Effects of dietary protein concentration on postweaning growth of Boer crossbred and Spanish goat wethers   总被引：2，自引：0，他引：2  

Prieto I  Goetsch AL  Banskalieva V  Cameron M  Puchala R  Sahlu T  Dawson LJ  Coleman SW 《Journal of animal science》2000,78(9):2275-2281

Boer (3/4) x Spanish (1/4) (BC; n = 23) and Spanish (SP; n = 22) goat wethers, 4 to 4.5 mo of age and 17.6 and 19.4 kg initial BW, respectively (SE = 0.57), were used to determine effects on growth of protein concentration in 70% concentrate diets provided for ad libitum intake for 30 wk in confinement. Offered diets contained 10.2, 14.2, 18.3, and 23.6% CP (DM basis), and CP concentration in consumed DM was 9.3, 13.8, 17.1, and 22.1% (P1, P2, P3, and P4, respectively); supplemental protein was from soybean meal for P1 and P2 and from soybean meal plus a blend of blood, fish, and feather meals for P3 and P4. Dry matter intake was similar between breeds and among diets (732, 712, 698, and 740 g/d for P1, P2, P3, and P4, respectively; SE = 27.0). Average daily gain was greater for P2 (P = 0.07) and P4 (P < 0.05) than for P1 (76, 90, 85, and 100 g/d for P1, P2, P3, and P4, respectively; SE = 5.3) and for BC than for SP (97 vs 78 g/d, SE = 3.7; P = 0.05). Similarly, ADG:DMI was lowest (P < 0.05) among diets for P1 (0.106, 0.126, 0.121, and 0.132 for P1, P2, P3, and P4, respectively; SE = 0.0053) and greater (P < 0.05) for BC than for SP (0.135 vs 0.108; SE = 0.0037). In conclusion, with 70% concentrate diets, the protein requirement for both BC and SP seemed to have been met by consumption of diets with at least 14% CP, with no apparent benefit from addition of ruminally undegraded protein.  相似文献   

Effect of an immunomodulatory feed additive on markers of immunity in pasture‐fed dairy cows     

MC Playford  K Dawson  SE Playford  AN Smith  SW Page  K Collins  N Forsberg 《Australian veterinary journal》2014,92(12):479-481

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Lunar receiving laboratory     

McLane JC  King EA  Flory DA  Richardson KA  Dawson JP  Kemmerer WW  Wooley BC 《Science (New York, N.Y.)》1967,155(3762):525-529

The Lunar Receiving Laboratory will be the permanent depository of a portion of the collection of lunar samples; it will safeguard the collection, providing continuing security and ensuring scientific integrity. In carrying out the time-dependent experiments and continuing functions of the laboratory, NASA will rely on visiting expert scientists supplementing a relatively small resident staff; outside scientists will be relied upon for most investigations and detailed analyses of samples. It is believed that the designed procedures and facilities provided will ensure the maximum scientific return from the Apollo Program in the way of information from lunar samples.  相似文献   

Cholinergic sensitivity: normal variability as a function of stimulus background   总被引：2，自引：0，他引：2  

L Z Bito  M J Dawson  L Petrinovic 《Science (New York, N.Y.)》1971,172(983):583-585

The sensitivity of the normally innervated iris sphincter to its neuro-transmitter, acetylchloline, and to relatd agents varies inversely with the preexisting physiological stimulus background, that is, the environmental light intnsity. This normal variability suggests the existence of a negative feedback mechahnism whereby sensitivity of the effector cell is modutlated by a product of neuronal activity.  相似文献   

Evolution or not     

Guilday JE  Dawson MR 《Science (New York, N.Y.)》1969,165(3892):443

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Paleogene terrestrial vertebrates: northernmost occurrence, ellesmere island, Canada     

Dawson MR  West RM  Langston W  Hutchison JH 《Science (New York, N.Y.)》1976,192(4241):781-782

Recently discovered Paleogene land vertebrates from the Eureka Sound Formation at about latitude 78 degrees north in Arctic Canada include fish, turtles, an alligatorid, and several taxa of mammals. The assemblage, which is probably early or middle Eocene in age, adds to previously known paleobotanical evidence in suggesting temperate to warm-temperate climatic conditions.  相似文献   

Physiology: a supplement     

Dawson WR 《Science (New York, N.Y.)》1982,218(4568):150-151

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Physiological and molecular characterisation of microbial communities associated with different water-stable aggregate size classes     

R.K. Väisänen  J.L. Garland  L.A. Dawson 《Soil biology & biochemistry》2005,37(11):2007-2016

We determined if the structure and function of microbial communities associated with different aggregate size classes was influenced when the aggregate formation occurred under either nitrogen (N) limitation (straw only incubation treatment) or carbon (C) limitation (straw+N incubation treatment). Using a combination of community-level physiological (BD Oxygen Biosensor assay) and molecular (terminal restriction fragment length polymorphism; T-RFLP) profiling methods, we found differences in both microbial community composition and the physiological response of these communities between different aggregate size classes. The response of fungal and bacterial communities to ‘straw only’ and ‘straw+N’ treatments differed in that bacterial community composition was affected by the treatments, whereas fungal community composition was not. The magnitude of change in the bacterial community response increased with decreasing aggregate size. However, there were no significant differences in the mean bacterial community richness (number of different terminal restriction fragments; TRFs) between different aggregate size classes for the two treatments. In general, microbial communities associated with larger aggregate size fractions (large and small macroaggregates) were found to have a significantly faster respiratory response than the communities associated with microaggregates. Application of the fungal inhibitor cycloheximide resulted in a significant reduction in the utilization of cellulose, chitin, mannose, xylan, and xylose by the microbial communities associated with all aggregate size classes, indicating that fungi are significant contributors to the utilization of these compounds. Our results demonstrate that the BD Oxygen Biosensor assay offers a valuable new tool for community level physiological profiling. When used in combination with census-based methods such as T-RFLP, a greater level of resolution can be achieved.  相似文献   

Long-term stability in core habitat of an endangered population of bottlenose dolphins (Tursiops truncatus): Implications for spatial management     

Steph Bennington  Will Rayment  Rohan Currey  Lucy Oldridge  Shaun Henderson  Marta Guerra  Tom Brough  David Johnston  Chloe Corne  David Johnson  Liz Slooten  Steve Dawson 《水产资源保护:海洋与淡水生态系统》2021,31(3):665-676

1. A small population of approximately 68 bottlenose dolphins, Tursiops truncatus, resident in Doubtful Sound, New Zealand, is subject to physiologically challenging conditions, and is exposed to anthropogenic pressure from tourism.
2. A voluntary Code of Management incorporating dolphin protection zones (DPZs), in which tour boat access is limited, was established in 2008.
3. Kernel density estimation (KDE) was used to quantify dolphin habitat use over a 13-year period in order to describe seasonal variation in habitat use and consistency of habitat use over a decadal period, and to provide quantitative estimates of the extent of overlap between DPZs and core areas (50% volume contour) of habitat use.
4. Habitat use varied seasonally, with the inner fjord area used more frequently in warmer months, and with a shift in use to the outer fjord in colder months. Patterns in habitat use were highly consistent over the 13-year duration of the study.
5. The spatial overlap between the area of core dolphin habitat and DPZs was low (<18%) overall, and some DPZs were rarely used during colder periods.
6. Consistency in habitat use through time vindicates spatial management, but low overlap between core habitat and current DPZs suggests that an expansion of the DPZ areas would confer greater protection.

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Conservation of Hector's dolphins: The case and process which led to establishment of the Banks Peninsula Marine Mammal Sanctuary     

S. M. Dawson  E. Slooten 《水产资源保护:海洋与淡水生态系统》1993,3(3):207-221

• 1. Entanglement in gillnets constitutes the greatest known threat to populations of small cetaceans. In 1988, in response to data on the distribution and abundance, incidental catch, reproduction and population biology of Hector's dolphins, and after an extended period of public consultation, New Zealand's Department of Conservation created a 1170 km² Marine Mammal Sanctuary. Within this area, gillnetting on a commercial scale is illegal and amateur fishers may only set gillnets in specific times and places.
• 2. This paper summarizes the salient points of research that led to the creation of the sanctuary, briefly describes the process by which the sanctuary was established, and offers some comments on the information required for conservation management of small cetaceans.

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