Measurement of the Ξ^-_b and Ω^-_b baryon lifetimes

Using a data sample of pp collisions corresponding to an integrated luminosity of $3~ \rm fb^{-1}$, the $\Xi_b^-$ and $\Omega_b^-$ baryons are reconstructed in the $\Xi_b^- \rightarrow J/\psi \Xi^-$ and $\Omega_b^- \rightarrow J/\psi \Omega^-$ decay modes and their lifetimes measured to be \tau (\Xi_b^-) = 1.55\, ^{+0.10}_{-0.09}~{\rm(stat)} \pm 0.03\,{\rm(syst)} ps, \tau (\Omega_b^-) = 1.54\, ^{+0.26}_{-0.21}~{\rm(stat)} \pm 0.05\,{\rm(syst)} ps. These are the most precise determinations to date. Both measurements are in good agreement with previous experimental results and with theoretical predictions

Evaluation of the endocrine response of cattle during the relocation process

To evaluate the endocrine responses associated with the relocation process, 22 Holstein heifers (326.4 ± 46.8 kg BW) were randomly assigned to control (CON) or relocation (RELOC) treatment groups. On d 0, heifers were weighed and fitted within dwelling rectal temperature (RT) monitoring devices and jugular catheters. On d 1, baseline blood samples were collected from all heifers for 2 h prior to the transportation event, then weighed. Controls were returned to tie stalls and RELOC were loaded into a modified stock trailer (12 individual stanchions) for a 4 h transportation event. Simultaneous blood samples were obtained at 30-min intervals from both groups throughout the 4 h transport event (TE-I). After transport, RELOC were unloaded at an unfamiliar location, weighed, and placed in tie stalls for a 2 h post-transportation period. All heifers were then placed into two separate holding paddocks with access to water and hay for 4 h. After 4 h, hay and water was withdrawn for 20 h. On d 2 RELOC heifers were exposed to a second transport event (TE-II); the timeline and procedures of TE-II were identical to those of TE-I (except for the starting point for RELOC heifers). All serum samples were analyzed for concentrations of cortisol, growth hormone (GH), and insulin-like growth factor-I(IGF-I). A 6% reduction in BW for the RELOC as compared to 2.5% reduction in BW for CON (PPPPP\u3e0.05) in area under the curve (AUC) for cortisol were observed during TE-I. However, AUC for total cortisol during TE-II was greater (PPP\u3e0.05) in IGF-I concentrations or in AUC between the treatment groups during TE-I and-II or from d 1 to d 2. Results provide evidence that the actual processes surrounding the transportation of cattle, can elicit a stress response, as defined by increased concentrations of cortisol, RT, and BW losses

Immune response in feeder cattle fed different sources of dietary lipid

Two studies were conducted utilizing crossbred beef steers to evaluate immune response following endotoxin challenge. In Trial 1 steers (n = 20; 688 lb BW) were fed diets containing rolled full-fat soybeans (SOY) or tallow (TALLOW). In Trial 2, steers (n=18; 780 lb BW) were fed diets containing TALLOW, flaxseed (FLAX), or a micro-algae (ALGAE) top-dressed to the TALLOW diet. Both FLAX and ALGAE were sources of omega-3 polyunsaturated fatty acids. In both trials, diets were fed for a 14-day acclimation period prior to intravenous injection of a bacterial lipopolysaccharide(LPS) endotoxin. Injection of LPS in Trial 1 resulted in higher rectal temperatures for animals fed TALLOW compared to those fed SOY. In contrast, plasma concentrations of tumor necrosis factor-α (TNF) were higher for animals fed SOY. Haptoglobin and fibrinogen increased and total white blood cell count decreased in response to LPS, but these measures were not different (P>0.1) between SOY and TALLOW. In Trial 2, rectal temperature was higher for TALLOW (P<0.05) than for FLAX at 3, 4, 5, and 6 hours after the initial injection of LPS. In addition, rectal temperature for TALLOW was higher (P=0.05) at hour 4 when compared to ALGAE and tended (P=0.1) to be higher at hour 5. Serum haptoglobin concentration at 24 hours was higher (P<0.05) for animals fed ALGAE than those fed FLAX or TALLOW. Haptoglobin and fibrinogen concentrations increased at 24 hours after injection with LPS, but were not different at other times among treatments in either trial. Results show that source and type of dietary fatty acid may impact immune response in cattle

Limit-feeding a high-energy diet to meet energy requirements in the dry period alters plasma metabolite concentrations but does not affect intake or milk production in early lactation

Limit-feeding dry cows a high-energy diet may enable adequate energy intake to be sustained as parturition approaches, thus reducing the extent of negative energy balance after parturition. Our objective was to evaluate the effect of dry period feeding strategy on plasma concentrations of hormones and metabolites that reflect energy status. Multiparous Holstein cows (n = 18) were dried off 45 d before expected parturition, paired by expected calving date, parity, and previous lactation milk yield, and randomly assigned to 1 of 2 dry-period diets formulated to meet nutrient requirements at ad libitum or limited intakes. All cows were fed the same diet for ad libitum intake after parturition. Prepartum dry matter intake (DMI) for limit-fed cows was 9.4 kg/d vs. 13.7 kg/d for cows fed ad libitum. During the dry period, limit-fed cows consumed enough feed to meet calculated energy requirements, and ad libitum-fed cows were in positive calculated net energy for lactation (NEL) balance (0.02 vs. 6.37 Mcal/d, respectively). After parturition, milk yield, milk protein concentration, DMI, body condition score, and body weight were not affected by the prepartum treatments. Cows limit fed during the dry period had a less-negative calculated energy balance during wk 1 postpartum. Milk fat concentration and yield were greater for the ad libitum treatment during wk 1 but were lower in wk 2 and 3 postpartum. Plasma insulin and glucose concentrations decreased after calving. Plasma insulin concentration was greater in ad libitum-fed cows on d -2 relative to calving, but did not differ by dietary treatment at other times. Plasma glucose concentrations were lower before and after parturition for cows limit-fed during the dry period. Plasma nonesterified fatty acid concentrations peaked after parturition on d 1 and 4 for the limit-fed and ad libitum treatments, respectively, and were greater for limit-fed cows on d -18, -9, -5, and -2. Plasma tumor necrosis factor-alpha concentrations did not differ by treatment in either the pre- or postpartum period, but tended to decrease after parturition. Apart from a reduction in body energy loss in the first week after calving, limit feeding a higher NEL diet during the dry period had little effect on intake and milk production during the first month of lactation

Short communication: Suppressor of cytokine signaling-2 mRNA increases after parturition in the liver of dairy cows

After parturition, the somatotropic axis of the dairy cow is uncoupled, partly because of reduced concentration of liver-specific GH receptor (GHR) 1A. Estradiol-17 beta (E-2) concentrations increase at parturition and E-2 upregulates suppressors of cytokine signaling-2 (SOCS-2) mRNA expression, potentially inhibiting GH signaling. Therefore, we hypothesized that SOCS-2 mRNA is upregulated after parturition. Multiparous Holstein cows (n = 18) were dried off 45 d before expected parturition and fed diets to meet nutrient requirements at ad libitum or limited dry matter intake during the dry period. All cows were fed the same diet ad libitum from calving until 4 wk after parturition. Blood samples were collected weekly and more frequently near parturition. Liver biopsies obtained at -21, -7, 2, and 28 d relative to parturition were assessed for SOCS-2 and GHR 1A mRNA by quantitative real-time reverse-transcription PCR. The relative amount of SOCS-2 mRNA increased after parturition with both treatments and was greater on d 2 for cows limit-fed during the dry period compared with cows fed at ad libitum dry matter intake. Plasma E2 concentrations increased on d -13, -5 and 1 relative to parturition and the increases were greater in limit-fed cows. Plasma GH concentration was greater for limit-fed cows and increased after parturition in all cows. The amount of GHR 1A mRNA did not differ between diets but decreased on d 2. In addition to reduced GHR 1A, increased SOCS-2 mRNA after parturition, perhaps because of increased E-2, may further uncouple GH signaling in the liver of the transition dairy cow