Effects Of Experimental Treatments Research Articles

Measuring Simultaneous Emotions: Existing Problems and a New Way Forward

AbstractStudies on discrete emotions typically work to evoke one emotion at a time. Yet many political phenomena cause multiple emotions. Threats, for example, cause, anger, and fear, have diametrically opposing behavioral consequences. As a result, the effect of experimental treatments can be masked by the countervailing influence of emotions with similar affect. This issue is exacerbated by existing measures of negative emotions, such as the Positive and Negative Affect Schedule (PANAS). We show that the PANAS is contaminated by systematic measurement error, as negative affect produced by one emotion influences responses on the other. To overcome this, we develop an alternative version of the PANAS that allows respondents to select which emotions they are feeling, then rate the severity. This technique accurately captures respondent’s emotional reactions, reducing measurement error and thus decreasing the correlation between fear and anger. The tactics we developed have broad relevance for experimental researchers analyzing emotional responses to politics.

Effects of dietary lavender essential oil on growth performance, intestinal function, and antioxidant status of broiler chickens

A total of 480 one-day-old male broiler chickens were used in a 42-d study to assess the effects of different inclusion levels of lavender essential oil (LEO) supplementation in comparison with an antibiotic growth promoter on growth performance and physiological characteristics of broiler chickens. On d 1, broiler chickens were randomly assigned into 4 experimental treatments (6 replicates of 20 broiler chickens each) including a basal diet without any additive (control, CON), the basal diet supplemented with 200 mg/kg virginiamycin (VIM), and the basal diet supplemented with either 300 (LEO300) or 600 (LEO600) mg/kg LEO. The results showed that experimental treatments had no significant effect on feed intake at any stage of the study. In addition, no effect of experimental treatments was observed on body weight gain (BWG) and feed conversion ratio (FCR) over the starter period (d 0–21). However, broiler chickens fed diets supplemented with LEO600 and VIM had greater BWG and exhibited a lower FCR during grower (d 21–42) and the entire production period (d 0–42; P < 0.05). Likewise, feeding LEO600 and VIM diets decreased Escherichia coli population in the ileum and cecal contents and increased villus height and villus height to crypt depth of jejunum compared with the CON diet (P < 0.05). Dietary supplementation of LEO increased activity of superoxide dismutase in serum and liver and glutathione peroxidase activity in serum, but reduced concentrations of malondialdehyde in the serum (P < 0.05). In conclusion, addition of 600 mg/kg LEO to broiler chicken diets has the potential to improve growth performance, gut microbiota balance, intestinal morphology, and antioxidant activity.

Synergistic impacts of co‐occurring invasive grasses cause persistent effects in the soil‐plant system after selective removal

AbstractHuman influence on the environment is so extensive that virtually all ecosystems on the planet are now affected by biological invasions. And, often, ecosystems are invaded by multiple co‐occurring non‐native species. Hence, it is important to understand the impacts these invasions are producing on biodiversity and ecosystem processes.Here, we present results of a 2‐year long field experiment where we tested the effects of co‐occurring invasive C4African grasses in a Cerrado area in central Brazil. We compared plant and arthropod communities, plant biomass, and soil nitrogen dynamics and soil chemical characteristics across five experimental treatments:Urochloa decumbensremoval;Melinis minutifloraremoval; bothU.decumbensandM.minutifloraremoval;U.decumbensandM.minutiflorainvaded plots; and uninvaded Cerrado. We hypothesized that selective removal of invasive grasses would have distinct effects on the native ecosystem structure and functioning. We expected that each invasive grass would produce a different type of impact on the native ecosystem and that their impacts would be synergistic when co‐occurring.Removal ofM.minutifloradoubled native plant diversity and biomass when compared to invaded plots, whereas removal ofU.decumbensdid not alter these parameters. Cerrado plots had four times more plant species than plots cleared of invasives. Removal of invasive grasses did not affect the species richness or community composition of soil epigeal fauna. Cerrado soils had lower fertility, organic matter content and pH than invaded soils. The effects were generally higher when both invasive grasses were removed, suggesting impacts were synergistic, butM.minutiflorahad greater effects on plants and soils thanU.decumbens. Both invasive species produced negative impacts, but a single species was the main driver. We also detected persistent effects of the invasive grass species on the ecosystem after 2 years of removal.We conclude that invasive species of the same functional group have similar types of effects in native ecosystems, but the magnitude of impact was largely dependent on invasive species biomass and cover. Where multiple invasive species are present, research and management of invaded ecosystems should tackle the interacting effects of co‐occurring invaders.

Multiplicative treatment effects in randomized pretest-posttest experimental designs.

In randomized pretest-posttest experimental designs, experimental treatments are commonly compared through an additive difference. The assumed additive effects of experimental treatments, in randomized pretest-posttest design, also correspond to additive differences between pre- and posttreatment measures. However, it is possible that experimental treatments differ in ratios and the treatment effects are multiplicative. Logarithmic-transformed ANOVA (LANOVA) and logarithmic-transformed ANCOVA (LANCOVA)-reparameterizations of log-log regression models-are proposed to test multiplicative effects given randomized pretest-posttest experimental designs. In addition, a new effect size measure is proposed for treatment effects that are multiplicative instead of additive. Model selection strategy, sample size planning, and power calculation for the proposed methods are also provided. Simulation studies were conducted to compare the Type I error rates and power of proposed methods to those of symmetrized change analysis, ANOVA, ANCOVA, gain score analysis, and ANCOVA with logarithmic-transformed dependent variable given population effect of both additive and multiplicative nature. An empirical data analysis follows to show the interpretational difference between multiplicative and additive effects. While logarithmic transformations are most often recommended to address skewness, our article shows how a log transformation can be used to reconceptualize the fundamental nature of the treatment effect. Finally, recommendations, limitations, and future directions are discussed. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Ecosystem consequences of multi-trait response to environmental changes in Japanese medaka, Oryzias latipes.

Intraspecific trait variation has large effects on the ecosystem and is greatly affected by human activities. To date, most studies focused on single-trait analyses, while considering multiple traits is expected to better predict how an individual interacts with its environment. Here, we used a mesocosm experiment with fish Oryzias latipes to test whether individual growth, boldness and functional traits (feeding rate and stoichiometric traits) formed one functional pace-of-life syndrome (POLS). We then tested the effects of among-individual mean and variance of fish functional POLSs within mesocosms on invertebrate community (e.g. zoobenthos and zooplankton abundances) and ecosystem processes (e.g. ecosystem metabolism, algae stock, nutrient concentrations). Stoichiometric traits correlated with somatic growth and behaviours, forming two independent functional POLS (i.e. two major covariance axes). Mean values of the first syndrome were sex- and environment-dependent and were associated with (i) long-term (10 generations; 4 years) selection for small or large body size resulting in contrasting life histories and (ii) short-term (6 weeks) effects of experimental treatments on resource availability (through manipulation of light intensity and interspecific competition). Specifically, females and individuals from populations selected for a small body size presented fast functional POLS with faster growth rate, higher carbon body content and lower boldness. Individuals exposed to low resources (low light and high competition) displayed a slow functional POLS. Higher mesocosm mean and variance values in the second functional POLS (i.e. high feeding rate, high carbon:nitrogen body ratio, low ammonium excretion rate) were associated to decreased prey abundances, but did not affect any of the ecosystem processes. We highlighted the presence of functional multi-trait covariation in medaka, which were affected by sex, long-term selection history and short-term environmental conditions, that ultimately had cascading ecological consequences. We stressed the need for applying this approach to better predict ecosystem response to anthropogenic global changes.

Short Communication: The effects of physical feed properties on gastric emptying in pigs measured with the 13C breath test

The performance of pigs is affected by the rate of nutrient absorption in the gastrointestinal tract, which depends in turn strongly on the rate of stomach emptying. The 13C breath test provides a non-invasive diagnostic tool to measure gastric emptying patterns. Despite the wide acceptance of this method in human intervention studies, it has not found its way to the domain of animal sciences. In this study, we used the breath test to measure gastric emptying in young growing pigs using [1-13C] octanoic acid to trace digesta solids and [1-13C] glycine to study liquids. Pigs were fed a starch-rich diet, varying in starch source (isolated starch from barley, maize or high-amylose maize) or form (isolated barley starch, ground barley or extruded barley), after which 13CO2 enrichment was frequently measured during 11 h. Outliers in 13CO2 enrichment in the response curve of each pig were identified with a Cookʼs distance outlier test in combination with a leave-one-out analysis. Effects of experimental treatments on breath test parameters were tested using a GLM. In general, pigs were easy to train and the tailor-made mask allowed effortless sampling. Gastric emptying of all pigs followed a biphasic pattern, with a higher 13C recovery during the first peak. The first peak in gastric emptying of solids reached its maximum enrichment within 2 h after feeding in all cases. For digesta liquids, this peak was reached earlier for pigs fed ground barley (2.2 h after feeding), compared to pigs fed diets containing isolated starch (2.8 h after feeding). The second peak in gastric emptying of solids was reached later for pigs fed ground barley (5.9 h after feeding), compared with pigs fed extruded barley (4.5 h after feeding) and pigs fed diets containing isolated barley starch (4.8 h after feeding). In conclusion, the 13C breath test is a convenient, non-invasive tool to gain more insights into the gastric emptying pattern of pigs.

Analysis of Plant Cell Walls by Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy.

Attenuated total reflectance Fourier transform mid-infrared (ATR-FTIR) spectroscopy is widely applicable for the chemical analysis of biological materials, relatively inexpensive, requires only simple sample preparation, and is of comparatively high-throughput compared to traditional wet chemical or chromatographic methods. It is particularly well suited for the nondestructive analysis of dried and finely ground plant samples for the subsequent prediction of cell wall and other compositional or processing parameters using chemometric regression models. Furthermore, analysis of mid IR spectra by nonregression methods (e.g., principal component analysis) provides a straightforward approach for multivariate comparison of the effects of experimental, processing, and environmental treatments, and genotypic and temporal differences on chemical composition including changes in cell wall composition. There is thus great potential for using ATR-FTIR in the lignocellulosic biomass industry at a number of levels. Here we describe methods for cell wall sample preparation and generation of ATR-FTIR spectra, and suggest techniques for the statistical analysis and/or chemometric pattern recognition between the analyzed samples.

Vitamin-c and thiamine have powerful experimental treatment effects suppressing mortality in critical care: implications for preventing patient deterioration in sepsis

Vitamin-c and thiamine have powerful experimental treatment effects suppressing mortality in critical care: implications for preventing patient deterioration in sepsis

엘리트선수 경력자의 유산소성 운동이 혈관탄성의 회복력에 미치는 영향

The purpose of this study is to examine the effects of regular exercise done in the past on the improvement of vascular compliance and provide specific data that regular exercise is a positive factor for vascular health by comparing vascular compliance changes before and after 12 weeks of aerobic exercise between elite athletes who have exercised for many years and ordinary people. 10 retired athletes who have more than 5 years of track record and no regular exercise for more than 3 years after retirement and 13 people who have not regularly exercised for more than 3 years were selected as the subjects of this study.BR For a period of 12 weeks, the 10 people in the exercise-experienced group and 13 people in the control group, selected as above, conducted 70-minute-aerobic exercise on a treadmill for 3 times a week with a rate of perceived effort less than 17. PASW 18.0 statistical program was used to calculate the mean and standard deviation of each item from the collected results. For the general characteristics of the subjects, descriptive statistics were performed and repeated measure ANOVA was also carried out for the effectiveness of experimental treatment on the exercise-experienced and control groups. The significance level was verified near at p.05BR The results showed that the vascular compliance values of the left hand, right hand, left foot and right foot of both of the control group and exercise-experienced groups was increased after 12 weeks of exercise. Hypothesis testing of each item revealed that there is no statistical significance in all parts of left hand, right hand, left foot and right foot. However, statistical significance was found in left foot (F=29.9769, p.001) and right foot (F=33.058, p.001) by hypothesis testing between items. In addition, positive changes of vascular compliance were observed to progress faster in the exercise-experienced group compared to the control group.

Statistical considerations in the design and analysis of non-inferiority trials with binary endpoints in the presence of non-adherence: a simulation study.

Protocol non-adherence is common and poses unique challenges in the interpretation of trial outcomes, especially in non-inferiority trials. We performed simulations of a non-inferiority trial with a time-fixed treatment and a binary endpoint in order to: i) explore the impact of various patterns of non-adherence and analysis methods on treatment effect estimates; ii) quantify the probability of claiming non-inferiority when the experimental treatment effect is actually inferior; and iii) evaluate alternative methods such as inverse probability weighting and instrumental variable estimation. We found that the probability of concluding non-inferiority when the experimental treatment is actually inferior depends on whether non-adherence is due to confounding or non-confounding factors, and the actual treatments received by the non-adherent participants. With non-adherence, intention-to-treat analysis has a higher tendency to conclude non-inferiority when the experimental treatment is actually inferior under most patterns of non-adherence. This probability of concluding non-inferiority can be increased to as high as 0.1 from 0.025 when the adherence is relatively high at 90%. The direction of bias for the per-protocol analysis depends on the directions of influence the confounders have on adherence and probability of outcome. The inverse probability weighting approach can reduce bias but will only eliminate it if all confounders can be measured without error and are appropriately adjusted for. Instrumental variable estimation overcomes this limitation and gives unbiased estimates even when confounders are not known, but typically requires large sample sizes to achieve acceptable power. Investigators need to consider patterns of non-adherence and potential confounders in trial designs. Adjusted analysis of the per-protocol population with sensitivity analyses on confounders and other approaches, such as instrumental variable estimation, should be considered when non-compliance is anticipated. We provide an online power calculator allowing for various patterns of non-adherence using the above methods.

Euclidean distance can recognize the Biojas® concentration that produces the ideal physiological status of pineapple in vitro plantlets

Biojas® is a fermented broth of Lasiodiplodia theobromae, a jasmonic acid–producing fungus characterized as a plant growth regulator and as biological control of phytopathogenic microorganisms and pests. The present work describes the use of Biojas® in in vitro culture of pineapple. On the other hand, plant scientists usually record multiple indicators in their experiments. The common statistical data evaluations involve univariate analyses such as t test, Mann-Whitney, and analysis of variance (ANOVA) followed by Tukey’s HSD. Such analyses do not evaluate integrally the effects of the experimental treatments because each indicator is analyzed independently. For this reason, we explored in this study the Euclidean distance combined with the data of the Biojas® treatment (0–2 mg l−1) on pineapple in vitro plantlets as an integrating indicator. Plant height; number of leaves; D leaf length, width, and area; diameter of the plant base; fresh and dry weights of the plant; levels of chlorophylls; transpiration rate; CO2 assimilation; and water use efficiency were recorded. Several statistically significant differences among Biojas® treatments were recorded. However, the most significant effects of Biojas® treatments were only noted in the plant height, length and area of D leaf, and water use efficiency. Variables mentioned above increased until 1.0 mg l−1 Biojas® and decreased with high levels of Biojas®. Calculation of the Euclidean distance from each Biojas® level to the ideal physiological status of the pineapple plantlets revealed that 1.0 mg l−1 Biojas® produced the pineapple plantlets with the best physiological status.

Rationale for blindness to treatment assignment in between-group experiments testing generalized communication and language

Blindness to participants’ assigned treatment group is an essential protection against detection bias in between-group experimental designs testing treatment effects on generalized communication and language competence. Blindness to treatment group cannot be achieved when the other people in the communication sample (e.g. parents or peers) or the reporters of children’s communication or language behavior (e.g. parents or teachers) are also the implementers of the treatment. Internally valid between-group experiments measure generalized communication and language in ways that are constant across treatment groups by examiners who are blind to treatment assignment. When language or communication samples are used to measure generalized skills or developmental level, staff members who are blind to treatment assignment must conduct the data reduction methods (e.g. transcription, verification, and coding). Otherwise, the children’s skill level can be inadvertently over-estimated in the treatment group relative to those in the control group.

High dietary zinc and glutamine do not improve the performance or reduce excreta moisture of broiler chickens fed diets with and without magnesium supplementation.

An experiment was conducted to investigate the effect of supplemental L-glutamine (L-Gln) and a higher concentration of zinc (Zn) on excreta moisture under nutritionally induced wet droppings via decreased intestinal water reabsorption. A 2 × 2 × 2 factorial arrangement of treatments was used to investigate 3 dietary factors of L-Gln supplementation (0 or 10g/kg), and added Zn concentration (80 and 160mg/kg) with or without magnesium chloride (MgCl) (2g/kg-only in grower diets). A total of 576 male day-old Ross 308 broiler chickens were assigned to the experimental diets. Each diet was replicated 6 times with 12 birds per replicate. Wheat-based diets were formulated to be isocaloric and isonitrogenous. Starter diets were given from day 0 to 9 followed by grower (day 10 to 23) and finisher diets (day 24 to 35). Excreta moisture was measured for all the growth phases. The moisture content of different segments of intestine was assessed for starter and grower phases of feeding. There was no significant effect of any of the 3 main treatments on body weight gain or feed intake of birds during the experiment. Birds fed higher Zn (160mg/kg) tended (P = 0.09) to have higher weight gain only in the first 9 days of age. Feeding 10g/kg L-Gln increased the feed conversion ratio of the birds only from hatch until day 9 after which there was no significant effect. No effect of experimental treatments was found on digesta or excreta moisture, except a reduction in ileal moisture at the starter phase resulting from higher Zn concentration in the diets. MgCl at 2g/kg was not effective in inducing wet droppings in birds fed grower diets. Under the conditions of this study, no positive response was observed in terms of performance or reduction in excreta moisture when birds were fed diets containing 10g/kg L-Gln or higher concentration of Zn.

Neurophysiological Characterization of a Non-Human Primate Model of Traumatic Spinal Cord Injury Utilizing Fine-Wire EMG Electrodes.

This study aims to characterize traumatic spinal cord injury (TSCI) neurophysiologically using an intramuscular fine-wire electromyography (EMG) electrode pair. EMG data were collected from an agonist-antagonist pair of tail muscles of Macaca fasicularis, pre- and post-lesion, and for a treatment and control group. The EMG signals were decomposed into multi-resolution subsets using wavelet transforms (WT), then the relative power (RP) was calculated for each individual reconstructed EMG sub-band. Linear mixed models were developed to test three hypotheses: (i) asymmetrical volitional activity of left and right side tail muscles (ii) the effect of the experimental TSCI on the frequency content of the EMG signal, (iii) and the effect of an experimental treatment. The results from the electrode pair data suggested that there is asymmetry in the EMG response of the left and right side muscles (p-value < 0.001). This is consistent with the construct of limb dominance. The results also suggest that the lesion resulted in clear changes in the EMG frequency distribution in the post-lesion period with a significant increment in the low-frequency sub-bands (D4, D6, and A6) of the left and right side, also a significant reduction in the high-frequency sub-bands (D1 and D2) of the right side (p-value < 0.001). The preliminary results suggest that using the RP of the EMG data, the fine-wire intramuscular EMG electrode pair are a suitable method of monitoring and measuring treatment effects of experimental treatments for spinal cord injury (SCI).

Studentized Sensitivity Analysis for the Sample Average Treatment Effect in Paired Observational Studies

A fundamental limitation of causal inference in observational studies is that perceived evidence for an effect might instead be explained by factors not accounted for in the primary analysis. Methods for assessing the sensitivity of a study’s conclusions to unmeasured confounding have been established under the assumption that the treatment effect is constant across all individuals. In the potential presence of unmeasured confounding, it has been argued that certain patterns of effect heterogeneity may conspire with unobserved covariates to render the performed sensitivity analysis inadequate. We present a new method for conducting a sensitivity analysis for the sample average treatment effect in the presence of effect heterogeneity in paired observational studies. Our recommended procedure, called the studentized sensitivity analysis, represents an extension of recent work on studentized permutation tests to the case of observational studies, where randomizations are no longer drawn uniformly. The method naturally extends conventional tests for the sample average treatment effect in paired experiments to the case of unknown, but bounded, probabilities of assignment to treatment. In so doing, we illustrate that concerns about certain sensitivity analyses operating under the presumption of constant effects are largely unwarranted.

Bee community preference for an invasive thistle associated with higher pollen protein content.

Non-native plant species reliant on insect pollination must attract novel pollinators in their introduced habitat to reproduce. Indeed, pollination services provided by resident floral visitors may contribute to the spread of non-native species, which may then affect the pollination services received by native plants. To determine the mechanisms by which an invasive thistle attracts pollinators in its introduced range, and whether its presence changes the pollinator visitation to native plant species, we compared bee visitation to native plants in the presence or absence of the invader. We experimentally tested the effect of a thistle invasion into a native plant community. We found that the non-native thistle was the most attractive of the plant species to visiting bee species. However, there was no effect of experimental treatment (presence of thistle) on bee abundance or visitation rate (bees per unit floral area per sample) to native plant species. Across 68 bee and 6 plant species, we found a significant correlation between pollen protein content and bee abundance and visitation rate. Thistle pollen also had a similar protein:lipid ratio to legumes, which correlated with bumble bee visitation. The high protein content of the thistle pollen, as compared to four native asters, may allow it to attract pollinators in novel ecosystems, and potentially contribute to its success as an invader. At the same time, this high protein pollen may act as a novel resource to pollinators in the thistle's invaded range.

Regression Adjustments for Estimating the Global Treatment Effect in Experiments with Interference

Abstract Standard estimators of the global average treatment effect can be biased in the presence of interference. This paper proposes regression adjustment estimators for removing bias due to interference in Bernoulli randomized experiments. We use a fitted model to predict the counterfactual outcomes of global control and global treatment. Our work differs from standard regression adjustments in that the adjustment variables are constructed from functions of the treatment assignment vector, and that we allow the researcher to use a collection of any functions correlated with the response, turning the problem of detecting interference into a feature engineering problem. We characterize the distribution of the proposed estimator in a linear model setting and connect the results to the standard theory of regression adjustments under SUTVA. We then propose an estimator that allows for flexible machine learning estimators to be used for fitting a nonlinear interference functional form. We propose conducting statistical inference via bootstrap and resampling methods, which allow us to sidestep the complicated dependences implied by interference and instead rely on empirical covariance structures. Such variance estimation relies on an exogeneity assumption akin to the standard unconfoundedness assumption invoked in observational studies. In simulation experiments, our methods are better at debiasing estimates than existing inverse propensity weighted estimators based on neighborhood exposure modeling. We use our method to reanalyze an experiment concerning weather insurance adoption conducted on a collection of villages in rural China.

Morpho-physiological Response of Saffron (Crocus Sativus L.) to Particle Size and Rates of Zinc Fertilizer

ABSTRACTA field study was conducted during 2015–2017 in order to evaluate effects of the foliar application of different sources and concentrations of zinc oxide (ZnO) on the yield and morpho-physiological characteristics of saffron. Experimental treatment included the foliar application of nano ZnO at a concentration of (3, 6, and 9 g L−1), foliar application of normal ZnO at a concentration of (3, 6, and 9 g L−1) and the control. Both types of ZnO had positive effects on the saffron yield and number of flowers, but the highest yield and flower number were obtained by the foliar application of 9 g L−1 normal ZnO followed by 6 g L−1 nano ZnO. Increasing concentrations of both fertilizers up to 3 g L−1 had no significant effect on crocin, but the crocin content significantly decreased at higher concentrations. Effects of experimental treatments were significant on all morpho-physiological traits. The maximum chlorophyll a (1.74 mg.g−1) was observed in normal ZnO at a concentration of 9 g L−1 followed by nano ZnO at a concentration of 3 g L−1. The increasing application of different types of fertilizers linearly increased the Peroxidase activity, but the highest activity of Catalase in normal ZnO and nano ZnO was measured after the foliar application at concentrations of 3 and 6 g L−1, respectively.

Antimicrobial activity of nest-lining feathers is enhanced by breeding activity in avian nests.

The use of feathers as nest material has been proposed as a kind of self-medication strategy because antimicrobial-producing microorganisms living on feathers may defend offspring against pathogenic infections. In this case, it is expected that density of antimicrobial-producing bacteria, and their antimicrobial effects, are higher in feathers that line the nests than in eggshells. Moreover, we know that feather pigmentation and breeding activity may influence density and antimicrobial production of bacteria. To test these predictions, we analyzed bacterial densities and antimicrobial activity of bacterial colonies isolated from bird eggshells and nest-lining feathers against bacterial strains comprising potential pathogens. Samples were collected from spotless starling (Sturnus unicolor) nests, and from artificial nests to isolate the effects of breeding activity on bacterial communities. The composition of feathers lining the nests was experimentally manipulated to create groups of nests with pigmented feathers, with unpigmented feathers, with both types of feathers or without feathers. Although we did not detect an effect of experimental feather treatments, we found that bacterial colonies isolated from feathers were more active against the tested bacterial strains than those isolated from eggshells. Moreover, bacterial density on feathers, keratinolytic bacteria on eggshells and antimicrobial activity of colonies isolated were higher in starling nests than in artificial nests. These results suggest that antimicrobial activity of bacteria growing on nest-lining feathers would be one of the mechanisms explaining the previously detected antimicrobial effects of this material in avian nests, and that breeding activity results in nest bacterial communities with higher antimicrobial activity.

Response of lactating Zaraibi goats fed with berseem and/or triticale forage on milk production, feed utilization and economic efficiency

Twenty eight female Zaraibi goats in 2nd, 3rd and 4th season of lactation with average body weight of 33.0 kg were divided randomly into 4 groups (7 does in each) to study the effect of substitution of berseem forage by triticale forage in diets of lactating Zaraibi goats on their performances for milk yield and composition. In addition, twelve Rahmani rams average body weight of 50 kg were used to evaluate the feeding value of tested diets. Half the crude protein (CP) requirements of lactating goats were covered from concentrate feed mixture (CFM) while other 50% of CP was covered from triticale forage in the first group (G1), mixture forage (50% triticale- 50% berseem) in the second group (G2), mixture forage (70% triticale- 30% berseem) in the third group (G3), and berseem forage in (G4). The obtained results showed that the dry matter (DM) percent of triticale was higher than berseem (16.50 vs. 13.98). Moreover, the ether extract (EE) and nitrogen free extract (NFE) were higher while CP and ash were lower in triticale forage than berseem. But, crude fiber (CF) was nearly similar in both forages. The daily dray mater intake (DMI) as g/ kg w0.75 and body weight (BW) tended to increase with mixture forage G2 (99.10 and 4.07, respectively) compared with G3(98.75 and 4.06, respectively) and G4 (95.27 and 3.91, respectively) and G1 (91.79 and 3.77, respectively). Ammonia-N (NH3-N) level and pH values tended to decrease in the rumen of Rahmani sheep fed triticale forage (G1) compared with other forages (G2, G3, and G4). Rumen volatile fatty acids (TVFA's) concentrations as well as microbial protein (MP) were higher with 50% triticale - 50% berseem than with other rations. The digestion coefficients of OM, CF and NFE were significantly improved with G2 and G3 compared with G1 and G4. The CP, DM and OM digestibility recorded the lowest values (P<0.05) with triticale forage. The total digestible nutrients (TDN) showed the higher estimates (P<0.05) with the mixture rations (G2 and G3), while digestible crude protein (DCP) was significantly higher with increasing berseem in the rations. Whereas, serum protein, albumin, globulin, urea-N and glucose did not significantly differed among the tested diets. Concerning milk production, the obtained data indicated that milk yield of Zaraibi goats was significantly (P<0.05) higher with mixture forage (1.350 kg/ h/ d) G2 and (1.310 kg/h/d) G3 compared with the other groups (1.230 and 1.260 for G1 and G4, respectively). The effect of experimental treatments on milk fat percentage was significant (P<0.05). While, other milk contain and milk quality parameters (such as pH value and acidity %) were not significant. Accordingly, it could be concluded that using mixture forage (triticale and berseem) in feeding Zaraibi goats has positive effect on feeding value, milk yield and milk composition as well as feed utilization efficiency. Triticale forage could be safety use in feeding Zaraibi goats as it is or mixed with berseem.