On estimating non‐additive genetic parameters in chickens 1

1. Several economically important traits in two Leghorn populations (over 9000 birds) were examined for additive and non‐additive components of genetic variance and sex‐linked effects. Data were analysed by two different statistical models based on least‐squares procedures.

2. Six different covariances were first calculated between relatives; i.e., full‐sibs, 3/4‐sisters, half‐sisters, dam‐daughters, grandam‐granddaughters and aunt‐nieces.

3. From the covariances, weighted least‐squares equations were used to obtain estimates of variance components for additive genetic, dominance, maternal and sex‐linkage effects.

4. The estimates of non‐additive components were highly variable but generally small compared with the additive genetic estimates.

5. In general this study suggests that for most traits, with the possible exception of rate of egg production, there is relatively little non‐additive genetic variation.

6. The consequences of possible negative correlations between additive effects and maternal effects are considered as they might apply to egg production in poultry.     

A survey of northern Victorian dairy farmers to investigate dairy calf management: colostrum feeding and management

Objectives

To describe colostrum management practices carried out in northern Victorian dairy herds and to identify weaknesses in these areas that may affect calf health and welfare by comparing the results with the current industry recommendations

Methods

A questionnaire to obtain information about colostrum management and calf‐rearing practices was sent to commercial dairy farming clients of Rochester Veterinary Practice between June and September 2013. The questionnaire consisted of a general herd overview and colostrum harvesting practices.

Results

The response rate was 39% (58/150). Many dairy producers were not meeting the current industry recommendations in the following areas: (1) time of removal calf from the dam, (2) relying on calf suckling colostrum from the dam to achieve adequate passive transfer, (3) failing to supplement calves with colostrum, (4) feeding inadequate volumes of colostrum, (5) delayed colostrum harvesting, (6) pooling of colostrum, (7) failing to objectively assess colostrum quality or relying on visual assessment and (8) storing colostrum for a prolonged periods of time at ambient temperatures.

Conclusion

The results from this survey highlight the need for greater awareness of industry standards for colostrum management and feeding hygiene.

     

Percutaneous absorption of chemicals: developing an understanding for the treatment of disease in frogs

The permeable nature of frog skin presents an alternative route for the delivery of therapeutic chemicals to treat disease in frogs. However, although therapeutic chemicals are often topically applied to the skin of frogs, their pharmacokinetics have rarely been reported. To provide evidence to guide both candidate drug and formulation selection, we highlight factors expected to influence percutaneous absorption through frog skin, including the anatomy and physiology of the skin and the physicochemical properties of applied therapeutic chemicals. Importantly, we also highlight the effects of the formulation on percutaneous absorption, especially the inclusion of potential penetration enhancers as excipients. Finally, we collate empirical data on the topical application of various therapeutic chemicals in postmetamorphic frogs and show that, in contrast to mammalian species, even large chemicals (i.e. >500 Da) and those with a wide range of log P values (?4 through +6) are likely to be absorbed percutaneously. Topical application in frogs thus promises a convenient and effective method for delivering systemic treatments of a diverse range of chemicals; however, further experimental quantification is required to ensure optimal outcomes.     

Water availability affects nectar sugar production and insect visitation of the cup plant Silphium perfoliatum L. (Asteraceae)

The perennial cup plant (Silphium perfoliatum L.) is considered as an alternative feedstock to maize for biogas plants. Due to its ecological advantages of an extensive management and function as food resource for pollinators, it can be grown in Ecological Focus Areas (EFAs) since 2018. However, studies at the Julius Kühn-Institute in Braunschweig (Germany) showed that the assumed advantage of the cup plant of a high drought tolerance could not be confirmed regarding aspects of crop production and yield. We complemented this experiment by assessing how different soil moisture conditions affect the production of floral resources and insect visitation. In 2014, we sampled three irrigated and three rainfed plots of the cup plant. We quantified the nectar volume and sugar mass per inflorescence, the number of inflorescences per plant and calculated the total nectar sugar production. We further counted insect visitation on the inflorescences. Due to reduced numbers of inflorescences per plant and an earlier harvest, the estimated nectar sugar production was 58 kg/ha regarding irrigated and 20 kg/ha regarding rainfed plots. Honeybee visitation per inflorescence was about twice as high in the irrigated plots. Furthermore, the early harvest is a disadvantage for wild pollinators with a late activity period.     

Zu Prekler’s „rationellem Baldwirth“

Ohne Zusammenfassung f. f?chf. Dberforftmeifter. f. bahr. Regierungs- und Forftrath von Mürzburg. f. preuk. Dberforftmeifter aus Breslau. f. f?chf. Dberforftmeifter. f. bahr. Regierungs- und Forftrath von Augsburg. f. bahr. Regierungs- und Forftrath aus Regensburg. Dberj?germeifter von Braunfchweig. f. bahr. Regierungs- und Forftrath aus München. f. f?chf. Dberf?rfter. f. f?chf. Dberforftmeifter. f. f?chf. Dberforftrath. herz. braunfchweig. Forftmeifter von Blanfenburg. Direftor der fürftlich Cfterhazh’fchen Herrfchaft Spoly Parsto. fürftl. fondershauf. Dberfortmeifter. f. bahr. Redierf?rfter don Schmarzenbach. f. preuk. Dberf?rfter. f. f. Forftrath aus Brekburg. f. preuk. Dberf?rfter von Altruppin. f. hann?v. Forftmeifter von Rienburg. Forftmeifter in preuk. Schleften. f. preuk. Dberforftmeifter von Berlin. herz. aftenburg. Dberfortmeifter. f. preuk. Dberf?rfter. f. f?chf. Dberf?rfter. f. ruff. Forftfomiff?r aus Marfchau. f. preuk. Forftinfpeftor. f. f?chf. Forftinfpeftor. grokh. meimar. Forftinfpeftor von Martfuhl. f. mürttb. Dberf?rfter und Brofeffor aus Hohenheim. f. hannov. Forftmeifter aus Hammeln. Dberforftmeifter aus Sotha. herz. altenburg. Dberf?rfter aus Hummelshain. herz. altenburg. Revierf?rfter aus Milchwig. herz. altenburg. geheimer Finanzrath und Dberforftmeifter. herz. altenb. Dberforftmeifter aus Hummelshain. grokh. f?chf. geheimer Dberforftrath aus Qifenach. herz. naffau. Dberforftrath aus Miesbaden. grokh. heff. Dberforftfefret?r aus Darmftadt. f. f?chf. Dberforftmeifter.     

Einfluss Weicher Röntgenstrahlen und Mechanischer Effekte auf das Keimen von Kartoffeln

Zusammenfassung Um eine schonende Keimhemmung bei Kartoffeln der SorteBona zu erzielen, wurden Versuche mit sehr weichen R?ntgenstrahlen von 12 keV Energie durchgeführt. Sogar mit einer Bestrahlungsdosis von 10.000 bis 15.000 r wird — bei der hier angewandten weichen R?ntgenstrahlung — eine über 22 Wochen andauernde Keimhemmung erreicht ohne Verschlechterung des ?usseren Ansehens und Geschmacks. Der Schwund der Knollen wurde einzeln bis 5.000 r gemessen und mit anwachsender Dosis bis zu 15.000 r eine starke Verminderung des Schwundes erzielt. Au?erdem wurde nachgewiesen, da? durch langstündiges, vorsichtiges Rollen in der beschriebenen Versuchsanordung ebenfalls eine Keimhemmung zu erreichen ist. Es wird versucht, diese Erscheinung biologisch und rechnerisch zu deuten. Aus praktischen Gründen w?re es wünschenswert, den neuen, erw?hnten Effekt weiter zu untersuchen.

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Summary In order to bring about sparing sprout inhibition of theBona variety of potatoes experiments were undertaken with very weak X-rays of an energy of 12 keV. A radiation dose of only 10.000 to 15.000 r (with the weak X-radiation employed in this instance) was sufficient to inhibit sprouting for over 22 weeks without adversely affecting the appearance and flavour. The tuber shrinkage was individually measured up to 5.000 r and a marked reduction of shrinkage obtained with an increasing dose up to 15.000 r. It was also shown that sprouting may be inhibited by protracted, careful rolling in the described order of experiments. An attempt is made to explain this phenomenon biologically and analytically. From practical considerations it would be desirable to make a further study of the novel effect referred to.

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Résumé Pour réaliser de fa?on délicate une inhibition de la germination des pommes de terre de la variétéBona, nous avons effectué des essais de traitement par les rayons X très mous d'une énergie de 12 keV. Même l'irradition à une dose de 10.000 à 15.000 r sufit déjà — dans le cas des rayons très mous utilisés dans ces essais — pour inhiber la germination pendant 22 semaines au moins sans nuire à l'aspect ni au go?t des tubercules. La perte de poids des tubercules fut mesurée isolément jusqu'à 5000 r. Les doses croissantes jusqu'à 15.000 r réduisaient fortement la perte de poids. Il a également été constaté que dans les conditions de l'essai, un roulement très lent et doux des tubercules permet aussi de retarder la germination. Nous avons tenté d'expliquer ce phénomène au point de vue biologique et statistique. Pour des raisons pratiques, il serait désirable que l'étude de cet effet nouvellement observé soit approfondie.

     

Malignant transformation of a unicameral bone cyst in a cat

A unicameral bone cyst in the proximal humerus of a 3-year-old Norwegian forest cat was diagnosed by dynamic contrast-enhanced magnetic resonance imaging, surgical exploration, and histopathology. Surgical curettage and incorporation of bone cement led to full recovery. An osteosarcoma developed at the surgical site 17 months later. Thoracic radiographs showed pulmonary lesions consistent with metastasis.     

Orthodontic correction of a complex malocclusion of the canine teeth of dento-alveolar and skeletal origin using a model cast device in the upper jaw of the dog

Malocclusion of the canines, which in dogs is frequent and often has a congenital pattern, remains a challenge to treat. Steeply positioned lower jaw canines are corrected by means of a specifically designed orthodontic intervention. The case at hand was characterized by a combination of a slight skeletal distal bite and compensatory distal tilt of the entire premaxilla (retrusion, caudal tilt) with a mesial tilt of the canines in the upper jaw (rostral and anterior tilt). An individual solution was found which resulted in a functional adjustment of both upper and lower jaws. A model cast device which included both appropriately tilted areas and screws to ensure distal adjustment solved the problem.     

Properties of threshold model predictions

Estimation of genetic parameters and accuracy of threshold model genetic predictions were investigated. Data were simulated for different population structures by using Monte Carlo techniques. Variance components were estimated by using threshold models and linear sire models applied to untransformed data, logarithmically transformed data, and transformation to Snell scores. Effects of number of categories (2, 5, and 10), incidence of categories (extreme, moderate, and normal), heritability in the underlying scale (.04, .20, and .50), and data structure (unbalanced and balanced) on accuracy of genetic prediction were investigated. The real importance of using a threshold model was to estimate genetic parameters. An expected heritability of .20 was estimated to be .22 and .10 by a threshold model and a linear model, respectively. Accuracy increased significantly with a larger number of categories, a more normal distribution of incidences, increased heritability, and more balanced data. Even threshold models were shown to be more efficient with more than two categories (e.g., binomial). Transformation of scale did not accomplish the purpose intended.     

Effects of a return chewing gum/packaging material mixture on in situ disappearance and on feed intake, nutrient digestibility, and ruminal characteristics of growing steers

In situ and in vivo digestibility experiments were conducted to determine the acceptability, digestibility, and safety of a return chewing gum/packaging (G/P) material mixture when fed to steers. In the in situ experiment, both ruminal and intestinal disappearances were measured. Two ruminally and duodenally cannulated steers, which were given free access to alfalfa hay (AH), were used in this study. Duplicate Dacron bags containing the G/P were incubated in the rumen for 0, 3, 6, 12, 24, and 48 h. After ruminal incubation, the 12-, 24-, and 48-h bags were placed in the duodenum and collected in the feces to determine intestinal disappearance. In situ ruminal DM disappearance was greater than 70% for all substrates tested at 0 h, indicating high solubility of the substrates in water, and began to reach a plateau after 12 h of incubation. Intestinal in situ disappearance was not different (P>.25) from zero. In the digestion trial, four ruminally cannulated steers (337+/-21.3 kg BW; mean +/- SD) were used in a 4x4 Latin square design with the following treatments: 0) 50% corn (C), 50% AH; 10) 45% C, 45% AH, 10% G/P; 20) 40% C, 40% AH, 20% G/P; 30) 35% C, 35% AH, 30% G/P. Steers fed G/P-containing diets had greater (P<.01) DMI than the control steers. Increasing the G/P resulted in a linear (P<.05) increase in DMI. Apparent DM digestibility tended to be higher (P<.10) for the G/P-containing diets than for the control. A quadratic effect (P<.05) on digestible DMI was observed, with greater (P<.01) digestible DMI values for G/P-containing diets (4.8 vs. 5.8 kg/d). Digestible organic matter and total nonstructural carbohydrate intakes followed trends similar to those of DM. Apparent aluminum digestibility of G/P-containing diets was not different (P>.13) from zero. The level of G/P in the diet had no effect (P>.2) on total VFA concentration or ruminal pH. There was a linear decrease (P<.01) in the molar percentage of isobutyrate and isovalerate in addition to a linear increase (P<.01) in butyrate and valerate with increasing levels of G/P. There was a quadratic effect (P<.01) on molar proportions of acetate and propionate and on the acetate:propionate ratio. Results of both experiments suggest that G/P may be fed to safely replace up to 30% of corn-alfalfa hay diets for growing steers with advantages in improving DMI and digestibility.