Search

Relative to temperate systems, there has been few reported detailed assessments of sward characteristics and associated grazing behavior from natural and established pastures in Nigeria. This study reviewed the important relationship between sward characteristics and grazing behaviour and discusses the implications of canopy characteristics for short-term intake. The review is divided into two sections with the first part highlighting the influence of sward characteristics (sward height, forage mass and sward maturity) as a means of manipulating grazing behaviour of ruminants. The second part brought to fore the process of grazing, bite feature and short-term grazing trials. The review showed that cattle prefer short dense leafy swards compared to senescent plant materials. This is based on research results suggesting that short dense sward possess high quantity of green materials which is relished by ruminants during grazing. The feasibility of intensifying grazing studies in the tropics, particularly in Nigeria, to examine the behaviour of ruminants in highly heterogeneous pastures has the potential to provide integrated (sward, animal, management) strategies for sustainable livestock production in Nigeria.Key Words: Sward characteristics; Grazing behaviour; Intake rate; Sward height; Forage mass; Ruminants.

Choosing foods that require more time to consume and have a low energy density might constitute an effective strategy to control energy intake, because of their satiating capacity. The current study assessed the eating rate of Dutch food, and investigated the associations between eating rate and other food properties. We also explored the opportunities for a diet with a low energy intake rate (kJ/min). Laboratory data on the eating rate of 240 foods—representing the whole Dutch diet—was obtained. The results show a wide variation in both eating rate (from 2 g/min for rice waffle to 641 g/min for apple juice) and energy intake rate (from 0 kJ/min (0 kcal/min) for water to 1766 kJ/min (422 kcal/min) for chocolate milk). Eating rate was lower when foods were more solid. Moreover, eating rate was positively associated with water content and inversely with energy density. Energy intake rate differed substantially between and within food groups, demonstrating that the available foods provide opportunities for selecting alternatives with a lower energy intake rate. These findings offer guidance when selecting foods to reduce energy intake.

Accurate measurement of herbage intake rate is critical to advance knowledge of the ecology of grazing ruminants. This experiment tested the integration of behavioral and acoustic measurements of chewing and biting to estimate herbage dry matter intake (DMI) in dairy cows offered micro-swards of contrasting plant structure. Micro-swards constructed with plastic pots were offered to three lactating Holstein cows (608±24.9 kg of BW) in individual grazing sessions (n=48). Treatments were a factorial combination of two forage species (alfalfa and fescue) and two plant heights (tall=25±3.8 cm and short=12±1.9 cm) and were offered on a gradient of increasing herbage mass (10 to 30 pots) and number of bites (~10 to 40 bites). During each grazing session, sounds of biting and chewing were recorded with a wireless microphone placed on the cows? foreheads and a digital video camera to allow synchronized audio and video recordings. Dry matter intake rate was higher in tall alfalfa than in the other three treatments (32±1.6 v. 19±1.2 g/min). A high proportion of jaw movements in every grazing session (23 to 36%) were compound jaw movements (chew-bites) that appeared to be a key component of chewing and biting efficiency and of the ability of cows to regulate intake rate. Dry matter intake was accurately predicted based on easily observable behavioral and acoustic variables. Chewing sound energy measured as energy flux density (EFD) was linearly related to DMI, with 74% of EFD variation explained by DMI. Total chewing EFD, number of chew-bites and plant height (tall v. short) were the most important predictors of DMI. The best model explained 91% of the variation in DMI with a coefficient of variation of 17%. Ingestive sounds integrate valuable information to remotely monitor feeding behavior and predict DMI in grazing cows. Fil: Galli, Julio Ricardo. Universidad Nacional de Rosario; Argentina Fil: Cangiano, Carlos Alberto. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires; Argentina Fil: Pece, M. A.. Universidad Nacional de Rosario; Argentina Fil: Larripa, M. J.. Universidad Nacional de Rosario; Argentina Fil: Milone, Diego Humberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigación en Señales, Sistemas e Inteligencia Computacional. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas. Instituto de Investigación en Señales, Sistemas e Inteligencia Computacional; Argentina Fil: Utsumi, S. A.. Michigan State University; Estados Unidos Fil: Laca, E. A.. University of California at Davis; Estados Unidos

Workplace exposure to persistent organic pollut- ants is a concern for human health. This study examined the presence of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in the indoor dust from two major e-waste recycling sites and a university electronic equipment repair workshop in Durban, South Africa, in order to evaluate the implication of dust for occupational exposure. The mean ∑(n=8)PBDEs and ∑(n=3)PCBs were 20,094 and 235 ng g −1 , respectively. The levels of PBDEs and PCBs obtained in one of the recycling sites (123-27,530 and 161- 593 ng g −1 ) were significantly higher than the levels obtained (91-7686 and

Little is known about how to manage grazing horses, including the thresholds under which energy supplementation is required. Here we investigated the effects of daily herbage allowance (DHA) and energy supplementation (ES) on daily herbage intake in lactating mares of light breeds grazing high-quality regrowth during summer. Three contrasting DHA, low (LOW), medium (MED), and high (HIGH), that is, 35.0, 52.5, and 70.0 g DM∙kg BW(-1)∙d(-1), respectively, were obtained by adjusting pasture strip width. Eighteen Anglo-Arab and French Saddle lactating mares were either supplemented with 2.6 kg DM barley/d (SUP group; n= 9) or left nonsupplemented (NSUP group; n = 9) throughout the experiment. For 3 successive 2-wk periods, 3 groups of SUP mares (n = 3) and 3 groups of NSUP mares (n = 3) grazed each DHA according to a 3 × 3 Latin square design. Pregrazing sward surface height (SSH) was similar between treatments (26.6 cm), but postgrazing SSH differed significantly between each DHA (2.9, 4.4, and 5.7 cm for LOW, MED, and HIGH, respectively; P < 0.001). Herbage DMI (HDMI) increased linearly from 18.5 to 23.4 g DM∙kg BW(-1)∙d(-1) with increasing DHA (i.e., 0.13 kg DM eaten/kg DM of herbage offered; P < 0.001) independently of ES and with no significant ES × DHA interaction. This increase in HDMI resulted from an increase in grazing time between LOW (961 min/d) and MED and HIGH (1,021 min/d; P < 0.01) and from an increase in intake rate between LOW and MED (11.8 g DM/min) and HIGH (13.6 g DM/min; P < 0.01). Total digestible DMI (TDDMI) and NE intake (NEI) increased linearly from 12.3 to 15.2 g DM∙kg BW∙(-1)d(-1) and from 136.6 to 165.8 kJ∙kg BW(-1)∙d (-1)with increasing DHA (P < 0.001), respectively. Total digestible DMI and NEI were significantly lower for NSUP than for SUP mares: 12.5 vs. 14.9 g DM∙kg BW(-1)∙d(-1) (P < 0.01) and 134.6 vs. 166.5 kJ∙kg BW(-1)∙d(-1) (P < 0.001), respectively. Whereas SUP mares always met their energy requirements, NSUP mares no longer met theirs when DHA fell below 66 g DM∙kg BW(-1)∙d(-1) (i.e., 39 kg DM∙mare(-1)∙d(-1)).

Animals gain benefits from group living through increased probability of predator detection, dilution of individual risk and confusion of predators during attack. A further benefit involves larger groups in which individuals may further decrease the amount of time spent being vigilant, while maintaining the probability of predator detection by allocation of this extra time to foraging activities. Living in groups or flocks, however, also incurs costs, e.g., by increasing inter-group competition, with negative impacts on intake rates. Our aim was to investigate the trade-offs between the costs of competition and the benefits of group living in contrasted habitats. For prey species that rely on sight for detecting predators, vegetation structure may influence the perceived predation risk. Hence, we experimentally examined the combined effects of vegetation height and inter-individual distance on foraging time, intake rate and foraging efficiency in a granivorous species, the Eurasian Skylark (Alauda arvensis). Our experimental results based on temporally captive birds indicate that time devoted to foraging decreased with increasing inter-individual distance, but was unrelated to cover height. Conversely, increasing both vegetation height and distance with other group members did translate into a foraging disadvantage, i.e. reduced intake rate as well as foraging efficiency. Overall, our results show that both vegetation structure and inter-individual distances modify patch profitability, and therefore provide another example of how flock dynamics can influence the trade-off between vigilance and foraging.

An indoor and a grazing experiment was conducted to determine how estimated feed intake and digestion by grazing goats consuming concentrate, bahaigrass pasture, and mimosa browse changed with body weight (BW), level of supplementation, and forage chemical composition. Twenty four Boer wether goats were assigned in a completely randomized design with repeated measures on the following 3 treatments: concentrate, mimosa browse, and bahiagrass pasture. Internal markers used to estimate both dry matter (DM) digestibility (DMD) and DM intake (DMI) included acid detergent lignin (ADL) and acid insoluble ash (AIA). Marker-derived estimates of DMD and DMI were compared with DMD measured by total fecal collection or directly measured by in vivo feed intake rate. Both ADL and AIA-based markers in mimosa and bahiagrass diets were similar from those derived by in vivo DMD; however, AIA-based marker in concentrate was under-estimated (P < 0.01). These results indicate that ADL and AIA indigestible markers performed similarly to in vivo DMD in mimosa and bahiagrass, although AIA concentration in mimosa seemed to be low compared to others. All markers yielded feed intake estimates that differed from those derived by ADL (P < 0.03), AIA (P < 0.01), and in vitro DMD (P < 0.001) compared to in vivo control, with ADL (P < 0.05) and in vitro DMD (P < 0.01) by period interactions, indicating that estimated intake from ADL and in vitro DMD increased more in mimosa browse diet with time period than in concentrate and bahiagrass diets with that estimated intakes being decreased with corresponding the second period due to lower in vitro DMD (21% to 4%) in second period compared to the first period in both concentrate and bahiagrass diets, respectively. In the present study, mean marker recoveries were higher (P < 0.01) for bahiagrass and mimosa diets than for the concentrate diets for both ADL- and AIA-based markers. It can be concluded that the use of natural markers in ADL and AIA offers advantages over the total fecal collection or direct measurement of in vivo intake methods for digestibility studies. Both ADL and AIA occur in common forages at readily measurable levels and laboratory procedures are not difficult or time consuming. Therefore, both ADL and AIA have possible use in digestibility studies where other methods may not be applicable.

Intake pattern of macronutrients (protein, lipid, carbohydrate) and socioeconomic status (SES) are major causes of high child and adolescent overweight and obesity prevalences in Mexico. An evaluation was done of the relationship between body mass index (BMI)-based nutritional status and body composition (BC), macronutrient intake rates (MIR) and SES indicators in 127 boys and 156 girls aged 12 to 16 years attending schools in Merida, Mexico. Anthropometric variables included height, weight, and BMI. The BC (body fat mass, fat-free mass, dry lean mass) was estimated by bioelectrical impedance (Bodystat 1500 MDD). The MIR were estimated following FAO/WHO/UNO standard (1985). Proxy socioeconomic indicators included parents' age (as a maturity indicator) and education, fathers' occupation, school type and monthly household food expenditure per capita. Excess weight (overweight + obesity) assessed by BMI, was higher in boys (40.16 %) than in girls (33.97 %). Boys had higher BMI, less fat mass and higher fat-free mass than girls. The MIR did not vary significantly in response to age, sex, BC or SES. Participants with higher SES were taller and heavier, had higher fat-free mass and lower fat mass. In the studied adolescents, anthropometric and BC values, and overweight and obesity rates were more associated with SES than MIR.

Water accounts for about 60% of the human body, and when the body loses it (e.g., through urine, sweat, etc.) in higher rate than its intake rate (through drinking), dehydration symptoms occur. The dehydration causes many severe health problems like organ and cognitive impairment. Therefore, it is critical for the human to drink water in a sustained manner to avoid dehydration. To prevent humans from dehydration, continuous day-scale tracking of the water intake is needed. In this paper, we propose an unobtrusive method to recognize the drinking activity as well as estimate the water intake amount in milliliter scale by leveraging smartwatches. Our basic idea is to track the arm motion and discriminate the drinking activities from the similar hand-based motions like food intake, phone calls, etc. Thereafter, we estimate the water intake amount from the drinking duration.

The objective of this study was to examine the effect of wintering pregnant, nonlactating dairy cows outdoors on either kale or grass, fed in 1 [11 kg dry matter (DM) of kale or grass + 3 kg DM of baled barley straw offered in the morning] or 2 allocations (5.5 kg DM of kale or grass grazed + 1.5 kg DM of barley straw offered morning and afternoon) per day. The body condition score (BCS) gain over the 47-d winter feeding period was higher for grass-fed (0.5 BCS units) than kale-fed cows (0.3 BCS units), but was unaffected by feeding frequency. Forage DM utilization was higher for kale-fed (97%) than grass-fed cows (76%), leading to higher estimated dry matter intake (DMI) in kale-fed (10.7 kg of DM/cow per day) than grass-fed cows (7.7 kg of DM/cow per day). Forage DM utilization and estimated DMI were not affected by feeding frequency. Prehension bite rate was greater for grass-fed (37.3 bites/min) than kale-fed cows (7.6 bites/min), but more mastication bites were required for kale-fed cows. Cumulative DMI after 2, 3, and 6 h was greater in cows allocated forage once than twice a day and for kale than grass after 3 and 6 h. Mean eating time was greater for cows offered forage once (477 min) than twice (414 min) per day. In conclusion, increasing feeding frequency from once to twice per day decreased the intake rate within the first 6 h after allocation, but did not affect total daily DMI, DM utilization or BCS gain. Thus, moving cows more frequently would not have any significant advantage. It may increase labor requirements, thereby creating a more challenging wintering management than feeding once per day.

Summary 1.Animals frequently exhibit consistent among-individual differences in behavioural and physiological traits that are inherently flexible. Why should individuals differ consistently in their expression of labile traits? Recently, positive feedbacks between state and behaviour have been proposed as a possible explanation for the maintenance of consistent among-individual differences in both state and behaviour. If state affects behaviour, and behaviour reciprocally affects state, then differences in either state or behaviour that arise among-individuals even by chance could be maintained over extended periods of time. 2.We tested for positive feedbacks experimentally using wild-caught red knots (Calidris canutus islandica). In the wild, knots exhibit consistent among-individual differences in digestive physiology (the mass of the muscular part of the stomach, the gizzard) and foraging behaviour (diet), two inherently labile traits. 3.Experimentally manipulated diet quality had a large effect on gizzard mass. Experimentally manipulated gizzard mass reciprocally influenced total food eaten during ad libitum trials. 4.The effect of gizzard mass on diet choice, though in the predicted direction, was not statistically significant. Individuals exhibited consistent differences in foraging behaviour of unknown origin independent of current gizzard mass, as well as large residual unexplained variance in foraging behaviour. These two sources of variation in foraging behaviour overruled the gizzard mass-dependent foraging behaviour and hence eroded the treatment-related differences in gizzard mass. 5.We conclude that positive feedbacks between diet choice and gizzard mass play at best a limited role in maintaining among-individual variation in gizzard mass in red knots. Furthermore, we suggest that many models of state-behaviour feedbacks likely overestimate their potential importance in maintaining long-term among-individual variation in labile traits because most models of state-behaviour feedbacks fail to account for the effects of additional factors that may act to disrupt the feedback loops. 6.The among-individual differences in diet choice observed during solitary foraging trials eroded the consistent among-individual differences in gizzard mass observed following periods of staple diet treatments in which knots foraged in social groups. Social foraging interactions may play an important role determining the expression of foraging behaviours such as intake rate that in turn influence gizzard mass. Further studies are needed to experimentally test the role of social interactions as a mechanism generating consistent among-individual differences in foraging behaviours and gizzard mass. This article is protected by copyright. All rights reserved.

Objective: To understand the effect of prevention and control of iodine deficiency disorders with iodized salt in Akto County, Xinjiang, China, to provide a scientific basis for formulating effective method of prevention. Methods: Sampling survey was conducted in Akto County in 2004, according to National Key Survey Scheme in High-risk Areas. Results: The median of the iodized salt was 32.8 mg/kg in 2004, with intake rate of qualified iodized salt of 100% in the residents. Goiter rate of the children was 22.0% by palpation, and 10.0% by B-ultrasound, with the coincidence rate of 66.8%. Compared with those in 2014, there were statistical differences (P

PURPOSE The use of dietary supplements (DS) has increased in most nations. We investigated the amount of DS intake in the Korean population by analyzing a national survey, to support the preparation of a national institutional strategy regarding DS intake and marketing. METHODS The data of the fifth Korea National Health and Nutrition Examination Survey (a year between 2010 and 2012) were investigated, analyzing the rate of DS intake, and the characteristics of the intake group and non-intake group in Korean preschool children. RESULTS The intake rate of DS was 49.0-54.2% (1,313,874-1,491,240) and 19.6-30.3% (250,603-421,922) in children from 1 to 6 years old and in those less than 1 year, respectively, from 2010 to 2012. The highest intake rate was observed in the age group of five. The mean age was significantly higher in the DS intake group than in the non-intake group. Intake of essential nutrients, minerals, and vitamins were also higher in the DS intake group. The level of family income was significantly associated with the intake rate (p

This study proposes an environmental- and health-risk-induced remediation design approach for benzene-contaminated groundwater. It involves exposure frequency and intake rates that are important but difficult to be exactly quantified as breakthrough point. Flexible health-risk control is considered in the simulation and optimization work. The proposed approach is then applied to a petroleum-contaminated site in western Canada. Different situations about remediation durations, public concerns, and satisfactory degrees are addressed by the approach. The relationship between environmental standards and health-risk limits is analyzed, in association with their effect on remediation costs. Insights of three uncertain factors (i.e. exposure frequency, intake rate and health-risk threshold) for the remediation system are also explored, on a basis of understanding their impacts on health risk as well as their importance order. The case study results show that (1) nature attenuation plays a more important role in long-term remediation scheme than the pump-and-treat system; (2) carcinogenic risks have greater impact on total pumping rates than environmental standards for long-term remediation; (3) intake rates are the second important factor affecting the remediation system's performance, followed by exposure frequency; (4) the 10-year remediation scheme is the most robust choice when environmental and health-risk concerns are not well quantified.

The history of the idea that predation rates are functions of the ratio of prey density to predator density, known as ratio dependence, is reviewed and updated. When the term was introduced in 1989, it was already known that higher predator abundance often reduced an individual predator's average intake rate of prey. However, the idea that this effect was a universally applicable inverse proportionality was new. That idea was widely criticized in many articles in the early 1990s, and many of these criticisms have never been addressed. Nevertheless, ratio dependence seems to be gaining in popularity and is the subject of a recent monograph by the originators. This article revisits the most important objections to this theory, and assesses to what extent they have been answered by the theory's proponents. In this process, several new objections are raised. The counterarguments begin with the lack of a plausible, generally applicable mechanism that could produce ratio dependence. They include the fact that ratio dependence is a special case of predator-density effects, which, in turn, are only one of many non-prey species effects that influence the consumption rate of a particular prey. The proclaimed simplicity advantage of ratio dependence is at best small and is outweighed by its disadvantages; it predicts biologically implausible phenomena, and cannot easily be extended to describe multi-species systems, trait-mediated interactions, coevolution, and a number of other important ecological phenomena. Any potential small simplicity advantage disappears with corrections to remove unrealistic low-density dynamics caused by ratio dependence. The frequent occurrence of strong predator dependence does not make ratio dependence a better ‘default’ model of predation than prey dependence, and empirical studies of the full range of non-prey species effects on the consumption rates of predators are needed.

The purpose of this study was to establish food ingestion factors needed to assess exposure to contaminants through food ingestion. The study reclassified the raw data of the Korean National Health and Nutrition Examination Survey in 2001 into 12 subcategories including grain products, meat products, fish and shellfish, and vegetables for international comparability of exposure evaluation. The criteria for food intake calculation were unified according to the characteristics of food groups, and recommended values for food ingestion factors were calculated through moisture correction and recategorization of cooked, processed, and mixed foods for each group. The average intake rate for grain and grain products was 6.25 g/kg-d per capita and the men's intake rate was approximately 8% higher than that of the women. The average intake rate of meat and meat products was 1.62 g/kg-d per capita and the men's intake rate was 30% higher than that of the women, on average. The average intake rate of fish and shellfish was 1.53 g/kg-d per capita, and the age groups of 1 to 2 and 3 to 6 recorded higher capita intake rates than other age groups, 2.62 g/kg-d and 2.25 g/kg-d, respectively. The average intake rate of vegetables was 6.47 g/kg-d per capita, with the age group of 1 to 2 recording the highest per capita intake rate of 9.79 g/kg-d and that of 13 to 19 recording the lowest mean. The study also offers recommended values for food ingestion factors of other food groups by gender, age, and region. The food ingestion exposure factors will need future updates in consideration of ongoing changes in food consumption behavior.

This study focuses on the spatial-temporal dynamics of predator–prey model with cross-diffusion where the intake rate of prey is per capita predator according to ratio-dependent functional response and the prey is harvested through nonlinear harvesting strategy. The permanence analysis and local stability analysis of the proposed model without cross-diffusion are analyzed. We derive the conditions for the appearance of diffusion-driven instability and global stability of the considered model. Also the parameter space for Turing region is specified by keeping the cross-diffusion coefficient as one of the crucial parameters. Numerical simulations are given to justify the proposed theoretical results and to show that the cross-diffusion term plays a significant role in the pattern formation.

The objective of this study was to investigate the feeding and ingestive behaviours of sheep and goats grazing on grass-legume pastures. Three 2-year female Nguni x Boer goats and three 3-year female Damara sheep were randomly allocated to grass-Lespedeza cuneata (grass-Lc) and grass-Leucaena leucocephala (grass-Ll) pastures. Times spent on browsing, grazing and idling were recorded from 0700 to 1600 h every 2 minutes for 3 consecutive days. Ingestive behaviour of each animal was observed for 10 minutes at 1000, 1200 and 1400 h for 6 days. Bite count and bite weight were used to determine intake rates during browsing. Goats spent 3.24 and 3.93 times longer than sheep in browsing, while sheep spent 2.75 and 2.27 times longer in grazing than goats on grass-Lc than grass-Ll pastures, respectively. Goats idled for longer periods than sheep on both pastures. Sheep had faster bite rates than goats, while Lespedeza cuneata elicited lower bite rates than L. leucocephala. Fastest feeding and bite rates were observed at mid day (1200 h) and lowest during the afternoon (1400 h). Intake rates of fresh herbage are higher at mid day than in the morning and afternoon. In conclusion, based on time spent browsing, L. leucocephala is better preferred as a forage browse compared to L. cuneata.

Javan gibbons consume different foods to fulfil their nutrient requirement. We analyzed foods eaten by Javan gibbons for their nutrient content in Citalahab area, Gunung Halimun-Salak National Park (GHSNP), Indonesia. The goal was to assess amounts of water content, ash, crude fats, crude protein, crude fibers, carbohydrate and gross energy to determine whether there was nutritional variation between foods eaten by females and males. A total 43 food plant parts representing 33 plant species were collected, processed and analyzed. Females and males in Javan gibbons have similar diets with regard to overall composition. Nutrient analyses revealed high water content, ash and crude protein in young leaves; flowers and ripe fruits contained the most carbohydrate; crude fats content was highest in unripe fruits; ripe fruits were rich in crude fibers and gross energy content was high in all the main plant foods. Individual exhibit higher intake of certain nutrients by increasing feeding intake rate seems to be the key to greater nutrient intake in individual. This data adds our knowledge about nutritional composition of foods eaten by Javan gibbons and provides valuable comparative data for optimizing the diets of Javan gibbons ex situ.

Residual feed intake (RFI) is commonly used as a measure of feed efficiency at a given level of production. A total of 16,872 pigs with their pedigree traced back as far as possible was used to estimate genetic parameters for RFI, growth performance, food conversion ratio (FCR), body conformation, and feeding behavior traits in 3 Danish breeds [Duroc (DD), Landrace (LL), and Yorkshire (YY)]. Two measures of RFI were considered: residual feed intake 1 (RFI1) was calculated based on regression of daily feed intake (DFI) from 30 to 100 kg on initial test weight and ADG from 30 to 100 kg (ADG2). Residual feed intake 2 (RFI2) was as RFI1, except it was also regressed with respect to backfat (BF). The estimated heritabilities for RFI1 and RFI2 were 0.34 and 0.38 in DD, 0.34 and 0.36 in LL, and 0.39 and 0.40 in YY, respectively. The heritabilities ranged from 0.32 (DD) to 0.54 (LL) for ADG2, from 0.54 (DD) to 0.67 (LL) for BF, and from 0.13 (DD) to 0.19 (YY) for body conformation. Feeding behavior traits including DFI, number of visits to feeder per day (NVD), total time spent eating per day (TPD), feed intake rate (FR), feed intake per visit (FPV), and time spent eating per visit (TPV) were moderately to highly heritable. Residual feed intake 2 was genetically independent of ADG2 and BF in all breeds, except it had low genetic correlation to ADG2 in YY (0.2). Residual feed intake 1 was also genetically independent of ADG2 in DD and LL. Both RFI traits had strong genetic correlations with DFI (0.85 to 0.96) and FCR (0.76 to 0.99). They had low or no genetic correlations with feeding behavior traits. Unfavorable genetic correlations were found between ADG2 and both BF and DFI. Among feeding behavior traits, DFI had low genetic correlations to other traits in all breeds. High and negative genetic correlations were also found between TPD with FR (-0.79 in YY to -0.88 in DD), NVD, and TPD (-0.91 in DD to -0.94 in YY) and between NVD and FPV (-0.83 in DD to -0.91 in YY) in all breeds. The genetic trend for feed efficiency was favorable in all breeds regardless of the definition of feed efficiency used. In summary, RFI1 and RFI2 were heritable and selection for reduced RFI2 can be performed without adversely affecting ADG and BF and could replace FCR in the selection index for the Danish pig breeds. Selection could also be based on RFI1 for breeds with fewer concerns about a negative effect of BF or for breeds that do not have BF records.

Aim To examine the effects of “Comfort upon Rising” care (CUR) as a new type of early morning care. Methods This was a quasi-experimental study using a convenience sampling and non-random assignment of 80 orthopedic postoperative inpatients needing ambulation assistance. The intervention group of 40 inpatients was given CUR designed to support the patients' needs. The control group of 40 inpatients was given conventional early morning care (CMC). Floor nurses conducted either CMC or CUR for subjects beginning the morning after surgery and continuing for 3 days. Mood was measured by the Wake-up Questionnaire (question I) and Profile of Mood States (POMS). Morning activities, which were daily living activities, breakfast behaviors including breakfast intake rate, were measured by Wake-up Questionnaire (question IV) and observation. Results Completing the study were 36 patients from the control group and 36 patients from the intervention group. Mood and activities in the morning were improved in the CUR group. Conclusion CUR is a patient-centered care based on patients' individual needs and promotes self-care. CUR is more effective than CMC in promoting natural recovery after an operation.

Capsule Context-specific equations are needed to reconstruct diet composition and intake rate of Red Knots by the use of shell fragments retrieved from droppings.Aims To explore whether the method to reconstruct Red Knot diet described by Dekinga & Piersma [Dekinga, A. & Piersma, T. 1993. Reconstructing diet composition on the basis of faeces in a mollusc-eating wader, the Knot Calidris canutus. Bird Study 40: 144-156] accurately predicts the diet of Red Knots Calidris canutus canutus outside Northwest Europe, at Banc d'Arguin, Mauritania.Methods Feeding experiments with captive Red Knots on the bivalves Dosinia isocardia or Loripes lucinalis were carried out at Banc d'Arguin, the main wintering area of Red Knot subspecies C. c. canutus. Ingested diets were compared with the reconstructed diets derived from the general method developed by Dekinga & Piersma (1993). Droppings collected over multiple years were also analysed to evaluate the calibration method from this study.Results Of the total ingested shell mass (DMshell) in both bivalves, approximately 65% of the shell mass was retrieved in the droppings (DMdrop). Therefore, dry mass of droppings in the field (DMdrop) has to be multiplied by 1.547 to calculate the ingested dry mass (DMshell). For size estimations of ingested shells from droppings, hinges should be used for D. isocardia and hinges including tops for L. lucinalis.Conclusion The correction factor of 1.547 found here is 50% larger than the factor 0.993 for heterodont bivalves from Europe established by Dekinga & Piersma (1993). Application of the published factor would lead to serious underestimation of energy intake rates based on dropping frequencies and dropping content (by as much as 35%), although it would have small effects on the relative species composition of the diet. Having shown that such correction factors can differ among sites and prey we recommend their determination in new ecological contexts.

The present study examined effects of production performance, immune activity and egg quality by raising on exercise yard in laying Hens, the results of which could be used as baseline data to enhance animal welfare and the safety of livestock products. A total of 90 Hy-line-Brown laying hens of 13 weeks old were used in the experiment for 38 weeks. The cage group (Cage group) was raised in a cage, where an area of was assigned to two hens, while hens in the exercise yard group ( group) was assigned to a combination of a chicken house () and a exercise yard () per a hen. Hens in the exercise yard group ( group) was assigned to a combination of a chicken house () and a exercise yard () per a hen. Treatment was replicated 3 times with ten birds per replication. Ten birds were arranged according to randomized block design. While initial egg production rate was significantly higher in the Cage group, group exhibited a slightly higher rate in the mid- and late-stage of the experiment, although the difference was not statistically significant. Exercise yard treatment groups exhibited a higher feed intake rate than the Cage group up until the hens were 39 weeks old (P

Eight mature horses were used in a 4 × 4 Latin square design to determine the effect of restricted pasture access on dry matter intake rate (DMIR), energy intake, and fecal pH. Horses were randomly assigned to one of four groups (HGRPs), each containing two horses. HGRPs were randomly assigned to one of four treatments consisting of 3, 6, 9, or 24 hours of pasture access, for a period of 7 days. Treatments were switched every 7 days. The 3- and 6-hour groups were fed free choice mature grass hay while not grazing. Daily pasture dry matter intake (DMI) for each HGRP was estimated by calculating the difference between initial herbage mass of the grazing cell before grazing and residual herbage mass after 7 days of grazing. Total dry matter intake was the sum of pasture and hay DMI for the 3- and 6-hour treatments. Fecal pH was measured on day 7 of each period. Response variables were analyzed using analysis of variance for Latin square design. Restricting pasture access decreased mean pasture DMI (P = .02), pasture dietary energy (DE) (P = .02), and fecal pH (P

Avaliaram-se os efeitos da estratégia de pastoreio rotacionado sobre a dinâmica do rebaixamento do milheto (Pennisetum glaucum (L.) R. Br.) pastejado por vacas leiteiras. Os tratamentos consistiram de um fatorial entre duas alturas pré-pastejo, 60 e 40cm, e duas pós-pastejo, 20 e 10cm, alocados em um delineamento em blocos ao acaso com quatro repetições. A estrutura do pasto foi avaliada durante o processo de pastejo a cada 10 minutos, por meio de medições de altura. A taxa de rebaixamento da altura do pasto no tratamento 40-20 apresentou-se relativamente constante ao longo de todo o rebaixamento. O tratamento 60-10 apresentou o maior declínio na taxa de rebaixamento. A taxa de rebaixamento no tratamento 40-10 diminuiu em ritmo mais lento em relação à dos tratamentos com 60cm de altura pré-pastejo. As maiores taxas de ingestão foram observadas nos tratamentos de altura pré-pastejo de 60cm, e considerou-se como a melhor estratégia de manejo a combinação 60-20cm de altura do pasto. This study aimed to evaluate the effects of rotational grazing strategies on the dynamics of the grazing pastures of millet (Pennisetum glaucum (L.) R. Br.) grazed by dairy cows. Treatments consisted of two pre-grazing heights (60 and 40cm) and two post-grazing heights (20 and 10cm) allocated in a randomized block design with four replications. The sward height was evaluated during grazing every 10 minutes. The rate of grazing down of the sward height of the pasture on the 40-20 grazing strategy was relatively constant throughout the grazing down. Treatment 60-10 showed the largest decline in the rate of grazing down. The rate of grazing down in the 40-10 treatment decreased with a slower intensity when compared to the treatments with 60cm of pre-grazing sward height. The major intake rates were observed in treatments with pre-grazing sward height of 60cm. The best management strategy was considered the combination of 60-20cm of sward height.

Digestive capabilities of nectar-feeding vertebrates to assimilate sugars affect their ability to acquire and store energy and could determine the minimal temperatures at which these animals can survive. Here, we described the sugar digestive capability of Leptonycteris nivalis and related it with its capacity to live in cold environments. We measured the enzymatic activity, food intake rate and changes in body mass of bats feeding at four different sucrose concentrations (from 5 to 35% wt./vol.). Additionally, we used a mathematical model to predict food intake and compared it with the food intake of bats. L. nivalis was able to obtain ~ 111.3 kJ of energy regardless of the sugar concentration of their food. Also, bats gained ~ 2.57 g of mass during the experimental trials and this gain was independent of sugar concentration. The affinity (1 / K m ) of sucrase (EC 3.2.1.48) was one order of magnitude higher relative to that reported for its sister species Leptonycteris yerbabuenae (0.250 and 0.0189 mmol − 1 L, respectively), allowing this species to have a higher energy intake rate. We propose that the high ability to acquire energy conferred L. nivalis the faculty to invade cold environments, avoiding in this way the ecological competition with its sympatric species L. yerbabuenae .

Feed intake behavior was studied between 9 weeks of age and slaughter in a total of 36 gilts, 32 immunocastrates, 33 surgically castrated barrows and 33 boars from 36 litters. Consequences for the concentration of substances contributing to off odor of pork (skatole, indole) were evaluated. Animals were kept in groups of 12 pigs of the same sex and treatment and fed ad libitum (13.4 MJ ME, 17% CP, 1.1% lysine). Individual feed intake behavior was recorded continuously by an electronic feeder. Immunocastration was carried out with two injections of Improvac with at least 4 weeks between both injections (1st: 12 to 17 weeks of age, 2nd: 19 to 21 weeks of age). Feed intake/day increased from an average of 0.91 ± 0.02 kg/day up to 3.15 ± 0.04 kg/day before slaughter. This increase was associated with a 50% reduction in the number of meals/day (from 15.8 ± 0.44 to 7.2 ± 0.29 meals/day). The larger meal sizes resulted from an increase in both, the duration of feed intake/meal and the feed intake rate (g/min). In addition, sex and treatment differences were observed: Feed intake in boars was lower than in all other groups due to a reduction in the number of meals/day and in the time spent feeding/day. In females, time spent feeding/day was quite similar to boars, but resulted from a higher number of meals of shorter duration. Barrows had a significantly higher feed intake because of a higher number of meals/day resulting in more time spent feeding/day. The feed intake rate was similar in boars, gilts and barrows and showed an increasing trend during the study, starting from about 15 g/min up to four times the amount. Immunocastration affected feed intake behavior severely, especially the meal size increased dramatically because of higher feed intake rate, which exceeded that of all other groups by 25% at the end of the study. The number of meals/day was not influenced by immunocastration and was almost identical to that of boars. Highest skatole concentrations were measured in fat of boars, whereas indole concentrations were higher in immunocastrates than in all other groups. In gilts and barrows, skatole concentrations were related to growth rate. Additionally, the feeding rate was an important factor explaining the variability in skatole/indole concentrations in adipose tissue. The physiological mechanisms however need further clarification.

The purpose of this study is to compare the clearance rate (CR) and intake rate (IR) of juvenile purple clam, Saxidomus purpuratus when feeding on different unialgal diet of red tide dinoflagellates (RTDs), and to know what is the most important cell characteristic of RTDs to cause the differences in feeding parameters. Experiments were performed to measure the CR and IR of juvenile S. purpuratus as a function of algal concentration when food was either the standard food, Isochrysis galbana or one of 9 RTDs. Patterns of CR with increasing algal concentration were similar among different RTDs. The highest Cmax was observed when S. purpuratus was feeding on A. affine, while the lowest on C. polykrikoides. The patterns of IR with increasing algal concentration were also similar among different RTDs. However, there were great differences in the maximum value of IR (Imax) among different RTDs. The highest Imax was observed when S. purpuratus was feeding on A. carterae, while the lowest on G. catenatum. Some RTDs similar in size showed different Cmax. Other RTDs different in size showed similar Imax. Life form of each RTD affected significantly the Imax, which was higher for single-celled RTDs than chain-forming RTDs. There were no significant differences in feeding parameters between toxic and nontoxic RTDs. Moreover, a toxic dinoflagellate, A. carterae recorded the highest Imax among RTDs. The most important characteristic of RTD as a factor affecting the feeding rate of S. purpuratus was life form, not size or toxicity of RTD species.

We present the results of a combined experimental and theoretical investigation of the dynamics of drinking in ruby-throated hummingbirds. In vivo observations reveal elastocapillary deformation of the hummingbird's tongue and capillary suction along its length. By developing a theoretical model for the hummingbird's drinking process, we investigate how the elastocapillarity affects the energy intake rate of the bird and how its open tongue geometry reduces resistance to nectar uptake. We note that the tongue flexibility is beneficial for accessing, transporting and unloading the nectar. We demonstrate that the hummingbird can attain the fastest nectar uptake when its tongue is roughly semicircular. Finally, we assess the relative importance of capillary suction and a recently proposed fluid trapping mechanism, and conclude that the former is important in many natural settings.

It has been suggested that goats with browsing experience might not affect their preference and fodder intake by the tannins contained in tropical browse. To test this hypothesis, polyethylene glycol (PEG 3600 MW), a tannin blocking agent, was used in cafeteria trials employing browses commonly available in their diet. The selectivity (SI), preference and intake rate (IR) as well as the effects of plant density, chemical composition (including tannin content) and PEG supplementation were assessed. Goats showed a low SI, explained as a behavioral adaptation in a tannin rich environment. PEG administration had no effect on the goats' preference or IR. The IR seemed affected by plant densities. Also, fiber components had higher associations with DM intake than the polyphenolic compounds at the levels found in the evaluated forages. It was concluded that tannins and PEG did not modify goats' preference in cafeteria trials. Hence, tannins have a limited involvement in short term preference regulation of goats ...

As a foundation for understanding the diet of African savanna elephants (Loxodonta africana), adult bulls and cows were observed over an annual cycle to determine whether harvesting (Pt), chewing (Ct) and handling times (Ht) differed across food types and harvesting methods (handling time is defined as the time to harvest, chew and swallow a trunkload of food). Bulls and cows were observed 105 and 26 times, respectively (94 and 26 individuals), with a total of 64 h of feeding recorded across 32 vegetation types. Some food types took longer to harvest and chew than others, which may influence intake rate and affect choice of diet. The method used to gather a trunkload of food had a significant effect on harvesting time, with simple foraging actions being comparatively rapid and more difficult tasks taking longer. Handling time was constrained by chewing for bulls, except for the processing of roots from woody plants, which was limited by harvesting. Time to gather a trunkload had a greater influence on handling time for cows compared to bulls. Harvesting and handling times were longer for bulls than cows, with the sexes adopting foraging behaviors that best suited their energy requirements.

A joint data analysis was performed to characterize forage intake rate and patterns of use of time by grazing heifers in cold season pastures. Heifers received or not energetic supplementation at different phenological stages of grasses (vegetative, pre-flowering and flowering). Experiments involved 360 heifers with initial age of eight months and average body weight of 145 ± 17 kg, on continuous grazing method and variable number of animals. Supplementaed heifers consumed 17.0% less forage and 22.2% less leaf blades than heifers exclusively on pasture. Grazing activity was concentrated in the afternoon shift, regardless of the feeding system and phenological stages evaluated, with the longest event of rumination during the night. Forage intake rate is similar, regardless of supplement intake and phenological stages of grasses. RESUMO Foi realizada uma análise conjunta de dados, com o objetivo de caracterizar a taxa de ingestão de forragem e os padrões de uso do tempo por novilhas em pastejo de forrageiras de estação fria. Essas novilhas recebiam ou não suplemento energético nos diferentes estádios fenológicos do pasto (vegetativo, pré-florescimento e florescimento). Os experimentos envolveram 360 novilhas, com idade inicial de oito meses e peso corporal médio de 145 ± 17 kg. O método de pastejo foi o de lotação contínua, com número variável de animais. Novilhas recebendo suplemento consumiram 17,0% a menos de forragem e 22,2% a menos de lâminas foliares que as novilhas exclusivamente em pastejo. A atividade de pastejo foi concentrada no turno da tarde, independente do sistema alimentar e dos estádios fenológicos avaliados, e no turno da noite acontece o evento mais longo de ruminação. A taxa de ingestão de forragem é semelhante, independente do consumo de suplemento e dos estádios fenológicos dos pastos.

Tese de doutoramento em Biociências, no ramo de especialização em Ecologia, apresentada à Faculdade de Ciências e Tecnologia da Universidade de Coimbra As zonas húmidas intertidais são habitats altamente produtivos e suportam milhares de aves aquáticas em todo o mundo, contudo são também um dos habitats mais ameaçados. A perda de habitats intertidais é considerada um dos principais factores que contribui para o actual declínio da maioria das populações de aves aquáticas. Globalmente, os habitats artificiais supratidais como as salinas costeiras podem funcionar como zonas tampão contra a perda de habitats costeiros naturais. Quando as zonas intertidais deixam de estar disponíveis devido à subida da maré, as aves são impelidas a voar para refúgios supratidais, onde permanecem até os locais de alimentação intertidais voltarem a ficar acessíveis. As salinas costeiras são habitats antropogénicos explorados para produção de sal. Ao contrário das zonas húmidas, a gestão dos níveis de água permite que o nível da água e a salinidade nos tanques das salinas sejam estáveis. A gestão adequada dos níveis de água, bem como o controlo da expansão da vegetação halófita são importantes para que as aves limícolas ocorram nas salinas. A diferente salinidade e hidrodinamismo nos tanques permitem o desenvolvimento de elevadas densidades de invertebrados bentónicos que constituem um importante recurso alimentar para as aves limícolas. A reduzida cobertura vegetal nos cômoros que delimitam os tanques das salinas permite a nidificação de algumas espécies de aves limícolas. As crias destas aves, mantêm-se restritas às águas salinas até serem voadoras e devem possuir adaptações fisiológicas ou comportamentais que lhes permitam lidar com a salinidade do habitat. Esta tese avaliou as vantagens e desvantagens das salinas como habitat de alimentação e de nidificação para aves aquáticas. No capítulo I avaliámos a potencialidade dos viveiros das salinas como zona de alimentação complementar para aves limícolas migradoras. A elevada densidade e biomassa de invertebrados bentónicos decresceu rapidamente após a exposição do sedimento. Demonstrámos que os viveiros podem acolher elevados números de aves limícolas em alimentação por um período reduzido. A desidratação do sedimento foi o factor mais preponderante para o declínio da comunidade bentónica no tanque. A dominância do poliqueta Capitella capitata pareceu ser responsável pela atracção de um elevado número de borrelhos-grande-coleira Charadrius hiaticula e ainda pela sua elevada taxa de alimentação. Algumas espécies de aves limícolas conseguiram garantir as suas necessidades diárias de biomassa e ganhar peso exclusivamente ou maioritariamente no tanque experimental. No capítulo II analisámos os efeitos da suspensão das acções de gestão num refúgio de preia-mar, por um período de um ano, nas populações de aves aquáticas através do desenho experimental pré-pós-controlo-impacte. A suspensão das acções de gestão por um ano, acarretaram um elevado efeito negativo para as populações de aves limícolas de pequena e média dimensão. A densidade dos diferentes grupos de aves recuperou de forma diferenciada. No capítulo III estudámos o papel que as características do local de nidificação, a predação e a nidificação na proximidade de espécies reprodutoras com comportamento anti-predatório agressivo, têm no sucesso reprodutor do borrelho-de-coleira-interrompida Charadrius alexandrinus. Os nossos resultados demostram que o sucesso reprodutor dos borrelhos nas salinas foi semelhante ao registado em habitats naturais. Os borrelhos seleccionaram os limites dos cômoros como local de nidificação. Nas salinas a predação foi o principal factor para destruição das posturas (42%). Nidificando na proximidade de pernilongos Himantopus himantopus o sucesso reprodutor do borrelho-de-coleira-interrompida aumentou significativamente. No capítulo IV comparámos a taxa metabólica basal (BMR), o peso, a taxa de crescimento, a concentração de iões no plasma, o hematócrito, as proteínas de stress e as respostas comportamentais das crias de pernilongo criadas em cativeiro e com acesso exclusivo a água doce, salina ou hipersalina. Todas as variáveis fisiológicas e morfológicas não diferiram entre as diferentes salinidades. Contudo, a taxa de movimentos da cabeça aumentou significativamente com o aumento da salinidade. No capítulo V descrevemos uma técnica de biópsia não letal para a recolha de amostras de tecido adiposo na região fúrcular de aves de pequeno e médio porte. A técnica foi avaliada em termos de tempo de processamento, da sua praticabilidade no campo e na saúde das aves. A biópsia envolveu a realização de uma incisão para a recolha de 2-16mg de tecido adiposo. As incisões demoraram 10-15 dias a sarar por completo e não evidenciaram efeitos negativos a curto prazo nos parâmetros fisiológicos. No seu conjunto os resultados desta tese evidenciam a necessidade da protecção e a gestão das salinas costeiras, bem como a manutenção de uma rede de refúgios de qualidade para a protecção das aves limícolas durante o seu ciclo anual. Intertidal wetlands are among the most productive habitats and support large number of waterbirds worldwide, however they are also one the most threatened habitats on earth. The loss of intertidal habitats is considered a key factor to explain the current decline of the majority of wader populations. At a global scale, anthropogenic supratidal habitats such as coastal salinas can function as buffer zones against the loss of natural coastal habitats. When the intertidal flats are no longer available as the tide advances, waders are forced to move to high-tide roosts, where they must remain until the receding tide exposes their feeding grounds again. Coastal salinas are man-made habitats exploited for the extraction of salt, by solar and wind evaporation of seawater. Unlike natural wetlands, the water level and salinity in salinas are stable and predictable as a result of management. The management of water level and saltmarsh overgrowth are particularly important for their use by waders. The different salinities and fluvial dynamics in salinas originate a particularly high benthic invertebrate prey density for waders. The un-vegetated linear paths between ponds are used also by ground-nesting waterbird species to breed. The chicks of waders are limited to hypersaline waters until began flying. They can present physiologic and behavioural adaptations to cope with the salinity. This thesis evaluates the advantages and disadvantages of salinas as breeding and foraging habitats for shorebirds. In Chapter I we assess the potential role of low salinity ponds as a complementary foraging area for waders during the autumn migration. The high density and biomass of benthic invertebrates decreased rapidly after sediment exposure. We showed that supply ponds could support large numbers of migratory foraging waders during a short time window. Substrate dryness was the major factor affecting the benthic invertebrate community rather than bird predation. The dominance of the polychaete worm Capitella capitata seems to attract large numbers of ringed plovers Charadrius hiaticula, and explains also their high food intake rate. Some wader species could reach their daily biomass needs and gain mass foraging only or mostly on the dewater pond. In Chapter II we took advantage of the suspension of management actions on a high-tide roost over one year, and used bird survey data before and after this event to analyze the effect of management suspension on waterbird populations. The effects on bird density were investigated trough a before-after control-impact design. We demonstrated that the suspension of management actions in high-tide roosts, even for a short period of time, carried large negative effects especially for small and medium wader populations during winter and migratory periods. Our results indicate that the densities of the several groups of bird recovered differently and small waders and spring migratory medium shorebirds did not recover the initial densities during the study period. In Chapter III we evaluated the role of nest-site characteristics, predation and nesting proximity to breeding species with aggressive antipredator behaviour on the Kentish plover Charadrius alexandrinus breeding success. Our results showed that in salinas the nesting success of kentish plover was similar than that in natural habitats. Kentish plover selected nest-sites on the edges of the paths. Predation was the main cause of nest loss in saltpans (42%). We found that breeding close to black-winged stilt Himantopus himantopus increased significantly nesting success of kentish plover. In Chapter IV we compared the basal metabolic rate (BMR), body mass, growth rate, plasma ions, hematocrit, heat shock proteins, and behavioural responses of captive-reared black-winged stilt chicks in fresh, saline and hypersaline water treatments. Our results showed that wild and captive-reared fledglings did not differ in BMR. All physiological and morphological variables did not differ among treatments. However, head-shaking rate increased significantly as salinity increased. Our results support the key role of behavioural adjustments in avoiding salt stress during growth. In Chapter V we describe a non-lethal biopsy technique to collect samples of visible adipose tissue from the furcular region in small and medium-sized bird species. The technique was evaluated in terms of processing time, feasibility in the field, and bird health. Biopsy procedures involved making a skin incision 2-3 mm long to collect 2-16 mg of adipose tissue. The incisions took 10-15 days to heal completely and had no apparent short-term negative effects in the suit of physiological parameters. Taken altogether, this research highlights the need to protect and manage coastal salinas, and promote the maintenance of a network of high quality roosts for the protection of wader populations during their annual cycle.

Liquid sugar baits are well accepted by the Argentine ant Linepithema humile andare suitable for the chemical control of this invasive species. We evaluated how sugar concentrations affect the foraging behavior of L. humile individuals. We quantified feeding variables for individual foragers (ingested load, feeding time and solution intake rate) when feeding on sucrose solutions of different concentrations, as well as post-feeding interactions with nestmates. Solutions of intermediate sucrose concentrations (10?30%) were the most consumed and had the highest intake rates, whereas solutions of high sucrose concentrations (60 and 70%) resulted in extended feeding times, low intake rates and ants having smaller crop loads. In terms of postfeeding interactions, individuals fed solutions of intermediate sucrose concentrations (20%) had the highest probability of conducting trophallaxis and the smallest latency to drop exposure (i.e. lowest time delay). Trophallaxis duration increased with increasing sucrose concentrations. Behavioral motor displays, including contacts with head jerking and walking with a gaster waggle, were lowest for individuals that ingested the more dilute sucrose solution (5%). These behaviors have been previously suggested to act as a communication channel for the activation and/or recruitment of nestmates. We show here that sucrose concentration affects feeding dynamics and modulates decision making related to individual behavior and social interactions of foragers. Our results indicate that intermediate sucrose concentrations (ca. 20%), appear to be most appropriate for toxic baits because they promote rapid foraging cycles, a high crop load per individual, and a high degree of stimulation for recruitment. Fil: Sola, Francisco Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental. Laboratorio del Grupo de Estudio de Insectos Sociales; Argentina Fil: Josens, Roxana Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental. Laboratorio del Grupo de Estudio de Insectos Sociales; Argentina

Many marine organisms ingest plastic items, providing a potential mechanism for the transfer and accumulation of hazardous chemicals associated with plastics. This chapter summarises the range of organisms known to ingest plastic items and the factors influencing the amount of plastic in their digestive tracts. Ingestion can be direct (primary ingestion) or indirect (secondary ingestion via contaminated prey), with direct ingestion being either deliberate (plastic items mistaken for prey items) or accidental (plastics consumed passively by, e.g. filter feeding). Ingestion rates can be summarised as the proportion of individuals to contain ingested plastic (frequency of occurrence = incidence) as well as the average plastic load per individual (expressed by number, mass or volume of items). The amount of plastic in the digestive tract of an organism is a balance between its intake rate and removal via excretion and/or regurgitation. Individual-level variation in plastic loads typically is large and strongly right skewed. Numerous factors probably account for this variation, including age-specific and individual differences in the likelihood of plastic ingestion and retention times, as well as temporal and spatial differences in plastic exposure. Retention times are poorly known for many groups of marine animals, and may be influenced by particle size, shape and type of plastic, as well as phylogenetic and age-related differences in how animals handle indigestible prey remains. Three categories of organisms can be recognised: species that regurgitate most plastic (e.g. gulls, terns and skuas), those that excrete most plastic shortly after ingestion (e.g. fur seals) and those that store plastic in their digestive tract for protracted periods before eroding them to the point where they can be excreted (e.g. petrels, phalaropes and some auks). Turtles probably lie between the last two groups, excreting most plastic, but retaining it far longer than prey items. Further information is needed on the importance of the retention time in the digestive tract of an animal for transfer of hazardous chemicals, but it is likely that long retention times enhance chemical uptake, at least for compounds included in plastics during manufacture. Species with broad, generalist diets that retain indigestible prey items in their digestive tracts for extended periods, such as petrels, storm petrels, phalaropes and turtles, probably are most likely to obtain large body burdens of hazardous chemicals from ingesting plastic items.

International audience; When prey are time limited in their access to food, any trade-off involving time should ultimately affect their intake rate. In many herbivores, males and females experience different ecological pressures affecting their survival and reproduction because of differences in morphology, physiology and energy/nutrient requirements. If males and females have different vigilance strategies that affect their intake rates differently, they will suffer different foraging costs. This is particularly relevant in sexually monomorphic herbivores, where the two sexes have similar basal energy/nutrient requirements and risk of predation. We investigated how gender, reproductive status, age, group size, predation risk, and food biomass affected vigilance, intake rate, and their trade-off in a monomorphic species, the plains zebra (Equus quagga). Males were more vigilant than females, and lactating females were less vigilant than other females; the levels of vigilance were low (ca. 10 % of feeding time). The effects on time spent feeding, bite rates and intake rates were small and statistically not significant. Reproductive status did not affect the strength of the relationship between vigilance and intake rate, but intake rates increased with group size and, for adult females, were higher in tall grass. While gender and reproductive status were major drivers of vigilance, and group size and food biomass of the rate of food intake, males and females adjust their bite rates and food intake with vigilance in similar ways. Our results support the hypothesis that in monomorphic animals, males and females seem to make similar trade-offs (i.e. adjustments) between vigilance and intake rate.

Fully intermeshing, corotating twin-screw extruders (TSEs) are frequently used in many operations that involve polymer blending, devolatilization, or the incorporation of solids such as fillers or reinforcing agents into a polymeric matrix. This is largely due to their flexible screw design, which can be fitted ‘to the job,’ good mixing capacity and self-wiping action. Besides, the advantage of TSEs over conventional single-screw extruders is their high solids intake rate and melting capacity.

One of the variables in the structure of the sward with the most influence on the short-term herbage intake rate by grazing ruminants is the canopy height. The objective of this study was therefore to characterise the effect of the canopy height on short-term herbage intake rate using Sorghum bicolor cv BR 501. as a reference. Two experiments were conducted at Research Station of the Federal University of Rio Grande do Sul, Brazil, between December 2009 and April 2010. The treatments in experiment 1 were used to determine the influence of the pre-grazing canopy height on the short-term herbage intake and consisted of six canopy heights (30, 40, 50, 60, 70 and 80 cm). The treatments in experiment 2 used the pre-grazing canopy height from experiment 1 that maximised the short-term herbage intake rate to evaluate the influence of the severity of grazing down (16, 33, 50, 67 and 84%) on the herbage intake. Both experiments used a completely randomised block design, with two replicates in experiment 1 and three replicates in experiment 2. Four heifers (24 ± 2 months and 306 ± 56.7 kg) were used in experiment 1. Three of these animals were used in experiment 2, which were then 26 ± 2 months and 339 ± 45.5 kg. The short-term herbage intake rate was measured by weighing the heifers pre- and post-grazing, corrected for insensible weight losses. The number of grazing jaw movements (biting and non-biting) was counted automatically using an IGER Behaviour Recorder. In both experiments, the sward measurements included the pre- and post-grazing canopy height, the pre-grazing herbage mass and the vertical distribution of morphological components. In experiment 2, the post-grazing herbage mass was also measured. The results showed that the grazing canopy height that maximised the short-term herbage intake rate was approximately 50 cm. The grazing down protocol showed that the short-term herbage intake rate was constant until the depletion of 40% of the optimal pre-grazing canopy height. After this level of depletion, there was a marked reduction in the short-term herbage intake rate. The results show that the best target management height in a Sorghum cv. BR 501 pasture, allowing for high levels of the short-term herbage intake rate, is 50 cm. With intermittent stocking, this level should be considered as the pre-grazing canopy height, and the level of herbage depletion should not exceed 40%.