排序方式： 共有10条查询结果，搜索用时 15 毫秒
1
1.
2.
Efrem Gebrehawariat Berhan Tamir Azage Tegegne 《Tropical animal health and production》2010,42(8):1705-1710
Thirty-six Boran × Friesian dairy cows (392 ± 12 kg; mean ± SD) in early parity were used in a randomised complete block design.
Cows were blocked by parity into three blocks of 12 animals and offered normal maize (NM) stover (T1), NM silage (T2) or quality
protein maize (QPM) silage (T3) basal diets supplemented with a similar concentrate mix. Feed intake, body weight and condition
changes and milk yield and composition were assessed. The daily intake of DM, OM, NDF and ADF for cows fed the NM stover-based
diet was higher (P < 0.05) than for the cows fed the NM silage and QPM silage-based diets. However, the daily intake of DOM (9.3 kg) and ME
(140.8 MJ) for cows on QPM silage-based diet was higher (P < 0.05) than for cows on NM stover-based diet (8.4 kg and 124.2 MJ) and NM silage-based diet (7.9 kg and 119.1 MJ). Body
weight of cows was affected (P < 0.05) by the diet, but diet had no effect (P > 0.05) on body condition score, milk yield and milk composition. The digestible organic matter in the NM stover-based diet
(724 g/kg DM) was lower (P < 0.05) than that in the NM (770 g/kg DM) and QPM silage-based diet (762 g/kg DM). It was concluded that the performances
of the cows on the NM silage and QPM silage diets were similar and were not superior to that of the NM stover-based diet. 相似文献
3.
King NP Sheffler W Sawaya MR Vollmar BS Sumida JP André I Gonen T Yeates TO Baker D 《Science (New York, N.Y.)》2012,336(6085):1171-1174
We describe a general computational method for designing proteins that self-assemble to a desired symmetric architecture. Protein building blocks are docked together symmetrically to identify complementary packing arrangements, and low-energy protein-protein interfaces are then designed between the building blocks in order to drive self-assembly. We used trimeric protein building blocks to design a 24-subunit, 13-nm diameter complex with octahedral symmetry and a 12-subunit, 11-nm diameter complex with tetrahedral symmetry. The designed proteins assembled to the desired oligomeric states in solution, and the crystal structures of the complexes revealed that the resulting materials closely match the design models. The method can be used to design a wide variety of self-assembling protein nanomaterials. 相似文献
4.
The effect of supplementation with increasing levels of dried leaves of sweet potato (Ipomoea batatas) on feed intake, body weight gain, and carcass yield characteristics of finisher Ross broiler chicks was studied at Haramaya
University, Ethiopia. Three hundred Ross broiler chicks aging 29 days and weighing 540 ± 5.28 g (mean ± SD) were randomly
distributed to 15 pens, each with 20 chicks, representing five treatment rations each with three replications. Dietary treatments
consisted of inclusions of dried leaves of sweet potato at levels of 0, 50, 100, 150, and 200 g/kg DM for treatments T1, T2,
T3, T4, and T5, respectively. The experiment lasted for 28 days, during which, dry matter intake (DMI), body weight gain,
and feed conversion efficiency; carcass yield characteristics; and weights and lengths of different parts of gastrointestinal
tract were measured. Data were subjected to statistical analysis using SAS (1998). Inclusion of dried leaves of sweet potato
at the level of 200 g/kg DM resulted in lower (P < 0.01) daily DMI as compared to chicks in control diet (T1). The daily body weight gain declined (P < 0.01) when the level of dried leaves of sweet potato in the diet was 150 and 200 g/kg DM. Inclusion of dried leaves of
sweet potato up to 100 g/kg DM did not affect (P > 0.05) eviscerated carcass weight, and weights of drumstick with thigh and breast meat were not affected (P > 0.05) by inclusion of dried leaves of sweet potato up to 150 g/kg DM. The results of this study revealed that inclusion
of dried leaves of sweet potato up to 100 g/kg DM in the finisher ration might be considered as the optimum level of supplementation
when chickens are sold on live weight basis, but if birds are sold on eviscerated carcass weight basis, inclusion up to 150 g/kg
DM might be economically feasible as it produced higher carcass yield components. 相似文献
5.
Tamir B Gebrehawariat E Tegegne A Kortu MY 《Tropical animal health and production》2012,44(7):1547-1553
Rumen degradability characteristics of dry matter (DM), organic matter (OM) and crude protein (CP) of normal maize (NM) stover (T1)-, NM silage (T2)- and quality protein maize (QPM) silage (T3)-based diets were studied using three rumen-fistulated Boran × Friesian non-lactating cows (371?±?32.00?kg) in 3?×?3 Latin Square Design. Cows were supplemented with a similar concentrate mix. In sacco degradability of DM and OM indicated that the (a) values of DM (128) and OM (114) for NM stover were lower (P?相似文献
6.
The study was aimed to characterize the inhibitory dopamine (DA) receptor in the pituitary of tilapia. DA D2 and D3 agonists inhibited GnRH-stimulated LH release from tilapia pituitary cells more efficiently than D4 agonists. However, no significant differences were observed between the efficiencies of D2 and D3 drugs. In order to elucidate the signal transduction of the tilapia DA receptor we performed transfection of COS-7 cells with tilapia D2 DA receptor that resulted in the inhibition of forskolin-stimulated cAMP accumulation. Moreover, the tilapia D2 dopamine receptor inhibits adenylate cyclase activity via coupling to pertussis toxin-sensitive G proteins of the Gi/Go family. Our results also show that estradiol up-regulates taDA-R mRNA. 相似文献
7.
The study investigated the effect of supplementation of a basal diet of Eleucine coracana (finger millet) straw with different protein sources mixed with wheat bran on feed utilisation in Ethiopian Highland lambs.
Twenty yearling intact male lambs (14.9 ± 0.30 kg; mean ± SD) were used in a randomised complete block design. Dietary treatments
included a basal diet of E. coracana straw ad libitum (T1); basal diet supplemented with a mixture of 222 g noug seed (Guizotia abyssinica) cake (NSC) and 78 g wheat bran (WB) (T2); basal diet with a mixture of 234 g cotton seedcake (CSC) and 66 g WB (T3); and
basal diet with a mixture of 5.4 g urea (U) and 294.6 g WB (T4). The supplements were offered at the daily rate of 300 g dry
matter (DM) per lamb in two equal portions at 0800 and 1600 hours. Supplementation of Ethiopian Highland lambs on E. coracana straw basal diet with varied protein sources increased (P < 0.01) the total DM, OM and CP intake and improved (P < 0.01) the daily body weight gain and feed conversion efficiency. Lambs in T2, T3 and T4 gained weight at the rate of 22.7,
21.9 and 14.1 g/day, respectively, while lambs on the control diet lost weight at a rate of −24.9 g/day. Supplementation also
improved (P < 0.01) the digestibility of DM, OM, CP and NDF of the total diet. It was concluded that supplementation of E. coracana straw with NSC, CSC and U mixed with WB improves feed utilisation, body weight gain and digestibility in Ethiopian Highland
lambs. 相似文献
8.
Yeruham I Schwimmer A Friedman S Leitner G Zamir S Ilsar-Adiri N Goshen T 《Berliner und Münchener tier?rztliche Wochenschrift》2005,118(5-6):220-223
Outbreaks of mastitis in a sheep flock and a goat herd caused by Pseudomonas aeruginosa, and their control are described.The morbidity rates of mastitis in a sheep flock and in a goat herd were 18.7 and 18.2 per cent, respectively. The lethality and involuntary culling rates of the animals with sub-clinical mastitis correspond to the morbidity rate.The highest morbidity rates were noted in yearlings--22.5 and 30 per cent, as well as in animals pre- and post partum (7 and 20 per cent, in sheep and goats, respectively). The morbidity periods in the flock and in the herd were 20 and 27 months, respectively. A strict-hygiene milking programme and maintenance of the milking devices was introduced. In addition, prevention of crowding, provision of dry bedding and thorough cleaning of water troughs have also been instituted. Ruthless culling of all infected and carrier animals was an essential part of the control program against Pseudomonas aeruginosa mastitis. 相似文献
9.
Nerya O Vaya J Musa R Izrael S Ben-Arie R Tamir S 《Journal of agricultural and food chemistry》2003,51(5):1201-1207
Tyrosinase is known to be a key enzyme in melanin biosynthesis, involved in determining the color of mammalian skin and hair. Various dermatological disorders, such as melasama, age spots, and sites of actinic damage, arise from the accumulation of an excessive level of epidermal pigmentation. The inadequacy of current therapies to treat these conditions as well as high cytotoxicity and mutagenicity, poor skin penetration, and low stability of formulations led us to seek new whitening agents to meet the medical requirements for depigmenting agents. The inhibitory effect of licorice extract on tyrosinase activity was higher than that expected from the level of glabridin in the extract. This led us to test for other components that may contribute to this strong inhibitory activity. Results indicated that glabrene and isoliquiritigenin (2',4',4-trihydroxychalcone) in the licorice extract can inhibit both mono- and diphenolase tyrosinase activities. The IC(50) values for glabrene and isoliquiritigenin were 3.5 and 8.1 microM, respectively, when tyrosine was used as substrate. The effects of glabrene and isoliquiritigenin on tyrosinase activity were dose-dependent and correlated to their ability to inhibit melanin formation in melanocytes. This is the first study indicating that glabrene and isoliquiritigenin exert varying degrees of inhibition on tyrosinase-dependent melanin biosynthesis, suggesting that isoflavenes and chalcones may serve as candidates for skin-lightening agents. 相似文献
10.
Drought-induced tree mortality has increased over the last decades in forests around the globe. Our objective was to investigate under controlled conditions the hydraulic adjustments underlying the observed ability of Pinus halepensis to survive seasonal drought under semi-arid conditions. One hundred 18-month saplings were exposed in the greenhouse to 10 different drought treatments, simulating combinations of intensities (fraction of water supply relative to control) and durations (period with no water supply) for 30 weeks. Stomata closed at a leaf water potential (Ψ(l)) of -2.8 MPa, suggesting isohydric stomatal regulation. In trees under extreme drought treatments, stomatal closure reduced CO(2) uptake to -1 μmol m(-2) s(-1), indicating the development of carbon starvation. A narrow hydraulic safety margin of 0.3 MPa (from stomatal closure to 50% loss of hydraulic conductivity) was observed, indicating a strategy of maximization of CO2 uptake in trees otherwise adapted to water stress. A differential effect of drought intensity and duration was observed, and was explained by a strong dependence of the water stress effect on the ratio of transpiration to evapotranspiration T/ET and the larger partitioning to transpiration associated with larger irrigation doses. Under intense or prolonged drought, the root system became the main target for biomass accumulation, taking up to 100% of the added biomass, while the stem tissue biomass decreased, associated with up to 60% reduction in xylem volume. 相似文献
1