second model, the two main conditions were parametrically modulated by the two categories, respectively (SOM, S5.1). The activation of the precuneus was higher for hard dominance-solvable games than for easy ones ( Fig. 4A and table S10). The activation of the insula was higher for the highly focal coordination games than for less focal ones ( Fig. 4B and table S11). Previous studies also found that precuneus activity increased when the number of planned moves increased (40, 41). The higher demand for memory-related imagery and memory retrieval may explain the greater precuneus activation in hard dominance-solvable games. In highly focal coordination games, the participants may have felt quite strongly that the pool students must notice the same salient feature. This may explain why insula activation correlates with NCI.Participants might have disagreed about which games were difficult. We built a third model to investigate whether the frontoparietal activation correlates with how hard a dominance-solvable game is and whether the activation in insula and ACC correlates with how easy a coordination game is. Here, the two main conditions were parametrically modulated by each participant's probability of obtaining a reward in each game (SOM, S2.2 and S5.2). We found a negative correlation between the activation of the precuneus and the participant's probability of obtaining a reward in dominance-solvable games ( Fig. 4C and table S12), which suggests that dominance-solvable games that yielded lower payoffs presented harder mental challenges. In a previous study on working memory, precuneus activity positively correlated with response times, a measure of mental effort (24). Both findings are consistent with the interpretation that subjective measures reflecting harder tasks (higher efforts) correlate with activation in precuneus. A positive correlation between insula activation and the participant's probability of obtaining a reward again suggests that coordination games with a highly salient feature strongly activated the "gut feeling" reported by many participants (Fig. 4D and table S13). A previous study found that the subjective rating of "chills intensity" in music correlates with activation of insula (42). Both findings are consistent with the interpretation that the subjective intensity of how salient a stimulus is correlates with activation in insula.As mentioned, choices were made significantly faster in coordination games than in dominancesolvable games. The results of the second and third models provide additional support for the idea that intuitive and deliberative mental processes have quite different properties. The "slow and effortful" process was more heavily taxed when the dominance-solvable games were harder. The "fast and effortless" process was more strongly activated when coordination was easy.
The National Institutes of Health's Mammalian Gene Collection (MGC) project was designed to generate and sequence a publicly accessible cDNA resource containing a complete open reading frame (ORF) for every human and mouse gene. The project initially used a random strategy to select clones from a large number of cDNA libraries from diverse tissues. Candidate clones were chosen based on 5'-EST sequences, and then fully sequenced to high accuracy and analyzed by algorithms developed for this project. Currently, more than 11,000 human and 10,000 mouse genes are represented in MGC by at least one clone with a full ORF. The random selection approach is now reaching a saturation point, and a transition to protocols targeted at the missing transcripts is now required to complete the mouse and human collections. Comparison of the sequence of the MGC clones to reference genome sequences reveals that most cDNA clones are of very high sequence quality, although it is likely that some cDNAs may carry missense variants as a consequence of experimental artifact, such as PCR, cloning, or reverse transcriptase errors. Recently, a rat cDNA component was added to the project, and ongoing frog (Xenopus) and zebrafish (Danio) cDNA projects were expanded to take advantage of the high-throughput MGC pipeline.
A combination of Sanger and 454 sequences of small subunit rRNA loci were used to interrogate microbial diversity in the bovine rumen of 12 cows consuming a forage diet. Observed bacterial species richness, based on the V1–V3 region of the 16S rRNA gene, was between 1,903 to 2,432 species-level operational taxonomic units (OTUs) when 5,520 reads were sampled per animal. Eighty percent of species-level OTUs were dominated by members of the order Clostridiales, Bacteroidales, Erysipelotrichales and unclassified TM7. Abundance of Prevotella species varied widely among the 12 animals. Archaeal species richness, also based on 16S rRNA, was between 8 and 13 OTUs, representing 5 genera. The majority of archaeal OTUs (84%) found in this study were previously observed in public databases with only two new OTUs discovered. Observed rumen fungal species richness, based on the 18S rRNA gene, was between 21 and 40 OTUs with 98.4–99.9% of OTUs represented by more than one read, using Good’s coverage. Examination of the fungal community identified numerous novel groups. Prevotella and Tannerella were overrepresented in the liquid fraction of the rumen while Butyrivibrio and Blautia were significantly overrepresented in the solid fraction of the rumen. No statistical difference was observed between the liquid and solid fractions in biodiversity of archaea and fungi. The survey of microbial communities and analysis of cross-domain correlations suggested there is a far greater extent of microbial diversity in the bovine rumen than previously appreciated, and that next generation sequencing technologies promise to reveal novel species, interactions and pathways that can be studied further in order to better understand how rumen microbial community structure and function affects ruminant feed efficiency, biofuel production, and environmental impact.
In postpartum beef cows, GnRH-induced ovulation of small dominant follicles decreased pregnancy rates and increased late embryonic/fetal mortality. In Exp. 1, single ovulation reciprocal embryo transfer (ET) was used to examine the relationship between preovulatory serum concentrations of estradiol at GnRH-induced ovulation in donor and recipient cows and establishment and maintenance of pregnancy. Suckled beef cows (n = 1,164) were administered GnRH (GnRH1, 100 μg) on d -9 (GnRH1), PGF(2α) on d -2, and GnRH2 (GnRH2, 100 μg) on d 0 (CO-Synch protocol) either with (donors; n = 810) or without (recipients; n = 354) AI. Single embryos (n = 394) or oocytes (n = 45) were recovered from the donor cows (d 7; ET) and all live embryos were transferred into recipients. Serum concentration of estradiol at GnRH2 was positively correlated with follicle size at GnRH2 (r = 0.45, P < 0.01) and progesterone at ET (r =0.34, P < 0.01). Donor cows with greater estradiol at GnRH2 were more likely to yield an embryo than an unfertilized oocyte (P < 0.01). Donor and recipient cows were retrospectively divided into 4 groups [low estradiol (<8.4 pg/mL) or high estradiol (≥8.4 pg/mL)] based on serum concentration of estradiol at GnRH2. Pregnancy rate at d 27 for low-low (n = 78), low-high (n = 80), high-low (n = 91), and high-high (n = 101) groups (donor-recipient, respectively) was 45, 65, 43, and 61% respectively (P < 0.02). Because recipient cows with greater estradiol concentration at GnRH2 had greater pregnancy rates in Exp. 1, the objective of Exp. 2 was to evaluate the effect of estradiol supplementation on pregnancy rate. Ovulation was synchronized in suckled beef cows (n = 600) using the CO-Synch protocol with the insertion of a controlled internal drug release (CIDR; intravaginal progesterone supplement) from d -9 until d -2. Approximately one-half of the cows (n = 297) received an injection of estradiol cypionate (ECP; 0.5 mg intramuscularly) 24 h before AI. Compared with the no treatment (Control) cows, ECP treatment increased (P < 0.01) pregnancy rates of cows induced to ovulate smaller dominant follicles (<12.2 mm). In conclusion, GnRH-induced ovulation of small dominant follicles was associated with reduced serum estradiol, fertilization rate (donor cows), and pregnancy establishment (recipient cows). Furthermore, ECP supplementation during the preovulatory period increased pregnancy rates in cows induced to ovulate smaller dominant follicles.
Reproductive performance was evaluated in composite heifers born over a 3-yr period that were randomly assigned to control (fed to appetite; n = 205) or restricted (fed at 80% of that consumed by controls adjusted to a common BW basis; n = 192) feeding for a 140-d period, beginning about 2 mo after weaning at 6 mo of age and ending at about 12.5 mo of age. Heifers were fed a diet of 67% corn silage, 18% alfalfa, and 9% of a protein-mineral supplement (DM basis). Restricted heifers consumed 27% less feed over the 140 d and had less ADG (0.53 +/- 0.01 vs. 0.65 +/- 0.01 kg/d; P < 0.001) than control heifers. After 140 d, all heifers were placed in common pens and subjected to an estrous synchronization protocol to facilitate AI at about 14 mo of age. Heifers were then exposed to bulls for the remainder of a 51-d breeding season. Average BW of heifers diverged within 28-d after initiation of feed restriction, and differences (P < 0.001) persisted through the prebreeding period (309 +/- 1 vs. 326 +/- 1 kg at approximately 13.5 mo of age) and subsequent grazing season (410 +/- 2 vs. 418 +/- 2 kg at about 19.5 mo of age). From the end of the 140-d restriction at about 12.5 to 19.5 mo of age, ADG was greater (P < 0.001) in restricted heifers than control heifers (0.51 +/- 0.01 vs. 0.47 +/- 0.01 kg/d). Proportion of heifers attaining puberty by 14 mo of age tended to be less (P = 0.1) in restricted (60 +/- 3%) than control-fed heifers (68 +/- 3%). Mean BW at puberty was less (P < 0.01) in restricted (309 kg) than control (327 kg) heifers. Pregnancy rate from AI tended to be less (P = 0.08) in restricted (48 +/- 4%) than control heifers (57 +/- 3%). Proportion of animals that were pubertal at breeding and pregnant from AI were positively associated (P < 0.1) with heifer age and ADG from birth to beginning of study. Final pregnancy rates were 87 and 91% for restricted and control heifers, respectively (P = 0.27). Day of breeding season that conception occurred was negatively associated with ADG from birth to weaning (P = 0.005), but was not associated with ADG within treatment (P = 0.60). Economic analysis revealed a $33 reduction in cost to produce a pregnant heifer under the restricted protocol when accounting for pregnancy rates and differences in BW and market prices between selection at weaning and marketing as open heifers at l.5 yr of age. A potential economic advantage exists for rearing replacement heifers on a restricted level of feeding during the postweaning period.
Traits used for identification of replacement beef heifers and feeding levels provided during postweaning development may have major financial implications due to effects on maintenance requirements and level of lifetime production. The current study evaluated the effects of 2 levels of feeding during the postweaning period on growth, G:F, and ultrasound carcass measurements of heifers, and the associations among these traits. Heifers (1/2 Red Angus, 1/4 Charolais, and 1/4 Tarentaise) born in 3 yr were randomly assigned to a control (fed to appetite; n = 205) or restricted (fed at 80% of that consumed by controls adjusted to a common BW basis; n = 192) feeding during a 140-d postweaning period. Heifers were individually fed a diet of 68% corn silage, 18% alfalfa, and protein-mineral supplement (DM basis) in pens equipped with Calan gates. Ultrasound measurements of LM area, intramuscular fat, and subcutaneous fat thickness over the LM were made on d 140 (382 +/- 0.8 d of age). Average daily DMI was 4.1 and 5.6 kg/d for restricted and control heifers, respectively (P < 0.001). Feed restriction decreased (P < 0.001) BW (292 vs. 314 kg), ADG (0.52 vs. 0.65 kg/d), LM area (55 vs. 59 cm2), intramuscular fat (3.2 vs. 3.5%), and subcutaneous fat thickness over the LM (3.2 vs. 3.9 mm), but increased G:F (0.12 vs. 0.11) when compared with control at the end of the 140-d study. The magnitude of the associations of DMI with ADG (r = 0.32 vs. 0.21), 140-d BW (r = 0.78 vs. 0.36), hip height (r = 0.57 vs. 0.17), LMA (r = 0.30 vs. 0.18), and BCS (r = 0.17 vs. 0.11) was greater in restricted- than control-fed heifers. Variance of residual feed intake, calculated within each treatment, was greater (P < 0.01) in control (0.088) than restricted (0.004) heifers, and magnitude of association between residual feed intake and average DMI was greater in control (r = 0.88) than restricted (r = 0.41) heifers. Pregnancy rate tended (P = 0.11) to be reduced in heifers that had been developed on restricted feeding (86.3 +/- 2.3 vs. 91.5 +/- 2.3%). However, ADG was greater (P < 0.001) in restricted than control heifers (0.51 vs. 0.46 kg/d) while grazing native range in the 7 mo after restriction. In summary, restricted heifers consumed 22% less feed on a per-pregnant-heifer basis during the development period and had a greater magnitude of association between DMI and several growth-related traits at the end of the 140-d postweaning feeding period, which is indicative of improved efficiency.
Cattle grazing winter range forages exhibit interannual variation in response to supplementation. This variation may be mediated by circulating concentrations and subsequent metabolism of glucose, which are influenced by forage quality and availability. A study conducted at the Corona Range and Livestock Research Center during 2 dry years evaluated responses of young postpartum beef cows (n = 51, initial BW = 408 +/- 3 kg, and BCS = 5.1 +/- 0.04 in year 1; n = 36, initial BW = 393 +/- 4 kg, and BCS = 4.5 +/- 0.05 in year 2) to supplements that met or exceeded metabolizable protein (MP) requirements. Supplements were fed at 908 g/d per cow and provided 327 g of CP, 118 g of ruminally undegradable protein (RUP), and 261 g of MP from RUP (RMP), calculated to meet the MP requirement; 327 g of CP, 175 g of RUP, and 292 g of MP from RUP (RMP+), which supplied 31 g of excess MP; or 327 g of CP, 180 g of RUP, 297 g of MP from RUP, and 100 g of propionate salt (NutroCal, Kemin Industries, Inc., Des Moines, IA; (RMP+)P), which supplied 36 g of excess MP. Body weights were recorded once every 2 wk, and blood samples were collected 1x/wk in year 1 and 2x/wk in year 2 for 100 d postpartum. Postpartum anestrous was evaluated by progesterone from weekly blood samples, and pregnancy was confirmed by rectal palpation at weaning. As MP from RUP with or without propionate increased, a decrease (P = 0.03) was observed in postpartum interval; however, differences in pregnancy percentage (P = 0.54) were not influenced by treatments. We hypothesized that additional AA from RUP along with propionate would increase supply of glucogenic precursors and, therefore, glucogenic potential of the diet. Therefore, a postpartum glucose tolerance test was conducted near the nadir of cow BW to evaluate the rate of glucose clearance. Glucose tolerance tests showed that (RMP+)- or (RMP+)P-supplemented cows had greater (P = 0.03) rates of glucose clearance, which might have influenced the observed abbreviation of the postpartum interval. A glucose tolerance test conducted at the end of supplemental treatments revealed no differences in glucose clearance (P = 0.47) among previously supplemented cows. These data suggest that not only vegetative quality, duration of lactation, and season of grazing, but also type of supplementation may play a pivotal role in the young postpartum beef cow's ability to respond and incorporate nutrients into insulin-sensitive tissues.
Body condition score is used as a management tool to predict competency of reproduction in beef cows. Therefore, a retrospective study was performed to evaluate association of BCS at calving with subsequent pregnancy rate, days to first postpartum ovulation, nutrient status (assessed by blood metabolites), and calf BW change in 2- and 3-yr-old cows (n = 351) managed and selected to fit their environment of grazing native range over 6 yr at the Corona Range and Livestock Research Center, Corona, NM. Cows were managed similarly before calving, without manipulation of management, to achieve predetermined BCS at parturition. Palpable BCS (scale of 1 to 9) were determined by 2 experienced technicians before calving. Cows were classified to 1 of 3 BCS groups prior calving: BCS 4 (mean BCS = 4.3 ± 0.02), 5 (mean BCS = 5.0 ± 0.03), or 6 (mean BCS = 5.8 ± 0.06). Cows were weighed weekly after calving and serum was collected once weekly (1 yr) or twice weekly (5 yr) for progesterone analysis to estimate first postpartum ovulation beginning 35 d postpartum. Year effects also were evaluated, with years identified as either above or below average precipitation. Days to first postpartum ovulation did not differ among calving BCS groups (P = 0.93). Pregnancy rates were not influenced by calving BCS (P = 0.83; 92%, 91%, 90% for BCS 4, 5, and 6, respectively). Days to BW nadir was not influenced by BCS at calving (P = 0.95). Cow BW was different at all measuring points (P < 0.01) with BCS 6 cows having the heaviest BW and cows with BCS 4 the lightest. Cows with calving BCS 4 and 5 lost more (P = 0.06) BW from the initiation of the study to the end of breeding than cows with BCS 6. However, cow BW change at all other measurement periods was not different (P ≥ 0.49) among calving BCS groups. Serum glucose and NEFA concentrations were not influenced by calving BCS (P ≥ 0.51). Calf BW at birth (P = 0.60), branding (55-d BW; P = 0.76), and weaning (205-d BW; P = 0.60) were not impacted by cow calving BCS. Body condition score did not influence overall pregnancy rates, indicating that young cows can have a reduced BCS and still be reproductively punctual. Therefore, these results indicate that reproductive performance of young cows with reduced BCS may not be affected when managed in extensive range conditions.
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