Ruminant livestock are important sources of human food and global greenhouse gas emissions. Feed degradation and methane formation by ruminants rely on metabolic interactions between rumen microbes and affect ruminant productivity. Rumen and camelid foregut microbial community composition was determined in 742 samples from 32 animal species and 35 countries, to estimate if this was influenced by diet, host species, or geography. Similar bacteria and archaea dominated in nearly all samples, while protozoal communities were more variable. The dominant bacteria are poorly characterised, but the methanogenic archaea are better known and highly conserved across the world. This universality and limited diversity could make it possible to mitigate methane emissions by developing strategies that target the few dominant methanogens. Differences in microbial community compositions were predominantly attributable to diet, with the host being less influential. There were few strong co-occurrence patterns between microbes, suggesting that major metabolic interactions are non-selective rather than specific.

Greater blood concentrations of nonesterified fatty acids (NEFA) and lesser blood concentrations of glucose are indicative of the normal process of nutrient partitioning that occurs in early postpartum dairy cows. The objective was to determine the relationship between blood NEFA and glucose concentrations and subsequent conception at first insemination in postpartum dairy cows. Holstein (n=148) and Guernsey (n=8) dairy cows were blood sampled at approximately d 10, 7, and 3 prepartum, on the day of calving and 3, 7, 14, and 21 d postpartum for measurement of NEFA and glucose concentrations. Serum and plasma were harvested and used for measurement of NEFA and glucose concentrations, respectively. Cows were given a presynchronization treatment (2 injections of PGF(2α) 14 d apart) with the second PGF(2α) injection occurring 14 d before the initiation of the timed AI (TAI) protocol. Blood for determination of progesterone concentrations was collected at each presynchronization injection and at the initiation of the TAI protocol that was used for first insemination (74±7 d postpartum). Cows were considered noncycling if serum progesterone concentrations at the 2 presynchronization PGF(2α) injections (d 37 and 51±7 postpartum) and at the initiation of the TAI protocol (d 65±7 postpartum) were ≤1 ng/mL, and there was no indication of ovulation or presence of a corpus luteum by ultrasound examination at the initiation of the TAI protocol. Pregnancy was determined at 33 d and again at 61 d after first insemination by using ultrasound. Across all days, serum NEFA and plasma glucose concentrations were not different between cows that ovulated before the initiation of the TAI program (cycling) compared with those that did not ovulate (noncycling). Serum NEFA concentrations, however, were less and plasma glucose concentrations were greater during the early postpartum period for cows that subsequently became pregnant at first insemination compared with those that failed to become pregnant. Logistic regressions were used to predict the probability of pregnancy based on NEFA and glucose concentrations from individual days. The prediction with the greatest likelihood ratio was for d 3 postpartum NEFA and glucose concentrations. Nutritional status during the early postpartum period (within 1 wk after calving), as indicated by blood NEFA and glucose concentrations, may affect subsequent fertility by a mechanism that is independent from interval to first ovulation.

By mapping translated metagenomic reads to a microbial metabolic network, we show that ruminal ecosystems that are rather dissimilar in their taxonomy can be considerably more similar at the metabolic network level. Using a new network bi-partition approach for linking the microbial network to a bovine metabolic network, we observe that these ruminal metabolic networks exhibit properties consistent with distinct metabolic communities producing similar outputs from common inputs. For instance, the closer in network space that a microbial reaction is to a reaction found in the host, the lower will be the variability of its enzyme copy number across hosts. Similarly, these microbial enzymes that are nearby to host nodes are also higher in copy number than are more distant enzymes. Collectively, these results demonstrate a widely expected pattern that, to our knowledge, has not been explicitly demonstrated in microbial communities: namely that there can exist different community metabolic networks that have the same metabolic inputs and outputs but differ in their internal structure.

Genetic and environmental variances and covariances and associated genetic parameters were estimated for weaning weight, asymptotic mature weight, and repeated mature weights. Data consisted of a set of weight measurements of 3,044 Angus cows born between 1976 and 1990. Mature weight was predicted by individually fitting Brody growth curves (asymptotic weight) and by using weights repeatedly measured after 4 yr of age. Variance and covariance components for mature weight were estimated by REML from a single-trait animal model with asymptotic weight, a two-trait animal model with asymptotic and weaning weight, and a two-trait animal model with repeated weights and weaning weight. Weaning and cow contemporary groups were defined as fixed effects. Random effects for weaning weight included direct genetic, maternal genetic, and permanent environmental effects; and for mature weight, direct genetic and repeated measurements (if in the model). Heritability estimates for weaning weight were similar for both two-trait models (.53 and .59). Estimates of heritability for mature weight were .44, .52, and .53 for the single-trait model with asymptotic weight, two-trait model with asymptotic weight, and two-trait model with repeated measures weights, respectively. The estimate of the genetic correlation between mature and weaning weight was higher for the repeated measures model (.85 vs. .63). A lower heritability estimate for mature weight from the single-trait model was likely due to postweaning culling. Therefore, a genetic evaluation of mature weight from field data should include a trait recorded earlier in life that is less subjected to selective data reporting.

The objective was to compare ovarian steroids and expression of mRNAs encoding cytochrome P450 side-chain cleavage, cytochrome P450 17 alpha-hydroxylase, cytochrome P450 aromatase, 3 beta-hydroxysteroid dehydrogenase Delta(4),Delta(5) isomerase, LH, and FSH receptors and estrogen receptor-beta in ovaries of cows with dominant and nondominant ovarian follicular cysts and in normal dominant follicles. Estradiol-17 beta, progesterone, and androstenedione concentrations were determined in follicular fluid using specific RIAs. Dominant cysts were larger than young cysts or dominant follicles, whereas nondominant cysts were intermediate. Estradiol-17 beta (ng/ml) and total steroids (ng/follicle) were higher in dominant cysts than in dominant follicles. Expression of LH receptor and 3 beta-hydroxysteroid dehydrogenase mRNAs was higher in granulosa cells of dominant cysts than in dominant follicles. Nondominant cysts had higher follicular concentrations of progesterone, lower estradiol-17 beta concentrations, and lower expression of steroidogenic enzyme, gonadotropin receptor, and estrogen receptor-beta mRNAs than other groups. In summary, increased expression of LH receptor and 3 beta-hydroxysteroid dehydrogenase mRNAs in granulosa and increased follicular estradiol-17 beta concentrations were associated with dominant cysts compared to dominant follicles. Study of cysts at known developmental stages is useful in identifying alterations in follicular steroidogenesis.

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We conducted a two-way selection experiment in a composite rabbit population to investigate the responses to selection for postweaning ADG and feed conversion (FC). Two generations of crossing, followed by four generations of random pair matings, preceded three generations of selection. Selection was practiced within four lines: high-feed conversion (HFC), low-feed conversion (LFC), high gain (HG), and low gain (LG). Data on 1,446 rabbits from the random mating and selection generations were fitted to an animal model to estimate heritabilities of and the genetic correlation between ADG and FC. The two-trait model included rabbit and common litter random effects and line, generation, and sex fixed effects. Estimates of heritability of ADG and FC were .48 and .29, respectively, and the genetic correlation between them was -.82. Common litter environmental effects accounted for a proportion of .11 and .13 of the phenotypic variation of the two traits, respectively. For ADG (in g/d) the regressions of mean breeding values on generation number during the selection period were 1.23 +/- .12 (P < .01) in the HG line and -.86 +/- .12 (P < .01) in the LG line; the regressions for FC (in g feed/g gain) were -.07 +/- .01 (P < .01) in the HFC line and .03 +/- .01 (P < .05) in the LFC line. Selection for ADG was effective in improving ADG and FC.

Identification of mRNAs that are present at early stages of embryogenesis is critical for a better understanding of development. To this end, cDNA libraries were constructed from germinal vesicle-stage oocytes, in vivo-produced four-cell- and blastocyst-stage embryos, and from in vitro-produced four-cell- and blastocyst-stage embryos. Randomly picked clones (10 848) were sequenced from the 3' end and those of sufficient quality (8066, 74%) were clustered into groups of sequence similarity (>95% identity), resulting in 2489 clusters. The sequence of the longest representative expressed sequence tag (EST) of each cluster was compared with GenBank and TIGR. Scores below 200 were considered unique, and 1114 (44.8%) did not have a match in either database. Sequencing from the 5' end yielded 12 of 37 useful annotations, suggesting that one third of the 1114 might be identifiable, still leaving over 700 unique ESTs. Virtual Northerns compared between the stages identified numerous genes where expression appears to change from the germinal vesicle oocyte to the four-cell stage, from the four-cell to blastocyst stage, and between in vitro- and in vivo-derived four-cell- and blastocyst-stage embryos. This is the first large-scale sequencing project on early pig embryogenesis and has resulted in the discovery of a large number of genes as well as possible stage-specific expression. Because many of these ESTs appear to not be in the public databases, their addition will be useful for transcriptional profiling experiments conducted on early pig embryos.