Two methods of removing bacteria from hydroponic nutrient solution [ultraviolet (UV) radiation and submicronic filter] were evaluated for efficiency and for their effects on lettuce (Lactuca sativa L.) production. Both methods were effective in removing bacteria; but, at high intensity, the ultraviolet sterilizer significantly inhibited the production of plants grown in the treated solution. Bacterial removal by lower intensity UV or a submicronic filter seemed to promote plant growth slightly, but showed no consistent, statistically significant effect. 相似文献
1. The feeding value of new low β‐N‐oxalyl‐amino‐L‐alanine (BOAA) lines of Lathyrus sativus (lathyrus) and the benefits of dehulling the seed or of pre‐adapting chicks to lathyrus‐based diets were examined in several experiments.
2. Chicks fed on diets containing 400 g/kg of the low (1.3 g BOAA/kg seed) and medium (2.2 g BOAA/kg seed) BOAA lines did not differ (P>0.05) in weight gain (WG) or in apparent fat and protein digestibilities compared to birds fed on a wheat‐based diet.
3. Consumption of 600 g low BOAA lathyrus/kg diet caused a slight, but significant (P< 0.05), decrease in WG. Food efficiency decreased as the amount of dietary lathyrus was increased, suggesting that lathyrus may contain an antinutritive factor(s) other than BOAA.
4. Removal of the hull (70 g hull/kg seed) from the seed did not affect chick performance (P> 0.05).
5. Pre‐adapting chicks for 7 d to diets containing up to 600 g medium line lathyrus/kg diet did not reduce the detrimental effects of the lathyrus.
6. Although dehulling and pre‐adaptation of chicks to lathyrus were not beneficial, the low and medium lines of lathyrus tested show potential for use in chick diets up to at least 400 g lathyrus/kg diet. 相似文献
The experiment was conducted on 364 male Wistar rats of which 74 were included into the "zero" group and the remaining 290 were divided into 5 experimental groups, corresponding to the dietary protein levels of 4, 5, 10, 15 and 20%. The protein source in the diet was skim milk powder. The animals were fed individually and ad libitum. The experiment was performed between the 21 and 66 days of life of the rats and during this period, the animals in each group were successively killed to determine the nitrogen content in the body. Between the N content in the body and the body mass of rats from "zero" group, the relationship N0/W0 was determined. In each experimental group, two relationships were determined: --final nitrogen against final body mass--Nf/Wf --gain of nitrogen against gain of body mass--delta N/delta W. The derivatives of both functions were used for calculation of the daily gains of nitrogen (delta Nd) 1. According to the relationship Nf/Wf there was a similar significant increase of nitrogen content in the body in all groups with increasing the body mass, according to bc = 1.0413. The percentage of nitrogen in the body increased significantly only at dietary protein levels over 10%. 2. The rate of nitrogen gain in the gain of body mass according to delta N magnitude of was relatively constant in all groups (bc = 1). Thus, N-% in delta W was also relatively constant. N-% in the body gain increased significantly only at dietary protein levels over 10%. 3. Differences in the gains of nitrogen, as calculated by the derivative dNf/dWf and by d delta N/d delta W, showed in the first line in low-protein groups (on 4 and 5% protein) due to the error of estimation of the initial-N according to the equation N0 magnitude of W0. The mean relative error of estimation the initial-N was +/- 3% but in groups on 4 and 5% protein it charged the gain of N with 9-12% in spite of excluding from the relationship delta N magnitude of delta W rats with delta W less than 10 g. 4. Only when delta N greater than or equal to 1.3 g and delta W greater than or equal to 43, the error of estimation of delta N, did not exceed 3%.(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
Bacterial isolations were reviewed from equine trachea, guttural pouch, uterus, wounds, abscesses, blood, synovial fluid, and abdominal fluid submitted to the Clinical Bacteriology Laboratory of the School of Veterinary Medicine at the University of Montreal for aerobic bacterial culture from 1986 to 1988. Of the 733 samples submitted, 324 (44%) were positive for bacterial growth, and 233 antimicrobial sensitivity tests were performed. Seventy-six percent of all positive samples yielded one bacterial species and two were isolated from 22% of positive samples. Streptococcus zooepidemicus, Escherichia coli, and Actinobacillus spp. were isolated from 39%, 18%, and 15% of the samples, respectively.
Bacterial growth was most common from guttural pouches, wounds and abscesses, and transtracheal washes (TTW), but was less common from uterus, blood, abdominal fluid, and synovial fluids. Streptococcus zooepidemicus was the most common bacterium recovered from guttural pouches, TTW, uterus, and wounds and abscesses. Escherichia coli predominated in abdominal fluids, blood, and synovia. Bacterial sensitivities to common antimicrobials are presented.
