Versuche zur Zyklussynchronisation bei Kühen aus Beständen rnit Fertilitätsproblemen und bei Hybriden zwischen Wisent und Rind mit der PRID-Spirale*

Inhalt: An 81 Versuchs- und 92 Kontrolltieren der Rasse “Potnische Schwarzbunte” aus 3 Problembetrieben wurde ein Versuch zur Sterilitätsprophylaxe rnit der PRID-Spirale durchgeführt. Anhand klinischer Befunde und Milchprogesteronwerten wurde die Untergruppe aus Kühen mit Ovardystrophie (18 Versuchs- und 22 Kontrolltiere) gebildet und extra ausgewertet. Der Behandlungsbeginn lag zwischen 60 und 80 Tage post partum. Die Versuchstiere wurden mit der PRID-Spirale 12 Tage lang behandelt, die Kontrolltiere erhielten Injcktionen rnit Kochsalzlösung und solche rnit Ovardystrophie wurden zusätzlich mit einer Eierstocksmassage behandelt. Die Versuchstiere wurden 56 und 72 Stunden nach Entfernung der Spirale blind besamt. Die Brunstin-duktionsrate betrug insgesamt 90,1%, bei denen rnit Ovardystrophie 77,7%. Die An-wendung der PRID-Spirale führte zur Verbesserung der Fertilitätslage. Die Gesamt-trächtigkeitsrate lag mit 87,6% bei den Versuchskühenüber derjenigen der Kontrollkü-he mit 79,3%. Die Behandlung der Tiere rnit Ovardystrophie erbrachte eine Gesamt-trächtigkeitsrate von 88,8% bei den Versuchs- und 72,7% bei den Kontrolltieren. Die Zwischentragezeit betrug bei den Versuchstieren 101,2 Tage und bei den Kontrolltieren 113,3 Tage (p ≤ 0,05). Bei den azyklischen Tieren lag die Zwischentragezeit bei 104,6 Tage bzw. 134,7 Tage (p ≤ 0,05). In einem anderen Versuch wurde 20 Hybriden zwischen Wisent und Hausrind rwecks Zyklussynchronisation die PRID-Spirale verabreicht. Die Brunstinduktionsrate betrug 66,6%, das Erstbesamungsergebnis nach Doppelbesamung 30%, die Gesamtträchtig-keitsrate nach dem Decken der umrindernden Kreuzungstiere rnit einem Bullen 90%. Die Deckperiode konnte verkürzt werden. Contents: Investigations on the synchronization of estrus cycle in cattle from farms with fertility problems and in cross-breeds between bison and cattle with a PRID-de-vice In 81 experimental and 92 control animals of the “Polish Black and White” breed derived from 3 farms with fertility problems an investigation was carried out for sterility prophylaxis using the PRID-device. Based on clinical findings and milk progesterone values cattle with ovarian dystrophy (18 experimental and 22 control animals) from a special group were used. The begin of treatment was between 60 and 80 days post partum. All experimental animals had received a PRID-device for a duration of 12 days. Control animals were injected with physiological saline solution and animals with ovarian dystrophy were treated additionally with ovarian massage. Experimental animals were inseminated 56 and 72 hrs after removal of the device. All animals taken, estrus was induced in 90.1% of the animals, while only 77.7% of animals with ovarian dystrophy came to estrus. Application of the PRID-device led to an improvement of fertility. Pregnancy rates in experimental animals were 87.6%, while only 79.3% of the control animals were pregnant. Treatment of animals with ovarian dystrophy resulted in 88.8% pregnancies for treated and 72.7% for control animals. Experimental animals were non-pregnant for a duration of 101.2 days, while control animals remained non-pregnant for 113.3 days (p < 0.05). Acyclic cattle had a non-pregnant period of 104.6 days and 134.7 days (p < 0.05) respectively. In a second experiment 20 cross-breeds between bison and domestic cattle were treated with a PRID-device for synchronization of the estrus cycle. The rate of estrus induction was 66.6%, the fertility after double insemination 30%, the total pregnancy rate improved after mating with a bull of animals that had not conceived to 90%.     

The Phytotoxicity of Various Graminicides in Durum Wheat in Greece

The effect of three herbicides, diclofop-methyl (DM), imazamethabenz-methyl (IM) and fenoxaprop-ethyl (FE), was investigated at the recommended rate (×) and double the recommended rate (2×) in a durum wheat crop. FE had the smallest effect on root system characteristics, while IM had the greatest effect. For all herbicides, the double rate treatment gave a greater statistical reduction than the single rate for root system characteristics. FE had the smallest effect on the activity of aerobic microorganisms, while DM gave the greatest reduction, 10 days after application, and all three herbicides reduced earthworm abundance. DM gave the smallest reduction in the number of tillers and in plant height, while the double rate of IM gave the greatest reduction. For all three herbicides, double the recommended rate resulted in a significant reduction in the weight of 1000 seeds, while no statistically significant deviations were noted at the recommended rate. Finally, the use of all three herbicides resulted in significantly lower statistical yields compared to the sample (control plot), although there were no significant statistical differences among them, for either recommended or double recommended rates.     

Laboratory and field observations on anti-tick properties of the plant Gynandropsis gynandra (L.) Brig.

A shrubby plant, abundant in east Kenya, Gynandropsis gynandra (L.) Brig., was shown to exhibit repellent and acaricidal properties to larvae, nymphs and adult Rhipicephalus appendiculatus and Amblyomma variegatum ticks. All stages of ticks avoided the leaves of the plant and a high percentage of the ticks which were continuously exposed to its leaves died; surviving ticks were weak and inactive but regained activity when exposed to fresh air. The effectiveness of the plant's leaves as a repellent and acaricide was most pronounced on nymphs and least pronounced on adults. Field investigations indicated that ticks were not found up to 2-5 m from the plant in areas where the plant was predominant. The potential of using the plant for tick control within an integrated tick management system in the resource-poor farming context in Africa was highlighted.     

Comparison of three in vitro techniques to estimate benzimidazole resistance in Haemonchus contortus of sheep

Three in vitro assays to detect benzimidazole resistance, namely, the egg-hatch assay, tubulin-binding assay, and a larval-development assay, were evaluated by estimating the level of benzimidazole resistance in three field isolates of Haemonchus contortus compared with a susceptible reference strain. Comparisons were also made with estimates of benzimidazole resistance of the three field strains obtained from an in vivo controlled anthelmintic efficacy test. All three in vitro tests showed similar, consistent results which also suggested greater sensitivity than the in vivo assay. These results indicate that selection of an in vitro technique to determine benzimidazole resistance should therefore be based on considerations other than precision, such as technical expertise, availability of equipment, cost and speed in which diagnosis is required.     

A Potential Screening System for Identifying Sorghum Ecotypes with Increased Lysine in the Seeds

Classical “high-lysine” sorghum lines are characterized by smaller seeds than average, due to a decrease in prolamin synthesis and a subsequent decrease in yield. To exploit the natural variation in lysine content and to identify ecotypes with a seed lysine content higher than average, characterized by plump seeds, a method was developed based on root-growth inhibition of seeds growing on a medium containing aminoethylcysteine (AEC), a lysine analogue. By using a collection of sorghum mutants and ecotypes a correlation coefficient of 0.926 between root length and lysine content was established. This method, which uses the root length of plants growing on aec to indicate which lines have a potential elevated lysine content, can be applied for the screening of sorghum germplasm. Since this is a non-destructive method it can also be used at the individual seed level, for example for screening progenies of regenerated plants from in vitro culture to exploit the somaclonal variation.     

Matching spatial databases and quantitative models in land resource assessment

Abstract. Good land management needs information about land resources and the processes taking place in the landscape. In practical land evaluation this information is often expressed in terms of land qualities. The original survey data are stored in geographical information systems where they can be used to estimate the values of appropriate land qualities. Land qualities are complex attributes of land used in planning that may be derived from the original attributes through empirical threshold or regression models, or from process-based deterministic or stochastic simulation models. In order to improve estimates of the distribution of land qualities in space and time, and hence to improve planning decisions, the models require data with a much better spatial resolution than is usually available. The problems and dangers associated with the ad hoc linkage of simulation models and GIS are discussed. Particular attention needs to be paid to the problems of error propagation and costs and benefits when using models.     

On the genetic basis of equine allergic diseases: II. Insect bite dermal hypersensitivity.

The horses studied were of the Swiss Warmblood breed and most were ELA-typed to assess a possible association of dermal hypersensitivity to insect bites with the major histocompatibility complex. Firstly, the occurrence of the condition was examined in 304 half-siblings sired by six stallions (A to F). Fourteen cases of dermal hypersensitivity were recognized and all were in the 153 offspring of Stallions C, E and F. Most animals of this group were also investigated for chronic hypersensitivity bronchitis: none of the sires displayed clinical signs of dermal hypersensitivity, but Stallions D, E and F were affected by chronic bronchitis. Among the animals investigated for both conditions only one horse showed coincidence of the two diseases as can be expected when the diseases are not correlated. The frequency of manifest dermal hypersensitivity and/or chronic hypersensitivity bronchitis varied in the half-sibling groups of individual sires. These findings suggest that the allergic conditions are independent entities. Secondly, the occurrence of dermal hypersensitivity was studied in three generations of horses at a stud at which Stallion C had exerted a particularly strong influence. A total of 302 animals, all born and raised at this stud, were surveyed over a period of 12 years. The descendants of Stallion C showed a significantly higher incidence (P less than 0.01) of dermal hypersensitivity (two daughters out of 19; eight second generation offspring out of 103; one third generation offspring out of 85) than did the controls of the same age classes but unrelated to Stallion C at the same stud (0 out of 95).(ABSTRACT TRUNCATED AT 250 WORDS)