Pre-weaning eating activity and morphological parameters in the small and large intestine of piglets     

Mette S. Hedemann  Lise Dybkjr  Bent Borg Jensen 《Livestock Science》2007,108(1-3):128-131

The effect of pre-weaning eating activity on the intestinal morphology in piglets was investigated on the day of weaning and 5 days post-weaning. The eating activity of each piglet was recorded by means of direct observations. On day 5 post-weaning the villous heights were reduced and the crypt depths were increased irrespective of the pre-weaning eating activity. In the caecum and colon the crypt depth was increased post-weaning and no effect of pre-weaning eating activity was observed. The muscle thickness in the small intestine did not change during the immediate post-weaning period whereas the muscle thickness in the large intestine was doubled in the same period. In conclusion, pre-weaning eating activity did not affect the structural alterations of the small and large intestine. However, the actual number of piglets consuming creep feed prior to weaning was low and the eating activity was highly variable. Therefore, more or later weaned piglets may be needed to show effects of pre-weaning eating activity.  相似文献   

Antifungal properties of terpenoids in Picea abies against Heterobasidion parviporum     

N. Kusumoto  T. Zhao  G. Swedjemark  T. Ashitani  K. Takahashi  A.‐K. Borg‐Karlson 《Forest Pathology》2014,44(5):353-361

The antifungal properties of 14 major oleoresin‐constitutive terpenoids of Norway spruce (Picea abies) against Heterobasidion parviporum were evaluated in vitro at three gradient concentrations, 0.1, 0.2 and 0.4 μmol/cm², on potato dextrose agar medium. Eight monoterpene hydrocarbons (+)‐ and (?)‐α‐pinene, (?)‐β‐pinene, (+)‐3‐carene, myrcene, (+)‐ and (?)‐limonene, terpinolene; four oxygenated monoterpenes α‐terpineol, terpinen‐4‐ol, 1,8‐cineole, bornyl acetate; and two resin acids abietic acid and dehydroabietic acid were selected. Abietic and dehydroabietic acids showed the highest antifungal activities at all concentrations. Among oxygenated monoterpenes, bornyl acetate and α‐terpineol showed antifungal activity at the highest concentration. Among monoterpene hydrocarbons, (+)‐α‐pinene showed similar activity to terpinen‐4‐ol and 1,8‐cineole at the highest concentration; however, it was lower than α‐terpineol and bornyl acetate. Other monoterpene hydrocarbons inhibited mycelial growth by <10%. Re‐extraction of medium surfaces after the test period revealed that most α‐terpineol and terpinen‐4‐ol remained unchanged on the surface but monoterpene hydrocarbons completely disappeared. However, notable fungal transformed products were observed on surfaces applied with 1,8‐cineole and bornyl acetate. Thus, mycelial growth inhibition of monoterpenoids might be caused by complex functions such as biodegradation and/or detoxification by interaction between mycelium and compound. These results provide a basis for future studies considering the role of chemodiversity in the comprehensive chemical defence of P. abies.  相似文献   

LH-β and FSH-β mRNA expression in nesting and post-breeding three-spined stickleback, Gasterosteus aculeatus, and effects of castration on expression of LH-β, FSH-β and spiggin mRNA     

Anna Hellqvist  Monika Schmitz  Christina Lindberg  Per-Erik Olsson  Bertil Borg 《Fish physiology and biochemistry》2001,25(4):311-317

The mRNA expression of the LH- and FSH- subunits were measured in nesting and post-breeding male three-spined sticklebacks, Gasterosteus aculetaus, as well as in castrated and sham-operated nesting males. Furthermore, expression of an androgen induced kidney protein, spiggin, and 11-ketotestosterone (11KT) levels, were measured in the castrated and sham-operated males. Nesting males had significantly higher levels of both LH- and FSH- mRNA expression compared to post-breeding males. Furthermore, sham-operated males had significantly higher levels of LH- mRNA and spiggin mRNA expression than the castrated fish. Expression of FSH-, on the other hand, did not differ between castrated and sham-operated males. There were strong positive individual correlations between circulating levels of 11KT on the one hand and expressions of LH- and spiggin mRNA, whereas the correlation between 11KT levels and FSH- mRNA was weak. The negative effect of castration on -LH mRNA indicates that gonadal hormones stimulate this expression, whereas this was not the case for -FSH. The observed decline in -LH expression after the end of the breeding season may be the result of cessation of the gonadal stimulation of the pituitary. On the other hand, it is not likely that this can explain the decline in FSH- expression.  相似文献   

Effects of aromatase inhibitors on reproduction in male three-spined sticklebacks, Gasterosteus aculeatus, exposed to long and short photoperiods     

C. Bornestaf  E. Antonopoulou  I. Mayer  B. Borg 《Fish physiology and biochemistry》1997,16(5):419-423

Three-spined stickleback Gasterosteus aculeatus, males were implanted with Silastic capsules filled with different aromatase inhibitors; 1,4,6-androstatriene-3,17-dione or the non-steroidal CGS16949 A, 4-(5,6,7,8-tetrahydrimidazol [1,5-a]pyridin-5-yl) benzonitrile monohydrochloride or empty capsules. The fish were then exposed to long or short photoperiod. Under the long photoperiod most fish in all treatments displayed a hypertrophied kidney (a secondary sexual character in sticklebacks) and completed, quiescent spermatogenesis, similar as in the natural spawning period. Under the short photoperiod the controls had unstimulated kidneys and an active spermatogenesis, whereas the males implanted with both aromatase inhibitors had stimulated kidneys, though not to the extent as in the long photoperiod, and completed, quiescent spermatogenesis. These findings suggest that aromatization is of importance for the inhibitory effects of short photoperiod on reproduction in the stickleback. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

RAPD analysis of interspecific relationships in presumably apomictic Cotoneaster species   总被引：3，自引：0，他引：3  

Igor V. Bartish  Bertil Hylmö  Hilde Nybom 《Euphytica》2001,120(2):273-280

A few of the approximately 300 Cotoneaster species described are diploid but the majority appear to be polyploid. The occurrence of apomixis inpolyploid Cotoneaster species has been reported but never proven with genetic markers. We have used 76 polymorphic RAPD markers to investigate the breeding system and phenetic grouping of some critical taxa, including a total of 19 plant accessions representing 13 mostly European species in the series Cotoneaster. Three to four individual plants, raised from seed from the same original plant, were analyzed for each of three accessions to investigate the possible occurrence of apomictic seed set. Absolutely congruent RAPD profiles were encountered among seedlings from one accession, whereas we found one or two marker differences among seedlings from the other two accessions. Genetic similarities among the different accessions were analyzed with a UPGMA-derived dendrogram. The most deviant taxon was the Chinese C. albokermesinus. A group withC. soczavianus and C. tomentosus was rather isolated from the remainder, as was also C. kullensis. Among the remaining taxa, two well supported clusters were found: (1) C. antoninae and C. uralensis, and (2) C. integerrimus and C. raboutensis, whereas the other five species (C. canescens, C. niger, C. scandinavicus, C. juranus, C. cambricus) formed a poorly supported cluster with no clear substructuring. A principal coordinate analysis yielded results that were in good correspondence with the dendrogram. Again C. albokermesinus appears to be totally isolated from the other species. In addition, two well-defined and rather isolated groups were found: (1) C. tomentosus and C. soczavianus, and (2) C. antoninae and C. uralensis, with the remainder comprising a loosely defined group. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Influence of wetland liming on water chemistry of acidified mountain streams in Lofsdalen,Central Sweden     

H. Borg  P. Andersson  P. Nyberg  E. Olofsson 《Water, air, and soil pollution》1995,85(2):907-912

Acidic precipitation has caused damage to the populations of fish and invertebrates in numerous streams in the southern part of the Swedish mountain range. In the middle of the 70's, the pH of precipitation decreased and has since then frequently been lower than 4.5. Many of the streamwaters were well buffered during most time of the year, but during periods with high discharge, the buffering capacity was completely exhausted, pH frequently decreased to around 4.5 and very high levels of Fe, Mn and Al occurred. In general, base cations (BC) and organic anions decreased during periods of high flow, while SO₄ increased or was relatively independent of flow. On an average, the ratio SO₄/BC was negatively correlated to pH, while organic anions/BC showed a weaker correlation to pH. In order to investigate if wetland liming could be used as a remedial measure in such areas, lime treatments were started in 1983 in the Lofsdalen area, province of Härjedalen. The liming stabilized the alkalinity and pH of the streams at circum-neutral levels, and reduced the leaching of Fe, Mn, and Al. The average levels of these elements decreased and the seasonal fluctuation decreased considerably.  相似文献   

Episodic Events in Water Chemistry and Metals in Streams in Northern Sweden during Spring Flood     

Frida Edberg  Hans Borg  Jan-Erik Åslund 《Water, air, and soil pollution》2001,130(1-4):1697-1702

Thirteen streams in the province of Jämtland in northern Sweden were monitored during spring in 1995 (December 94 – July 95) to study changes in water chemistry and metal concentrations during snow melt. The brooks are not treated with lime, with one exception, and can be approximately divided into three groups according to watershed characteristics; A) > 65% above tree line, B) > 65 % wetland, C) > 55% forested. During peak flow, pH dropped 0.5–2.5 units and alkalinity generally to zero. The brooks above tree line were lowest in base cations and reached the lowest pH-values (4.4–4.6) during peak flow, while sulphate levels were about the same as in the forested watersheds. During peak flow, organic anions showed the highest increase in the wetland and forested catchments. Compared to base flow, Al, Zn, Pb and to some extent Mn was enriched during peak flow. The results also illustrate the difficulties in generalising the reasons for alkalinity losses during spring flood in this kind of streams. In some of the brooks, the use of either base cations or silica, when calculating dilution effects, gave deviating results concerning the relative contribution of strong acids in the snow pack.  相似文献   

Nutrient and persistent pollutant deposition on the Bothnian Bay ice and snow fields     

Lars Rahm  Bertil Håkansson  Per Larsson  Elisabet Fogelqvist  Gudrun Bremle  Jorge Valderrama 《Water, air, and soil pollution》1995,84(1-2):187-201

A study of atmospheric deposited nutrients and some persistent pollutants has been carried out on the ice and snow fields of the subarctic Bothnian Bay, the northernmost basin of the Baltic Sea. Total amounts of 600, 500 and 400 tons NO₃-N, NH₄-N and N_org-N, respectively are deposited in the snow while the corresponding amounts for P_tot-P is 40 tons. The corresponding amount for PCB and lindane are 1.0 and 0.2 kg, respectively. The measurements were carried out on the snow-covered ice four to six weeks old. A part of the deposited snow has been incorporated -into the snow-ice and an attempt to estimate its mean thickness and its amount of nutrients has been made. The total amounts now reach 1700, 1300 and 1100 tons of NO₃-N and NH₄-N and N_org-N, respectively in the snow and ice together. The results obtained support the use of land-based stations in estimates of seasonal atmospheric nutrient deposition to the Bothnian Bay. The observed concentrations of chloroorganic compounds correspond to those land-based observations reported from the same latitude in the northern hemisphere and reported in literature.  相似文献   

Metal fluxes to Swedis forest lakes     

Hans Borg  Kjell Johansson 《Water, air, and soil pollution》1989,47(3-4):427-440

Data on atmospheric deposition, transport via run-off water and contents in soil were used to estimate the fluxes of Zn, Cd, Cu, Pb, and Hg to Swedish forest lakes. The calculations refer to a hypothetical lake with a surface area of about 9% of the total catchment area. There are clear differences in the pathways and transport mechanisms for the different elements. The dominating pathway for the input of Zn and Cd to lakes is via run-off from the drainage area. About 60 to 95% of the total load comes from run-off, highest in the acidified areas. The acidification status of the soil is by far the most important factor regulating the mobility of these elements. The amounts of Hg and Pb deposited on the drainage area are mainly accumulating in the surficial soil layers. The transport of these elements is primarily associated with humic substances. About 30 to 50% of the total load of Pb and 25 to 75% of the total load of Hg to lakes originates from run-off. The transport mechanisms for Cu are similar to those of Pb and Hg, but due to the lower anthropogenic airborne load, the direct deposition is of less importance.  相似文献   

Reacidification Effects on Water Chemistry and Plankton in a Limed Lake in Sweden     

Frida Edberg  Paul Andersson  Hans Borg  Christina Ekström  Einar Hörnström 《Water, air, and soil pollution》2001,130(1-4):1763-1768

Water chemistry and plankton has been monitored in three Lakes in Tyresta National park SE of Stockholm since 1977. Liming operations started in Lake Långsjön and Lake Trehörningen in 1978 and were repeated every 3–5 years, while Lake Årsjön is an unlimed reference Lake. During 1991–1999, the annual pH median in Lake Långsjön and Lake Årsjön ranged between 6.6–7.1 and 5.2–5.8, respectively, and the composition of phyto- and zooplankton in these lakes did not change markedly. After a final treatment in 1991, the liming of Lake Trehörningen was terminated intentionally. As a result, pH decreased from an annual median 7.1 in 1991, to 6.1 in 1999 (5.8 in 1998). Total organic carbon (TOC) did not change markedly during this period, while the levels of calcium decreased. Metals, known to be influenced by acidification, especially cadmium, manganese and aluminium (Al), increased. The labile-inorganic forms of Al also reached higher levels, especially in 1998. Following the decreasing pH, the total number of phytoplankton taxa decreased by ca 40%. Among zooplankton, the cladocerans Holopedium gibberum, Diaphanosoma brachyurum and Daphnia longispina, common during the limed period, became rare.  相似文献