Advances in helioseismology

Globally coherent oscillation modes were discovered in the sun about a decade ago, providing a unique seismological probe of the solar interior. Current observations detect modes that are phase-coherent for up to 1 year, with surface velocity amplitudes as low as 2 millimeters per second, and thousands of mode frequencies have been measured to accuracies as high as 1 part in 10(5). This article discusses the properties of these oscillation modes and the ways in which they are adding to our understanding of the structure and dynamics of the sun.     

Effects of increased ambient temperature and supplemental altrenogest before pregnancy establishment in gilts

Heat stress (HS) mitigation strategies are critically needed to combat the substantial economic effects on animal agriculture. The manifestations of seasonal infertility include delayed puberty onset, reduced conception rates, decreased litter size, and increased wean to estrus interval. To assess the effects of HS during early gestation and evaluate the benefit of supplemental altrenogest (ALT) as a mitigation strategy, 30 crossbred postpubertal gilts (157 ± 11 kg body weight) were subjected to estrous synchronization via 14 d oral administration of ALT. Artificial insemination during estrus was performed, and gilts were then placed into one of four treatment groups: HS (35 ± 1 °C for 12 h/31.60 ± 1 °C for 12 h) with (HSALT, n = 7) or without (HSCON, n = 7) 15 mg/d ALT supplementation or thermal neutral (TN; 20 ± 1 °C) conditions with (TNALT, n = 8) or without (TNCON, n = 8) 15 mg/d ALT supplementation until 12 d post-estrus (dpe). Administrating ALT occurred at 0600 hours from 3 to 12 dpe, and rectal temperatures (T_R) and respiration rates (RR) were recorded. Blood was collected via jugular venipuncture on 0, 4, 8, and 12 dpe. Gilts were euthanized humanely at 12 dpe followed by the collection of ovarian tissue, and uterine flushing for conceptus collection. In HS compared with TN gilts, RR and T_R were increased (P < 0.01) but unaffected by ALT supplementation. Feed intake was reduced (P < 0.01) by HS but unaltered by the ALT treatment. Corpora lutea (CL) weight was reduced (P < 0.01) in HSCON gilts when compared with TNCON and HSALT gilts despite progesterone concentrations in serum and luteal tissue not being affected by treatment (P ≥ 0.10). CL diameter was reduced (P ≤ 0.05) in HSALT gilts compared with other treatments. Interleukin-1β (IL1B) uterine flush concentration was not affected (P > 0.20) by environment or ALT supplementation, although moderate (P = 0.06) interaction between environment and ALT existed, as IL1B concentration in TNALT was increased (P = 0.03) compared with TNCON gilts. While environment did not affect conceptus development (P = 0.90), ALT supplementation advanced conceptus elongation (P < 0.01). Collectively, these data demonstrate that HS may affect luteal development before pregnancy establishment, and ALT increases conceptus elongation by 12 dpe.     

Effects of maternal protein-energy malnutrition and cold stress on neutrophil function of bovine neonates

The effects of maternal protein or calorie deprivation (or both) on the bactericidal activity of neutrophils and sera from newborn calves subjected to cold stress were studied. Nutritional deficiencies in the dam had little effect on in vitro bactericidal activity of neutrophils and base-line sera taken at birth. Neutrophils obtained at birth destroyed Staphylococcus aureus but not Escherichia coli when incubated with either unheated or heated autologous base-line sera. Heat treatment of base-line sera to inactivate complement did not alter bacterial growth. When incubated in the presence of autologous base-line sera, neutrophils from 3-day-old calves were no more active in the destruction of either bacterium than were neutrophils from newborn calves. However, addition of day 3 (immunoglobulin-containing) sera enabled day 3 neutrophils to destroy E coli (P < 0.0001). The increased destruction of E coli by day 3 neutrophils and day 3 sera was not affected by heat treatment of the sera. Maternal protein deficiency significantly increased (P < 0.05) destruction of E coli by day 3 neutrophils and sera. This effect was independent of energy levels. There were no differences observed in the bactericidal activity of neutrophils and sera taken from calves exposed to 1 C or 21 C environmental chambers for 3 days. Also, cold stress-nutritional stress interactions were not detected.     

Effects of supplemental protein type on productivity of primiparous beef cows

Effects of supplemental degradable (DIP) and undegradable (UIP) intake protein on forage intake, BW change, body condition score (BCS), postpartum interval to first estrus, conception rate, milk production and composition, serum metabolites and metabolic hormones, and calf gain were determined using 36 primiparous Gelbvieh x Angus rotationally crossed beef cows. On d 3 postpartum, cows (average initial BW = 495 +/- 10 kg and BCS = 5.5 +/- 0.1) were randomly assigned to one of three dietary supplements (12 cows/treatment). Date of parturition was evenly distributed across treatment (average span of calving date among treatments = 2.4 +/- 2.5 d). Individually fed (d 3 through 120 postpartum) dietary supplements were 0.82 kg of corn and 0.23 kg of soybean meal per day (DIP), the DIP + 0.12 kg of blood meal and 0.13 kg of corn gluten meal per day (DIP + UIP), and 0.82 kg of corn, 0.07 kg of blood meal, and 0.08 kg of corn gluten meal per day in an isonitrogenous replacement of soybean meal (UIP IsoN). Cows had ad libitum access to native grass hay (8.5% CP) and trace-mineralized salt. Total OM intake was greater (P = 0.06) for DIP + UIP than UIP IsoN cows. At 30 d postpartum, DIP + UIP cows produced more milk than UIP IsoN, with DIP being intermediate; however, at 60 d postpartum, DIP + UIP and DIP cows were not different, but both had greater milk production than UIP IsoN (treatment x day interaction; P = 0.08). A treatment x day interaction (P = 0.06) for BCS resulted from DIP + UIP cows having the greatest BCS at 60, 90, and 120 d d postpartum and DIP having greater BCS than UIP IsoN cows only on d 60 postpartum. Serum insulin concentrations were highest (treatment x day interaction; P = 0.09) for DIP + UIP cows at 30 d postpartum but did not differ among treatment thereafter. Serum insulin-like growth factor-binding protein (IGFBP)-2 (34 kDa) and -3 (40 and 44 kDa) were greatest (P < 0.0003) for DIP cows. Serum urea-N concentrations were greater (P < 0.01) in DIP + UIP cows than in either DIP or UIP IsoN cows. However, postpartum interval to first estrus, conception rate, and calf weaning weights were unaffected (P = 0.35, 0.42, and 0.64, respectively) by treatment. Although UIP in addition to or in replacement of DIP affected milk production and blood metabolites, the productivity of these primiparous beef cows was not altered. Thus, the type of supplemental protein does not seem to influence productivity of primiparous beef cows in production systems with conditions similar to our experimental conditions.