangaea broke up. The sequence of fragmentation events leading to the present-day distribution started with the Seychelles, then Asia split from Africa+Madagascar, and finally Africa and Madagascar separated.