Energy digestibility of giant pandas on bamboo‐only and on supplemented diets

Endangered giant pandas (Ailuropoda melanoleuca) are bears (Family Ursidae), within the order Carnivora. They specialize on an herbivorous diet of bamboo yet retain a gastrointestinal tract typical of their carnivorous ancestry. The evolutionary constraints of their digestive tract result in a low extraction efficiency from bamboo (<40% in reported studies). The goal of this study was to determine the energy digestibility of bamboo by giant pandas used in digestibility trials and through subsequent analyses with bomb calorimetry. Seven digestibility trials were conducted (three with bamboo‐only diets and four with supplemental diets). Energy digestibilities ranged from 7.5–38.9% for mixed diets and 9.2–34.0% for bamboo‐only diets. The bamboo‐only trials summarized here represent, to our knowledge, the first empirical data available for energy digestibility on a bamboo diet for giant pandas. Zoo Biol 30:121–133, 2011. © 2010 Wiley‐Liss, Inc.     

Study of crude protein intake and growth response in captive subadult giant pandas (Ailuropoda melanoleuca)

Feeding trials were conducted on seven subadult giant pandas (1.5–4.7 years old). The giant pandas consumed diets with 20 various levels of crude protein (CP): 132.9, 186.8, 206.0, 233.1, 251.4, 255.2, 288.5, 290.8, 299.1, 334.6, 370.7, 378.7, 379.9, 399.2, 372.6, 411.4, 436.1, 484.4, 509.3, and 563.7 g/day. According to the differences in the body weight (BW) gain (weight/month (W/M)) and the amounts of ingested CP, subadult giant pandas are divided into at least three age groups: 1.5–2.0, 2.5–3.9, and 4.0–4.7 years. Although there apparently is no direct relationship between the ΔW/M and the CP consumed by all the giant pandas, a linear relationship existed between the square root of CP ingested (g) per unit BW (W^0.75, Kg) and weight gain per month (ΔW/M, Kg/M) of giant pandas aged 1.5–2.0 years. No such relationship existed in the giant pandas aged 2.5–4.7 years, but ΔW/M decreased with the increasing CP per unit gross energy (GE) consumed (CP/GE). For the 1.5–2.0‐year‐old giant pandas, CP for maintenance was determined at 3.6576 g/Kg W^0.75/day when ΔW/M was 0, and CP for growth was 1.7541 g/Kg W^0.75/day when ΔW/M was equal to 1 Kg/M; thus, suitable intake of total CP is 9.95 g/Kg W^0.75/day. The average value of ingested CP was 13.54 ± 3.01 g/KgW^0.75/day for 2.5–3.9‐year‐old pandas, and 12.25 g/KgW^0.75/day for 4.5–4.7‐year‐old pandas. Zoo Biol 21:223–232, 2002. © 2002 Wiley‐Liss, Inc.     

Composition of captive giant panda milk

Eleven milk samples were collected from three female giant pandas (Ailuropoda melanoleuca) during 23 days after delivery. Concentrations of crude protein (CP), lactose (Lac), and three vitamins (VA, VD, VE) in these samples were tested. Concentration of CP, Lac, VA, VD, and VE of these samples in wet basis averaged 6.77±0.78%, 3.23±0.54%, 0.073±0.043 mg/L, 0.24±0.08 mg/L, and 6.76±1.01 mg/L, respectively. Results demonstrated that nutrients concentrations of milk samples had no significant difference among different pandas (P>0.05). The average content of milk protein between 3–6 days and 7–23 days had significant difference (P<0.01). Results indicate that panda milk is similar to that of other carnivores. It has higher protein but lower lactose than milk in domestic ungulates and humans. Zoo Biol 0:1–6, 2005. © 2005 Wiley‐Liss, Inc.     

降低圈养大熊猫排粘液频率的措施初探

大熊猫(Ailuropoda melanoleuca)是中国特有的珍稀动物,在其整个消化道内膜上,都分布有丰富的粘液腺。在野外,这些粘液腺的分泌物包裹于大熊猫摄食的竹茎、竹叶和竹笋表面而排出体外;圈养条件下,常常见到这些分泌物积聚到一定数量而成团排出,这即被称为大熊猫的排粘液现象(王平     

Behavioral preferences for bamboo in a pair of captive giant pandas (Ailuropoda melanoleuca)

Giant pandas (Ailuropoda melanoleuca) are members of the order Carnivora. Their diet, however, consists almost entirely of bamboo. Herbivores are under strong pressure to be selective in what they eat because of the low digestibility of plant material. The purpose of this study was to determine whether two captive giant pandas exhibited preferences among three species of bamboo: black (Phyllostachys nigra), bissetii (Phyllostachys bissetii), and arrow (Pseudosasa japonica). Eighteen classic choice trials were conducted in which the species were randomly paired and placed in one of two predetermined locations in the giant pandas' indoor enclosures. The pandas preferred leaves to culms or branches for each bamboo species. In the first hour of exposure, both pandas exhibited a preference for arrow bamboo. A comparison of total bamboo consumption over the course of the night indicated a strong preference for arrow bamboo by the male. The female exhibited equal preference for both arrow and bissetii over black bamboo. Further examination of feeding behavior determined that the pandas processed arrow bamboo behaviorally more efficiently than the other two species. This is the first study to experimentally assess bamboo preferences in giant pandas, and may have implications for husbandry and management programs as well as strategies for in situ conservation. Zoo Biol 24:177–183, 2005. © 2005 Wiley‐Liss, Inc.     

Seasonal shifts in giant panda feeding behavior: relationships to bamboo plant part consumption

The giant panda (Ailuropoda melanoleuca) is classified as a carnivore, yet subsists on a diet comprised almost exclusively of bamboo. Wild and captive giant pandas use highly selective foraging behaviors for processing and consuming bamboo. These behaviors are for the first time quantified in captive giant pandas over a 5‐year period of time showing highly specific seasonal trends. Giant panda feeding behavior was recorded using live video observations of two giant pandas housed at the Memphis Zoo from November 2003 to June 2008. Leaf was the primary plant part consumed from June to December, whereas culm was consumed primarily from February to May, with both bears displaying similar seasonal shifts in plant part consumption. From May to June, leaf consumption increased significantly (P‐values<0.001); from June to August, leaf consumption remained high and stable. From December to March, leaf consumption decreased significantly (P‐values<0.001). Specific behaviors for bamboo leaf and culm consumption were also observed. Both bears formed wads of leaves before ingestion while feeding on leaf, but the male employed this feeding behavior more often than the female (54 and 33%, respectively). Both bears used similar culm‐stripping behavior (26 and 25%), used to remove the outer layer and isolate the pith for consumption. This study indicates that unique seasonal foraging behaviors observed in wild pandas are also apparent in captive animals in relation to plant part selectivity and feeding behaviors. Zoo Biol 29:470–483, 2010. © 2009 Wiley‐Liss, Inc.     

Preliminary investigation on iodine nutrition in captive giant pandas

Background/ObjectiveThe giant panda belongs to the family Ursidae and, as a species of bear, still retains the simple digestive system of a Carnivoran. However, under the pressure of a specific habitat they had to adapt to a plant mono-diet consisting of bamboo with different species and growth stages around the year. A plant-based diet has relatively low iodine content with risk of iodine deficiency. Furthermore, bamboo contains cyanogenic glycosides releasing cyanide whose detoxification metabolite the thiocyanate acts as antagonist against iodine uptake and storage in the thyroid. To date very little is known about the iodine nutritional status of the giant panda, thus this study was conducted to receive the first information about the iodine nutrition of captive giant panda.Subjects/MethodsHere we investigated the iodine content of bamboo with different plant parts/vegetation stage and species and further compounds of the captive giant panda diet. Next, the urinary iodine (UI) and urinary thiocyanate (UT) levels of infant, sub-adult, adult and geriatric captive giant pandas was measured during the periods when the pandas consume both bamboo leaves- and culm (bamboo leaf-culm stage). Afterwards, the UI of 19 adult giant pandas was measured again for the different iodine intake during bamboo shoot stage. Finally, in this study part also the fecal iodine concentration was analyzed for calculation of total iodine excretion in relation to the iodine intake.ResultsBamboo leaves had the highest iodine content (453 μg/kg dry matter (DM)), followed by the shoots (84 μg/kg DM, p < 0.05), while bamboo culm had the lowest value (12 μg/kg DM, p < 0.05). During bamboo leaf-culm stage, giant pandas of different age groups had different UI and UT levels (p < 0.05). Furthermore, UI and UT were positively correlated among sub-adult, adult and geriatric giant pandas (p < 0.05). In adult giant pandas during bamboo shoot stage, the iodine excretion in feces was not different from that in urine while their total iodine excretion was less than their iodine intake (p < 0.05). Moreover, during bamboo shoot stage, the UI level of adult giant pandas was much lower than noted during bamboo leaf-culm stage (p < 0.05).ConclusionsOur results indicate that UI of captive giant pandas was related to their age as well as to the vegetation stage/part of bamboo they consumed reflecting a different periodic iodine supply. Thiocyanate and fecal excretion should be emphasized when considering the iodine nutrition of giant pandas.     

圈养大熊猫食谱组成与营养成分分析

为了探讨圈养大熊猫主食竹食谱组成及主要影响因素,并为圈养单位提供科学合理的食物营养配比和饲养管理建议。本研究通过对成都大熊猫繁育研究基地１０ 只成年大熊猫４ 年（２００９. ０３ －２０１３.０２）的饲养数据,３只成年大熊猫１ 年（２０１２. ０７ －２０１３. ０６）的觅食行为观察数据,以及投饲的３ 种竹笋和５ 种主食竹常规养分和总黄酮含量的统计分析。结果发现,基地圈养大熊猫偏好竹笋,喜食巴山木竹叶、白夹竹茎和苦竹茎,随机采食箬竹叶和刺竹茎;基地大熊猫根据投饲竹种类和季节的变化,形成了较为稳定的食谱组成;对投饲竹各部位成分比较分析发现,投饲竹养分含量的变化呈现出一定的规律性：其中粗蛋白、粗脂肪、蛋白质和能量比都以竹叶最高,竹枝次之,竹茎最低;干物质和粗纤维的含量则以竹茎最高,竹枝次之,竹叶最少;竹茎和竹枝呈现钙少磷多的现象,而竹叶则是钙多磷少;各投饲竹不同部位总黄酮含量以叶中最高,枝中其次,茎中最低。研究结果表明,圈养大熊猫主食竹食谱的选择遵循能量和营养学的规律,选择适口性强、营养价值高的食物假说。     

Complete nutrient composition of commercially raised invertebrates used as food for insectivores

A variety of invertebrates are commonly fed to insectivorous animals by both zoos and hobbyists, but information as to the nutrient composition of most commercially raised species is limited. Adult house crickets, house cricket nymphs (Acheta domesticus), superworms (Zophobas morio larvae), giant mealworm larvae, mealworm larvae and adult mealworms (Tenebrio molitor), waxworm larvae (Galleria mellonella), and silkworm larvae (Bombyx mori) were analyzed for moisture, crude protein, crude fat, ash, acid detergent fiber (ADF), neutral detergent fiber (NDF), minerals, amino acids, fatty acids, and vitamins. Earthworms (Lumbricus terresstris) were analyzed for moisture, crude protein, crude fat, ash, ADF, NDF, minerals, amino acids, and vitamins A and D₃. Proximate analyses were variable, with wide ranges found for moisture (57.9–83.6%), crude protein (9.3–23.7%), crude fat (1.6–24.9%), ADF (0.1–7.4%), NDF (0.0–11.5%), and ash (0.6–1.2%). Energy content ranged from a low of 674 kcal/kg for silkworms to 2,741 kcal/kg for waxworms.Using an amino acid scoring pattern for rats, the first limiting amino acid for all invertebrates tested was the total sulfur amino acid methionine+cystine. Deficiencies by nutrient (% of samples deficient vs. NRC requirements for rats on a dry matter (DM) basis) were as follows: calcium (100%), vitamin D₃ (100%), vitamin A (89%), vitamin B₁₂ (75%), thiamin (63%), vitamin E (50%), iodine (44%), manganese (22%), methionine‐cystine (22%), and sodium (11%). Deficiencies by invertebrate species (number of nutrients deficient vs. the NRC requirements for rats on a DM basis) were as follows: waxworms (9), superworms (8), giant mealworm larvae (7), adult mealworms (6), mealworm larvae (5), adult house crickets (4), house cricket nymphs (4), silkworms (4), and earthworms (4). These data provide a basis for determining nutrient intake of captive insectivores, and will aid in the development of gut‐loading diets to provide captive insectivorous animals with appropriate levels of necessary nutrients. Zoo Biol 21:269–285, 2002. © 2002 Wiley‐Liss, Inc.     

臭氧处理对圈养大熊猫食用竹笋的保鲜

<正>竹笋是大熊猫(Ailuropoda melanoleuca)最为喜爱的天然食物。竹笋相对于竹叶和竹茎含水量更丰富,粗纤维含量更低,适口性更好;大宗养分、微量元素、必需氨基酸等含量丰富(周昂等,1996;唐平等,1997;周材权等,1997),而丹宁等具有微毒性的次生代谢物含量却最少(赵晓红等,2001),更利于大熊猫对生活必需营养的吸收     

Dietary vitamin and mineral concentrations of two juvenile female giant pandas (Ailuropoda melanoleuca)

During a 7 mo exhibit loan, diets of two juvenile female giant pandas (Ailuropoda melanoleuca) were monitored. Mineral [calcium (Ca), copper (Cu), phosphorus (P), potassium (K), zinc (Zn)] and vitamin (beta-carotene and total tocopherol) concentrations in the diet were quantified as well as in a serum sample obtained from one of these animals. Diets consumed by the pandas contained (dry matter basis): 0.82% Ca, 0.62% P, 1.05% K, 14.3 mg/kg Cu, 31.8 mg/kg Zn, 12.2 mg/kg beta-carotene, and 12 mg/kg total tocopherol. Serum values for these vitamins and minerals were within reported normal limits for the spectacled bear (Tremarctos ornatus). This diet appeared to provide adequate nutrition for maintenance and growth.     

The utilization of canola and its constituents by lactating dairy cows

Three feeding trials and one nylon bag trial were conducted to determine the effect of supplementing a barley-based control diet with 3.5% canola oil (CO), 22% presscake (CPC) or 9% whole seed (WCS) on feed intake, digestibility, milk yield and composition of lactating dairy cows. Ruminal utilization of canola meal (CM), CPC and WCS was also determined. Increasing the level of fat in the diet had no significant effect on intake of concentrate or digestible energy, or on total tract digestibility of dry matter (DM), crude protein (CP) and acid detergent fibre. Addition of canola in the form of CPC and WCS gave greater energy and ether extract digestibility than C and CO (P < 0.05). Diet had no significant effect on milk production, yield of milk CP, milk lactose + ash, gross energetic efficiency of milk production, milk urea or minerals. Milk fat and 4% fat corrected milk (FCM) yield were similar with the C and CPC diets, and with the CO and WCS diets. But the CO and WCS diets gave less milk fat and FCM than the C diet (P < 0.05). Milk crude protein was higher (P < 0.05) on the WCS diet than on the C, CO and CPC diets, which were similar. Diets WCS, C and CO promoted similar levels of blood urea (BU) but BU levels with CPC and CO were lower than with the C diet (P < 0.05). Ruminal DM and CP disappearance of CM was lower than for WCS and CPC at all incubation times (P < 0.05).     

Effect on digestion and performance of dietary protein content and of increased substitution of lucerne hay with soya-bean protein concentrate in starter diets for young rabbits

The aim of this work was to study the effect of protein source / availability on the intestinal microbiota, digestive traits and nutritional performance of early-weaned rabbits. The effects of supplemental antibiotics in the drinking water were also evaluated. Four isoenergetic and isofibrous diets were formulated: a control diet with a high protein (207 g/kg dry matter (DM)) and lucerne hay content (HPHL), a diet with low crude protein (CP) (179 g/kg DM) and high lucerne hay content (LPHL) and low protein diets in which the lucerne hay in diet LPHL was replaced partially (LPML) or totally (LPLL) with soya-bean protein concentrate. Rabbits, weaned at 25 days (52 per diet), were fed the experimental diets for a 2-week period and thereafter received a commercial diet until 56 days of age. The incidence of mortality was investigated using 70 animals per diet without supplemental medication. The profile of the ileal microbiota was studied at 35 days of age in rabbits treated (18 per diet) or not (12 per diet) with antibiotic. As expected, supplementation with antibiotics effectively reduced fattening mortality rate and microbial biodiversity. However, lowering of also the dietary CP content led to a reduction in the mortality rate ( P < 0.05), both in animals treated with (by 80%) or without (by 39%) antibiotics. In addition, there was a reduction ( P < 0.05) in the frequency of Clostridium perfringens in non-medicated animals. Neither jejunal morphology nor growth performance, over the whole fattening period, was affected by dietary CP content of the experimental diets. However, with HPHL, feed efficiency was higher (by 4.8%; P < 0.01) than with LPHL diets. Substitution of lucerne hay with soya-bean meal in low protein diets did not affect apparent faecal or ileal digestibility of DM and CP. However, the ileal digestibility of cystine, alanine, aspartic acid, and proline was lowered ( P < 0.05) with increasing substitution by soya bean. Nevertheless, ileal CP flow, incidence of mortality and presence of C. perfringens were unaffected. Our results suggest that a reduction in dietary CP, resulting in reduced lumenal flows of nitrogen through the ileum, may be beneficial for young rabbits and limit the numbers of potentially harmful bacteria in the lower gut. Modulation of dietary CP should be contemplated as a strategy to increase the intestinal health in rabbits.     

相岭山系大熊猫的营养和能量对策

１９９４年至１９９６年,在冕宁县冶勒自然保护区设点,对相岭山系大熊猫的营养和能量利用进行了研究。研究结果表明,该山系的大熊猫不仅能消化食物中的粗蛋白和粗脂肪,也能部分消化半纤维素。当以秆叶为食时,其粗蛋白、粗脂肪和半纤维素消化率分别为６１．５％、５０．３％和２３．３％;而当以竹笋为食时,消化率分别为７１．９％、６１．５％和２９．６％;对竹笋中营养养物质的利用率高于秆叶。由于不同季工节食物组成、干物     

Feed intake,diet utilization,and composition of browses consumed by the Sumatran rhino (Dicerorhinus sumatrensis) in a North American zoo

The Sumatran rhino (Dicerorhinus sumatrensis), presently indigenous to the Malay peninsula and the islands of Sumatra and Borneo, is faced with extinction. It is estimated that fewer than 400 individuals still exist in the wild. In response, concerted efforts have been made to maintain and breed this species in captivity, and proper diet and nutrition underlie reproduction. The present feeding trial characterizes a diet fed to three Sumatran rhinos at the Cincinnati Zoo and Botanical Garden. The diet consists of mixed alfalfa/orchard grass hay, a variety of browses, grain pellets, produce (apples and bananas), and a vitamin E supplement. All three rhinos maintained body weight (614–761 kg), regular patterns of bowel movements, and fecal consistency and composition throughout the three 5‐day trials. Dry matter intake (DMI) ranged from 1.40 to 2.49% of body mass. Browse contributed by far the majority of nutrients to the diets in this study, from 62 to 83% of DMI. The nutrient composition of six species of subtropically grown browses (two from differing locations, for a total of eight browses characterized) showed that leaves did not differ from twigs in water or lignin content, but leaves contained higher concentrations of protein (both crude and bound) and ash, as well as lower fiber fractions. Of the macrominerals analyzed, only phosphorus differed between leaves and twigs, with twigs containing significantly more. No differences were seen between leaves and twigs in iron, molybdenum, or zinc content, but leaves contained lower concentrations of copper and higher concentrations of manganese and selenium compared with twigs from the same plants. Dry matter digestibility averaged approximately 50%. The only overt imbalances detected when comparing rhino diets with nutrient recommendations for domestic equids were excess calcium relative to phosphorus intake and low copper intake. These data, combined with information on native browse composition, intake, and digestibility, should greatly assist in providing suitable diets for this highly endangered species. Zoo Biol 19:169–180, 2000. © 2000 Wiley‐Liss, Inc.     

Effects of increasing amounts of hempseed cake in the diet of dairy cows on the production and composition of milk

This study explored the potential for using seed cake from hemp (Cannabis sativa L.) as a protein feed for dairy cows. The aim was to evaluate the effects of increasing the proportion of hempseed cake (HC) in the diet on milk production and milk composition. Forty Swedish Red dairy cows were involved in a 5-week dose-response feeding trial. The cows were allocated randomly to one of four experimental diets containing on average 494 g/kg of grass silage and 506 g/kg of concentrate on a dry matter (DM) basis. Diets containing 0 g (HC0), 143 g (HC14), 233 g (HC23) or 318 g (HC32) HC/kg DM were achieved by replacing an increasing proportion of compound pellets with cold-pressed HC. Increasing the proportion of HC resulted in dietary crude protein (CP) concentrations ranging from 126 for HC0 to 195 g CP/kg DM for HC32. Further effects on the composition of the diet with increasing proportions of HC were higher fat and NDF and lower starch concentrations. There were no linear or quadratic effects on DM intake, but increasing the proportion of HC in the diet resulted in linear increases in fat and NDF intake, as well as CP intake (P < 0.001), and a linear decrease in starch intake (P < 0.001). The proportion of HC had significant quadratic effects on the yields of milk, energy-corrected milk (ECM) and milk protein, fat and lactose. The curvilinear response of all yield parameters indicated maximum production from cows fed diet HC14. Increasing the proportion of HC resulted in linear decreases in both milk protein and milk fat concentration (P = 0.005 and P = 0.017, respectively), a linear increase in milk urea (P < 0.001), and a linear decrease in CP efficiency (milk protein/CP intake; P < 0.001). In conclusion, the HC14 diet, corresponding to a dietary CP concentration of 157 g/kg DM, resulted in the maximum yields of milk and ECM by dairy cows in this study.     

Determining nitrogen requirements of Aceros and Buceros hornbills

Over 2 months, seven feeding trials were conducted at St. Catherines Island, GA, to quantify protein intake and utilization in captive mature nonreproducing Aceros (n=3 spp.) and Buceros (n=2 spp.) Hornbills were fed homogeneous isocaloric diets. A mixture of Bird of Paradise pellets, grapes, and raisins was offered to the birds as grape‐sized balls, supplemented with diced cantaloupe melon to maintain hydration. To vary the protein level (range 10.8–22.6%) within the diets, different amounts of a powdered soy protein supplement were added to the mixture. Test diets were fed for 3 consecutive days. Birds were weighed to test for differences among diets. All excreta and diet samples were collected for nitrogen (N) analysis. Feeding trials were separated by a 4‐day period, in which the bird's regular diet was fed. Data were analyzed for N balance, N equilibrium (regression of N intake vs. N excretion) and body mass. Regression analysis of N balances of the nine birds showed that the N equilibriums ranged from 0.081 to 0.595 g N/kg^0.75/d with an average of 0.387±0.298. No differences in N balances were found between Aceros and Buceros hornbills. The methodology of this study suggested a dietary crude protein (CP) requirement of 7.3±3.0% dry matter (DM) in a diet containing 4.0 kcal. However, this value was determined by extrapolation and has not been experimentally determined to be adequate. In this study, the hornbills maintained body mass on a diet containing 10.8% CP (with energy at 4.0 kcal/g DM). Zoo Biol 27:282–293, 2008. © 2008 Wiley‐Liss, Inc.     

Effects of fibre concentration of diets consisting of hay and slowly degradable concentrate on ruminal fermentation and digesta particle size in mid-lactation dairy cows

Four multiparous ruminally cannulated Holstein cows (mean bodyweight [BW] 615 kg) in mid-lactation (103 days in milk and 32 kg milk x d(-1) at start of the experiment) were used in an one-factorial experiment to evaluate the effects of fibre level (19, 24, 28, 32 and 39% physically effective NDF [peNDF] in dry matter [DM]) in diets consisting of hay and slowly degradable concentrate on rumen fermentation patterns and digesta particle size, under a constant intake level (146 g DM x kg(-0.75). The different fibre concentrations in the diet were achieved by adjusting the hay to concentrate ratio. The above-mentioned levels of peNDF corresponded to 70, 60, 50, 40 and 25% concentrate in diet DM, respectively, and followed the lactation curve of the cows. The ruminal pH was positively and linearly correlated to the percentage of fibre (peNDF, NDF or CF) in ration DM with R2 of 0.76-0.88 (p < 0.001) for solid digesta (particle-associated rumen fluid, PARL), and R2 of 0.26-0.29 (p < 0.05) for fluid digesta (free rumen liquid, FRL). The lowest fibre level in the diet (19% peNDF) or the highest level of concentrate (70% on DM basis) caused pH values lower than 6.0 at almost all sampling times only in PARL but not in FRL, and significantly increased the proportion of large particles in rumen digesta, which in turn was reflected by a depression of fibre digestibility. A level of 24% peNDF or 60% concentrate in the diet maintained the ruminal pH higher than 6.0 and 5.8 in FRL and PARL, respectively. Therefore, the inclusion of more than 60% slowly degradable concentrate in dairy cows diets fed approximately 18 kg DM x d(-1) is discouraged. Based on the response of ruminal solid digesta to dietary fibre, it can be concluded that the recommendations of feeding a structural value > or =1 per kg DM (De Brabander et al. 1999) underestimated, and 400 g CF per 100 kg BW (Hoffmann 1990) overestimated the evaluation of structural effectiveness of the present diet.     

气候变化对邛崃山系大熊猫主食竹和栖息地分布的影响

气候变化对生物多样性的影响,特别是珍稀濒危物种的影响是当前的研究热点。全球气候变化对大熊猫的影响一直受到广泛关注。根据野外调查的大熊猫活动痕迹点、竹类分布点和主食竹扩散距离数据,采用Maxent模型,利用植被、地形、气候等因素,在RCP8.5下分析了2050年和2070年邛崃山系大熊猫主食竹分布及栖息地变化趋势。结果显示:(1)未来大熊猫适宜生境及主食竹气候适宜区面积均有所减少,到2070年分别减少37.2%和4.7%;(2)未来主食竹分布范围总体向高海拔扩展,但面积持续减少,到2070年分布面积比当前减少8.3%;(3)大熊猫栖息地未来有向高海拔扩张的趋势,在低海拔地区退缩明显,到2070年较当前减少27.2%;但到2070年大熊猫栖息地面积加上非栖息地有主食竹分布的面积,较现有大熊猫栖息地面积大1.5%;(4)受气候变化影响较严重的区域是邛崃山系南部以及低海拔地区,其余区域所受影响相对较小;(5)未来需要加强对受气候变化影响严重区域的监测与保护,特别是邛崃山系中部的大熊猫集中分布区。     

Protein requirements of three species of parrots with distinct dietary specializations

Dietary protein deficiency is considered a major obstacle in the evolution of highly specialized nectarivorous and frugivorous birds. Proposed physiological mechanisms that enable such specialists to subsist on low‐protein diets include minimized endogenous protein losses, which contribute to reduced protein requirements. I compared these traits among nectarivorous red lories (Eos bornea), frugivorous Pesquet's parrots (Psittrichas fulgidus), and granivorous budgerigars (Melopsittacus undulatus). My results suggest that, relative to budgerigars, red lories and Pesquet's parrots have low endogenous protein losses and reduced crude protein (CP) requirements. Based on nitrogen balance analyses, diets containing 1.0%, 3.2%, and 8.2% CP (on a dry matter (DM) basis) would meet the minimal protein requirements for maintenance for red lories, Pesquet's parrots, and budgerigars, respectively. Low endogenous protein losses and reduced protein requirements are effective physiological adaptations that allow birds such as red lories and Pesquet's parrots to specialize on low‐protein foods. Zoo Biol 22:163–177, 2003. © 2003 Wiley‐Liss, Inc.