两种饲喂方式对哺乳母猪生产性能的影响研究

选取年龄、胎次、品种基本一致的哺乳母猪20头,随机分成对照组和试验组,试验分两批进行,每批10头.在相同的环境条件下,母猪自由饮水,饲喂同一哺乳母猪料.母猪分娩后4 d内,采用原场饲养制度,逐步增加哺乳母猪采食量,第5天开始,对照组采用不限量饲喂,试验组采用限量和添加哺乳母猪补充料的饲喂方式,仔猪21日龄断奶.结果显示两组仔猪21日龄的断奶窝重、母猪断奶后再发情时间和母猪哺乳失重等差异均不显著(P>0.05).     

Quantification of stress sensitive markers in single fecal samples do not accurately predict excretion of these in the pig

All feces produced during 24 h were collected from five pigs and cortisol and immunoreactive cortisol metabolites (CICM), and IgA were quantified. Within pigs, the concentrations of CICM and IgA varied extensively between random samples obtained from a single fecal dropping, and deviated in most cases significantly from the true concentration measured in total fecal output (CV 6.7-130%). The CICM and IgA contents varied considerably (CV 8.1-114%) within and between individual fecal droppings from the same pig compared to the total fecal excretion. In conclusion, single random samples could not be used to reliably quantify the total fecal concentration or excretion of CICM or IgA in pigs. Analyses of all feces collected during shorter periods than 24 h did not provide an accurate estimate of the daily excretion of CICM. Thus, the concentration of stress sensitive molecules in random single fecal samples as an indicator of animal welfare should be interpreted with prudence.     

DNA‐analysis to monitor fisheries and aquaculture: Too costly?

Evidence from DNA‐analysis is commonplace in human criminal investigations, and while it is increasingly being used in wildlife crime, to date, its application to control and enforcement activities in fisheries and aquaculture has only been sporadic. Contemporary DNA‐analysis tools are capable of addressing a broad range of compliance issues, species identification, mislabelling of fish products, determining the origin of catches and the farm of origin of aquaculture escapees. Such applications have the potential to ensure traceability along the fish product supply chain and to combat consumer fraud and Illegal, Unreported and Unregulated fishing. Nevertheless, DNA‐analysis is not yet used routinely in investigations into compliance with fisheries and aquaculture legislation. One potential reason for this is that DNA‐analysis techniques may have been regarded as too expensive. However, costs have plummeted over the past decade prompting us to objectively assess whether the costs associated with routine use of DNA‐analysis techniques for fisheries and aquaculture control and enforcement activities do constitute an impediment. Based on a number of recent fisheries and aquaculture compliance investigations that incorporated DNA‐analysis, our results indicate that the use of genetic analysis was justified and worthwhile in all cases examined. We therefore conclude that the costs associated with DNA‐analysis do not represent a barrier to the routine adoption of DNA‐analysis techniques in fisheries and aquaculture compliance investigations. Thus, control and enforcement agencies should be encouraged to use such techniques routinely.     

Wood density and anatomy of water-limited eucalypts

We hypothesized that seedlings grown under water-limited conditions would develop denser wood than seedlings grown under well-watered conditions. Three Eucalyptus species (E. grandis Hill (ex Maiden), E. sideroxylon Cunn. (ex Woolls) and E. occidentalis Endl.) were grown in a temperature-controlled greenhouse for 19 weeks with watering treatments (well-watered and water-limited) applied at six weeks. The water-limitation treatment consisted of four drought cycles. Wood density increased by between 4 and 13% in the water-limited seedlings, but this increase was mainly due to extractive compounds embedded in the cell wall matrix. Once these compounds were removed, the increase was 0-9% and was significant for E. grandis only. Water-limitation significantly reduced mean vessel lumen area; however, this was balanced by a trend toward greater vessel frequency in water-limited plants, and consequently there was no difference in the proportion of stem area allocated to vessels. Conduit efficiency value was lowest in the water-limited plants, indicating that there was a cost in terms of stem hydraulic conductivity for decreasing vessel lumen area. Wood density was negatively correlated with vessel lumen fraction in well-watered plants, but this relationship broke down in the water-limited plants, possibly because of the significantly larger proportion of the stem taken up by pith in water-limited seedlings. Diurnal variation in leaf water potential was positively correlated with wood density in well-watered plants. This relationship did not hold in the water-limited plants owing to the collapse of the pressure gradient between soil and leaf. We conclude that drought periods of greater than 1 month are required to increase wood density in these species and that increases in wood density appear to result in diminished capacity to supply water to leaves.     

林业发展所面临的形势及国民经济发展对林业的需求分析

文章着重分析了内蒙古当前林业发展形势及国民经济发展对林业的需求 ,并客观的论述了自治区林业发展的有利条件和制约因素 ,希望能够对今后的林业建设有所帮助 ,从而把握机遇 ,加快环境建设步伐 ,早日改善环境状况。     

Separation of pair housed roosters is associated with transient increased corticosteroid excretion

Immunoreactive corticosterone and corticosterone metabolites (ICCM) were quantified in excreta of permanently single housed (n = 10) and permanently pair housed (n = 20) roosters. The pair housed roosters were separated and single housed, and ICCM were quantified in the droppings before and during 15 days after separation. There was no statistically significant difference in ICCM excretion in the droppings between the permanently single or pair housed roosters. After separation, however, the previously pair housed roosters showed a significantly transient elevated excretion of ICCM in droppings the second day after separation indicating that the separation and relocation is associated with an activation of the hypothalamic-pituitary-adrenal axis.The excretion of ICCM in droppings was not correlated to the concentration of ICCM in droppings. It is thus important that excretion of ICCM be expressed as amount excreted per time unit since the total excretion is dependant on both concentration of ICCM and amount of droppings produced.     

Quantitative comparison of three commonly used treatments for navicular syndrome in horses

OBJECTIVE: To quantitatively compare 3 commonly used treatments for navicular syndrome (NS) in horses: heel-elevation shoeing alone, heel-elevation shoeing and phenylbutazone administration, heel-elevation shoeing and injection of the distal interphalangeal joint (DIPJ) with triamcinolone acetonide (TA), and all 3 treatments in combination. ANIMALS: 12 horses with NS. PROCEDURE: A force plate was used to measure baseline peak vertical ground reaction force (PVGRF) of the forelimbs. Each horse's forelimbs were shod with 3 degrees heel-elevation horseshoes; PVGRF was measured 24 hours and 14 days after shoeing. Fourteen days after shoeing (following data collection), phenylbutazone (4.4 mg/kg, i.v., q 12 h) was administered (5 treatments). Two hours after the fifth treatment, PVGRF was measured; TA (6 mg) was injected into the DIPJ of the forelimb that generated the lower baseline PVGRF Fourteen days later, PVGRF was measured. Phenylbutazone was administered as before, and PVGRF was measured. Percentage body weight of force (%BWF) was calculated from PVGRF measurements and used for comparisons. RESULTS: 14 days after shoeing, mean %BWF in both forelimbs significantly increased from baseline; additional administration of phenylbutazone significantly increased %BWF applied from the more lame forelimb. Compared with shoeing alone, there was no significant change in %BWF after injection of the DIPJ with TA in shod horses. CONCLUSIONS AND CLINICAL RELEVANCE: Heel-elevation shoeing alone and in combination with phenylbutazone administration quantitatively decreased lameness in horses with NS. Although not significant, additional DIPJ injection with TA resulted in further quantitative decrease in lameness, compared with that achieved via shoeing alone.