Differential Rotation and Dynamics of the Solar Interior

Splitting of the sun's global oscillation frequencies by large-scale flows can be used to investigate how rotation varies with radius and latitude within the solar interior. The nearly uninterrupted observations by the Global Oscillation Network Group (GONG) yield oscillation power spectra with high duty cycles and high signal-to-noise ratios. Frequency splittings derived from GONG observations confirm that the variation of rotation rate with latitude seen at the surface carries through much of the convection zone, at the base of which is an adjustment layer leading to latitudinally independent rotation at greater depths. A distinctive shear layer just below the surface is discernible at low to mid-latitudes.     

Electron temperatures and densities in the venus ionosphere: pioneer venus orbiter electron temperature probe results

Altitude profiles of electron temperature and density in the ionosphere of Venus have been obtained by the Pioneer Venus orbiter electron temperatutre probe. Elevated temperatutres observed at times of low solar wind flux exhibit height profiles that are consistent with a model in which less than 5 percent of the solar wind energy is deposited at the ionopause and is conducted downward through an unmagnetized ionosphere to the region below 200 kilomneters where electron cooling to the neutral atmosphere proceeds rapidly. When solar wind fluxes are higher, the electron temperatures and densities are highly structured and the ionopause moves to lower altitudes. The ionopause height in the late afternoon sector observed thus far varies so widely from day to (day that any height variation with solar zenith angle is not apparent in the observations. In the neighborhood of the ionopause, measuremnents of plasma temperatures and densities and magnetic field strength indicate that an induced magnetic barrier plays an important role in the pressure transfer between the solar wind and the ionosphere. The bow, shock is marked by a distinct increase in electron current collected by the instrument, a featutre that provides a convenient identification of the bow shock location.     

Experimental Leptospira borgpetersenii serovar hardjo infection of pregnant cattle

Objective To observe the effect upon the foetus of experimental infection of pregnant cattle with Leptospira borg-petersenii serovar hardjo .
Design A disease transmission study using pregnant cattle.
Procedure Fourteen heifers serologically negative to L hardjo were artificially inseminated and later challenged with a north-Queensland isolate of L hardjo by conjunctival inoculation. The heifers were serologically monitored and their urine examined for the presence of leptospires using culture and fluorescent-antibody tests at appropriate intervals. Elective caesarean sections were performed on pregnant heifers at 6.5 weeks after the challenge. Foetuses were examined using serological, histopathological, microbiological and fluorescent-antibody tests.
Results Ten of the heifers became pregnant, but three subsequently aborted before challenge. After challenge, all 14 heifers seroconverted and L hardjo was isolated from the urine of 6 of the 7 pregnant heifers. No evidence of foetal L hardjo infection was detected. Two of the foetuses had histopatho-logical lesions consistent with Neospora s p infection.
Conclusion It is likely that the isolate of L hardjo used in this study does not normally infect the foetus. Neospora s p may be a more significant cause of bovine reproductive wastage.     

Effect of increasing ruminal butyrate on portal and hepatic nutrient flux in steers.

Six Holstein steers (mean +/- SE BW = 344 +/- 10 kg) fitted with hepatic, portal, and mesenteric vein and mesenteric artery catheters and a ruminal cannula were used in a 6 x 6 Latin square design to evaluate the effects of increasing ruminal butyrate on net portal-drained visceral and hepatic nutrient flux. Steers were fed a 40% brome hay, 60% concentrate diet in 12 portions daily at 1.25 x NEm. Water (control) or butyrate at 50, 100, 150, 200, or 250 mmol/h was supplied continuously via the ruminal cannula. Simultaneous arterial, portal, and hepatic blood samples were taken at hourly intervals from 15 to 20 h of ruminal infusion. Portal and hepatic blood flow was determined by continuous infusion of P-aminohippurate, and net nutrient flux was calculated as the difference between venous and arterial concentrations times blood flow. Ruminal and arterial concentrations and total splanchnic flux of butyrate increased (P less than .01) with increased butyrate infusion. Arterial concentrations of acetate (P less than .10), alpha-amino-N (P less than .05), and glucose (P less than .01) decreased with increased butyrate, whereas arterial beta-hydroxybutyrate (P less than .01) and acetoacetate (P less than .05) increased. Increased butyrate produced an increased portal-drained visceral flux of acetoacetate and an increased net hepatic flux of beta-hydroxybutyrate. Urea N and glucose net portal and hepatic fluxes were not affected by ruminal butyrate. Alpha-amino-N uptake by the liver decreased with increased butyrate (P less than .10). Simple linear regression (r2 = .985) indicated that 25.8% of ruminally infused butyrate appeared in portal blood as butyrate. Only 14% could be accounted for as net portal-drained visceral flux of acetoacetate plus beta-hydroxybutyrate.     

Effects of interval-feeding whole sunflower seeds during mid to late gestation on performance of beef cows and their progeny

This experiment was conducted to determine the effects of interval feeding of whole sunflower seeds on the performance of beef cows and their progeny. During mid to late gestation, 144 multiparous, spring-calving beef cows (588 kg of initial BW; 5.6 initial BCS; 4 to 13 yr old) were individually fed 1 of 3 supplements 4 d/wk for a 76-d period. Supplements (DM basis) included: 1) 0.68 kg of soybean meal/feeding (NCON); 2) 3.01 kg of a soybean hull-based supplement/feeding (PCON); and 3) 1.66 kg of whole sunflower seeds high in linoleic acid/feeding (WSUN). Supplements were formulated to provide similar amounts of CP and ruminally degraded intake protein; PCON and WSUN were also formulated to be isocaloric. During the supplementation period, cows had free-choice access to bermudagrass (Cynodon dactylon) and tall-grass prairie hay. By the end of the 76-d supplementation period, cows fed PCON (P < 0.01) and NCON (P < 0.01) had gained more BW than cows fed WSUN (33, 23, and 10 kg, respectively). However, from the end of this supplementation period to the beginning of the breeding season 84 d later, cows supplemented with PCON had lost more (P < 0.01) BW than cows supplemented with WSUN (-123 kg vs. -111 kg). Cow BW change through weaning (-50 kg, P = 0.43) and final cow BW (536 kg, P = 0.70) at weaning were not different among supplement groups. Furthermore, cow BCS was similar among supplement treatment groups at the end of the supplementation period (5.3, P = 0.09), at the beginning of the breeding season (4.8, P = 0.38), and at weaning (4.7, P = 0.08). No difference among treatments was detected for calf birth weight (36 kg, P = 0.42), calf weaning weight (235 kg, P = 0.67), percentage of cows exhibiting luteal activity at the beginning of the breeding season (57%, P = 0.29), or pregnancy rate (88%, P = 0.44). However, first service conception rate was greater (P = 0.01) for cows fed PCON (79%) and tended (P = 0.07) to be greater for cows fed WSUN (74%) than for cows fed NCON (53%). After weaning, all steer calves were placed in a feedlot and fed a high-concentrate finishing diet for an average of 188 d. Supplements fed to dams during gestation did not influence feedlot performance or carcass characteristics. Prepartum energy supplementation, regardless of energy source or prepartum energy balance, resulted in improved conception rate, but other measures of reproduction, calf and feedlot performance, and carcass characteristics were not affected.     

Dietary zilpaterol hydrochloride. II. Carcass composition and meat palatability of beef cattle

Experiments were conducted at 3 US locations (California, Idaho, and Texas) to determine the effects of dietary zilpaterol hydrochloride and duration of zilpaterol feeding on carcass composition and beef palatability. At each site, 160 steers and 160 heifers were stratified within sex by initial BW (study d -1) and assigned randomly within BW strata to 1 of 4 treatments in a randomized complete block design (4 blocks/treatment for each sex). The 4 treatments were arranged in a 2 (no zilpaterol vs. zilpaterol) x 2 (20- or 40-d duration of zilpaterol feeding) factorial. When included in the diet, zilpaterol was supplemented at 8.3 mg/kg (DM basis). Each pen consisted of 10 animals. After slaughter 2 carcasses per pen (n=64 per trial site) were selected. The entire right side of the selected carcasses was collected for dissection and chemical analysis of the soft tissue. Additionally, the left strip loin was collected for Warner-Bratzler shear force determinations and aged to 28 d postmortem. Sensory analysis was conducted on the Idaho trial site samples only. All data were pooled for analyses. Feeding zilpaterol hydrochloride increased carcass muscle deposition (P<0.01) of both steer and heifer carcasses. However, carcass percentage fat of steers and heifers was not affected (P>0.11) by the zilpaterol treatment. In heifer carcasses, carcass moisture percentage was increased (P=0.04) and bone percentage was decreased (P=0.02), whereas in steer carcasses, carcass moisture and bone percentage were not affected (P>0.10). In heifer carcasses, carcass ash percentage was not affected (P=0.61) by zilpaterol, whereas in steer carcasses, carcass ash percentage tended (P=0.07) to be increased. The protein-to-bone ratio was increased (P<0.001) by zilpaterol hydrochloride treatment in both steers and heifers, whereas the protein-to-fat ratio was not affected (P=0.10). Cooking loss of the LM was not affected (P=0.41) by zilpaterol treatment of steers or heifers. However, LM Warner-Bratzler shear force was increased (P=0.003) on average (3.3 vs. 4.0 kg) due to zilpaterol hydrochloride treatment of both steers and heifers. In both steers and heifers, LM sensory panel scores of overall juiciness (6.2 vs. 6.0), tenderness (6.2 vs. 6.0), and flavor intensity (6.2 vs. 6.0) tended (P=0.06) to be decreased in cattle supplemented with zilpaterol. Zilpaterol hydrochloride is a repartitioning agent that seems to affect carcass composition primarily through protein deposition. However, zilpaterol treatment can adversely affect tenderness and other palatability traits.     

Wounds of the pastern and foot region managed with phalangeal casts: 50 cases in 49 horses (1995–2006)

Objective   Describe the use of a phalangeal cast as treatment for wounds in the pastern and foot region of horses. Secondly, to evaluate the healing and soundness of horses treated with phalangeal casts.
Design   Retrospective study of 49 horses.
Procedures   Medical records of 49 horses that were treated with a phalangeal cast for 50 cases of wounds in the pastern and foot region at equine referral hospitals from 1995 to 2006 were reviewed and follow-up information was obtained.
Results   Treatment consisted of wound debridement, lavage, wound closure (28 wounds), cast application and antibiotics (84%). At follow-up, the majority of horses were sound (42 of 47 wounds, 89.4%), three horses were still lame and one horse was euthanased because of persistent lameness. Three horses were lost to follow-up. There was no statistical difference between the outcomes of horses treated acutely (<24 h) or after a 24-h delay. Similarly, the involvement of synovial structures in the wound did not significantly influence outcome.
Conclusions   In this study, wounds involving the pastern and foot that were treated with a phalangeal cast carried a good prognosis for soundness (89.4%) and cosmetic healing (89.5%). The phalangeal casts were well-tolerated and effective.     

Supplementation of dried distillers grains with solubles to beef cows consuming low-quality forage during late gestation and early lactation

Three experiments were conducted to evaluate supplementation of dried distillers grains with solubles (DGS) to spring-calving beef cows (n = 120; 541 kg of initial BW; 5.1 initial BCS) consuming low-quality forage during late gestation and early lactation. Supplemental treatments included (DM basis) 1) 0.77 kg/d DGS (DGSL); 2) 1.54 kg/d DGS (DGSI); 3) 2.31 kg/d DGS (DGSH); 4) 1.54 kg/d of a blend of 49% wheat middlings and 51% cottonseed meal (POS); and 5) 0.23 kg/d of a cottonseed hull-based pellet (NEG). Feeding rate and CP intake were similar for DGSI and POS. In Exp. 1, cows were individually fed 3 d/wk until calving and 4 d/wk during lactation; total supplementation period was 119 d, encompassing 106 d of gestation and 13 d of lactation. Tall-grass prairie hay (5.6% CP, 50% TDN, 73% NDF; DM basis) was fed for ad libitum intake throughout the supplementation period. Change in cow BW and BCS during gestation was similar for DGSI and POS (-5.0 kg, P = 0.61 and -0.13, P = 0.25, respectively) and linearly increased with increasing DGS level (P < 0.01). Likewise, during the 119-d supplementation period, BW and BCS change were similar for DGSI and POS (-72 kg, P = 0.22 and -0.60, P = 0.10) and increased linearly with respect to increasing DGS (P < 0.01). The percentage of cows exhibiting luteal activity at the beginning of breeding season (56%, P = 0.31), AI conception rate (57%, P = 0.62), or pregnancy rate at weaning (88%, P = 0.74) were not influenced by supplementation. In Exp. 2, 30 cows from a separate herd were used to evaluate the effect of DGS on hay intake and digestion. Supplementation improved all digestibility measures compared with NEG. Hay intake was not influenced by DGS (P > 0.10); digestibility of NDF, ADF, CP, and fat linearly increased with increasing DGS. In Exp. 3, milk production and composition were determined for cows (n = 16/treatment) of similar days postpartum from Exp. 1. Daily milk production was not influenced by supplementation (6.3 kg/d, P = 0.25). Milk fat (2.1%) and lactose (5.0%) were not different (P > 0.10). Milk protein linearly increased as DGS increased (P < 0.05) and was greater for DGSI compared with POS. Similar cow performance was achieved when cows were fed DGS at the same rate and level of CP as a traditional cottonseed meal-based supplement. Increasing amounts of DGS did not negatively influence forage intake or diet digestibility.     

Effect of live weight gain of steers during winter grazing: II. Visceral organ mass, cellularity, and oxygen consumption

Two experiments were conducted to examine the effect of BW gain during winter grazing on mass, cellularity, and oxygen consumption of splanchnic tissues before and after the feedlot finishing phase. In each experiment, 48 fall-weaned Angus x Angus-Hereford steer calves were assigned randomly to one of three treatments: 1) high rate of BW gain grazing winter wheat (HGW), 2) low rate of BW gain grazing winter wheat (LGW), or 3) grazing dormant tallgrass native range supplemented with 0.91 kg/d of a 41% CP supplement (NR). At the end of winter grazing, four steers were selected randomly from each treatment for initial slaughter to measure organ mass, cellularity, and oxygen consumption. All remaining steers were placed into a feedlot and fed to the same backfat end point (1.27 cm). Six steers were selected randomly from each treatment for final organ mass, cellularity, and oxygen consumption. Initial empty BW (EBW) was greatest (P < 0.001) for HGW, intermediate for LGW, and least for NR steers in both Exp. 1 and 2 (355 > 263 > 207 +/- 6.5 kg and 337 > 274 > 205 +/- 8.7 kg, respectively). For both experiments, the initial total gastrointestinal tract (GIT; g/kg of EBW) proportional weight was greater (P < 0.05) in NR steers than in LGW, and LGW steers had greater (P < 0.05) initial GIT proportional weight than HGW steers. Proportional weight of total splanchnic tissues (TST; g/kg of EBW) did not differ (P < 0.19) among treatments. Initial duodenal RNA concentration and RNA:protein were greater (P < 0.02) in LGW than in HGW steers, and NR steers were intermediate. Initial in vitro liver O2 consumption was greater (P < 0.09) in HGW and LGW than in NR steers (34.5 > 16.9 mL/min), whereas initial small intestinal oxygen consumption was greater (P < 0.01) in LGW than in HGW and NR steers (12.1 > 5.2 mL/min). Ruminal papillae oxygen consumption did not differ (P < 0.55) among treatments. The rate of decrease of GIT (g x g EBW(-1) x d(-1)) during finishing was greater in NR than in HGW and LGW steers in both Exp. 1 and 2, but mesenteric fat (g x g EBW(-1) x d(-1)) increased for NR steers, resulting in a similar (P < 0.75) increase in TST across the finishing period for all treatments. Similar rates of increase in TST across the finishing phase corresponded with similar rates of live and carcass weight gain among treatments. Our data support the hypothesis that increased visceral organ mass increases maintenance energy requirements of growing cattle.