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901.
Grondwaterherverspreiding vind vinnig in die hele grondprofiel van drie subhabitatte nl. Eragrostis pallens, Ochna pulchra en Grewia flavescens van ‘n Burkea‐savanna plaas. Na ‘n reënbui van 50 mm herversprei water binne 12 uur tot op ‘n diepte van 90 cm in ‘n sandgrond wat as die Chesterserie van die Huttonvorm geklassifiseer is. In die E. pallens en O. pulchra subhabitatte vind wateropname hoofsaaklik in die boonste 60 cm van die grondprofiel plaas terwyl vog vrylik beskikbaar is in die ondergrond selfs in die droogste maande nl. Junie, Julie en selfs Augustus. In die G. flavescens subhabitat vind wateropname deur die hele grondprofiel plaas tot op ‘n diepte van 120 cm. Die G. flavescens subhabitat blyk meer onderhewig aan vogstremminge te wees.  相似文献   
902.
Summary

The feet of three two‐humped camels (Camelus bactrianus), one lama (Lama glama) and four alpacas (Lama pacos) from zoos and a circus in the Netherlands were examined for the mange‐mite Choroptes bovis. Mites were found on two of the camels, the lama, and three of the alpacas. On one camel and one alpaca small mange lesions on the feet were present. This is the first report of Chorioptes bovis and chorioptic mange in the two‐humped camel.  相似文献   
903.
Summary

The macroscopic and histological appearance of jejunal antimesenteric incisions approximated with two different absorbable suture materials (monofilament versus multifilament) and three closure techniques (appositional single layer, crushing single layer, and double layer) were compared in healthy dogs at 14 or 28 days, postoperatively. No significant differences between the two suture materials were observed for most of the macroscopic or histological variables. However, the monofilament suture material caused significantly more fibrous tissue reaction in the muscular layer of the jejunum than did the multifilament suture material. Of the three enterotomy closure techniques used in this study, the appositional single‐layer method proved to be the best. The double‐layer closure method caused a significant decrease in the incisional circumference, the relative circumference, and volume of the jejunum, and a significant increase in jejunal wall thickness. Our findings suggest that canine jejunal enterotomy incisions can be closed using an appositional suture pattern with relatively rapidly absorbable monofilament suture material. The use of double‐layer suture patterns for closure of jejunal enterotomy incisions should be avoided because the size of the intestinal lumen may be reduced.  相似文献   
904.

Four cow routing treatments related to fully automatic milking were compared consecutively in one group of 24 Holstein Friesian cows. The objective of the experiment was to investigate how cow traffic towards the automatic milking system (AMS) should be routed and whether a preselection or a waiting area in front of the AMS should be used. The treatments were (1) free routing with selection of cows in the AMS (FREE); (2) free routing with a preselection system in front of the AMS (FREE_SS); (3) free routing with a preselection system and a waiting area in front of the AMS (FREE_WA); and (4) one-way gates resulting in forced routing with preselection and a waiting area in front of the AMS (FORCED_WA). Evaluation of the treatments revealed that FREE may be questionable with regard to the cows' visiting frequency to the AMS and that the use of a waiting area in combination with free routing (FREE_WA) may slow down the passing through the AMS. FORCED_WA may be the best option in relation to the cows' use of the AMS, but this traffic system seems to postpone or even thwart the feeding. The treatment that appears to give the best results is FREE_SS. The type of AMS visit appeared to have a marked influence on the cows' subsequent behaviour. Cows returned to the AMS sooner after non-milking visits and failed attachments (P<0.01). This increases the occupation rate of the AMS and may induce some extra unrest in the herd.  相似文献   
905.
Abstract

An experiment was conducted to investigate changes in the lumen and wall of the intestinal tract of weaned pigs caused by fructo-oligosaccharides (FOS) and consequences for growth. Twelve male pigs weaned at 24 days were individually housed and fed either control, 0.25% FOS, or 3% FOS diets for 21 days after weaning. The pH of chyme in the caecum and proximal colon were lower (p<0.001) in 3% FOS compared to other treatments. Mean molar proportions (%) of total SCFA values along the large intestine were significantly affected by FOS diet. Acetic acid was significantly higher in control compared with other treatments. Butyric acid and isobutyric acid were significantly increased in 0.25 and 3% FOS compared to the control. Feed intake, empty body weight gain, disaccharidase activities and villous height in the small intestine were not significantly affected by FOS. It was concluded that dietary FOS stimulates fermentation in the large intestine, but does not significantly affect enzyme activity, ammonia content, villous height and growth.  相似文献   
906.
Abstract

This study investigated the effectiveness of the proprietary laser methane detector (LMD) in enteric methane monitoring from individual dairy cows and sheep. Three experiments were carried out. First, the relationship between LMD and indirect open-circuit respiration calorimetric chamber measurements was tested. Sensitivity and specificity for cows were 95.4% and 96.5%. For sheep, sensitivity was 93.8% and specificity was 78.7%. Second, the effect of cow's activity on enteric methane emissions was investigated. During drinking and feeding, cows produced significantly more (p<0.001) methane emissions than when idle. Third, effect of different micrometeorological factors on LMD measurements under outdoor grazing conditions was investigated. Wind speed, relative humidity, pressure and wind direction relative to methane point-source had significant effect on methane measurements (p<0.001) under outdoor conditions. With further validation, the LMD has potential to provide reliable estimates from ruminants and hence provide a useful technique for on-farm monitoring and decision support for greenhouse gas mitigation strategies.  相似文献   
907.
Abstract

Rainfall variability is a major determinant of system dynamics and profitability of livestock enterprises in arid and semi‐arid environments. Range managers consequently require detailed information on the financial and ecological implications of various stocking strategies in order to formulate viable management systems. Data collected over seven seasons (1986–1993), from a series of extensive grazing trials in the semi‐arid savanna of KwaZulu‐Natal with cattle stocked at three rates (0.17, 0.23 and 0.30 LSU ha?1) were used to develop a bioeconomic stocking model (LOWBEEF). The model comprised two biological sub‐models (BEEF and GRASS), and an integrated economic component. The BEEF sub‐model related seasonal live mass gain to stocking rate and rainfall. The GRASS sub‐model related residual herbage at the end of summer to summer stocking intensity, range condition (indexed as the sum of proportions of three key forage species, Themeda triandra, Panicum maximum and P. coloratum) and rainfall. The period over which supplementary feeding would be required to maintain cattle mass was related to residual summer herbage mass. The biological sub‐models were linked to an economic component model (ECON) to reflect the influence of various environmental and economic parameters on profitability.  相似文献   
908.
Efficient oral endotracheal intubation of laboratory animals is a challenging technique in veterinary research. This study introduces a miniaturized lighted stylet for rabbit intubation. An experiment with repeated measures on two factors was used to assess the feasibility and efficacy of this method. The first factor compared stylet intubation vs. laryngoscopic intubation. The second compared three practitioners, one with prior experience and two without. Success rates on the initial attempt were not statistically different (χ2 = 2.46, P = 0.12). The time difference between methods was significant (F = 41.007, P < 0.001), although the effect of practitioners was not (F = 1.038, P = 0.365). The mean ± SD of the intubation time, combining results from the three practitioners, was 20.34 ± 17.15 s for the stylet method and 57.58 ± 64.21 s for the laryngoscopic method. The results of this study demonstrate that lighted stylet intubation is efficient, robust, and independent of practitioner experience.  相似文献   
909.
910.
Faecal nitrogen (FN) concentration is used as a marker for habitat quality and digestive efficiency in free‐ranging herbivores. In herbivores, FN can be separated into undigested plant N (analysed as the N concentration of the neutral detergent residue) and metabolic faecal N (MFN). It has been suggested that by differential analysis of the faecal fibre‐bound N, the MFN fraction can be further split into a bacterial N and an endogenous N fraction [Hesta et al., Br. J. Nutr. 90 (2003) 1007]. We applied these methods to 96 faecal samples of 48 mammalian herbivore species from zoos. Species were grouped into coprophageous and non‐coprophageous hindgut fermenters and ruminating and non‐ruminating foregut fermenters. Diet was not controlled. The FN decreased with body mass, possibly reflecting higher proportions of concentrates in diets of smaller animals. The proportion of MFN increased with FN, indicating that higher quality food might enhance the gastrointestinal bacterial flora. The only outlier to this pattern was the lesser panda (Ailurus fulgens), confirming the low relevance of fermentative digestion in this herbivorous ‘carnivore’. No relevant differences between the four digestion types were noted. The proportion of endogenous faecal N (32–80% of FN) was always higher than that of bacterial faecal N (7–30%), which contradicts basal understanding of herbivore digestive physiology. Thus, the method of Hesta et al. (2003) does not appear applicable to herbivores. While the results do not exclude the possibility that detailed differences might occur between digestion types, they indicate a high degree of similarity between herbivores that rely on bacterial fermentation, regardless of their digestion type, with respect to metabolic faecal losses.  相似文献   
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