Impacts of Increasing Additions of Choline Chloride on Growth Performance and Carcass Characteristics of Broiler Chickens Reared to 66 Days of Age.

The most recent research cited by the NRC Nutrition Requirements of Poultry to establish choline recommendations was published in 1987, so choline guidelines for modern broilers are outdated and may be insufficient to optimize growth. The objective was to determine the effect of additional dietary choline chloride supplementation on growth performance and carcass characteristics of modern broilers reared for 66 days. As-hatched Ross 708 × Yield Plus broiler chicks (n = 2160; 30 birds per pen) were randomly allotted to one of six experimental corn and soybean meal-based diets formulated to contain an additional 0, 400, 800, 1200, 1600, or 2000 mg of choline chloride above the choline content of the basal diet ingredients. Diets were fed in four phases, and birds were processed at day 66 of age. Growth performance and breast myopathy incidence was not impacted by added choline. While there were differences in breast, wing, thigh, and drum yields, the effects of added choline were not linear. Supplemental choline chloride was not beneficial for growth performance but did impact the carcass characteristics of modern, large frame broilers reared for 66 days.

The NEON Daily Isotopic Composition of Environmental Exchanges Dataset.

The National Ecological Observatory Network (NEON) provides open-access measurements of stable isotope ratios in atmospheric water vapor (δ2H, δ18O) and carbon dioxide (δ13C) at different tower heights, as well as aggregated biweekly precipitation samples (δ2H, δ18O) across the United States. These measurements were used to create the NEON Daily Isotopic Composition of Environmental Exchanges (NEON-DICEE) dataset estimating precipitation (P; δ2H, δ18O), evapotranspiration (ET; δ2H, δ18O), and net ecosystem exchange (NEE; δ13C) isotope ratios. Statistically downscaled precipitation datasets were generated to be consistent with the estimated covariance between isotope ratios and precipitation amounts at daily time scales. Isotope ratios in ET and NEE fluxes were estimated using a mixing-model approach with calibrated NEON tower measurements. NEON-DICEE is publicly available on HydroShare and can be reproduced or modified to fit user specific applications or include additional NEON data records as they become available. The NEON-DICEE dataset can facilitate understanding of terrestrial ecosystem processes through their incorporation into environmental investigations that require daily δ2H, δ18O, and δ13C flux data.

Effect of Pre-Blended Phosphates on the Freezing Quality Characteristics of Ground Woody Breast Meat Compared to Normal Meat.

Woody breast (WB) myopathy affected meat has a tough texture, higher cook loss, and decreased water holding capacity (WHC), and thus lower consumer acceptability. The WB meat can be ground and further converted into further processed products or frozen, stored, and shipped to further processors. Freezing and thawing of ground WB meat may further affect the quality of WB meat products. Hence, research is required to determine the effect of pre-blended phosphates on the quality of ground WB meat as well as its cryoprotective effect during frozen storage. The objective of this experiment was to investigate the effect of pre-blended phosphate levels on meat quality in WB and normal breast (NB) fillets before and after freezing. NB fillets and severely affected WB fillets were procured from a local commercial processor. The meat was separated into various treatment groups according to the sodium tripolyphosphate (STPP) inclusion levels (0, 0.25, and 0.5% w/w). The meat was ground with respective phosphate treatments and subdivided into vacuum-sealed bags (n = 240; 1 kg each). Half of the bags (n = 120) from each treatment were taken for meat quality analysis, while the other bags were placed in a freezer (-18 °C) for 6 days. Fresh samples were analyzed within 6-8 h while the frozen samples were thawed for 18 h at 4°C prior to analysis. Samples (n = 10) were analyzed for gel strength, pH, color (L* a* b*), proximate composition, and randomly selected samples (n = 5) were analyzed for aerobic plate count (APC). Experiments were repeated in two separate replications and the data was analyzed using the Proc Glimmix model procedure in SAS (v. 9.4) (Cary, NC, USA) with LSMeans Separation at p ≤ 0.05. The gel strength (g) of the fresh ground NB meat (883.7 g) was higher than the gel strength of woody meat (720.8 g) with 0% phosphate (p ≤ 0.05). Addition of phosphate (0.25 and 0.5%) significantly increased the gel strength of fresh woody meat but it was significantly lower than NB meat added with 0.25 and 0.5% phosphate treatment. After freezing, ground NB meat samples with 0.25 and 0.5% phosphate had higher gel strength compared to fresh and frozen ground WB meat (p ≤ 0.05). Pre-blended STPP raised the pH in all treatments (p < 0.05). Treatments did not have any clear impact on APC of ground WB or NB meat. Addition of pre-blended sodium tripolyphosphate increases the functionality of fresh and frozen ground WB meat, as well as NB meat.

Species differences in urine scent-marking and counter-marking in Peromyscus.

Species comparisons indicate that scent-marking may differ as a function of mating system and co-housing with the opposite sex ("pairing"). We previously demonstrated that pairing may decrease male solicitation to unfamiliar females in the monogamous Peromyscus californicus but not in the non-monogamous P. leucopus. Whether urine scent-marking of females changes following pairing and whether scent-marking of paired males varies in response to scent-marks of their cagemate versus those of an unfamiliar female has not been examined. Therefore, we tested P. californicus and P. leucopus for within and between species differences in urine scent-marking of: 1) paired and non-paired females in an unscented arena, and 2) paired males in response to their female cagemate's or an unfamiliar female's scent-marks (counter-marking). Consistent with previous findings, P. californicus of both sexes deposited more urine scent-marks and covered greater surface area than P. leucopus. In both species, female scent-marking did not differ according to pairing status and male counter-marking did not differ in response to the scent-marks of their female cagemate versus an unfamiliar female. More females of both species and more P. leucopus, but not P. californicus, males scent-marked more around the perimeter than centrally. Potential explanations for these findings are discussed.