Nutrient intake of horses in Thoroughbred and Standardbred stables

SUMMARY Twenty-five Thoroughbred (TB) and 25 Standardbred (SB) stables were visited to determine their feeding practices. The ingredients of the main feed of the day for a mature gelding of average size in full training were weighed at each stable. Nutrient content of diets was calculated using published data for the individual ingredients. Results are expressed as mean±sd. The estimated body weight of TB horses was 493±34 kg and 437±32 kg for SB horses. There was considerable variation in diet composition and nutrient intake between stables. The TB trainers fed 11.0±2.4 kg and SB trainers 11.8±2.5 kg per day. The concentrate component of the diet weighed 7.8±1.6 and 7.7±2.3 kg for TB and SB stables, respectively, and the roughage component for TB horses 3.3±1.4 and SB horses 4.1±1.4 kg per day. The digestible energy intake of horses at TB stables was 129±29 MJ per day and at SB stables 132±31 MJ per day. Crude protein intake of TB horses was 1452±363 g and SB horses 1442±338 g per day. There were differences in some feeding practices at TB and SB stables. Standardbred trainers fed more roughage than TB trainers. Standardbred trainers fed chaffed lucerne (alfalfa) and cereal hays as the major roughage, whereas TB trainers fed more hay. The major hay type fed by TB trainers was lucerne, whereas many SB trainers preferred clover hay. Both trainers fed oats as the major grain, but TB trainers fed slightly more maize (corn) than SB trainers. The SB trainers fed barley as part of the concentrate component of the diet, whereas TB trainers usually fed boiled barley and linseed oil in winter only. Although many trainers used vitamin and mineral supplements, this appeared unnecessary in many Instances, especially with respect to Iron. Calcium and NaCI supplementation was necessary for some diets. We concluded that while there was a wide range in feed intake and diet composition for both TB and SB horses, average nutrient intakes were similar to National Research Council (1989) recommendations for horses performing intense work.     

Growth and erosion of thin solid films

Thin films that are grown by the process of sputtering are, by and large, quite unlike the smooth, featureless structures that one might expect. In general, these films have a complicated surface morphology and an extended network of grooves and voids in their interiors. Such features can have a profound effect on the physical properties of a thin film. The surface irregularities and the bulk defects are the result of a growth instability due to competitive shadowing, an effect that also plays a role in geological processes such as erosion. For amorphous thin films, the shadow instability can be described by a remarkably simple model, which can be shown to reproduce many important observed characteristics of thin film morphology.     

Relationship of Progesterone,Bovine Pregnancy-Associated Glycoprotein-1 and Nitric Oxide with Late Embryonic and Early Fetal Mortalities in Dairy Cows

The aim of the present study was to determine the relationship of progesterone (P4), bovine pregnancy-associated glycoprotein-1 (bPAG-1) and nitric oxide (NO) levels with late embryonic (LEM; day 28 to day 42) and early fetal mortalities (EFM; > day 42 to day 56) in dairy cows. Transrectal ultrasonography (6–8 MHz) was performed in 100 Holstein-Friesian cows at days 28, 42 and 56 after artificial insemination (AI; day 0) to diagnose pregnancy and to monitor the fate of the embryo. After ultrasound scanning of each cow, a milk sample was collected for assessment of P4 by an ELISA test and a blood sample was collected for assessment of bPAG-1, by using a double-antibody radioimmunoassay, and serum NO metabolites (nitrate + nitrite). Based on ultrasonographic examinations and bPAG-1-RIA, 41 of 100 inseminated cows were confirmed pregnant at day 28 after AI. Nine cows suffered of LEM, and 6 cows suffered of EFM and the overall pregnancy loss rate was 36.6% (15/41) between days 28 and 56 of pregnancy. By logistic regression analysis, there were no significant relationships between the level of P4 and bPAG-1 at day 28 after AI and the occurrence of LEM and EFM. Also, there were no significant relationships between the levels of P4 and bPAG-1 at day 42 and the occurrence of EFM. On the other hand, a significant relationship (P<0.05) was found between NO level at day 28 and the occurrence of LEM. In conclusion, measurement of the serum NO concentration at day 28 of pregnancy might help to predict the outcome of pregnancy by day 42 in dairy cows but further studies are needed to confirm this.     

The Post‐Cervical Insemination does not Impair the Reproductive Performance of Primiparous Sows

The study evaluated the reproductive performance of primiparous sows submitted to post‐cervical insemination (PCAI) compared with cervical artificial insemination (CAI). Difficulty with catheter introduction, the occurrence of bleeding or semen backflow during insemination, and volume and sperm cell backflow up to 60 min after insemination were also evaluated. Sows were homogenously distributed, according to body weight loss in lactation, lactation length, weaned piglets, weaning‐to‐oestrus interval and total born in previous farrowing, in two treatments: PCAI (n = 165) with 1.5 × 10⁹ sperm cells in 45 ml (2.4 ± 0.04 doses per sow) and CAI (n = 165) with 3 × 10⁹ sperm cells in 90 ml (2.5 ± 0.04 doses per sow). During PCAI, sows were inseminated in the absence of boars. Transabdominal real‐time ultrasonography was performed at oestrus onset, immediately before the first insemination and at 24 h after last insemination. There was no difference (P > 0.05) between treatments in farrowing rate (91.5% × 89.1%) and litter size (12.5 × 11.9 piglets born, respectively for PCAI and CAI sows). Successful passage of the intrauterine catheter in all the inseminations was possible in 86.8% (165/190) of sows initially allocated to PCAI treatment. Difficulty of introducing the catheter in at least one insemination did not affect the reproductive performance of PCAI sows (P > 0.05). Bleeding during insemination did not affect (P > 0.05) the farrowing rate in both treatments, but litter size was reduced in CAI and PCAI sows (P ≤ 0.06). Percentage of spermatozoa present in backflow within 1 h after insemination was greater in CAI than PCAI sows (P < 0.01). More than 85% of primiparous sows can be successfully post‐cervical inseminated with doses containing 1.5 × 10⁹ sperm cells in the absence of the boar during insemination without impairing the reproductive performance.     

On the magnitude and dynamics of eddy covariance system residual energy (energy balance closure error) in subsurface drip-irrigated maize field during growing and non-growing (dormant) seasons

We investigated the magnitude and dynamics of the eddy covariance system (ECS) residual energy (energy balance closure error) for a subsurface drip-irrigated maize (Zea mays L.) field in 2005 and 2006 growing and non-growing (dormant) seasons. The corrections for coordinate rotation, oxygen, frequency, and Webb–Pearman–Leuning corrections improved the slope of the total convective energy (latent heat + sensible heat) with respect to the net available energy (from 0.68 to 0.84), but the data filtering (for horizontal and frictional wind speeds higher than 2 m s^?1 and lower than 0.2 m s^?1) had little effect on the slope. Also, the number of data points available for the analyses was reduced by 53 % after filtering. Overall, the daytime residual energy varied between ?100 and 200 W m^?2 during the dormant seasons and between ?500 and 600 W m^?2 during the growing seasons. Most of the nighttime residual energy ranged within ±40 W m^?2 during the calendar year in 2005 and within ?60 and 20 W m^?2 in 2006. During nighttime, the total convective energy is vertically distributed with respect to (R _n ? G), indicating that the total convective energy is independent of the variations in (R _n ? G). Secondly, it was observed that nighttime residual energy did not show any seasonal variation patterns throughout the two consecutive years and confined mostly within a narrow range of ±40 W m^?2, showing no dependency on seasonal changes in surface conditions. The maximum variation in residual energy was usually around frictional wind speed of 0.3–0.5 m s^?1 (varying between ?150 and 300 W m^?2) and then decreasing to a range of ±100 W m^?2 at higher frictional wind speeds. On average, the residual energy decreased by about 33 W m^?2 (after the intercept) for every 1.0 m s^?1 increase in frictional wind speed, whereas the residual energy decreased by about 4 W m^?2 (after the intercept) for every 1.0 m s^?1 increase in horizontal wind speed. Similar diurnal residual energy distribution patterns, with different magnitudes, were observed during growing and dormant seasons. Even though a slight decrease in residual energy was observed with increase in leaf area index (LAI) in both growing seasons, LAI did not have considerable influence on the seasonal variation in the residual energy. The residual energy was also evaluated by separating the data into morning and afternoon hours. We observed that the root-mean-squared difference value is slightly greater for the morning data than the afternoon, indicating greater residual energy in the morning hours due to weaker turbulent mixing than the afternoon. Overall, significant reduction in the available evapotranspiration data after applying a series of corrections possess challenges in terms of utilization of ECS for in-season irrigation management and crop water requirement determinations that needs to be further researched and addressed.     

Field trial of a staphylococcal mastitis vaccine in dairy herds: clinical, subclinical and microbiological assessments

Objective To assess the efficacy of a new staphylococcal mastitis vaccine under commercial dairying conditions.
Design A field trial involving 1819 cows and heifers conducted on seven dairy herds in Victoria. The trial was done 'blind'; approximately half the animals were vaccinated and the remainder were untreated controls.
Procedure The vaccine was given twice during the last 10 weeks of pregnancy. Effects of vaccination were assessed, during the ensuing lactation, on the basis of clinical and sub-clinical mastitis and microbiological investigations of the milk.
Results A total of 273 cases of clinical mastitis were recorded. Staphylococcus aureus was isolated from 112 of these, 45 cases in vaccinates and 67 cases in controls; the difference was not statistically significant. One herd was notable in having a high incidence of clinical staphylococcal mastitis. This herd accounted for 15.8% of the animals in the field trial but 54.5% of cases of clinical staphylococcal mastitis. For this herd, vaccinated animals had significantly lower incidence of clinical staphylococcal mastitis and prevalence of subclinical mastitis, relative to controls. An unexpected feature of the trial as a whole was the low incidence of clinical mastitis from which S aureus was isolated in pure culture (26.3% of cases) and the high incidence of clinical Streptococcus uberis mastitis (22.7% of cases).
Conclusions The trial showed that the vaccine was efficacious in reducing the incidence of clinical mastitis and prevalence of subclinical mastitis in a herd that had a serious staphylococcal mastitis problem.     

Primary Production in Antarctic Sea Ice

A numerical model shows that in Antarctic sea ice, increased flooding in regions with thick snow cover enhances primary production in the infiltration (surface) layer. Productivity in the freeboard (sea level) layer is also determined by sea ice porosity, which varies with temperature. Spatial and temporal variation in snow thickness and the proportion of first-year ice thus determine regional differences in sea ice primary production. Model results show that of the 40 teragrams of carbon produced annually in the Antarctic ice pack, 75 percent was associated with first-year ice and nearly 50 percent was produced in the Weddell Sea.     

Rutile-bearing refractory eclogites: missing link between continents and depleted mantle

A mass imbalance exists in Earth for Nb, Ta, and possibly Ti: continental crust and depleted mantle both have subchondritic Nb/Ta, Nb/La, and Ti/Zr, which requires the existence of an additional reservoir with superchondritic ratios, such as refractory eclogite produced by slab melting. Trace element compositions of minerals in xenolithic eclogites derived from cratonic lithospheric mantle show that rutile dominates the budget of Nb and Ta in the eclogites and imparts a superchondritic Nb/Ta, Nb/La, and Ti/Zr to the whole rocks. About 1 to 6 percent by weight of eclogite is required to solve the mass imbalance in the silicate Earth, and this reservoir must have an Nb concentration >/= 2 parts per million, Nb/La >/= 1.2, and Nb/Ta between 19 and 37-values that overlap those of the xenolithic eclogites. As the mass of eclogite in the continental lithosphere is significantly lower than this, much of this material may reside in the lower mantle, perhaps as deep as the core-mantle boundary.