Percentage Unit Increase Research Articles

Effect of a lime-based bedding conditioner on physical-chemical characteristics and microbiological counts of recycled manure solids.

Bedding materials are aimed at providing a safe and comfortable resting environment for cows. Control of pathogen proliferation in these substrates is crucial to prevent intramammary infections in dairy cows, as these can significantly impact milk quality, cow health, and farm productivity. This is particularly relevant in the case of organic bedding substrates, including manure-derived materials. This study aimed to evaluate the in vitro effect of a lime-based conditioner (LBC), composed of CaCO3MgCO3 and Mg(OH)2, at increasing concentrations on the physical-chemical characteristics and bacterial counts of untreated anaerobically digested manure solids (ADMS) and separated raw manure solids (SRMS). Unused ADMS and SRMS were evaluated at four LBC weight-based concentrations: 0 (as untreated control), 10, 15, and 20% of LBC inclusion. The bedding materials were assessed immediately after LBC addition (0 h) and after 24, 72, and 168 h of storage at 28°C. The dry matter content (DM), and pH were measured for all the time points. Standard microbiological methods were used to assess total bacterial counts (TBC), other Gram-negative bacteria, coliforms, Escherichia coli, and streptococci and streptococci-like organism (SSLO). It was observed a linear increase in both DM and pH with increasing concentrations of LBC. Specifically, for each percentage unit increase of LBC, the DM of ADMS and SRMS increased by 0.73 and 0.71%, respectively. Similarly, for each percentage unit of LBC, the pH of ADMS and SRMS increased by 0.15 and 0.19, respectively. Conversely, a linear decrease in TBC, Gram-negative bacteria, coliforms, E. coli, and SSLO was observed with increasing concentrations of the LBC. Manure-derived materials without the inclusion of the LBC had bacterial counts that tended to remain high or increase over time. Otherwise, bedding materials with LBC application had reduced bacterial counts. Based on the results of the present study, it was observed that the higher the concentration of LBC, the more significant the reduction of bacterial counts. Specifically, bacterial recovery was lower when higher concentrations of LBC were applied. Our findings underscore the potential of LBC in effectively controlling environmental bacteria and improving the physical-chemical characteristics of manure-derived bedding materials to improve cow health and welfare.

Understanding potential opportunities and risks associated with feeding supplemental rumen available fats to mitigate enteric methane emissions in lactating dairy cows

Supplemental dietary rumen available fats show promise as enteric methane (eCH4) mitigators for lactating dairy cows. However, concerns include variability in eCH4 response and possible negative effects on dairy cow performance. Successful implementation of this mitigation option requires better prediction of responses specifically to rumen available FA as well as understanding the modulating effects of other dietary and animal characteristics. Using meta-analytic and meta-regression techniques, 35 published studies with diet definition were used to assess changes in eCH4 emissions and lactation performance associated with supplemental fat, specific supplemental rumen available FA types, and other dietary characteristics. Enteric CH4 (g/d) was reduced by 3.77% per percentage unit of supplemental rumen available EE (RAEE). Supplemental rumen available PUFA (C18:2 and C18:3) and UFA (C18:1, C18:2, C18:3) mitigated eCH4 (g/d) emissions in dairy cows by 6.88 and 4.65% per percentage unit increase, respectively. The anti-methanogenic effects of PUFA, MUFA and MCFA increased with correspondingly greater basal dietary levels of each FA type. Higher rumen-degradable starch (RDS; > 18% DM) in the basal diet promoted greater reductions in eCH4 yield (eCH4/DMI, g/kg) with supplemental rumen available PUFA and UFA. Both milk fat percentage and yield (kg/d) were reduced with rumen available fat supplementation with a reduction of 7.8% and 6.0%, respectively, relative to control diets. Our results highlight the importance of determining basal levels of the rumen available FA before providing supplemental rumen available FA as an option for enteric eCH4 mitigation. Dairy nutritionists can use estimates generated from this analysis to predict changes in eCH4 emissions and dairy cow performance associated with dietary supplementation of rumen available EE and specific rumen available FA types for the purpose of eCH4 mitigation.

Fat supplement for dairy cows during early lactation – potentials, challenges, and risks – a meta-analysis

ABSTRACT The most critical challenge in early lactation is to meet the increasing energy demand for milk production, which results in a negative energy balance (EB). The objective of this study was to evaluate the productive performance and plasma metabolite responses of early lactating dairy cows fed diets supplemented with increasing levels of different fat sources. Diets were categorized as diets supplemented with saturated fatty acid rich fat sources (SFAR), with Ca-soaps of fatty acids (CaFA), and with polyunsaturated fatty acid rich fat sources (PUFAR). There was an interaction between crude fat level and source for dry matter intake (DMI); each percentage-unit increase reduced DMI by 0.38 and 0.77 kg/d in CaFA and PUFAR, respectively, and increased DMI by 0.55 kg/d in SFAR. Corrected milk yield increased by 0.44 kg/d for each percentage-unit increase in crude fat level. Plasma non-esterified fatty acid (NEFA) concentration increased with 0.04 mmol/L per percentage-unit increase. In conclusion, the increased crude fat level increased corrected milk yield. Fat supplementation in early lactation does not seem to cause negative effects on productive performance or metabolism, and despite a small increase, both plasma NEFA and β-hydroxybutyrate (BHB) concentrations stayed below the threshold for incidence of subclinical ketosis.

Response of maize yield to changes in soil organic matter in a Swedish long‐term experiment

AbstractAgricultural practices that lead to soil carbon sequestration may be a win–win strategy for mitigating global warming and improving soil fertility and resource use efficiency. The mechanisms through which soil organic carbon (SOC) concentration affects crop yields are numerous but difficult to separate. The objective of this study was to disentangle these processes and estimate to what extent the yield response to SOC is mainly driven by changes in physical or biochemical properties and processes. This was achieved by analysing the response of yields in continuous maize to SOC concentrations during 20 years (2000–2019), which had evolved in 14 experimental treatments in a Swedish long‐term field experiment at Ultuna since 1956, ranging from 0.94% to 3.65% in the topsoil (0–20 cm). Average maize yields during this period varied between 1.9 and 8.4 Mg dry mass per hectare in the different treatments. The treatments comprise applications of different mineral nitrogen (N) fertilizers and organic amendments and combinations thereof. Our analysis showed that maize yield in the treatments that were not severely limited by nitrogen supply or soil acidity increased by 16% for each percentage unit increase in SOC. We applied the widely used concept of critical N concentration in plant biomass to diagnose the N status in maize in the different treatments (N nutrition index [NNI]) and parameterized a response function between yield and pH (RpH). Dry soil bulk density (BD) was used as a proxy for soil physical properties. These three variables NNI, RpH and BD explained 95% of the variation in maize yields among treatments. Further analysis of the relationship between BD, SOC and plant available water capacity revealed that about two thirds of the yield increases in response to SOC change could be ascribed to associated changes in soil physical properties. Our analysis suggests that the extra storage capacity of water, which increased by up to 15 mm in the topsoil for each unit percentage increase in SOC, was the main driver for the observed yield responses. We conclude that measures for increasing SOC in soils most likely are an effective adaptation strategy for reducing the risk of crop damage during dry spells, which probably are becoming more frequent in the future due to climate change, even in relatively humid climates as in Sweden.

PSXI-19 A Novel Calculation Method in the Difference Procedure for Determining Energy Digestibility of Ingredients for Pigs

Abstract The objective was to suggest a novel calculation method in the difference procedure for determining the apparent total tract digestibility (ATTD) of gross energy (GE) of ingredients for pigs. This procedure involves formulating a basal diet (BD) and a test diet (TD) which contains a test ingredient (TI), feeding these diets to pigs, determining ATTD of GE in the diets, and calculating ATTD of GE in a TI by extrapolation. To calculate ATTD of GE in a TI, it is necessary to calculate the proportional contribution of GE in the BD (PBD) and the TI (PTI) to the TD using the following equations: PBD = (analyzed GE of BD × inclusion rate of BD)/analyzed GE of TD; PTI = (analyzed GE of TI × inclusion rate of TI)/analyzed GE of TD. One of the assumptions for the difference procedure is that GE values in a BD and a TI are additive (PBD + PTI = 1). However, the analyzed GE in the TD is not always exactly equal to the calculated value based on analyzed GE values in the BD and the TI. To investigate the influence of non-additivity of GE in a TD on the ATTD of GE in a TI, 33 observations were collected from 9 studies that determined ATTD of GE using the difference procedure. A ratio of analyzed GE in TD to calculated GE in TD (GEAnalyzed:GECalculated, %) ranged from 98.7 to 101.3%. The following relationship was established: PTD = PTI + PBD = (GEAnalyzed:GECalculated)–1. Corrected PBD and PTI were calculated: corrected PBD = PBD × (GEAnalyzed:GECalculated)–1; corrected PTI = PTI × (GEAnalyzed:GECalculated)–1; and corrected PTD = corrected PBD + corrected PTI = 1. Four values for the ATTD of GE in TI were obtained or calculated: 1) presented in the literature (ATTDLiterature), 2) calculated based on the PTI (ATTDNon-corrected), 3) calculated based on the corrected PTI (ATTDCorrected), and 4) calculated based on the calculated GE in TD (ATTDCalculated). Three ratios (%) for each observation were computed, namely, ATTDLiterature:ATTDCalculated, ATTDNon-corrected:ATTDCalculated, and ATTDCorrected:ATTDCalculated. The GEAnalyzed:GECalculated was used as an independent variable against the ratios as dependent variable. Results indicated that a 1 percentage unit increase in GEAnalyzed:GECalculated led to 3.47% (r2 = 0.67) and 4.28% (r2 = 0.92) increases in ATTDLiterature:ATTDCalculated and ATTDNon-corrected:ATTDCalculated, respectively. However, for the ATTDCorrected:ATTDCalculated, a 1 percentage unit increase in GEAnalyzed:GECalculated only increased the value by 0.54% (r2 = 0.88). Overall, even a small deviation between analyzed and calculated GE can cause large errors in the digestibility of TI, but the use of corrected proportional contributions suggested in the present work can mitigate the problem.

Selected Factors Affecting the Subsectors of the Philippine Agriculture: A Panel Regression Analysis

The study examined the effects of exports to Gross Domestic Product (GDP), employment, and production loans granted in the GDP agriculture of the Philippines. This paper employed descriptive and quantitative techniques to analyze the behavior of GDP, production loans granted (PLG), exports to GDP (EGDP), and employment (EMP) from 2005 to 2015 totalling 33 observations of agriculture, forestry, and fishery sectors. Specifically, panel data analysis was used to assess the effects of APLG, EMP, GDPt-1 and AEGDPt-1 in GDP. The fixed effect model corrected from autocorrelation and heteroscedasticity, a one percentage unit increase in the exports to GDP, on the average, leads to Php 774.96 increase in the GDP, other things equal; and a one-unit increase in employment, on the average, leads to PhP23.55 increase in the GDP, other things equal; a one peso increase in the production loans granted lagged by one period, on the average, leads to Php 0.4760 increase in the GDP, other things equal. Using the fixed effect model, all the explanatory variables such as, exports to GDP, employment and production loans granted lagged by one period exhibited significant effect on the GDP agriculture. Hence, the model is considered satisfactory from statistical perspective. The results from the fixed effect model were consistent with the priori expectations that exports to GDP, employment and production loans granted lagged by one period positively affect the GDP agriculture.

PSXI-15 Evaluation of low-lignin alfalfa ‘Hi-Gest® 360’ on the Canadian prairies: productivity, nutrient profile, and rumen degradation kinetics

Abstract The study was conducted at Saskatoon, SK, Canada in the Dark Brown soil zone (52°07′N,106°38′W), to compare low-lignin Hi-Gest®360 alfalfa (Hi-Gest; Medicago sativa L.) to a conventional alfalfa (AC Grazeland) under two cutting regimes. Each cultivar was seeded in 2017 as both a monoculture and binary mixture (binary; Hi-Gest+HB and Grazeland+HB) with AC Success hybrid bromegrass (HB). Plot size was 1.2m×6m with 4 rows. Three years (2018–2020) result suggested that the first cut DMY was 1695±241 and 2151±276 kg/ha for the Hi-Gest and Grazeland, respectively. Hi-Gest had greater (P < 0.05) TDN (68.4 vs. 66.6%, DM basis), NEm (1.7 vs. 1.6 Mcal/kg), IVNDFD48: (42.9 vs. 37.8%), but lower second cut DMY (1288 vs. 1560 kg/ha), ADF (26.3 vs. 28.7%), NDF (34.7 vs. 36.6%), compared to AC Grazeland. Under two cutting, Hi-Gest was numerically lower in total DMY (2983 vs. 3712 kg/ha; P = 0.114) relative to Grazeland. In first cut forage, Hi-Gest also was numerically lower in ADL (5.9 vs. 6.5%; P = 0.57) relative to AC Grazeland. Hi-Gest was similar (P = 0.15) with AC Grazeland in effectively degradable dry matter (EDDM; 622 g/kg DM), effectively degradable CP (EDCP; 689 g/kg CP). Hi-Gest alfalfa had greater (P = 0.05) effectively degradable neutral detergent fiber (EDNDF; 19% more; 340 vs. 285 g/kg NDF) relative to AC Grazeland alfalfa. In binary system, Hi-Gest+HB had (P = 0.02) greater EDCP (12% more; 526 vs. 468 g/kg CP), and numerically greater EDNDF (4.4% more; 259 vs. 248 g/kg NDF; P = 0.10) but had similar EDDM (409 g/kg DM) relative to Grazeland+HB mixture. Each percentage unit increase in alfalfa ADL concentration decreased EDNDF by 2.3 percentage units (EDNDF, % NDF = 46.0–2.93×ADL, % DM, r2=0.26, P < 0.01). Although Hi-Gest yielded less (~25% less) than AC Grazeland, Hi-Gest had greater nutritive value compared to AC Grazeland; differed little for yield and quality in binary mixture, suggesting Hi-Gest can be a viable alternative legume for western Canadian prairies.

Effects of feeding corn distillers dried grains with solubles diets without or with supplemental enzymes on growth performance of pigs: a meta-analysis.

A meta-analysis was conducted to determine the effects of the dietary energy system (net energy or metabolizable energy), oil content of corn distillers dried grains with solubles (cDDGS), diet inclusion levels, and pig age on growth performance of pigs fed cDDGS-based diets. Mean differences of average daily gain (ADG), average daily feed intake (ADFI), and gain:feed (G:F) were calculated and expressed as a percentage change relative to feeding corn–soybean meal (SBM)- and cDDGS-based diets to nursery [body weight (BW) < 25 kg] and growing-finishing (BW > 25 kg) pigs, and to compare the effects of supplementing various types of exogenous enzymes without or with phytase on growth performance. A total of 27 studies with 106 growth performance observations were included in the cDDGS dataset, and 34 studies with 84 observations for enzyme responses in cDDGS diets were used in the enzyme dataset. Approximately, 64.7% of the observations showed no change, and 26.7% of observations showed a reduction in ADG, ADFI, and G:F when feeding cDDGS-based diets to the nursery and growing-finishing pigs compared with feeding corn–SBM-based diets. Furthermore, feeding cDDGS diets resulted in decreased (P < 0.01) mean difference of ADG (–4.27%) and G:F (–1.99%) for nursery pigs, and decreased (P < 0.01) mean difference of ADG (–1.68%) and G:F (–1.06%) for growing–finishing pigs. Every percentage unit increase in the inclusion level of cDDGS in growing–finishing pig diet was associated with a decrease (P < 0.01) in ADG (–0.10%) and ADFI (–0.09%). Feeding high oil (≥10% ether extract) cDDGS-based diets to pigs resulted in a 2.96% reduction in ADFI whereas feeding reduced-oil (<10% ether extract) cDDGS-based diets reduced G:F by 1.56% compared with pigs fed corn–SBM-based diets. Supplementation of exogenous enzymes improved (P < 0.05) the mean difference of ADG and G:F by 1.94% and 2.65%, respectively, in corn–SBM-based diets, and by 2.67% and 1.87%, respectively, in cDDGS diets. Supplementation of exogenous protease, enzyme cocktail, or xylanase improved (P < 0.05) ADG by 7.29%, 2.64%, and 2.48% in pigs fed corn–SBM-based diets, respectively. There were no differences between the dietary addition of single enzymes and enzyme combinations for any growth performance parameters in corn–SBM- or cDDGS-based diets. In conclusion, feeding cDDGS-based diets slightly reduces the growth performance of nursery and growing–finishing pigs, but supplementation of xylanase or enzyme cocktail can improve G:F of pigs fed cDDGS-based diets.

PSVIII-11 Effects of feeding diets containing corn distiller’s dried grains with solubles (DDGS) on growth performance in broilers: a meta-analysis

Abstract Published studies involving different feeding strategies and diet inclusion rates of corn distillers dried grains with solubles (cDDGS) for broilers have resulted in variable growth performance responses. Therefore, a meta-analysis was conducted to quantitatively summarize the impact of feeding diets containing cDDGS on growth performance of broilers using a total of 16 publications with 56 observations in the database. The mean difference (MD) of BWG, FI, and G/F ratio were expressed as percentage between feeding corn-soybean meal-based (CSB) diet and addition of cDDGS into CSB diet of broilers. Individual observations were analyzed using a multivariable model (Proc GLIMMIX, SAS) to evaluate growth performance responses based on feeding phase, inclusion level of cDDGS, and oil content of cDDGS as a fixed effect. Broilers fed cDDGS diet had decreased BWG (-0.1 %, P &amp;lt; 0.01) and increased FI (0.3 %, P &amp;lt; 0.01) compared with broilers fed CSB diet. Moreover, every percentage unit increase in the inclusion level of cDDGS in CSB diet was associated with a decrease in BWG (0.30 %, P &amp;lt; 0.01) and FI (2.64 %, P &amp;lt; 0.01). The MD of BWG was greater for broilers fed cDDGS in the starter (4.70 %, P &amp;lt; 0.01) and entire (3.00 %, P &amp;lt; 0.01) period compared with the finisher feeding period. However, entire feeding period showed greater MD of G/F ratio (2.11 %, P &amp;lt; 0.01) compared with starter and finisher periods. The MD of BWG (-1.02 %, P &amp;lt; 0.01) and FI (-2.48%, P &amp;lt; 0.01) were decreased for broilers fed more than 20 % in the diet. In conclusion, including more than 20 % cDDGS into the broiler diet decreased BWG and FI. The recommended inclusion level of cDDGS into the broiler diet is 10 to 20 % during the entire period.

Student Characteristics Associated with Passing the Exam in Undergraduate Pharmacology Courses\u2014a Cross-sectional Study in Six University Degree Programs

Adequate knowledge in pharmacology is crucial in many professions but a non-negligible proportion of students fail the exams and knowledge of underlying factors is largely lacking. This study was performed to evaluate to what extent various factors are related to student performance in pharmacology-related courses in higher education, linking administrative data to attendance at non-mandatory teaching sessions and questionnaire replies. A total of 596 students (median age: 22 years; 70% female) were included from eight courses which are part of either the medical, pharmacy, dentistry, nursing, or biomedical analyst degree programs at the Sahlgrenska Academy, Gothenburg, Sweden. In all, 380 (64%) students passed the regular program- and course-specific exam. Multivariate logistic regression analysis revealed that a high participation rate in non-mandatory teaching sessions, as well as a perceived great interest in pharmacology, was associated with students’ passing of the exam; adjusted odds ratio (95% confidence interval): 1.30 (1.19 to 1.42; per 10 percentage unit increase in attendance) and 3.38 (1.86 to 6.12), respectively. Working for wages during the course weeks and pre-university grades used in the program application were significant factors in subgroups of students, negatively and positively associated with the exam results, respectively. Age, having Swedish as a second language, and time spent studying were only associated with the exam result in the univariate analyses. To conclude, both students and teachers can contribute significantly to successful education within pharmacology, students by participating in the teaching sessions and teachers by encouraging students to find the subject interesting.

High cardiovascular risk patients benefit more from bariatric surgery than low cardiovascular risk patients.

Atherosclerotic cardiovascular disease (ASCVD) and Framingham risk scores (FRS) are used to calculate 10-year risk of coronary death, nonfatal myocardial infarction, or fatal/nonfatal stroke. Our goal is to evaluate the association between preoperative cardiovascular risk and weight loss. We retrospectively reviewed bariatric surgeries from 2010 to 2016. Patients who met criteria for calculating 10-year ASCVD score and FRS were included. Data collected included baseline demographics, perioperative parameters, and postoperative outcomes at 12months. Simple linear regression and multiple linear regression models were applied to test influence of individual or multiple factors of interest on 12-month weight loss outcomes. Of 1330 bariatric patients studied, 360 patients met criteria for ASCVD and FRS calculation. Sleeve gastrectomy (LSG) was the most prevalent surgery 63.05%, followed by Roux-en-Y gastric bypass (LRYGB) 20.55%, revision procedures 11.9%, and adjustable gastric banding (LAGB) 4.4%. Initial BMI was 42.71 ± 7.85kg/m2 for females and 42.72k ± 7.42kg/m2 for males, with a 12-month percentage of estimated BMI loss (%EBMIL) of 66.51% in females and 60.29% in males. Preoperative 10-year ASCVD score was higher in males than females with a 34.73% relative risk reduction (RRR) in males and 35.3% RRR in females at 12-month follow-up. Regarding FRS, preoperative risk was 33.13 ± 21.1% in males and 15.71 ± 14.52% in females, with an RRR of 25.8% in males and 32.2% in females. Univariate analysis of preoperative FRS and %EBMIL showed that for every percentage unit increase in the patient's preoperative FRS, %EBMIL decreases 0.31 percentile unit (P < 0.001). Furthermore, preoperative ASCVD score is also significantly associated with %EMBIL-for every percentage unit increase in preoperative ASCVD score, %EBMIL decreases 0.42 percentile credits. Study results suggest ASCVD and FRS are equally reduced after bariatric surgery, especially after LSG and LRYGB. Moreover, preoperative FRS and ASCVD risk score showed an inversely proportional relationship with %EBMIL loss at 12 months.

Impact of adherence on subcutaneous interferon beta-1a effectiveness administered by Rebismart® in patients with multiple sclerosis.

BackgroundAdherence to disease-modifying drugs (DMDs) is one of the key factors for achieving optimal clinical outcomes. Rebismart® is an injection device for subcutaneous administration of interferon beta-1a (INF β-1a) that is also able to monitor adherence objectively. The aim of this study was to describe adherence to INF β-1a using the said electronic autoinjection device and to explore the relationship between adherence and relapses in a Spanish cohort.MethodsThis is a retrospective observational study in which 110 Spanish patients self-administered INF β-1a subcutaneously using an electronic autoinjection device between June 2010 and June 2015. The primary end point was the percentage of adherence measured by Rebismart® to subcutaneous INF β-1a injections calculated as number of injections received in time period versus number of injections scheduled in time period. Other variables recorded were demographic and clinical data. Statistical analysis was performed using SPSS 19.0 software.ResultsMedian adherence for the total study period was 96.5% (interquartile range [IQR]: 91.1–99.1). Similar values were observed during the first 6 months: 98.7% (IQR: 91.3–100), and the last 6 months: 97.6% (IQR: 91.1–99.8). Median duration of treatment was 979 days (IQR: 613.8–1,266.8). During the entire treatment period, 77.3% of patients were relapse free and mean annualized relapse rate was 0.14 (standard deviation: 0.33). Increased adherence was associated with better clinical outcomes, leading to lower relapse risk (odds ratio: 0.953; 95% confidence interval: 0.912–0.995). Specifically, every percentage unit increase in adherence resulted in a 4.7% decrease in relapse.ConclusionPatients with multiple sclerosis who self-injected INF β-1a with Rebismart® had excellent adherence, correlating with a high proportion of relapse-free patients and very low annualized relapse rate.

Byproduct yields of serially harvested calf-fed Holstein steers fed zilpaterol hydrochloride.

A 2 × 11 factorial treatment structure was applied in a completely randomized experimental design to investigate differences in noncarcass tissue among serially harvested Holstein steers. Steers ( = 110) were randomly assigned to 1 of 2 dietary treatments: a ration supplemented with zilpaterol hydrochloride (ZH) fed at a rate of 8.3 mg/kg DM for 20 d followed by a 3-d withdrawal or a control ration with no ZH included in the diet. Within treatment, steers were assigned to harvest groups of 254, 282, 310, 338, 366, 394, 422, 450, 478, 506, or 534 d on feed (DOF) prior to initiation of the trial. Cattle fed ZH realized an empty BW (EBW) increase ( ≤ 0.03) of 2.8% (644.2 vs. 626.4 kg [SEM 5.4]) and a HCW increase of 5.0% (429.1 vs. 408.4 kg [SEM 4.0]) with a concomitant 12% reduction (45.1 vs. 51.2 kg [SEM 3.1]) in gastrointestinal contents and 2.1 percentage unit increase in dressed carcass yield (62.1 vs. 60.0% [SEM 0.01]). Additionally, ZH supplementation decreased (P ≤ 0.03) the absolute weight of the liver and kidneys by 0.3 and 0.1 kg, respectively. When noncarcass components were expressed on an empty body basis (g/kg EBW), reductions ( ≤ 0.01) in the limbs (18.8 vs. 19.5 g/kg EBW [SEM 0.1]), hide (81.1 vs. 78.1 g/kg EBW [SEM 0.7]), liver (14.2 vs. 13.2 g/kg EBW [SEM 0.2]), kidneys (2.6 vs. 2.3 g/kg EBW [SEM 0.04]), small and large intestines (74.9 vs. 69.6 g/kg EBW [SEM 1.2]), and gastrointestinal tract (119.8 vs. 113.4 g/kg EBW [SEM 1.3]) were observed with ZH supplementation. Additionally, there was a tendency ( = 0.07) for the proportion of total offal to be reduced (253.2 vs. 247.4 g/kg EBW [SEM 2.5]) with ZH supplementation. Empty BW and HCW linearly increased ( < 0.01) by 1.16 and 0.758 kg/d ( < 0.01), respectively, with additional DOF. The weight of the liver and intestines linearly increased ( < 0.01) by 0.007 and 0.133 kg/d ( < 0.01), respectively, with additional DOF. These data indicate the magnitude of change in noncarcass tissues that can be expected when calf-fed Holstein steers are supplemented with ZH.

Influence of ensiling, exogenous protease addition, and bacterial inoculation on fermentation profile, nitrogen fractions, and ruminal in vitro starch digestibility in rehydrated and high-moisture corn

Exogenous protease addition may be an option to increase proteolysis of zein proteins and thus starch digestibility in rehydrated and high-moisture corn (HMC) ensiled for short periods. In addition, microbial inoculation may accelerate fermentation and increase acid production and thus increase solubilization of zein proteins. Four experiments were performed to evaluate the effect on fermentation profile, N fractions, and ruminal in vitro starch digestibility (ivSD) of the following: (1) rehydration and ensiling of dry ground corn; (2) exogenous protease addition to rehydrated un-ensiled and ensiled corn; (3) exogenous protease addition or inoculation in rehydrated ensiled corn; and (4) exogenous protease addition or inoculation in HMC. Experiments 1, 2, and 3 were performed with 7 treatments: dry ground corn (DGC); DGC rehydrated to a targeted dry matter content of 70% (REH); REH treated with exogenous protease (REH+); REH ensiled for 30 d (ENS); ENS treated with exogenous protease (ENS+); ENS treated with a microbial inoculant containing Lactobacillus plantarum, Lactobacillus casei, Enterococcus faecium, and Pediococcus sp. (ENSI); and ENS treated with exogenous protease and microbial inoculant (ENSI+). Experiment 1 compared DGC, REH, and ENS with ivSD being greater for ENS (64.9%) than DGC and REH (51.7% on average). Experiment 2 compared REH and ENS without or with exogenous protease addition (REH+ and ENS+, respectively). Ensiling and exogenous protease addition increased ivSD, but exogenous protease addition was more effective in ENS than REH (6.4 vs. 2.6 percentage unit increase). Experiment 3 compared the effects of exogenous protease addition and inoculation in ENS corn (ENS, ENS+, ENSI, and ENSI+). The addition of protease, but not inoculant, increased ivSD. Inoculation reduced pH and acetate, propionate, and ethanol concentrations, and increased lactate and total acid concentrations. In experiment 4, 8 treatments were a combination of HMC noninoculated or inoculated with 1 of 3 microbial inoculants and with or without exogenous protease addition. The inoculant treatments contained (1) Lactobacillus buchneri 40788 and Pediococcus pentosaceus, (2) L. buchneri 40788, and (3) a mixture of P. pentosaceus and Propionibacterium freudenreichii. Protease, but not inoculation, increased ivSD by 7.5 percentage units (44.4 vs. 51.9%). Protease addition increased ivSD in rehydrated corn and HMC. Microbial inoculation improved fermentation profiles but did not affect ivSD.

Effects of phytase supplementation on phosphorus retention in broilers and layers: A meta-analysis

Phytase, a widely used feed additive in poultry diets, increases P availability and subsequently reduces inorganic-P supplementation and P-excretion. Phytase supplementation effect on P-retention in poultry has been investigated, but the effect sizes were highly variable. The present study's objective was to conduct several meta-analyses to quantitatively summarize the phytase effect on P-retention in broilers and layers. Data from 103 and 26 controlled experiments testing the phytase effect on P-retention were included in 2 separate meta-analyses for broilers and layers, respectively. The mean difference calculated by subtracting the means of P-retention for the control group from the phytase-supplemented group was chosen as an effect size estimate. Between-study variability (heterogeneity) of mean difference was estimated using random-effect models and had a significant effect (P < 0.01) in both broilers and layers. Therefore, random-effect models were extended to mixed-effect models to explain heterogeneity and obtain final phytase effect size estimates. Available dietary and bird variables were included as fixed effects in the mixed-effect models. The final broiler mixed-effect model included phytase dose and Ca-to-total-P ratio (Ca:tP), explaining 15.6% of the heterogeneity. Other variables such as breed might further explain between-study variance. Broilers consuming control diets were associated with 48.4% P-retention. Exogenous phytase supplementation at 1,039 FTU/kg of diet increased P-retention by 8.6 percentage units on average. A unit increase of phytase dose and Ca:tP from their means further increased P-retention. For layers, the final mixed-effect models included dietary Ca, age, and experimental period length. The variables explained 65.9% of the heterogeneity. Layers receiving exogenous phytase at 371 FTU/kg were associated with a 5.02 percentage unit increase in P-retention. A unit increase in dietary Ca from its mean increased P-retention, whereas an increase in the experiment length and layer's age decreased P-retention. Phytase supplementation had a significant positive effect on P-retention in both broilers and layers, but effect sizes across studies were significantly heterogeneous due to differences in Ca contents, experiment length, bird age, and phytase dose.

Addition of potassium carbonate to continuous cultures of mixed ruminal bacteria shifts volatile fatty acids and daily production of biohydrogenation intermediates

A recent study reported a 0.4 percentage unit increase in milk fat of lactating dairy cattle when dietary K was increased from 1.2 to 2% with potassium carbonate. Because milk fat yield has been associated with ruminal production of certain conjugated linoleic acid (CLA) isomers, 2 studies were conducted to determine if increasing potassium carbonate in the rumen would alter patterns of fermentation and biohydrogenation. In experiment 1, 5 dual-flow continuous fermenters were injected just before each feeding with a 10% (wt/wt) stock potassium carbonate solution to provide the equivalent of 1.1 (K1), 2.2 (K2), and 3.3 (K3) % of diet dry matter (DM) as added K. One of the remaining fermenters received no K (K0) and the last fermenter (NaOH) was injected with adequate NaOH stock solution (10%, wt/wt) to match the pH observed for the K3 treatment. For experiment 2, 6 dual-flow continuous fermenters were used to evaluate 6 treatments arranged in a 2×3 factorial to examine 2 levels of soybean oil (0 and 3.64% of diet DM) and added K at 0, 1.6, and 3.3% of diet DM. In both experiments, fermenters were fed 55 to 57g of DM/d of a typical dairy diet consisting of 1:1 forage (10% alfalfa hay and 90% corn silage) to concentrate mix in 2 equal portions at 0800 and 1630h, and fed the respective diets for 10-d periods. Potassium carbonate addition increased pH in both experiments. Acetate:propionate ratio and pH in experiment 1 increased linearly for K0 to K3. Acetate:propionate ratio was lower for NaOH compared with K3 but the pH was the same. The trans-11 18:1 and cis-9,trans-11 CLA production rates (mg/d) increased linearly from K0 to K3, but K3 and NaOH did not differ. Production of trans-10 18:1 decreased and that of trans-10,cis-12 tended to decrease from K0 to K3, but production of trans-10,cis-12 CLA remained high for NaOH. Addition of K to the cultures in experiment 2 decreased propionate and increased acetate and acetate:propionate ratio for the 0% fat diet but not for the 3.64% fat diet. Addition of K increased stearic acid and cis-9,trans-11 CLA but decreased daily production of trans-10 C18:1 and trans-10,cis-12 CLA. The results indicate that increasing potassium carbonate in the diet shifts both fermentation and biohydrogenation pathways toward higher milk fat percentage in dairy cows, but the effects are only explained in part by elevation of pH.

Fiber monosaccharides and digestibility of Milenio grass under N fertilization

Nutritive value of tropical forages is extremely dependent on management strategies adopted. The objective of this study was to evaluate the effects of N fertilization doses (0, 150, 300, or 450kgN/ha/year) on chemical composition, in vitro digestibility, and neutral monosaccharides from cell walls of Panicum maximum Jacq. cv. IPR-86 Milenio. Grass samples were collected after 35 d of regrowth from paddocks managed under rotational stocking (35-d resting and 5-d occupation). All nutrient concentrations were affected by N fertilization, except ether extract. Although crude protein (CP) increased linearly with N dose, most nutrients were altered according to a quadratic trend. Each kilogram of N resulted in a 0.13 percentage unit increase in CP content (P<0.01). Nitrogen fertilization led to a quadratic increase of cellulose (P<0.01) and lignin (sa) (P<0.01) and, thus, ADF content (P<0.01). In contrast, hemicellulose was quadratically decreased (P<0.01), resulting in lower contents of NDF with N application rates higher than 89.3kg/ha/year (P<0.01). For fiber monosaccharides, arabinose decreased quadratically (P<0.01), following hemicellulose decrease. Hemicellulose is mainly composed of arabinose and xylose. Glucose content increased linearly with the N supply (P<0.01), and hence, cellulose accumulation. The xylose content was unaffected by treatments. Glucose and xylose were quantitatively more important than arabinose in cell walls of Milenio grass. In vitro digestibilities of DM, OM, and ADF increased linearly with N fertilization (P<0.01), whereas NDF digestibility followed a quadratic trend (P<0.01), with a maximum response at 349kgN/ha. Improvements in digestibility were also observed for neutral monosaccharides (P<0.01). For all treatments, xylose was less digestible than arabinose and glucose. In conclusion, N fertilization increased CP content, stimulated the formation of glucose and arabinose in cell walls, leading to a higher forage quality. Forage quality was enhanced with N doses up to 300kg/ha/year.

Transfer rate of α-linolenic acid from abomasally infused flaxseed oil into milk fat and the effects on milk fatty acid composition in dairy cows

The objectives of the present study were to evaluate the transfer efficiency of α-linolenic acid (ALA) from the abomasum into milk fat, its interaction with milk fat content and yield, and the relationship between ALA and C16:0 in milk fat. Three rumen-fistulated multiparous Holstein cows at midlactation were used in a 3×3 Latin square design. Treatments consisted of abomasal infusion of (1) 110mL of water/d (control), (2) 110mL of flaxseed oil/d (low flaxseed oil, LFO), and (3) 220mL of flaxseed oil/d (high flaxseed oil, HFO). Experimental periods were continued for 2 wk and fat supplements were infused abomasally during the last 7 d of each period. Average dry matter intake and milk yield were not affected by oil infusion. Milk fat and lactose content tended to be greater with flaxseed infusion compared with the control. Plasma ALA was 2.9- and 4.0-fold greater with LFO and HFO, respectively. The apparent transfer efficiency of ALA to milk was 44.8 and 45.7% with LFO and HFO, respectively. The C16:0 content in milk fat was decreased by 3.59 and 5.25 percentage units, whereas the ALA content was increased by 1.68 and 3.09 percentage units with LFO and HFO, respectively. Similarly, C18:2n-6 was increased by 0.95 and 1.31 percentage units with LFA and HFO, respectively, without changes in other fatty acids (FA). Total polyunsaturated FA was 4.4 and 2.7% lower in the HFO and LFO, respectively, than in the control. Furthermore, C16:0 content in the milk fat was reduced to a greater extent than the increase in ALA content, as a 1.68 and 3.09 percentage unit increase occurred in ALA compared with a 3.6 and 5.25 percentage unit decrease in C16:0 for LFO and HFO, respectively, such that a negative correlation existed between ALA and C16:0 (r=−0.72). In conclusion, abomasal infusion of flaxseed oil dramatically increased the ALA content in plasma and milk fat. Because the replacement of C16:0 with ALA and C18:2n-6 occurred without changes in other FA presumed to be synthesized de novo in the mammary gland, this suggests that the preformed C16:0 was replaced, rather than being caused, by an overall suppression of de novo FA synthesis in the mammary gland.

Serum Long-Chain n-3 Polyunsaturated Fatty Acids, Mercury, and Risk of Sudden Cardiac Death in Men: A Prospective Population-Based Study

ObjectivesFish consumption has been associated with reduced risk of cardiovascular diseases (CVD), especially sudden cardiac death (SCD). Fish is the major source of long-chain n-3 polyunsaturated fatty acids (PUFA) eicosapentaenoic acid and docosahexaenoic acid. It is also a major source of methylmercury, which was associated with increased risk of CVD in this study population. Impact of interaction between long-chain n-3 PUFA and methylmercury on the SCD risk is unknown.MethodsA total of 1857 men from the prospective, population-based Kuopio Ischaemic Heart Disease Risk Factor study, aged 42–60 years and free of CVD at baseline in 1984–1989, were studied. Serum long-chain n-3 PUFA was used as the marker for long-chain n-3 PUFA intake and hair mercury as the marker for mercury exposure.ResultsDuring the mean follow-up of 20.1 years, 91 SCD events occurred. In the multivariate Cox proportional hazards regression models, serum long-chain n-3 PUFA concentration was not associated with the risk of SCD until hair mercury was accounted for; then the hazard ratio (HR) in the highest vs. lowest tertile was 0.54 [95% confidence interval (CI) 0.32 to 0.91, p for trend = 0.046]. When the analyses were stratified by hair mercury content, among those with lower hair mercury, each 0.5 percentage unit increase in the serum long-chain n-3 PUFA was associated with HR of 0.77 (95% CI 0.64 to 0.93), whereas no association was seen among those with higher hair mercury (p for interaction = 0.01). Among the individual long-chain n-3 PUFA, docosahexaenoic acid was most strongly associated with the risk.ConclusionHigh exposure to mercury may reduce the benefits of long-chain n-3 PUFA on SCD.

Dietary Electrolyte Requirement of Broiler Chicks as Affected by Dietary Protein Content

A soy protein based semi-purified diet was used to estimate the optimum electrolyte balance (meq Na , K , Cl /kg diet) at 3 levels of dietary crude protein. Results indicated that in diets containing 14.3% Crude + + Protein (CP), the optimum electrolyte balance was approximately 250 meq/kg; at 21.4% CP the optimum was about 325 meq/kg and at 28.6% CP it was about 400 meq/kg. A conventional 21% CP corn-soy broiler diet which, by calculation, contained 228 meq Na , K , Cl /kg was used in two subsequent experiments. In both + + experiments, it was found that feed intake, gain and feed efficiency were significantly improved (p<0.05) by the addition of 100 meq Na , K /kg diet in diets containing 56.4 meq Cl/kg, thus, confirming an optimum + + electrolyte balance of about 325 meq/kg in diets containing 21% CP. It was concluded that the optimum dietary electrolyte balance of broiler chicks is dependent on diet crude protein content. Further, within the range of 14-28% CP, the optimum electrolyte balance is increased by about 11 meq/kg per 1 percentage unit increase in diet crude protein content.