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1.
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Grazing and fencing field were sampled to explore their effects on vegetation characteristics and forage nutritional quality by the combined analytical method in the temperate desert steppe. The results showed that, grazing significantly decreased the height, coverage and biomass of the plant community, and significantly increased the species richness index (P<0.01). Moreover, grazing significantly increased the Crude protein (CP), Crude fat (CF), Dry matter digestibility (DMD) and Metabolic energy (ME), and significantly decreased the Neutral detergent fibers (NDF) and Acid detergent fibers (ADF) (P<0.01). The species richness index was positively correlated with CP, CF, DMD and ME, but negatively correlated with NDF and ADF (P<0.01). CP, CF, DMD and ME were negatively correlated with NDF and ADF (P<0.01). In summary, grazing significantly increased species richness index and forage nutritional quality. Therefore, it is recommended to carry out appropriate grazing on the fencing temperate desert steppe to make full use of grassland resources and protect species diversity. © 2019 Authors. All rights reserved.  相似文献   

3.
The effect of age at first calving (AFC) and breed type (BG) on cow length of productive life in the herd (LPL) and cumulative kilograms of calves weaned per cow (KWC) was studied. Data on 313 Brahman, 183 Nellore, and 269 crossbred cows (undefined crosses of European × Zebu cattle) born from 1986 to 2002 were used. Three hundred and ninety-one out of the 765 cows had non-censored data. LPL curves by BG and AFC (<2.5, 2.5 to <3, 3 to <3.5, and ≥3.5 years of age) were obtained using life table procedures. The magnitude of the effect of AFC and BG on LPL was determined using Cox proportional hazard regression procedures. KWC data (n = 359) were analyzed by a linear model that included the effects of period of birth of the cow (in years), BG, and AFC. There was no difference in the survival curves between BG (p > 0.05), but there was for the hazard ratio of culling (p < 0.05). Brahman and Nellore cows produced more kilograms of calves (p < 0.05) than crossbred cows. AFC influenced LPL (p = 0.014) and KWC (p = 0.012). Cows with AFC <3 years of age stayed longer in the herd and weaned more KWC than those with a higher AFC (p < 0.05).  相似文献   

4.
This experiment was conducted to investigate the effects of dietary energy on antioxidant capacity, liver glucose–lipid-related gene expressions and meat fatty acid of Holstein bulls. Thirty-six Holstein bulls (age, 17.0 ± 0.49 months; body weight, 493.3 ± 39.7 kg) were randomly allocated to three dietary treatments. The metabolizable energy of diets was 10.12, 10.90 and 11.68 MJ/kg. Bulls in each dietary treatment were sampled at the age of 20, 23 or 26 months. Results showed that serum glutathione peroxidase and superoxide dismutase decreased with the increasing age. Dietary energy and age had interaction effects on the expressions of fatty acid synthase, peroxisome proliferator-activated receptor alpha, acyl coenzyme A oxidase 1 and carnitine palmitoyl-transferase 1 alpha. Besides, the increase of age and dietary energy increased the expression of liver phosphoenolpyruvate carboxykinase 1. The expressions of liver glucose-6-phosphatase, tumour necrosis factor alpha and sterol regulatory element binding protein 1 increased with the increasing age. The increase of age and dietary energy increased the proportions of C18:1cis-9, C18:2n-6trans and monounsaturated fatty acid. In summary, the increase of age and dietary energy enhanced the intensity of metabolic changes and inflammatory responses. Dietary energy and age affected the expressions of liver lipid metabolism-related genes, further affected meat fatty acid composition of Holstein bulls.  相似文献   

5.
Scattering slash (downed woody materials) after tree removal is increasingly prescribed by land managers as a treatment to promote the establishment and growth of understory vegetation in pinyon–juniper woodlands. However, the effects of scattering slash on soil resources and plant communities are poorly understood and often confounded with the release from tree competition. In order to examine how slash affects plant establishment, soil stability, soil nutrients, and soil microbiota, we initiated a 2 × 2 full factorial experiment with two levels of seeding and two levels of slash additions within 30 intercanopy spaces, repeated at two intact pinyon–juniper woodland sites with different soil characteristics in northwestern Arizona. Pretreatment data were collected in 2003 and posttreatment responses were measured in 2004 and 2005. Total plant cover increased within all treatments; however, grasses increased significantly only in the seed-and-slash treatment at both sites. In addition, a greater proportion of seed-and-slash plots contained more reproductively active grasses compared to seed-only plots. Slash treatments also resulted in significantly less sediment movement compared to nonslash treatments. Changes in soil nutrients were not observed, except available NO3-N decreased significantly in slash treatments. Arbuscular mycorrhizal potential and microbial biomass carbon increased as a result of the slash treatment. Addition of woody materials appeared to have general effectiveness at improving the ecological function of soils and promoting understory establishment and thus may be considered a desirable treatment for improving degraded conditions.  相似文献   

6.
1. Different concentrations of zinc–methionine (Zn-Met) were given to pigeon squabs, and the resulting effects on growth, immune functions and intestinal microflora were investigated from hatching to 28 d of age. A total of 180 artificially hatched pigeon squabs were randomly allotted to each of three treatments with three replicates of 20 squabs. The three treatments given were either one ml (2 mg/ml) Zn-Met, one ml (10 mg/ml) Zn-Met or one ml 0.9% NaCl solution.

2. The results showed that Zn-Met improved the growth performance of squabs. The average daily and average weekly weight gain was significantly greater in squabs treated with Zn-Met than in the control group.

3. The group given 2 and 10 mg supplemental Zn-Met had heavier thymus, spleen and bursa of Fabricius than the control group at d 28.

4. Maternal antibody titres against Newcastle disease haemagglutination inhibition and alpha-naphthyl acetate esterase were significantly higher in squabs treated with supplemental 2 and 10 mg Zn-Met compared to the control group at d 14 and d 28.

5. Additionally, the squabs given supplemental 2 mg Zn-Met exhibited significantly higher Bacillaceae, Lactobacillus, Enterococcus and Bifidobacterium populations at d 14 and d 28, but lower Escherichia coli populations at d 28 compared to the control group. On the contrary, Lactobacillus, Enterococcus and Bifidobacterium populations were significantly decreased with 10 mg Zn-Met at d 28.

6. This study indicates that supplementation with Zn-Met has a positive effect on growth performance, immune function and regulation of intestinal flora in pigeons. An inclusion level of 2 mg seems to be better than 10 mg Zn-Met per day per bird.  相似文献   


7.
Reducing methane emission from ruminant animals has implications not only for global environmental protection but also for efficient animal production. Tea saponins (TS) extracted from seeds, leaves or roots of tea plant are pentacyclic triterpenes. They have a lasting antiprotozoal effect, but little effect on the methanogen population in sheep. There was no significant correlation between the protozoa counts and methanogens. The TS decreased methanogen activity. It seems that TS influenced the activity of the methanogens indirectly via the depressed ciliate protozoal population. The TS addition decreased fungal population in the medium containing rumen liquor in in vitro fermentation, but no such effect was observed in the rumen liquor of sheep fed TS. Tea saponins had a minor effect on the pattern of rumen fermentation and hence on nutrient digestion. When added at 3 g/day in diets, TS could improve daily weight gain and feed efficiency in goats. No positive associative effect existed between TS and disodium fumarate or soybean oil on methane suppression. Inclusion of TS in diets may be an effective way for improving feed efficiency in ruminants.  相似文献   

8.
A retrospective study was carried out to evaluate the reproductive performance of Holstein–Friesian cattle in Alage Dairy Farm in the Rift Valley of Ethiopia using data recorded from July 1983 to June 2005. Data of cows with complete information were considered, and a total of 1,104 records for calving to conception (Cal-Con), calving interval (CI), and number of services per conception (NSC), and 721 records for age at first service (AFS) and at first calving (AFC) were analyzed. The overall means (±S.E.) of AFS, AFC, Cal-Con and CI, and NSC were 991.4 ± 24.3, 1,265 ± 24.3, 285.8 ± 18.9, 561.3 ± 18.9 days and 1.69 ± 0.1, respectively. Parity significantly influenced NSC, Cal-Con, and CI. Season and year showed a significant effect on all the parameters, indicating the role of the environment and more specifically the influence of nutritional conditions at least for the long AFS and AFC, management practices, and climate on reproductive performance of the study herd. A more focused study to discern the elements of the reproductive constraints have been recommended.  相似文献   

9.
Tropical Animal Health and Production - We evaluated the relationship between the temperature–humidity index (THI) and health and growth performance in Japanese black calves in Japan. Data...  相似文献   

10.
Altered nursing or nutrition before artificial insemination (AI) can be used as a doe biostimulant to improve lactating rabbits reproduction. The timing of a shift from free to a 3-day controlled nursing to AI or the nursing method at fast-refeeding can affect the efficacy of these stimulations. In an earlier study the effects of a 3-day controlled nursing on days 8, 9 and 10 or in controlled nursing rabbits, the impact of a 24-h fast with 48–50 h re-feeding were investigated. This follow-up work tested a 3-day biostimulation with controlled nursing on days 9, 10 and 11. Another aim was to assess the same doe fast-refeeding but now in free-nursing rabbits. Pannon White does (n=480) were artificially inseminated 11 days post-partum. Control (C) does nursed freely. Rabbits simulating local farm practice (F) had controlled nursing until day 14 using a metal-plate as separation and then free nursing to weaning (day 35). In biostimulations with altered nursing, there was a shift from free to a 3-day controlled nursing (days 9–11) with a wire-mesh separation (BW), a metal-plate insertion (BM) or nest-tray removal (BN) and return to free nursing on day 12 until weaning. The C, F, BW, BM and BN does were fed ad libitum. At biostimulation with fast-refeeding (BF), the free-nursing does were subjected to a 24 h water-only fast between days 8 and 9 and a 48–50 h ad libitum re-feeding before AI. Doe reproduction and growth of the current litter were differently affected by the treatments. In the C, F, BW, BM, BN and BF does, sexual receptivity was 83, 90, 68, 80, 74 and 85% (P=0.05), the kindling rate was 79, 76, 74, 89, 68, 70% (P=0.05), the number of kits born alive was 7.9, 8.0, 8.8, 9.1, 7.9, 6.8 (P=0.005), kit weight at weaning 982, 991, 953, 986, 955, 964 g (P=0.012) and at 70 days of age 2383, 2407, 2220, 2350, 2279, 2382 g, respectively (P=0.001). Among biostimulations with altered nursing, the 3-day controlled nursing with a metal-plate separation (BM) can be advised for the practice because only this method was efficient in this (days 9–11) and previous (days 8–10) studies. There appears to be an interaction between doe nursing and feeding, since the same fast led to different production of free-nursing does compared to those in a previous work that nursed controlled.  相似文献   

11.
Instrumental learning plays an important role in dog–human interactions. The recent demand for pet dog training has resulted in the development of various training methods. The present exploratory study aims to compare the effects of 2 training methods on both the behavioral welfare of the dog and the dog–owner relationship: the first method is based on positive reinforcement (appearance of an appetitive stimulus), whereas the second method is based on negative reinforcement (disappearance of an aversive stimulus). The study compared behaviors linked to signs of stress and attentive behaviors toward the owner in 2 dog training schools, which used different methods. Walking on-leash activity and obeying the “sit” command were studied. The results show that dogs from the school using a negative reinforcement–based method demonstrated lowered body postures and signals of stress, whereas dogs from the school using a positive reinforcement–based method showed increased attentiveness toward their owner. However, neither method affected avoidance behaviors. This exploratory study reveals the differential effects of the 2 training methods on dogs' behaviors; it suggests that training methods based on positive reinforcement are less stressful and potentially better for their welfare.  相似文献   

12.
Many rangeland processes are driven by microclimate and associated ecohydrological dynamics. Most rangelands occur in drylands where evapotranspiration normally dominates the water budget. In these water-limited environments plants can influence abiotic and biotic processes by modifying microclimate factors such as soil temperature and potential soil evaporation. Previous studies have assessed spatial variation in microclimate and associated ecohydrological attributes within an ecosystem (e.g., under vs. between woody canopies) or across ecosystems (e.g., with differing amounts of woody canopy cover), but generally lacking are assessments accounting systematically for both, particularly for evergreen woody plants. Building on recently quantified trends in near-ground solar radiation associated with a piñon–juniper gradient spanning 5% to 65% woody canopy cover, we evaluated trends in soil temperature and associated estimates of potential soil evaporation as a function of amount of woody canopy cover for sites overall and for associated canopy vs. intercanopy locations. Quantified soil temperature trends decreased linearly with increasing woody canopy cover for intercanopy as well as canopy patches, indicating the coalescing influence of individual canopies on their neighboring areas. Notably, intercanopy locations within high-density (65%) woody canopy cover could be as much as ~10°C cooler than intercanopy locations within low-density (5%) cover. Corresponding potential soil evaporation rates in intercanopies within high-density woody canopy cover was less than half that for intercanopies within low density. Our results highlight ecohydrological consequences of density-dependent shading by evergreen woody plants on soil temperature and potential soil evaporation and enable managers to rapidly estimate and compare approximate site microclimates after assessing amounts of woody canopy cover. Such predictions of microclimate have general utility for improving management of rangelands because they are a fundamental driver of many key processes, whether related to understory forage and herbaceous species or to wildlife habitat quality for game or nongame species.  相似文献   

13.
Xylazine–ketamine combination was evaluated for its efficacy and safety after epidural administration in uraemic and healthy goats. The combination (xylazine 0.025 mg/kg and ketamine 2.5 mg/kg) was administered to uraemic (n = 6) and healthy (n = 6) animals in the lumbosacral epidural space. The combination was evaluated in terms of clinical, physiological, haematological and biochemical parameters. The onset of analgesia was faster in healthy animals than in uraemic animals. Xylazine and ketamine produced complete analgesia of tail, perineum, inguinal and thigh regions in all animals of both groups. However, healthy animals showed longer duration of complete analgesia than did uraemic animals. Greater ataxia was recorded in healthy animals than in uraemic animals. The heart rate showed a significant decrease in both groups; however, respiratory rate and rectal temperature did not show any significant changes. Haemoglobin, packed cell volume and total leukocyte count decreased non-significantly in both groups. Total leukocyte count was significantly higher in uraemic animals. A significantly higher value of urea nitrogen and creatinine was recorded in uraemic animals. The blood electrolytes (Na+, K+ and Cl) and blood gases (P o 2 and P co 2) did not show any significant changes in both groups; however, base excess was significantly higher in uraemic animals. The effects produced by the combination on different systems were transient and values normal as the effect of the drugs wore off. The results suggest that the combination when used epidurally in uraemic goats produced effective and safe surgical analgesia.  相似文献   

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1.?The study was conducted to determine the effects of dietary supplementation of enzyme and oregano essential oil at two levels, alone or together, on performance, digestive enzyme, nutrient digestibility, lipid metabolism and immune response of broilers fed on wheat–soybean meal based diets.

2.?The following dietary treatments were used from d 0 to 21. Diet 1 (control, CONT): a commercial diet containing no enzyme or oregano essential oil, diet 2 (ENZY): supplemented with enzyme, diet 3 (EO250): supplemented with essential oil at 250 mg/kg feed, diet 4 (EO500): supplemented with essential oil at 500 mg/kg feed, diet 5 (ENZY + EO250): supplemented with enzyme and essential oil at 250 mg/kg, and diet 6 (ENZY + EO500): supplemented with enzyme and essential oil at 500 mg/kg.

3.?Birds fed on diets containing ENZY, EO250 and ENZY + EO250 had significantly higher weight gain than those given CONT diet from d 0 to 7. No significant effects on feed intake, feed conversion ratio, mortality, organ weights except for jejunum weight and intestinal lengths was found with either enzyme or essential oil, alone or in combination, over the 21-d growth period. The supplementation of essential oil together with enzyme decreased jejunum weight compared with essential oil alone.

4.?Supplementation with enzyme significantly decreased viscosity and increased dry matter of digesta, but did not alter pH of digesta. There was no effect of essential oil alone at either concentration on viscosity, dry matter or pH of digesta. A significant decrease in viscosity of digesta appeared when essential oil was used with together enzyme.

5.?The supplementation of essential oil at both levels with or without enzyme significantly increased chymotrypsin activity in the digestive system, and improved crude protein digestibility.

6.?The higher concentration of essential oil with and without enzyme significantly increased serum total cholesterol concentrations. No significant effect on immune response was found with either enzyme or essential oil, alone or together.

7.?Enzymes and essential oil had different modes of actions. The supplementation of enzyme with essential oil in diets is likely more effective in view of performance, nutrient digestibility, enzyme activities and immune system.  相似文献   


16.
The medical records of 63 dogs with pituitary-dependent hypercortisolism (PDH) before and during treatment with trilostane were reviewed retrospectively. The correct trilostane dosage in dogs with PDH was based on the resolution of clinical signs and the results of an adrenocorticotropic hormone (ACTH) stimulation test. The mean (±SD) dose rate of trilostane to achieve good clinical control was 2.8 ± 1.0 mg/kg bodyweight. Trilostane treatment resulted in a significant decline in basal plasma cortisol concentrations. The median plasma ACTH concentration (39 pmol/L, range 7–132 pmol/L; n = 60) at the optimal trilostane dosage time was significantly higher (P < 0.001) than before treatment (13 pmol/L, range 2–102 pmol/L). These values did not overlap with plasma ACTH concentrations (range 212–307 pmol/L) of five PDH dogs with trilostane-induced hypocortisolism.The median cortisol/ACTH ratio in well-controlled dogs (0.23, range 0.03–2.5; n = 46) was significantly lower (P < 0.001) than before treatment (2.59, range 0.27–13.25). Trilostane treatment resulted in an insignificant decrease in plasma aldosterone concentration (PAC), but the median plasma renin activity (PRA) at the time the trilostane dosage was considered optimal (265 fmol/L/s, range 70–3280 fmol/L/s; n = 18) was significantly higher (P < 0.001) than prior to treatment (115 fmol/L/s, range 15–1330 fmol/L/s). Similarly, the median PAC/PRA ratio during trilostane treatment (0.16, range 0.003–0.92; n = 17) was significantly lower (P < 0.001) than before treatment (median 0.44, range 0.04–1.33). Trilostane affected both the hypothalamic-pituitary-adrenocortical and the renin–aldosterone axes. The results also suggested that basal plasma ACTH concentration may be used to detect trilostane overdosage.  相似文献   

17.
  1. The effects of dietary electrolyte balance (DEB) and electrolyte–betaine (El-Be) supplements on heat-stressed broiler performance, acid–base balance and water retention were evaluated during the period 31–40 d of age in a 2 × 3 factorial arrangement of treatments.

  2. A total of 240 broilers were assigned to 6 treatment groups each with 8 replicates of 5 birds per cage and were exposed to cyclic high temperature (32 – 24 ± 1°C). Birds were provided with diets having DEB of either 180 or 220 mEq/kg. El-Be supplements were either added to the diet, water or not added to either of them to complete the array of 6 treatment groups.

  3. An additional 80 birds were kept at thermoneutral temperature (20 ± 1°C) and were provided with tap water and diets with DEB of either 180 or 220 mEq/kg to serve as negative controls.

  4. Exposure to high temperature depressed growth performance, increased rectal temperature and decreased potassium (K+) retention. In high-temperature room, birds fed on diets with DEB of 220 mEq/kg tended to increase BW from 35–40 d of age. However, at thermoneutral temperature, broilers fed on diets with DEB of 220 mEq/kg increased K+ retention.

  5. Adding El-Be supplements in feed or water improved feed conversion ratio (FCR), enhanced water consumption and increased K+ and sodium (Na+) retention.

  6. Interactions between DEB and El-Be supplements tended to affect body weight gain and FCR during the periods 35–40 and 31–40 d of age, respectively. It is suggested that when using a diet with DEB of 180 mEq/kg, adding the El-Be supplements in drinking water was more beneficial than in feed. Adding the supplements in feed or water was equally useful when using DEB of 220 mEq/kg.

  相似文献   

18.
The use of soy-based products in pig diets had raised concerns regarding the reproductive toxicity of genistein, the predominant isoflavone in soybeans. Genistein was reported to exhibit weak estrogenic activity but its mechanism of action is not fully recognized. The aim of the study was to examine the in vitro effects of genistein on (1) progesterone (P4) and estradiol (E2) secretion by porcine granulosa cells harvested from medium follicles, (2) the viability of cultured granulosa cells, and (3) the mRNA and protein expression of estrogen receptors α and β (ERα and ERβ) in these cells. In addition, to verify the role of protein tyrosine kinase (PTK)–dependent mechanisms possibly involved in genistein biological action, we tested the effects of lavendustin C, the nonsteroidal PTK inhibitor, on granulosa cell steroidogenesis. We found that genistein inhibited (P < 0.05) basal P4 secretion by granulosa cells harvested from medium follicles of pigs. In contrast, lavendustin C did not affect basal P4 secretion by the cells. Moreover, genistein increased (P < 0.05) basal granulosal secretion of E2. In contrast, lavendustin C did not alter basal E2 secretion by porcine granulosa cells. In addition, we demonstrated that genistein increased mRNA and protein expression of ERβ (P < 0.05) in the examined cells. The expression of ERα mRNA was not affected by genistein and ERα protein was not detected in the cultured granulosa cells of pigs. In summary, the genistein action on follicular steroidogenesis in pigs involved changes in the granulosal expression of ERβ. However, the genistein action on P4 and E2 production by granulosa cells harvested from medium follicles did not seem to be associated with PTK.  相似文献   

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ObjectiveTo compare the sedative and cardiopulmonary effects of intranasal (IN) and intramuscular (IM) administration of dexmedetomidine and midazolam combination in New Zealand White rabbits.Study designA randomized, crossover experimental study.AnimalsA total of eight healthy New Zealand White rabbits, aged 6–12 months, weighing 3.1 ± 0.3 kg (mean ± standard deviation).MethodsThe animals were randomly assigned to administration of dexmedetomidine (0.1 mg kg–1) with midazolam (2 mg kg–1) by either IN or IM route separated by 2 weeks. The electrocardiogram, pulse rate (PR), peripheral haemoglobin oxygen saturation (SpO2), mean noninvasive arterial pressure (MAP), respiratory frequency (fR) and rectal temperature were measured before drug administration (baseline), T0 (onset of sedation) and at 5 minute intervals until recovery. The onset of sedation, duration of sedation and sedation score (SS) were also recorded.ResultsThe PR was significantly lower in treatment IM than in treatment IN over time (p = 0.027). MAP < 60 mmHg developed in two and four rabbits in treatments IN and IM, respectively. SpO2 progressively decreased over time in both treatments. fR was lower than baseline at several time points in both treatments. Onset of sedation was shorter in treatment IN (90 ± 21 seconds) than in treatment IM (300 ± 68 seconds) (p = 0.036). Duration of sedation was longer in treatment IM (55.2 ± 8.7 minutes) than in treatment IN (39.6 ± 2.1 minutes) (p = 0.047). No significant difference in SS was observed between treatments (p > 0.05).Conclusions and clinical relevanceCombination of dexmedetomidine (0.1 mg kg–1) and midazolam (2 mg kg–1) decreased fR, PR and SpO2 regardless of the administration route in New Zealand White rabbits. A more rapid action and shorter duration of sedation were observed after treatment IN than after treatment IM administration.  相似文献   

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