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1.
In standard laboratory environments mice are housed at 20–24 °C. However, their thermoneutral zone ranges between 26 °C and 34 °C. This challenge to homeostasis is by definition stressful, and could therefore affect many aspects of physiology and behavior. We tested the hypothesis that mice under standard laboratory conditions are not housed at a preferred temperature, and predicted that this would be evident in thermotaxis and other behavioral responses to ambient cage temperature. We assessed the temperature preferences of C57BL/6J mice in standard laboratory housing from 4 to 11 weeks of age. Forty-eight mice (24 male and 24 female in groups of three) all born on the same day were randomly assigned to one of eight age treatments. One cage of males and one cage of females were tested each consecutive week. Mice were tested in a set of three connected cages with each cage's temperature set using a water bath. On days 1–3 each group of mice was acclimated to each of the three temperatures (20 °C, 25 °C, or 30 °C) in a random order. Then each group was given free access to all temperatures on days 4–6, and video taped continuously. The location of each mouse and the occurrence of three behavioral categories (Active, Inactive, and Maintenance) were recorded by instantaneous scan samples every 10 min over the 3 days, and time budgets calculated. While both sexes chose warmer temperatures overall (P < 0.001), they preferred warmer temperatures only for maintenance and inactive behavior (P < 0.001). This effect was most pronounced in females (P = 0.017). As temperature selection varied with time of day (P < 0.001), these behavioral differences cannot be due to ambient temperature dictating behavior. We conclude that C57BL/6J mice at 20–24 °C are not housed at their preferred temperature for all behaviors or genders, and that it may not be possible to select a single preferred temperature for all mice.  相似文献   

2.
Motivation tests were conducted to assess preference strength for diet form and a cage enrichment device by Orange-winged Amazon parrots (Amazona amazonica) held in individual cages, N = 10. Each cage was equipped with two trough-type feeders, one of which had a hinged lid that required lifting to access feeder content; cost of lifting the lid could be increased by the addition of up to 480 g upon it, ~1.5 times the mass of an Amazon parrot. Motivation tests were conducted using three different diet forms of pellets (regular-sized, 0.16 g/pellet (cylindrical-shaped); large-sized, 3.4 g/pellet (cylindrical); and over-sized, 3–5 g/pellet (cuboid-to-spheroid)) manufactured from the same diet formulation. When regular pellets were concomitantly freely available, birds were still highly motivated to gain access to either large-sized or over-sized pellets, with 7 of 10 birds lifting the maximum weight of 480 g. In motivation tests comparing over-sized vs. large-sized pellets, birds worked more for over-sized pellets (when large-sized pellets were freely available) than vice versa: motivation for over-sized pellets exceeded that for large-sized pellets by approximately 242.67 ± 64.4 g (F = 14.2, P = 0.0055; Sign Test, P = 0.0078). Additional tests assessed motivation to access 2.5 cm/side wooden cube enrichment devices when regular or over-sized pellets were freely available. Birds removed more cubes when fed regular pellets (Sign Test, P = 0.0078) and lifted an average of 221.33 ± 64.62 g more to access them (F = 11.73, P = 0.009; Sign Test, P = 0.0063), than when over-sized pellets were freely available, suggesting that enrichment devices may act as foraging substitutes. Likewise, both wooden cubes and over-sized pellets elicited comparable podomandibulation (handling with beak and foot) behavior, and podomandibulation was reduced when parrots were fed regular as opposed to over-sized pellets (58 ± 10 s [mean ± SE] vs. 4.27 min ± 31 s; P < 0.0001). Finally, there was no evidence of contrafreeloading: in control experiments, birds only removed pellets which were freely available, when the same pellets were concomitantly available in weighted-lid feeders (F = 120.20, P < 0.0001). In summary, these results show that captive Orange-winged Amazon parrots strongly prefer pellet forms that are substantially larger than what is commercially recommended for them; preferred forms more closely resemble that of native wild foods, such as palm fruits.  相似文献   

3.
Cage size is widely recognised as an important determinant of captive animal welfare, but in contrast, cage shape has received far less attention. Husbandry recommendations for flying birds state that cages should be long in shape because this allows greater potential for flight. However, so far no studies have investigated the impact of cage shape on the behaviour or welfare of captive flying birds. We measured the effects of cage size and shape on the condition and behaviour of captive wild-caught European starlings (Sturnus vulgaris) using a 2 × 3 factorial design in which birds were individually housed for 1 week in cages of one of two volumes (either medium at 0.3 m3 or large at 1 m3), and one of three shapes (long with an aspect ratio (i.e. length/height) of 3.43), standard with an aspect ratio of 1.72 or tall with an aspect ratio of 0.86). We found effects of cage size and the interaction of cage size and shape on the behaviour and condition of birds. In interpreting the welfare implications of our results we focused on stereotypic behaviour as measured by incidence of somersaulting and a novel statistic that quantifies sequential dependencies in the birds’ locations within the cage. The lowest measures of stereotypic behaviour were recorded in the large cages and the medium long cage. Cage shape was more important in determining the quantity of stereotypic behaviour in the medium cages than the large cages. Our findings support the recommendation that starlings be housed in long-shaped cages.  相似文献   

4.
Laboratory mice housed under standard vivarium conditions with an ambient temperature (Ta) of ~22 °C are likely to be cold stressed because this Ta is below their thermoneutral zone (TNZ). Mice raised at Tas within the TNZ adapt to the warmer temperatures, developing smaller internal organs and longer tails compared to mice raised at 22 °C. Since mice prefer Tas equal to their TNZ when housed in a thermocline, we hypothesized that mice reared for long periods (e.g., months) in a thermocline would undergo significant changes in organ development and tail length as a result of their thermoregulatory behavior. Groups of three female BALB/c mice at an age of 37 days were housed together in a thermocline consisting of a 90 cm long aluminum runway with a floor temperature ranging from 23 to 39 °C. Two side-by-side thermoclines allowed for a total of 6 mice to be tested simultaneously. Control mice were tested in isothermal runways maintained at a Ta of 22 °C. All groups were given cotton pads for bedding/nest building. Mass of heart, lung, liver, kidney, brain, and tail length were assessed after 73 days of treatment. Mice in the thermocline and control (isothermal) runways were compared to cage control mice housed 3/cage with bedding under standard vivarium conditions. Mice in the thermocline generally remained in the warm end throughout the daytime with little evidence of nest building, suggesting a state of thermal comfort. Mice in the isothermal runway built elaborate nests and huddled together in the daytime. Mice housed in the thermocline had significantly smaller livers and kidneys and an increase in tail length compared to mice in the isothermal runway as well as when compared to the cage controls. These patterns of organ growth and tail length of mice in the thermocline are akin to warm adaptation. Thus, thermoregulatory behavior altered organ development, a process we term behaviorally mediated, warm adaptation. Moreover, the data suggest that the standard vivarium conditions are likely a cold stress that alters normal organ development relative to mice allowed to select their thermal preferendum.  相似文献   

5.
Melopsittacus undulatus is a companion parrot worldwide diffused. Many parrots are considered endangered or vulnerable. The preservation of semen is crucial in endangered species, thus, M. undulatus could be a good model to study sperm characteristics and semen cryopreservation in these other endangered parrots. In this study the effect of the breeding management (males bred in promiscuous aviary or in couple) on sperm characteristics (motility, membrane integrity and morphometry) of fresh and cryopreserved semen was evaluated. The computer-assisted sperm analysis (CASA) revealed a significant effect of the husbandry method on semen characteristics in budgerigars: male housed in couple with the female in individual cages allowed the higher results in term of both semen quantity and sperm quality. Total and progressive motility were significantly higher in males bred in couple (68.7 ± 8.9% and 54 ± 15.9%, respectively) than in promiscuous aviary (48.3 ± 15.1% and 24.4 ± 12.4%, respectively), such as sperm velocity (average path velocity, straight line velocity, and curvilinear velocity). The type of sperm movement (amplitude of lateral head displacement, beat cross frequency, straightness, and linearity), sperm membrane integrity and morphometry parameters seemed not affected by the husbandry method. The standardization of a CASA procedure for the semen analysis in M. undulatus allow further studies on parrot semen manipulation and cryopreservation, but the method used for the breeding of the male could have a significant effect on the semen quality.  相似文献   

6.
Five-week-old Pannon White rabbits were housed in a closed climatized rabbitry and randomly assigned to either pens (56 rabbits) having a basic area of 1 m2 with a stocking density of 16 and 12 rabbits/m2 or to 18 individual cages (0.24 m2/cage). The pens and the cages were divided into two halves and animals could move freely between the two halves through swing doors. The walls of one half of the pens and cages were completely covered with mirrors while the other half was covered with white plastic panels. A 24 h video recording was made twice a week using infrared cameras and the number of rabbits in each pen and cage was counted every 15 min. The duration of the trial was 6 weeks. The lighting period was 16L/8D. In each half of the cage or pen, a feeder and nipple drinkers were available and feed intake was measured separately. Throughout the entire rearing period, 72% of the individually caged rabbits showed a preference for the cage half enriched with mirrors (P < 0.001). This preference decreased slightly with increasing age. Preference toward the cage half provided with mirror walls was independent of the time of day; in other words, during the active period (23:00–05:00) corresponding to the dark part of the day, rabbits continued to prefer the mirrored half even if the vision of the reflected image was reduced. The presence of conspecifics at different stocking densities (12 vs. 16 rabbits/m2) did not reduce this interest in mirrors: averaging the ages, 66% of animals living at 16 rabbits/m2 stocking density and 63% of those living at 12 rabbits/m2 density were found in the half pen with mirrors (P < 0.001). Group-penned rabbits showed a marked preference toward mirrors during the active period (73–76% for 12 and 16 rabbits/m2 stocking densities, respectively; P < 0.001). The results suggest that the presence of mirrors offers advantages perhaps related to comfort and welfare, and therefore might be used as environmental enrichment for fattening rabbits and advised for rabbits caged individually for long periods.  相似文献   

7.
Environmental enrichment (EE) is known to have behavioral and physiological anxiolytic effects in several animal models. However, it is as yet unclear how EE modulates behavior of wild animals and the underlying molecular mechanisms. The adult male field mouse Mus booduga (n = 42) captured at agricultural field, were housed in non-enriched standard condition (SC) for 7 days and considered as directly from wild (DW). Another two groups of mice were housed in either EE or SC for 30 days. Behavioral testing was carried out to assess their anxiety-like behavior in the elevated plus-maze (EPM). We found that on EPM, mice housed in EE display less anxiety like behavior when compared to mice housed in SC. Exposure to plus-maze did not increase the levels of corticosterone (CORT) in prefrontal cortex (PFC) and circulating CORT, and adrenocorticotropic hormone (ACTH) in the mice housed in EE but not in the mice housed in SC. We observed a trend in the EE induced inhibition of expression of corticotropin releasing hormone (CRH), glucocorticoid receptor (GR), E2 ubiquitin-conjugating enzyme (Ubc9) and steroid receptor coactivator-1 (SRC-1) mRNA levels, which are all known to be involved in the stress response signaling pathway. Our study suggests that EE exerts therapeutic and anxiolytic effects against stressors.  相似文献   

8.
《Process Biochemistry》2010,45(10):1738-1745
A novel feather-degrading Stenotrophomonas maltophilia R13 was isolated from rhizospheric soil of reed. The strain R13 produces keratinolytic enzyme using chicken feather as the sole carbon and nitrogen source. Addition of 0.1% glucose and 0.12% polypeptone to the feather medium increased the enzyme production. The optimum temperature and initial pH for the enzyme production were 30 °C and 7.0. The maximum yield of the enzyme was 82.3 ± 1.0 U/ml in the optimal feather medium; this value was about 5.5-fold higher than the yield in the basal feather medium. S. maltophilia R13 possessed disulfide reductase activity along with keratinolytic activity. As a result of feather degradation, 18 free amino acids were produced in the culture; the concentration of total amino acid was 2298.8 μM. The strain R13 produced IAA in the optimal feather medium without l-tryptophan supplementation, indicating simultaneous production of keratinolytic activity and IAA by S. maltophilia R13. The strain R13 grown in the optimal feather medium also inhibited mycelial growth of some phytopathogenic fungi. This result suggests that antifungal activity of the strain R13 could be produced in the same conditions observed for keratinolytic activity. Thus, S. maltophilia R13 could be not only used to enhance the nutritional value of feather meal but is also a potential bioinoculant in agricultural environments.  相似文献   

9.
The mechanisms underlying the sensitization of sexual behaviors by repeated administration of estradiol benzoate (EB) to ovariectomized (OVX) rats are not well understood. Here we tested whether two housing conditions play a role. Sexual behavior in the female rat is dependent on the activation of ERα (estrogen receptor alpha) by estradiol. Corncob (CC) bedding has been reported to have adverse effects on the reproductive behavior and physiology of rats, and to disrupt ERα signaling in mice. In addition, some rodent behaviors are stimulated by olfactory stimuli and enhanced in the presence of estradiol. Upon arrival to the facilities OVX Long–Evans rats were housed on either Sani-Chips (SC) or CC in a room that housed only females (F) or males and females (M). Females were first given four sexual training sessions with 10 μg EB + 500 μg progesterone (P; administered 48 h and 4 h prior to training, respectively), followed by a 2-week hormone washout period. Next, 10 μg EB was administered s.c. every 4 days, 48 h prior to each of 8 test sessions in a unilevel 4-hole pacing chamber. On the final training day (i.e., when primed with EB + P), no inhibitory effects of corncob bedding were found, however a facilitation of the lordosis quality occurred in SC/F. Although all groups appear to have sensitized to the repeated administration of EB, CC/F animals displayed fewer high quality lordosis magnitudes and hop/darts, and received fewer mounts and intromissions overall. They also had a lower lordosis quotient (LQ) on tests 2–4 although this effect disappeared by test 5. These results suggest that although CC may inhibit some components of female sexual behavior when primed with EB alone, cues from sexually vigorous males can overcome that inhibition. Moreover, they suggest that male cues can facilitate mechanisms of estradiol sensitization. We recommend that quality control studies be conducted at individual institutions to assess any impact of corncob bedding on animal physiology and behavior.  相似文献   

10.
The impact of a social stress in gestation and an enriched pen in lactation on components of sow maternal behavior was studied in a 2 × 2 factorial experiment. At breeding, 41 sows were assigned to a social mixing stress treatment (T) during mid-gestation or a control group (C). During lactation, half of the T and C sows were housed in straw enriched pens (E) (1.57 m × 4.10 m) and the others in standard farrowing crates (S) (0.68 m × 2.10 m). The mixing stress consisted in introducing each T sow to the home pen of two unfamiliar sows twice for 1 week, from d 39 to 45 and 59 to 65 of gestation. Aggressive behavior was observed and lesion scores were taken to confirm that a social stress occurred. During lactation, the responses of sows to a simulated piglet crush test on d 3 and an isolated piglet playback test on d 21 were observed. Postural budgets of sows were automatically detected using accelerometers on d 5 and 19 of lactation. Sow-initiated social contacts with the piglets were observed continuously from video recordings on d 6 and 20 of lactation. Data were analyzed with a mixed models procedure. The social stress treatment had an impact on the response of sows to isolated piglet vocalizations with T sows showing longer latencies to respond vocally than C sows (P = 0.035). In early lactation, T sows spent more time lying ventrally than C sows (P = 0.007). Furthermore, the social stress had an impact on the space use in the enriched housing, with T sows spending less time in the nesting straw area of the pen than C sows (P = 0.018). Housing also impacted maternal behavior with E sows tending to spend more time lying ventrally than S sows in late lactation (P = 0.067) and tending to have more social contacts with their piglets than S sows in early lactation (P = 0.058). In conclusion, the social stress during gestation had a slight negative impact on sow maternal behavior, and while an enriched farrowing pen allowed for more opportunities to express maternal behavior, it did not counteract the negative effects of gestation stress.  相似文献   

11.
This work describes the preparation of combi-CLEAs of pectinases using feather meal as novel proteic feeder. Initially, four solvents were tested as precipitant agents, and ethanol was chosen as the best solvent. Subsequently, a 23 factorial design was carried out to define the optimal conditions for combi-CLEAs preparation, which were set as 110 mM of glutaraldehyde, 0.66 mg protein mL−1 and 5 h of reaction time. Then, the effect of BSA or feather meal (FM) as proteic feeders was evaluated. Combi-CLEAs, combi-CLEAs-BSA and combi-CLEAs-FM were characterized and evaluated by their activity recovery, optimal pH and temperature, operational and thermal stabilities and e effectiveness on juice clarification. The addition of feather meal increased two-fold the activity recovery compared to BSA. The thermal stability was similar for all combi-CLEAs, providing stabilization factors of 1.12, 1.48 and 1.53, respectively, for the combi-CLEA, combi-CLEA-FM and combi-CLEA-BSA, compared to free enzyme. CLEAs presented turbidity reduction near to 50%, 2.5-fold than soluble enzyme. Feather meal was used for the first time as proteic feeder for CLEA preparations and appears to be a good, and low price, alternative.  相似文献   

12.
Chryseobacterium gleum exhibited complete dissolution of whole chicken-feathers (10 g l?1, pH 8) after 72 h at 30 °C through synthesis of keratinolytic protease when inoculated at 1% (v/v). This enzyme was purified to 67-fold with yield of 2.25% having a specific activity of 1670 U mg?1 and ~36 kDa Mw. MALDI-TOF MS of this keratinase showed some similarity with the keratinase peptides of Bacillus subtilis (BOFXJ2). The keratinase action was inhibited by EDTA, iodoacetamide and metal ions like mercury, copper and zinc (1 mM each), while it was enhanced by iron and calcium. Keratinase showed presence of 3 mM of Fe M?1 as tested by atomic absorption spectroscopy and addition of Fe in its apoenzyme retained about 79% of original residual feather degradation activity which portrayed it to be metalloprotease. Purified keratinase revealed significant degradation (85%) of feather concentrate (20 g l?1) to 3.9 μM ml?1 of free amino groups in 24 h at an initial pH of 8.0, 30 °C and 120 rpm shaking. This keratinase activity can be controlled precisely by presence of chemical or metal ions which could be of use in biotechnology industry while the culture can be used in poultry waste management.  相似文献   

13.
The Ansell's mole-rat (Fukomys anselli, Bathyergidae) is a small-sized social subterranean rodent whose distribution is confined to the Lusaka area in Zambia. It is an established model species for various laboratory studies, but until now the knowledge of its biology under natural conditions has been limited. Here, we provide the first comprehensive natural history and ecological data on a free living population from Miombo woodland. The Ansell's mole-rat lives in groups of up to 13 individuals (mean 9.7 ± 2.5; N = 9 complete, fully established family groups) with a single breeding pair per group. The family groups occupy very large and complex burrow systems consisting of 0.5–2.8 km of tunnels (mean = 1.2 ± 0.6 km, N = 15), which are densely branched and reticulated especially around nests. Burrow systems of neighbouring family groups were often interconnected by a freely passable tunnel, which has never before been documented in any African mole-rats. Mole-rat food density in the study area was relatively low (10.0 ± 8.4 m?2) but its biomass was large (457 ± 889 g m?2). This, together with a relatively workable soil (cone resistance = 529 ± 26 N cm?2 at the end of June, with 10% soil humidity), indicates moderate ecological conditions, which disagrees with the aridity food-distribution hypothesis (AFDH) considering small body size and sociality in bathyergids adaptations to harsh environments.  相似文献   

14.
15.
The genetic diversity among five populations (Bhadbada reservoir, Mohinisagar reservoir, Bansagar reservoir, Bargi reservoir and Gandhisagar reservoir) was revealed using random amplified polymorphic DNA markers. 10 random primers screened, 5 primers revealed various banding patterns and yielded 71 total loci as an average of which 39.60 (55.77%) were polymorphic between the population and 86.84% within the population of Sperata seenghala. Population wise the highest genetic polymorphism was obtained in Bhadbada reservoir as 67.61% whereas the lowest was in Gandhisagar reservoir as 49.30%. However, Analysis of Molecular Variance indicated low genetic diversity (Hpop = 0.0921 ± 0.1249; I = 0.1584 ± 0.1942) in Bansagar reservoir. Relative genetic differentiation (GST = 0.3993) and restricted gene flow (Nm = 0.7523) as an average indicated low gene diversity among the fish populations. The un-weighted pair group method with averages (UPGMA) dendrogram showed 05 major clusters, each cluster representing a population. Fish population of Mohinisagar reservoir showed high genetic distance (0.3981) with respective Bargi reservoir population and highest genetic identity (0.8846) reflected between Bansagar and Gandhisagar reservoir. Highest genetic distance between Mohinisagar and Bargi reservoir fish populations shows no significant correlation between genetic and geographical distance of the genotypes collected from different lentic and geographical isolated water bodies. This investigation indicated that lowest genetic diversity existed in different geographic populations of S. seenghala. All the five populations were found to be low in genetic variation, which is useful information for future conservation measures of S. seenghala confined in natural water bodies of Madhya Pradesh.  相似文献   

16.
In most proestrous hamsters, novel wheel exposure phase advances activity rhythms and blocks the preovulatory LH surge, which occurs 2 h earlier the next day. Because wheel immobilization does not prevent these effects we hypothesized that arousal alone blocks and phase advances the LH surge. Ovariectomized (ovx) hamsters received a jugular vein cannula and estradiol benzoate (EB) or vehicle was injected sc. The next day (Day 1), at zeitgeber time (ZT) 4–5 (ZT 12 = lights off), after obtaining a blood sample, each hamster was exposed to constant darkness (DD), and either remained in her home cage or was transferred to a new cage and exposed to a running wheel or a 2-hour arousal paradigm. Blood samples were obtained in dim red light and activity was recorded hourly until ~ ZT 10–11 on Days 1 and 2. For the next 1–2 weeks, activity was monitored in DD. Plasma LH and corticosterone were assessed by RIA. Novel wheel exposure or arousal at ZT 4 greatly attenuated the Day 1 LH surge in ovx + EB hamsters, and phase advanced the Day 2 LH surge by about 2 h. In proestrous hamsters, novel wheel exposure led to a prolonged (> 2 h) increase in corticosterone levels only when LH surges were blocked. Phase advances in activity rhythms were enhanced by estradiol and arousal. The results suggest that estradiol modulates the effectiveness of non-photic stimuli. The role of the increased activity of the hypothalamic–pituitary–adrenal axis associated with novel wheel-induced attenuation of LH surges in ovx + EB hamsters remains to be determined.  相似文献   

17.
《Aquatic Botany》2007,87(2):111-115
In this study, 169 stream lily (Helmholtzia glaberrima) seedlings from six micro-drainages were genotyped with AFLP markers to quantify the impact that topographic landscape features and altitude may have in shaping patterns of genetic diversity within individual populations. A global analysis of genetic diversity detected significant genetic differentiation among micro-drainages (FST = 0.22, P < 0.01). The observed genetic structure of sampled sites conformed to a hierarchical model of gene flow. Assignment tests also supported a hierarchical model of gene flow as only one dispersal event among the sampled micro-drainages was detected. This suggests that opportunities for seed dispersal in H. glaberrima are highly constrained by patterns of hydrographic networks even at a local scale. In contrast, altitude had little impact on partitioning of genetic diversity as no increase in genetic diversity was evident among individuals in the upper (0.18 ± 0.02), and lower (0.17 ± 0.02) areas of micro-drainages. Overall these results suggest that the influence of freshwater landscape features can vary widely the effect on the patterns of genetic diversity of seedlings in stream lily populations.  相似文献   

18.
The signalling of cytokine receptors plays a crucial role in regulating tolerance and immunity. Impaired immunological processes result in autoimmune inflammation that target the hair follicles, causing many hair disorders, mainly alopecia areata (AA). Therefore, polymorphisms in cytokine receptor genes are suggested to have a significant impact on the pathogenesis of AA, a disease with a multifactorial basis and uncertain etiology. In the present study, 152 AA patients of the Jordanian population were investigated for their genetic susceptibility to develop AA compared to 150 control subjects. Genomic DNA extraction and genotyping had conducted for IL17RA (rs879575, rs2229151, and rs4819554), IL2RA (rs3118470), IL23R (rs10889677), and IL31RA (rs161704) using the Sequenom MassARRAY® system. The allele frequency of IL17RA rs879575 is significantly higher in patients, while no statistical differences were found for IL2RA, IL23R, and IL31RA SNPs. Also, the recessive model of IL31RA rs161704 showing that AA genotype is significantly associated with AA development. To date, there is no published data regarding the association between AA and the selected genetic variants in our population. However, this study's findings assert that SNPs of IL17RA and IL31RA are linked to AA susceptibility in Jordanian patients.  相似文献   

19.
Khat (Catha edulis) is a lucrative cash crop in many African countries and other areas of the world. Leftover khat can be used as a feedstuff for ruminants, although seasonal production limits the extent of utilization. Practical methods of feed conservation to preserve nutritional value would be beneficial. Thus, a study was conducted to investigate effects of feeding different forms of leftover khat on intake, digestion, and growth performance of a tropically adapted indigenous goat genotype of eastern Ethiopia. Twenty-four (six per treatment) individually housed Hararghe Highland yearling male goats with an initial body weight of 18 ± 0.4 kg were used in an on-station experiment, and 32 similar yearlings with an initial body weight of 19 ± 0.4 kg were employed under on-farm conditions. The on-farm experiment occurred at two villages, with four farmer groups (two farmers per group co-managing animals) per village. Four animals in each farmer group were subjected to each of the four different treatments. Experiments were 90 days in length, with inclusion of a subsequent 10-day period on-station to determine digestibility. Khat in fresh, dry, and silage forms was fed at 1.5% body weight (dry matter; DM), whereas control animals did not receive khat. Animals on-station consumed grass hay ad libitum and those on-farm grazed/browsed surrounding areas. Grass hay DM intake on-station was greater (P < 0.05) without than with khat (528, 358, 387, and 368 g/day; SE = 20.3), although total DM intake was increased by feeding khat regardless of form (528, 649, 622, and 639 g/day for control, fresh, dry, and silage, respectively; SE = 22.9). Digestibility of organic matter was increased (P < 0.05) by feeding each form of khat (62.3%, 75.7%, 75.2%, and 72.4% for control, fresh, dry, and silage, respectively; SE = 1.63). Nitrogen balance was increased by fresh and ensiled khat (P < 0.05) (?0.54, 2.07, 0.80, and 0.86 g/day for control, fresh, dry, and silage, respectively). Average daily gain (ADG) was increased by khat regardless of form on-station (13, 49, 33, and 39 g; SE = 4.6), and on-farm ADG was less for control than for fresh and dry forms (P < 0.05) (32, 56, 47, and 42 g for control, fresh, dry, and silage, respectively SE = 2.0). The ratio of ADG:DM intake on-station was lower for control than for fresh (P < 0.05) and silage (P < 0.05) (26, 76, 54, and 61 g/kg for control, fresh, dry, and silage, respectively; SE = 7.6). In conclusion, feeding leftover khat to Highland goats consuming low to moderate quality forage-based diets can increase growth performance. Khat can be preserved for use as a feedstuff throughout the year by drying or ensiling without marked effect on performance.  相似文献   

20.
Gastrodia elata Blume, a mycoheterotrophic orchid native to the Far East, is an endangered medicinal plant in China. Genetic variation among 19 natural populations of G. elata was examined in central China by using allozyme polymorphism (16 loci in six enzymatic systems). The species exhibited high level of genetic diversity (P = 56.3%, A = 2.2 and HE = 0.221), which was mainly attributed to its perennial habit and mixed reproduction system (both sexual and asexual). Evident genetic differentiation in G. elata natural populations was suggested by FST = 0.241. AMOVA analysis showed 31.3% of the total molecular variation was attributed to inter-population differentiation. Obvious genetic structure and genetic depauperation of some populations indicate forest fragmentation and over-collection have affected genetic variation of G. elata. A conservation strategy, which is conserving populations with great genetic distinction or high level of genetic variation from four management units, is recommended.  相似文献   

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