Stillbirth/perinatal weak calf syndrome in dairy heifers: results of a pilot study

A pilot study of 10 Dutch dairy herds was performed to investigate possible causes of stillbirth/perinatal weak calf syndrome in heifers. Possible causes and advice for further investigations on farms affected by this syndrome are discussed based on the results of investigations of blood and urine from pregnant young stock, postmortem examination of still-born calves, and a questionnaire held among farmers. Infections with Neospora caninum, Salmonella spp. or Leptospira hardjo, or a deficiency of iodine could be excluded.     

Validation of ultrasonography in detecting structural disease of the urogenital tract of the koala,Phascolarctos cinereus

A retrospective review of case records of ultrasonography and necropsy outcomes of 62 koalas was used to investigate the accuracy of ultrasonography in assessing koala urogenital tract structural disease at the Port Macquarie Koala Hospital. The results showed high concordance, supporting ultrasonography as an effective tool for evaluating structural disease of the koala urogenital tract, most commonly seen with chlamydiosis. The study also illustrates the advances benefiting animal welfare that can be made by wildlife carer groups through using a scientific, evidence‐based approach.     

The importance of two-seeded pods in red clover (Trifolium pratense L.)

Summary The effect of selection for two-seeded pods in diploid and tetraploid populations and the effect of chromosome doubling on two-seededness were studied. The material obtained was examined to find out how important two-seeded pods are for seed set, grain weight and seed yield.In a mixoploid plant the percentage two-seeded pods in the tetraploid heads was far smaller than that in the diploid heads. Only when the character had developed relatively strongly in the diploid, did it exceed a very low value.By selection of individual plants in the best families of a diploid group of plants the percentage two-seeded pods could be raised from on average 7.4 to 30.6% as early as the following generation. Similar selection in tetraploid material with 2.5% two-seeded pods did not increase the percentage.The reduction of grain weight of seed in two-seeded pods compared with that in one-seeded pods was greater in the tetraploid plants than in the diploids.No effect of two-seededness on seed yield was found in our material. A marked effect on seed-set was observed in a diploid population (286 plants) when the percentages two-seeded pods rose about 16%.As the correlation between the calculated number of heads and the seed yield per plant is high, it may be adopted that in our material the number of heads per plant was decisive of seed yield. This will contribute to the small effect of two-seededness on the seed yield of the plant.The results of the present study showed that the production of tetraploids with a high percentage two-seeded pods will take more advantage of selection of diploid material followed by doubling of chromosomes than of direct selection in the tetraploids.Protrusion of pods in heads indicates a very high percentage two-seeded pods. This will enable relatively rapid selection for two-seeded pods.A quite small percentage two-seeded pods also occurred in two tetraploid populations that had not been selected for two-seeded pods.     

Experiences with the breeding of red clover resistant to the stem eelworm

Summary The methods used in collecting stem eelworms from diseased plants, in raising and inoculating plants, in assessing resistance and in crossing selected plants in cages using bumble-bees for pollination are described in detail.Research showed that in swollen seedlings the eelworms had multiplied (susceptible plants) whereas this is not the case in non-swollen plants with a stunted growth and brown stripes (resistant plants).The increase of eelworms in greatly swollen plants of Roosendaal red clover took place at a greater speed than in slightly swollen plants. In healthy-looking plants mostly no or few eelworms had invaded. It seems that these plants have escaped a degree of infection necessary to judge their resistance.It appeared that varieties of red clover which are susceptible or resistant to stem eelworms of a given origin from the Netherlands were susceptible or resistant in about the same degree to eelworms derived from a quite different part of this country. A good conformity between laboratory and field resistance was found.If in spring bumble-bee boxes are hung in trees according to the method described, in about 10 to 20% of the boxes a good bumble-bee nest is found in the beginning of July. These populations are suitable to use for the crossing of clover plants in cages. Inside the cages seed production per plant was generally much lower than outside.By intercrossing resistant plants of Dutch local varieties and selection in the progenies, fairly resistant families were obtained within some years.     

Modeling the efficiency of phosphorus utilization in growing pigs

Microbial phytase has been used to reduce P excretion from swine to mitigate environmental pollution. The objective of the study was to quantify the effect of feeding a low-P phytase-supplemented diet on growth and P utilization in growing pigs using mathematical models. A total of 20 weaned piglets (BW = 6.5 kg) housed in metabolism cages were randomly assigned to a standard diet (STD) or P-amended diet containing reduced P content and supplemented with phytase (AMN) with 10 pigs/diet. Body weight and feed consumption were recorded weekly so complete growth and cumulative P intake (cPI) curves could be modeled. A function with fixed point of inflexion (Gompertz) and a variable point of inflexion (generalized Michaelis-Menten) were considered in determining bioequivalence by analyzing BW vs. age relationships, whereas the monomolecular function was used to describe BW vs. cPI. All functions were incorporated into a nonlinear mixed effects model, and a first-order autoregressive correlation structure was implemented to take into account repeated measures. There was no difference between the 2 groups in final BW when the Gompertz equation was fitted (176 vs. 178 kg with SE of 7 kg for the STD and AMN, respectively) or the rate parameter (0.0140 vs. 0.0139 with SE of 0.0004 for the STD and AMN, respectively). The generalized Michaelis-Menten equation also showed a similar trend. When BW was expressed as a function of cPI the derivative with respect to cPI represented P efficiency, so it was possible to analyze the expected difference of the 2 diets in using P for BW gain and express it as a continuous function of cPI. The analysis showed through the entire growth period the difference in P efficiency was different from zero. On average, 56 g of supplemented inorganic P was consumed by a pig fed the AMN to reach market weight. In contrast, 309 g of supplemented inorganic P was consumed by the group fed the STD to reach similar BW. It would depend on other factors, but feeding pigs the AMN can result in economic benefit. Pigs fed the AMN excreted 19% less P compared with those fed the STD. In conclusion, nonlinear mixed model analysis (with repeated measures) was suitable for growth and efficiency analysis and showed that pigs fed the AMN consumed less than 20% of the inorganic P and performed as well as those fed the traditional inorganic P supplemented diet. The implications for mitigating P pollution, especially in areas where P loading is already problematic, are substantial.     

Kinematic Motion Patterns of the Cranial and Caudal Canine Cervical Spine

Objective: To define the kinematic motion patterns of the canine cervical spine, with a particular emphasis on identifying differences between the cranial (C₂–C₄) and caudal (C₅–C₇) segments, and to determine the significance of coupled motions (CM) in the canine cervical spine. Study Design: Cadaveric biomechanical study. Sample Population: Cervical spines of 8 Foxhounds. Methods: Spinal specimens were considered free of pathology based on radiographic, computed tomography, and magnetic resonance imaging examinations. All musculature was removed without damaging ligaments or joint capsules. Spines were mounted in a customized pure‐moment spine testing jig, and data were collected using an optoelectronic motion capture system. Range of motion, neutral zone and CM in flexion/extension, left/right lateral bending and left/right axial rotation were established. Data were analyzed using mixed‐effects maximum likelihood regression models. Results: Total flexion/extension did not change across the 4 levels. There was no difference between flexion and extension, and no CM was identified. Lateral bending was not different across levels, but tended to be greater in the cranial spine. Axial rotation was ～2.6 times greater in the caudal segments. Lateral bending and axial rotation were coupled. Conclusions: Kinematics of the cranial and caudal cervical spine differed markedly with greater mobility in the caudal cervical spine.