Field Investigation of Perinatal Mortality in Friesian Cattle Associated with Myocardial Degeneration and Necrosis

Perinatal mortality and stillbirths were investigated in an extensively managed herd of Friesian cows and heifers calving over a 2‐year period: 504 cows were calved and 215 heifers. Cows were bred to Friesian and Jersey bulls using natural service. The perinatal fetal mortality rate was 7.5% for cows and 30% for heifers. An experienced stockman managed these calvings and veterinary assistance was required only on nine occasions. All stillborn fetuses were examined post‐mortem by the Veterinary Laboratories Agency, Carmarthen and no infectious agent was identified on any occasion. Thyroid hyperplasia was found in two fetuses. In blood samples taken from 10 late pregnant heifers, mean glutathione peroxidase values were 7.9 ± 1.7 IU/ml Packed Cell Volume (PCV). Tissues from eight fetuses were submitted to the University of Liverpool for histopathological examination; all presented lesions consistent with myocardial degeneration and necrosis of the left ventricle. Following treatment of 205 late pregnant heifers with sodium selenite and vitamin E, the overall perinatal mortality rate in these cattle fell to below 11%.     

Uranium power and horizontal proliferation of nuclear weapons

Only a few nonnuclear weapons states with uranium-fueled power plants have kept the weapons option open, and none has evidenced activities intended for diverting fissionable material from its civilian system. Analysis of alternative strategies shows that acquisition of nuclear weapons material would probably depend on military production facilities rather than diversion. Horizontal proliferation is primarily a political issue and is related only marginally to uranium power development. Restrictions of the Nuclear Non-Proliferation Act on the supply of equipment and fuel by the United States appear to have induced, in some nonnuclear weapons states, the building of small-scale facilities that can be modified for production of weapons material. More attention should be given to the international political, economic, and military factors that persuade such states to abjure nuclear weapons.     

Predicting perchlorate exposure in milk from concentrations in dairy feed

Perchlorate has been detected in U.S. milk samples from many different states. Applying data from a recently reported 9-week experiment in which 16 Holstein dairy cows were administered perchlorate allowed us to derive an equation for the dose-response relationship between perchlorate concentrations in feed/drinking water and its appearance in milk. Examination of background concentrations of perchlorate in the total mixed ration (TMR) fed in addition to the variable dose supplied to treated cows as a ruminal infusate revealed that cows receive significant and variable exposure to perchlorate from the TMR. Weekly examination of the TMR disclosed that a change in ingredients midway through the experiment caused a significant (78%) change in TMR perchlorate concentration. Analyses of the ingredients comprising the TMR revealed that 41.9% of the perchlorate came from corn silage, 22.9% came from alfalfa hay and 11.7% was supplied by sudan grass. Finally, USDA Food and Nutrition Survey data on fluid milk consumption were used to predict potential human exposure from milk that contained concentrations of perchlorate observed in our previous dosing study. The study suggests that reducing perchlorate concentration in dairy feed may reduce perchlorate concentrations in milk as well as the potential to reduce human exposure to perchlorate in milk.     

Sacral osteochondrosis in two German Shepherd Dogs

Two young adult male castrated German Shepherd Dogs were referred for evaluation of intermittent episodes of hindlimb pain. Physical examination suggested lumbosacral stenosis, and plain radiographs and computed tomography revealed lesions consistent with sacral osteochondrosis. One dog had osteochondral fragments removed surgically; the other was managed conservatively. The surgically treated dog had complete resolution of clinical signs whereas the dog managed conservatively had repeated episodes of mild pain and received one short course of non-steroidal anti-inflammatory medication in 18 months. Sacral osteochondrosis has not been previously reported in Australia.     

The acid buffer capacity of some finnish forest soils: Results of acid addition laboratory experiments

Batch acid addition experiments were carried out to determine the acid buffer capacities (amount of acid required to lower soil pH by one unit) of forest soils. Samples of O, E, B (or BC), and C horizons taken from 29 podzolic profiles in southern Finland were used in the experiments. Subsamples of soil were equilibrated for 24 h with NaCl solution containing additions of HCl acid. Cation exchange, mineral dissolution (weathering), and the protonation of organic matter all appeared to have been involved in the buffering of the acid additions. For the O horizon samples, most of the cations released in response to the acid additions were base cations. For the mineral soil samples, most of the cations released were Al³⁺ ions. With the exception of a few samples, the added acid was not fully neutralised and pH was lowered even with the lowest addition treatment. However, the acid addition treatments corresponded to many times the regional annual acid deposition load (1.6–2.0 cmol(c) m^?2). Calculated acid buffer capacities (cmol(c) kg^?1 pH^?1) ranged from 9.8 to 40.8 for O horizon soil samples and from 0.1 (C horizon) to 5.2 (E horizon) for the mineral soil samples. Total acid buffer capacities for a profile (to a depth of 50 cm) ranged from 500 to 2349, with a mean value of 1091 cmol(c) m^?2 pH^?1. It is concluded that, in addition to CEC and base saturation, acid buffer capacity is a useful measure to describe the ecological effects of acid deposition on soil.     

Ion mass budgets for small forested catchments in Finland

Ion mass and H⁺ budgets were calculated for three pristine forested catchments using bulk deposition, throughfall and runoff data. The catchments have different soil and forest type characteristics. A forest canopy filtering factor for each catchment was estimated for base cations, H⁺, Cl^? and SO ₄ ^2? by taking into account the specific filtering abilities of different stands based on the throughfall quality and the distribution of forest types. Output fluxes from the catchments were calculated from the quality and quantity of the runoff water. Deposition, weathering, ion exchange, retention and biological accumulation processes were taken into account to calculate catchment H⁺ budgets, and the ratio between external (anthropogenic) and internal H⁺ sources. In general, output exceeded input for Na⁺, K⁺, Ca²⁺, Mg²⁺, HCO ₃ ^? (if present) and A^? (organic anions), whereas retention was observed in the case of H⁺, NH ₄ ⁺ , NO ₃ ^? and SO ₄ ^2? . The range in the annual input of H⁺ was 22.8–26.3 meq m^?2 yr^?1, and in the annual output, 0.3–3.9 meq m^?2 yr^?1. Compared with some forested sites located in high acid deposition areas in southern Scandinavia, Scotland and Canada, the catchments receive rather moderate loads of acidic deposition. The consumption of H⁺ was dominated by base cation exchange plus weathering reactions (41–79 %), and by the retention of SO ₄ ^2? (17–49 %). The maximum net retention of SO ₄ ^2? was 87% in the HietajÄrvi 2 catchment, having the highest proportion of peatlands. Nitrogen transformations played a rather minor role in the H⁺ budgets. The ratio between external and internal H⁺ sources (excluding net base cation uptake by forests) varied between 0.74 and 2.62, depending on catchment characteristics and acidic deposition loads. The impact of the acidic deposition was most evident for the southern Valkeakotinen catchment, where the anthropogenic acidification has been documented also by palaeolimnological methods.     

Sialomucin Complex (Muc4) Expression in Porcine Endometrium During the Oestrous Cycle and Early Pregnancy

The non‐invasive type of implantation in the pig is characterized by the maintenance of a thick glycocalyx coating on the uterine epithelial surface microvilli. Present study investigated the alteration in the sialomucin complex (Muc4) expression during the oestrous cycle and early pregnancy in the pig. Endometrial tissue samples were immunostained with the primary antibody to the Muc4 transmembrane subunit ASGP‐2. Muc4 immunostaining increased in the surface and glandular epithelia between days 5 and 10 of oestrous cycle. Immunostaining continued to increase on day 12 with the greatest intensity of uterine Muc4 immunostaining detected on day 15 of the oestrous cycle and early pregnancy. Endometrial Muc4 expression in cyclic gilts decreased dramatically during early proestrous but continued to remain abundant in the surface and glandular epithelium of pregnant gilts during the period of conceptus attachment to the uterine surface.