Defining optimal dietary starch, oil, and amino acid inclusion levels for broilers experiencing a coccidiosis challenge.

Alternative methods to alleviate coccidiosis in broilers are of interest to producers, including dietary strategies to minimize disruptions in growth rate and efficiency when faced with health challenges. Our objective was to determine optimal combinations of dietary starch, amino acids (AA), and oil to benefit productivity of broilers experiencing Eimeria-induced immune activation. Two trials were conducted using 1,536 male Ross 308 broiler chicks in floor pens randomly assigned to 1 of 17 experimental treatments. All birds received common starter (d 0-10) and finisher (d 24-35) diets, and only differed based on their assigned experimental grower diet (d 10-24). Trial 1 experimental grower diets ranged from 2,700 to 3,300 kcal/kg AME. Trial 2 included 10 experimental grower diets following a simplex lattice design consisting of 3 basal lots formulated to have the highest starch (45.4%), oil (10.2%), or AA density (120, 1.33% digestible Lys) and mixed in 4 equally spaced levels for each component (0, 0.33, 0.67, 1). These mixtures enabled varying densities of AA (80-120% of recommendation), starch:oil (4:1-20:1), and AME (2,940-3,450 kcal/kg). Bird and feeder weights were collected on d 0, 10, 24, and 35, and birds were exposed to an Eimeria challenge on d 11 or 12. In trial 2, excreta samples were collected for AME determination and carcasses were processed on d 36. Data were analyzed using ANOVA, t test, or regression. In Trial 1, BW gain and feed conversion were improved (P < 0.05) by increasing dietary AME. In Trial 2, birds receiving diets containing AA at 93 to 107% of recommendations and higher oil exhibited improved (P < 0.05) performance, but increased starch at the expense of oil reduced performance (P < 0.05). Relative breast and fat pad weights were not influenced by diet in Trial 2. We determined that broilers mildly challenged with Eimeria would exhibit highest BW gain when receiving diets containing 35.8% starch, 8.9% oil, and 101.3% of AA recommendations, which can be utilized by producers to maintain productivity under health-challenged conditions.

Global human-edible nutrient supplies, their sources, and correlations with agricultural environmental impact.

Food production, sustainable development, population growth, and agricultural environmental impacts are linked global problems that require complex solutions. Many efforts evaluating these challenges primarily evaluate dietary strategies designed for health and environmental objectives without considering the subsequent adaptations required by the global food supply. Here we use a complementary approach to summarize trends and variability in the current agricultural system in the context of the growing population and impending environmental challenges. Globally, agricultural systems produce sufficient nutrients to feed 10 billion people with the exception of Ca, DHA + EPA, vitamins B4, D, and E. In a network analysis, greenhouse gas emissions were conditionally dependent on ruminant meat and milk, while water use was conditionally dependent on vegetable and fruit production; however, supplies of most nutrients were also dependent on these same production categories, suggesting trade-offs between nutritional and environmental objectives. Future work should evaluate strategies to address these compromises (i.e., improving water use efficiency and reducing greenhouse gas emissions), to explore to what extent such compromises are biophysically essential or merely a product of the current agricultural system structures. Given the time-sensitive nature of population growth and environmental concerns, strategies to make more effective use of currently produced agricultural products will also be critical complementary strategies to sustainably feed the growing population which can work in concert with other agricultural-, diet- and policy-focused efforts.

Rumen fermentation and epithelial gene expression responses to diet ingredients designed to differ in ruminally degradable protein and fiber supplies.

Although numerous studies exist relating ruminal volatile fatty acid (VFA) concentrations to diet composition and animal performance, minimal information is available describing how VFA dynamics respond to diets within the context of the whole rumen environment. The objective of this study was to characterize how protein and fiber sources affect dry matter intake, rumen pH, fluid dynamics, fermentation parameters, and epithelial gene expression. Four diet treatments (soybean meal or heat-treated soybean meal and beet pulp or timothy hay) were delivered to 10 wethers. The soybean meals served as crude protein (CP) sources while the beet pulp and timothy hay represented neutral detergent fiber (NDF) sources. Feed intake, rumen pH, fluid pool size, and fluid passage rate were unaffected by treatment. Butyrate synthesis and absorption were greater on the beet pulp treatment whereas synthesis and absorption of other VFA remained unchanged. Both CP and NDF treatment effects were associated with numerous VFA interconversions. Expression levels of rumen epithelial genes were not altered by diet treatment. These results indicate that rumen VFA dynamics are altered by changes in dietary sources of nutrients but that intake, rumen environmental parameters, and the rumen epithelium may be less responsive to such changes.

Seryl-tRNA synthetase-mediated essential amino acids regulate ß-casein synthesis via cell proliferation and mammalian target of rapamycin (mTOR) signaling pathway in bovine mammary epithelial cells.

Essential amino acids (EAA) play an important role in promoting milk protein synthesis in primary bovine mammary epithelial cells (BMEC). However, the regulatory mechanisms involved in the relationship between EAA and milk protein synthesis have not been fully explored. This study examined the effects of seryl-tRNA synthetase (SARS) on EAA-stimulated ß-casein synthesis, cell proliferation, and the mammalian target of rapamycin (mTOR) system in BMEC. First, BMEC were cultured in medium either lacking all EAA (-EAA) or that included all EAA (+EAA) for 12 h. The BMEC were then supplemented with the opposing treatments (-EAA supplemented with +EAA and vice versa) for 0 h, 10 min, 0.5 h, 1 h, 6 h, or 12 h, respectively. After the treatment-specific time allotment, proteins were collected for Western blotting. Subsequently, a 2 × 2 factorial design was used to evaluate the interactive of SARS inhibition (control or SARS inhibited) and EAA supply (+EAA or -EAA) on gene and protein abundance, cell viability, and cell cycle in BMEC. Based on the data obtained in the first experiment, the changes in protein abundance of ß-casein and SARS depended on EAA treatment time in similar patterns. The protein abundance of ß-casein, SARS, and mammalian target of rapamycin (mTOR)-related proteins, cell viability, cell cycle progression, and the mRNA abundance of cyclin D1 (CCND1, cell cycle progression marker) and marker of proliferation Ki-67 (MKI67, cell proliferation marker) were stimulated by the presence of EAA. Correspondingly, when cells were deprived of EAA, cell proliferation and abundance of these proteins and genes were reduced overall. Moreover, the decreases in these aspects were further exacerbated by inhibiting SARS, suggesting that an interaction between EAA and SARS is important for regulating protein synthesis. The results indicated that SARS stimulated the mTOR signaling pathway when EAA were present, enhanced EAA-stimulated cell proliferation, and contributed to increased ß-casein production in BMEC.

Meta-analysis of 2-hydroxy-4-methylthio-butanoic acid supplementation on ruminal fermentation, milk production, and nutrient digestibility.

Methionine is considered one of the most important essential AA for milk protein synthesis in dairy cows. Supplementation of unprotected, free Met is nearly 100% degraded by ruminal microorganisms, which complicates supplementation. 2-Hydroxy-4-methylthio-butanoic acid (HMTBa) can be converted to Met in the body and is used as a Met source in dairy production. However, results of published studies assessing the effects of supplementing Met sources, including HMTBa, on performance variables are inconsistent. A meta-analysis was performed to quantitatively summarize the accumulated results of HMTBa supplementation on animal performance and nutrient digestibility. Data pertaining to HMTBa dose, dietary composition, and major performance variables (rumen volatile fatty acid composition, milk production, nutrient digestibility) were collected from 39 articles containing 169 treatment means. Publications were from scientific journals published from 1970 to 2018; 1 internal report from Novus International Inc. (St. Charles, MO) was also included. The HMTBa effects on response variables were analyzed using linear mixed models with random study effects. Other explanatory variables tested included neutral detergent fiber and crude protein percent as well as days in milk. Results showed that HMTBa supplementation increased blood Met concentration and milk fat yield but had no effect on nutrient digestibility.

Relationships between postruminal casein infusion and milk production, and concentrations of plasma amino acids and blood urea in dairy cows: A multilevel mixed-effects meta-analysis.

The relationships between postruminal casein infusion and production variables and concentrations of plasma AA and blood urea were evaluated using multilevel mixed-effects models derived from literature data collected in dairy cows. The data set contained 147 treatment means [i.e., 66 controls (CTL) and 81 casein-infused (CAS) means]. Each CAS mean was paired with its corresponding CTL mean to create 81 mean differences (CAS minus CTL), which were analyzed as absolute and percentage-based units (i.e., percentage increase or decrease in CAS relative to CTL). The primary variable of interest was the difference in estimated metabolizable protein (MP) supply (ΔMP) between CAS and CTL. The other explanatory variables were based on levels in CTL: MP supply, MP balance, the ratio of duodenal microbial protein (MCP) to MP supply (MCPMP), the stage of lactation (early or mid/late) and the type of forage (grass/legume- or corn silage-based). The MP supply and MP balance influenced negatively the relationship between ΔMP and the response of true protein yield. Responses of milk urea, blood urea, and plasma urea cycle AA concentrations were associated positively with ΔMP, indicating that a large amount of infused AA was catabolized to urea. Responses of plasma essential AA concentrations were related positively to ΔMP. The relative effect of ΔMP was highest for responses of plasma His concentration in cows fed grass/legume-based diets and at high MCPMP ratios. This relationship suggests that positive responses of plasma His concentrations are associated with diets relying heavily on microbial protein synthesis (high MCP), low in crude protein (low estimated MP supply), or both. The relationship between ΔMP and responses of plasma group 2 AA (Ile, Leu, Lys, and Val) concentrations was approximately 2 times greater than that for group 1 AA (His, Met, and Phe+Tyr) at mean MCPMP and MP supply. This could reflect the low hepatic removal group 2 AA compared with group 1 AA in dairy cows. Collectively, these results provide novel information on how dietary and cow conditions may alter responses to protein supplementation.

Neoadjuvant chemoradiation for localized adenocarcinoma of the pancreas.

BACKGROUND: The use of neoadjuvant (preoperative) chemoradiotherapy (CRT) for pancreatic cancer has been advocated for its potential ability to optimize patient selection for surgical resection and to downstage locally advanced tumors. This article reports our experience with neoadjuvant CRT for localized pancreatic cancer. METHODS: Since 1995, 111 patients with radiographically localized, pathologically confirmed pancreatic adenocarcinoma have received neoadjuvant external beam radiation therapy (EBRT; median, 4500 cGy) with 5-flourouracil-based chemotherapy. Tumors were defined as potentially resectable (PR, n = 53) in the absence of arterial involvement and venous occlusion and locally advanced (LA, n = 58) with arterial involvement or venous occlusion by CT. RESULTS: Five patients (4.5%) were not restaged due to death (n = 3) or intolerance of therapy (n = 2). Twenty-one patients (19%) manifested distant metastatic disease on restaging CT. Twenty-eight patients with initially PR tumors (53%) and 11 patients with initially LA tumors (19%) were resected after CRT. Histologic examination revealed significant fibrosis in all resected specimens and two complete responses. Surgical margins were negative in 72%, and lymph nodes were negative in 70% of resected patients. Median survival in resected patients has not been reached at a median follow-up of 16 months. CONCLUSIONS: Neoadjuvant CRT provided an opportunity for patients with occult metastatic disease to avoid the morbidity of resection and resulted in tumor downstaging in a minority of patients with LA tumors. Survival after neoadjuvant CRT and resection appears to be at least comparable to survival after resection and adjuvant (postoperative) CRT.

Development of a clindamycin-impregnated fiber as an intracanal medication in endodontic therapy.

The effectiveness of traditional endodontic intracanal medications in reducing bacterial numbers and preventing acute flare-ups and pain continues to be questioned. In the present study, a new local delivery device was developed that releases a substantive dose of clindamycin into root canals. Clindamycin-impregnated ethylene vinyl acetate (EVA) fibers were produced, and the sensitivity of common endodontic microbes to the fibers were established. An in vitro model was developed to persistently infect 32 extracted human teeth with endodontic pathogens to test the efficacy of the clindamycin/EVA fibers in reducing the number of colony-forming units. The clindamycin/EVA fibers were shown to be effective in reducing growth of common endodontic microbes on blood agar plates, and in significantly reducing growth of Prevotella intermedia, Fusobacterium nucleatum, and Streptococcus intermedius in extracted human teeth, thus indicating merit in further exploring the potential of these fibers as intracanal medications.

Bioavailability of 125I bromelain after oral administration to rats.

Bromelain is a sulphydral protease, derived from the stem and fruit of pineapples. Semi-purified preparations of bromelain are used in the treatment of inflammation and oedema. There is however no unequivocal proof of the absorption of the enzyme after oral administration. In this study, 125I-bromelain was administered orally to rats and blood sampled at various times. The total radioactivity, the TCA precipitable 125I-compounds and the molecular weight profile of 125I-proteins in the plasma were determined. A maximum level, equivalent to 270 ng ml-1 bromelain was found at 1 h after administration. Approximately 40 per cent of the 125I in plasma could be precipitated by 10 per cent trichloroacetic acid. Electrophoretic analysis showed one major peak of radioactivity in the plasma samples, with a molecular weight of 26-32,000 daltons. This is identical to the main molecular weight fraction in the Bromelain mixture and corresponds to the molecular weight of the purified enzyme. In the 1 h plasma sample this peak contained 0.003 per cent of the administered dose per millilitre.