Diurnal variation in fecal concentrations of acid-detergent insoluble ash and alkaline-peroxide lignin from cattle fed bermudagrass hays of varying nutrient content

Background

The effect of time of fecal sampling on the accuracy of acid-detergent insoluble ash (ADIA) and alkaline-peroxide lignin (APL) for the prediction of fecal output (FO) in cattle was evaluated. Eight ruminally cannulated cows (594 ± 35.5 kg) were allocated randomly to 4 bermudagrass [Cynodon dactylon (L.) Pers.] hay diets markedly different in crude protein concentration (79–164 g/kg) with 2 replicates per diet for 3 periods. Cows were offered hay individually at 20 g DM/kg of body weight daily in equal feedings at 08:00 and 16:00 h for a 10-d adaptation period followed by 5-d of total fecal collection. Fecal grab samples also were taken each day during the fecal collection period at 06:00, 12:00, 18:00, and 24:00 h either directly from the rectum or from freshly voided feces. Samples were composited within cow and time across the 5 d total fecal collection period. Additionally, forage, ort, and fecal samples were analyzed for concentrations of APL and ADIA.

Results

Fecal concentrations of ADIA and APL were not affected by sampling time (P ≥ 0.22), even though diet affected (P < 0.01) fecal ADIA and APL concentrations. There were no diet × sampling time interactions (P ≥ 0.60). Estimates of FO and dry matter digestibility (DMD) from ADIA and APL were not affected (P ≥ 0.16) by sampling time or the diet × sampling time interaction (P ≥ 0.74). Estimates of FO and DMD from markers from different sampling times or all different combinations of sampling time were not different (P ≥ 0.72) from those of total collection among internal markers.

Conclusion

Little variation in concentrations of ADIA and APL in daily fecal excretion across time increases flexibility in fecal grab sampling schedules for predicting FO and DMD.     

Temperature and surface-ocean water balance of the mid-holocene tropical western pacific

Skeletal Sr/Ca and 18O/16O ratios in corals from the Great Barrier Reef, Australia, indicate that the tropical ocean surface approximately 5350 years ago was 1 degrees C warmer and enriched in 18O by 0.5 per mil relative to modern seawater. The results suggest that the temperature increase enhanced the evaporative enrichment of 18O in seawater. Transport of part of the additional atmospheric water vapor to extratropical latitudes may have sustained the 18O/16O anomaly. The reduced glacial-Holocene shift in seawater 18O/16O ratio produced by the mid-Holocene 18O enrichment may help to reconcile the different temperature histories for the last deglaciation given by coral Sr/Ca thermometry and foraminiferal oxygen-isotope records.     

D-optimal designs for mixed discrete and continuous outcomes analyzed using nonlinear models

Many dose-response experiments in toxicology and other biological sciences are designed to measure multiple outcomes. Unfortunately, most of these studies are powered or designed for a single response, and the inference on the under-powered endpoints is limited. As additional design challenges, the outcomes may have different regions and shapes of activity or have different response types. As a new application to the traditional D-optimality criterion, we have developed optimal designs for mixed discrete and continuous outcomes that are analyzed with nonlinear models. These designs use a numerical algorithm to choose the location of the dose groups and proportion of total sample size allocated to each group that minimize the generalized variance of a model-based covariance matrix that incorporates the correlation between outcomes. Using this methodology, we designed a dose-response experiment with binary, count, and continuous outcomes to evaluate neurotoxicity. In this example, the optimal designs placed dose groups at the predicted dose thresholds and throughout the active range. The designs were generally robust to different correlation structures. In addition, when the expected correlation was moderate or large, we observed a substantial gain in efficiency compared to optimal designs created for each outcome separately.     

Effects of bovine cytochrome P450 single-nucleotide polymorphism, forage type and body condition on production traits in cattle

Relating single-nucleotide polymorphisms (SNP) to cows with acceptable productivity could benefit cattle breeders in areas where tall fescue is the predominant forage. This study aimed to (i) identify SNPs in bovine cytochrome P450 3A28 (CYP3A28) and (ii) determine the associations between SNP genotype, forage and cow body condition (BC). Genotype (CC, CG or GG) and forage [Kentucky-31 wild-type endophyte-infected tall fescue (KY+) vs. bermudagrass] effects on milk volume and quality were determined in Herd 1 cows (123 cows); in Herd 2 (99 cows), genotype and BC (low vs. moderate) effects on ovarian follicle size, calving date and calving per cent were determined; and in Herd 3 (114 cows), effects of genotype and fescue cultivar [KY+ vs. non-toxic endophyte-infected tall fescue (HiMag4)] were related to calving per cent, calving date and weaning weights of both cow and her calf. A cytosine (C) to guanine (G) transversion at base 994 (C994G) in CYP3A28 was identified. There was a genotype × forage type interaction (p < 0.05) on milk protein in Herd 1 cows; CC cows grazing bermudagrass had greater milk protein percentage in relation to other cows in the herd. In Herd 2, BC and genotype × BC tended (p < 0.10) to influence follicle size and Julian calving date respectively. Diameter of the largest follicle tended to be larger in moderate BC than in low-BC cows; whereas, CC and CG cows in moderate BC and homozygous (CC and GG) cows in low BC tended to calve 14 days earlier in relation to CG cows in low BC. In Herd 3, there was a genotype × forage type interaction (p < 0.05) on calving per cent, Julian calving date and calf weaning weight. In this study, genetic alterations (G allele at C994G) coupled with nutritional factors (low BC and toxic tall fescue) resulted in overall lower productivity in cows.     

Control of tomato powdery mildew (Leveillula taurica) in the Comarca Lagunera, Coahuila State, Mexico, supported by the spray forecast model Tomato.PM

Tomato powdery mildew [Leveillula taurica (Lev.) Arm.] is a common disease of tomato crops in the Comarca Lagunera region of the state of Coahuila, Mexico. To control the disease, fungicides are commonly sprayed up to 18 times on a weekly basis in this region. Effectiveness of the spray forecast model Tomato.PM, developed for California conditions, to reduce fungicide spraying, was evaluated. Disease dynamics on plants treated with three different fungicides (azoxystrobin, myclobutanil and wettable sulfur), with and without model recommendations, was analyzed in three experiments at three locations. When spraying followed model recommendations, it was possible to eliminate 11-16 fungicide applications with no significant effect on fruit yield. All three fungicides reduced the severity of disease but their effects varied with the cropping cycle. A significant increase in total yield due to fungicide spraying was observed in one out of three experiments.     

X‐linked CD40 ligand deficiency in a 1‐year‐old male Shih Tzu with secondary Pneumocystis pneumonia

An approximately 1‐year‐old male intact Shih Tzu dog was referred to a tertiary facility with a history of progressive tachypnea, increased respiratory effort, and weight loss over a 3‐month period that failed to improve with empirical antimicrobial treatment. Upon completion of a comprehensive respiratory evaluation, the dog was diagnosed with severe Pneumocystis pneumonia and secondary pulmonary hypertension. Clinical signs resolved and disease resolution was confirmed after completion of an 8‐week course of trimethoprim‐sulfonamide, 4‐week tapering dose of prednisone to decrease an inflammatory response secondary to acute die‐off of organisms, a 2‐week course of clopidogrel to prevent clot formation, and a 2‐week course of a phosphodiesterase‐5 inhibitor to treat pulmonary hypertension. Immunodiagnostic testing and genetic sequencing were performed to evaluate for potential immunodeficiency as an underlying cause for the development Pneumocystis pneumonia, and identified an X‐linked CD40 ligand deficiency.     

Overexpression of transforming growth factor alpha in psoriatic epidermis

Transforming growth factor alpha (TGF-alpha) is produced by and required for the growth of epithelial cells and is angiogenic in vivo. Since epidermal hyperplasia and angiogenesis are hallmarks of psoriasis, TGF-alpha gene expression was analyzed in epidermal biopsies of normal and psoriatic skin. TGF-alpha messenger RNA and protein are much more abundant in lesional psoriatic epidermis than in normal-appearing skin of psoriatic patients or in normal epidermis. In contrast, messenger RNA levels of transforming growth factor beta 1 (TGF-beta 1), which inhibits epithelial cell growth, are not significantly different in normal, uninvolved, and lesional psoriatic epidermis. Thus, psoriatic epidermal hyperplasia may involve increased expression of a keratinocyte mitogen (TGF-alpha) rather than deficient expression of a growth inhibitor (TGF-beta 1).