Kinetics of particulate and solute marker passage in sheep supplemented with cationomycin and lasalocid antibiotics. Comparisons among methods for calculating mean retention time.

Passage of particulate and solute markers in the digestive tract was studied in sheep fed a roughage-pelleted diet supplemented or not with ionophore antibiotics. Methods of marker administration (continuous infusion vs pulse-dose) and mathematical treatment of data were investigated. Antibiotic supplementation did not affect markers' mean retention time (MRT) significantly, regardless of sampling site, technique of marker administration or MRT calculation methods used. The pulse dose technique led to 20-30% higher estimate of particle markers MRT in the entire gut and stomachs of sheep than did the continuous infusion method. Similar results were obtained between these methods for solute markers MRT at both sampling sites. Total MRT in the digestive tract could be partitioned among compartments using a deterministic model when applied to pulse-dose kinetics. Such a partitioning appeared unsatisfactory with continuous-infusion data. Estimations of particle or solute markers MRT in the rumen from duodenal and faecal marker kinetics were significantly different and rarely correlated.     

Fluid and particle retention in the digestive tract of the addax antelope (Addax nasomaculatus)--adaptations of a grazing desert ruminant.

Retention time of food in the digestive tract is a major aspect describing the digestive physiology of herbivores. Differences in feed retention times have been described for different ruminant feeding types. In this study, a dominantly grazing desert ruminant, the addax (Addax nasomaculatus), was investigated in this respect. Eight animals with a body weight (BW) of 87+/-5.3 kg on an ad libitum grass hay (Chloris gayana) diet were available. Co-EDTA and Cr-mordanted fibers (<2 mm) were used as pulse-dose markers. Mean retention time (MRT) in the digestive tract was calculated from faecal marker excretion. Average daily intake of the addax was found to be 1.7 kg dry matter (DM) or 60+/-8.3 g DM/kg BW(0.75). The MRT of fluid and particles in the reticulo-rumen (MRT(fluid)RR and MRT(particle)RR) were quantified to be 20+/-5.8 and 42+/-7.0 h respectively. When compared to literature data, MRT(fluid)RR was significantly longer than in cattle species, and MRT(particle)RR was significantly longer than in 11 taxa of all feeding types. The ratio of MRT(particle)RR/MRT(fluid)RR (2.3+/-0.5) was found to be within the range described for grazing ruminants. The long retention times found in the addax can be interpreted as an adaptation to a diet including a high proportion of slow fermenting grasses, while the long retention time of the fluid phase can be interpreted as a consequence of water saving mechanisms of the desert-adapted addax with a potentially low water turnover and capacious water storing rumen.     

Fluid and particle retention in the digestive tract of the addax antelope (Addax nasomaculatus)--adaptations of a grazing desert ruminant

Retention time of food in the digestive tract is a major aspect describing the digestive physiology of herbivores. Differences in feed retention times have been described for different ruminant feeding types. In this study, a dominantly grazing desert ruminant, the addax (Addax nasomaculatus), was investigated in this respect. Eight animals with a body weight (BW) of 87+/-5.3 kg on an ad libitum grass hay (Chloris gayana) diet were available. Co-EDTA and Cr-mordanted fibers (<2 mm) were used as pulse-dose markers. Mean retention time (MRT) in the digestive tract was calculated from faecal marker excretion. Average daily intake of the addax was found to be 1.7 kg dry matter (DM) or 60+/-8.3 g DM/kg BW(0.75). The MRT of fluid and particles in the reticulo-rumen (MRT(fluid)RR and MRT(particle)RR) were quantified to be 20+/-5.8 and 42+/-7.0 h respectively. When compared to literature data, MRT(fluid)RR was significantly longer than in cattle species, and MRT(particle)RR was significantly longer than in 11 taxa of all feeding types. The ratio of MRT(particle)RR/MRT(fluid)RR (2.3+/-0.5) was found to be within the range described for grazing ruminants. The long retention times found in the addax can be interpreted as an adaptation to a diet including a high proportion of slow fermenting grasses, while the long retention time of the fluid phase can be interpreted as a consequence of water saving mechanisms of the desert-adapted addax with a potentially low water turnover and capacious water storing rumen.     

Effects of dietary fibre on digesta passage, nutrient digestibility, and gastrointestinal tract morphology in the granivorous Mongolian gerbil (Meriones unguiculatus)

To investigate digestive tract performance in Mongolian gerbils (Meriones unguiculatus), food intake and digestibility, digesta passage rate, and gastrointestinal tract morphology were measured in captive animals fed low- or high-fibre diets. We used two markers (Co-ethylene diamine tetra-acetic acid for solutes and Cr-mordanted cell walls for particles) to measure differential passage rates of digesta fractions in order to test for the presence of a colonic separation mechanism (CSM). Although dry-matter intakes on the high-fibre diet did not differ from those on the low-fibre diet, digestibilities of dry matter, neutral-detergent fibre, acid-detergent fibre, crude protein, and crude fat were all significantly lower on the high-fibre diet. Gross energy intake on the high-fibre diet also did not differ from that on the low-fibre diet, but energy lost in faeces was much higher than on the low-fibre diet; thus, energy digestibility and digestible energy intake were significantly lower on the high-fibre diet. The lengths and dry-tissue masses of all segments of the gastrointestinal tract tended to enlarge in response to increased dietary fibre, but only the total tract contents, contents of the small intestine, and length and dry-tissue mass of the caecum increased significantly. The mean retention time (MRT) of the particle marker was significantly greater than that of the solute marker on the low-fibre but not the high-fibre diet; the solute/particle differential retention ratio was 0.62 on the low-fibre diet and 0.90 on the high-fibre diet. Thus, there was no evidence for selective retention of the solute marker on either diet. The MRT of the particle marker was significantly lower on the high-fibre diet and in the same direction as the MRT of the solute marker. These results suggest that the granivorous Mongolian gerbil has no CSM but can adjust its digestive tract capacity to accommodate greater quantities of low-quality food.     

Seasonal dynamics of digestion in relation to diet quality and intake in European roe deer (Capreolus capreolus)

Three tame, hand-reared adult roe deer (Capreolus capreolus) were fed a low-quality diet (blueberry stems) or high-quality concentrate either restricted or ad libitum in summer and winter. Total mean retention time (TMRT) and rumen retention time (RRT) were significantly longer, indigestible fill was significantly higher and apparent digestibility and intake were significantly lower when fed blueberry stems compared to concentrate. The feeding regimes of concentrate did not affect the digesta kinetic estimates, except that total fill and apprent digestibility were significantly higher when deer were fed ad libitum than when they were fed a restricted ration. TMRT was significantly longer when they were fed a restricted ration of blueberry stems than for ad libitum intake, whereas all other estimates were equal. Intake was significantly higher and TMRT and RRT were significantly shorter in summer compared to winter when they were fed concentrate. These findings support the theory that roe deer, as small-bodied concentrate selectors, are adapted to high intake, rapid turnover, and rapid digestion when fed high-quality concentrate. When fed a low-quality diet the roe deer may be limited by rumen bulk. A strategy based on increased rumen retention accompanied by increased cell-wall digestion has therefore severe limitations in roe deer. This indicates that roe deer are dependent on a selective feeding strategy to enhance winter survival.     

Digestion of selected foods by Yunnan snub-nosed monkey Rhinopithecus bieti (Colobinae)

Three digestion trials were conducted to quantify aspects of digestive physiology in the Yunnan snub-nosed monkey Rhinopithecus bieti, a foregut fermenter that feeds primarily on lichens. Mean retention time (MRT, the average time plastic markers spent in the animal) had a mean estimate of 47 hr (n = 3) with high variability between trials (standard deviation = 17 hr). Recently captured animals, presumably with gut flora and digestive physiology close to wild animals, had a longer retention time than did long-term captives, although lack of standardization across trials (such as in activity level) confounds analysis. Apparent digestibilities for dry matter (71-80%) were in line with other studies of colobine digestion, but fall below those of ruminant ungulates feeding on lichens. Fecal analysis accurately determined the relative proportions of leaves vs. lichens in diets; mature leaves and lichens were not nutritional equivalents but appeared to be physiological equivalents in terms of digest passage. Fecal analysis does not, however, accurately determine the relative proportions of food types with different digestibilities, such as fruit vs. leaves.     

Slow Lorises (<Emphasis Type="Italic">Nycticebus</Emphasis> spp.) Really Are Slow: a Study of Food Passage Rates

The characteristics of food ingested by a primate affect its assimilation of energy by modulating food passage rate. In general, digestive time increases in folivorous primates and decreases in frugivorous primates when they are fed higher fiber diets but this relationship is understudied in exudativorous primates. We compared the food passage rate of five slow loris species. We studied 34 wild-caught slow lorises (15 Nycticebus coucang, 15 N. javanicus, and 4 N. menegensis) in an Indonesian rescue center and four captive-born slow lorises (2 N. bengalensis and 2 N. pygmaeus) in a UK institution. We fed the Indonesian subjects two different diets: a captive-type diet comprising fruits, vegetables, and insects and a wild-type diet formulated to be similar in nutrients to that consumed by slow lorises in the wild, consisting of gum, insects, vegetables, and nectar. We fed the UK subjects a diet of gum, vegetables, insects, and hard-boiled eggs. We formulated this diet to mimic the wild diet, with notably higher fiber fractions and lower soluble sugars than the previous diet. We measured two variables: the transit time (TT) and the mean retention time (MRT). We mixed 1 tsp. of glitter in bananas or gum as our markers and fed them to the slow lorises immediately before their main diet. We noted the date and time of feeding and of appearances of the marker in feces. We weighed food given and left over for each individual to calculate ingested foods and nutrients. We found that TTs were not affected by diet treatment but MRTs were significantly longer for all species fed the wild-type diet. Our results show that Nycticebus spp. have long MRTs for their body weight, and N. pygmdaeus may have the slowest MRT of all primates in relation to body mass. The digestive flexibility of exudativorous primates should allow them to maximize fermentation opportunities when they ingest more (appropriate) fiber by increasing the amount of time the fiber substrate stays in the large intestine. Exudativorous primates appear to have plastic digestive strategies that may be an adaptation to cope with relatively nutrient-poor staple food sources such as gum. The provision of gum in a captive setting may therefore provide benefits for gut health in slow lorises.     

Dairy goats adjust their meal patterns to the fibre content of the diet

Few studies have investigated how meal patterns of ruminants are affected by diet fibre content. Dairy goats (N = 32) in late lactation and early gestation were housed in eight groups of four goats, with all combinations of breed (Alpine and Saanen) and lactation number (1 and 2) represented in each group. Each goat had access to its own individual feed trough placed on a weigh scale with data logged automatically. All goats were fed the same total mixed ration (TMR; 30% concentrate and 44.6% NDF in DM) ad libitum for a control period of 22 days. Using the same feed ingredients, half of the groups were then offered a High fibre diet (20% concentrate; 47.3% NDF), and the other half a Low fibre diet (40% concentrate; 41.5% NDF) for a treatment period of 16 days. Daily meal patterns (meal frequency, duration and size, feeding rate, daily feed intake and daily feeding time) were computed for each animal using a meal criterion of 8 min. The last 10 days for each period (control and treatment) were used to calculate individual period means and individual differences between the two periods. During the control period, the goats ate on average 12.1 ± 0.49 meals/day, consuming 4.2 ± 0.10 kg fresh TMR daily. When the ration changed, all measures of feeding behaviour except meal size changed asymmetrically for the goats on the two diets. Goats fed the High fibre diet reduced their meal frequency by 10%, and the first meal after feed distribution lasted 11% longer, leading to a 9% reduction in feeding rate and no significant changes in daily feed intake and daily feeding time. Goats on the Low fibre diet did not significantly change their meal frequency or meal size, but the combined changes nevertheless led to a 9% increase in daily feed intake. On the Low fibre diet, goats were able to increase their feeding rate by a third, leading to a reduction in meal durations, thus reducing daily feeding time by 13%. Goats adapt their feeding behaviour to the fibre proportion of the offered diet, with more changes when fibre content is lowered, which needs to be taken into account when comparing phenotypes and adaptability of small ruminants to different diets.     

Diet choice by goats as effect of milk production level during late lactation

The diet self-regulation ability of goats during late lactation has been studied with regard to their production level. Two groups of seven Girgentana goats producing 1100 ± 157 g/day (H group) and 613 ± 138 g/day (L group) were housed in individual pens and were given alfalfa pelleted hay (1.5 kg), whole grains of maize (0.5 kg), barley (0.5 kg), faba bean (0.5 kg) and pelleted sunflower cake (0.5 kg) on a daily basis. During a 7-day pre-experimental period, goats received a mixed ration based on the same feeds used during the experimental period (1.5 kg of hay and 0.4 kg of each concentrate). Individual choice of feeds was continuously recorded for 7 days using a 24-h IR video surveillance system equipped with four video cameras. The nutrient intake in both groups was much higher than needed. Goats in the H group ate more (2016.3 v. 1744.3 g dry matter (DM)/day) and selected less hay (26.9% v. 34.6% DM), more high-protein feeds (faba bean and sunflower cake: 14.0% and 15.9% v. 8.8% and 7.9% DM, respectively) and less maize (21.5% v. 25.0% DM), reaching a higher CP concentration in the diet (17.3% v. 15.0% DM) compared with the goats in the L group. During the 24-h trial period, hay was more constantly selected (on average never reaching <20% of the total hourly basis feeding time, apart from the first hour after feed administration) compared with concentrate feeds. This feeding behaviour has probably exercised a ‘curative’ effect that enabled the goats to continue to take in very high levels of starch and protein, without manifesting any symptom of metabolic disease. Shifting goats from the pre-experimental diet, based on a mixture of the same feeds used during the experimental period, to the free-choice feeding caused more than 20% increase in milk production in both groups. From the results of the intake, we are unable to conclude that the goats can select their diet to meet their requirements, as goats consumed much more than needed. However, when free to choose their diet, the animals improved milk performance, despite the late-lactation stage.     

Food intake, conversion efficiency, and feeding behaviour of tobacco hornworm caterpillars given artificial diet of varying nutrient and water content

ABSTRACT Fifth stadium tobacco hornworm caterpillars, Manduca sexta (L.), given artificial diet diluted to varying extents with either cellulose or water compensated for the food's reduced nutrient content by eating more of it. This compensation was, however, in most cases not sufficient to maintain normal growth rates. When the water content of the diet was reduced, the insects ate less than the usual fresh weight of food but maintained their intake of nutrients. Nevertheless, growth rate was impaired. The insects were better able to compensate for dilution of their food with water than with cellulose. The efficiency of conversion of ingested food (ECI) was decreased when the diet was adulterated with cellulose. At moderate dilution (50% nutrient) this was due mostly to decreased approximate digestibility (AD), but at greater dilution (25% and 10% nutrient content) the efficiency of conversion of digested food (ECD) was decreased. ECI was maintained when the water content of the diet was increased to give 50% nutrient concentration, but was decreased when water content was changed more radically (200%, 25% and 10% nutrient diets). This was due mostly to increased metabolic costs (decreased ECD) in all cases. The retention time of food in the gut was progressively decreased (i.e. speed of passage was increased) as nutrients were replaced by cellulose. By contrast, dilution of the diet with water resulted in only slight changes in retention time, except at extreme dilution (10% nutrient content) when retention time was reduced. Compensation of food intake was achieved by spending more (or less) time eating. Video analysis of feeding behaviour showed that there were significant changes in the length of feeding bouts and of interfeed gaps when caterpillars fed on diets of altered composition. For diets diluted with cellulose, changes in bout length and bout frequency contributed substantially to the increased time spent feeding on the adulterated food. For diets diluted with water, however, almost all of the compensatory change in behaviour was due to increased bout length, with bout frequency affected only slightly. This suggests that volumetric feedback contributes principally to the termination of feeding bouts in caterpillars, while nutrient flow may affect both the initiation and termination of feeding.     

Intake,digestion and selection of roughage with different staple lengths by sheep and goats

The diet selection, ingestive and digestive responses of goats and sheep offered a single forage, which was prepared with three staple lengths: long (L), medium (M) and short (S) (mean particle size (mm): 13.29, 7.26 and 0.69, respectively) were studied in three experiments. The sheep (Scottish Blackface wethers) increased their dry matter intake (sheep DMI: 60.1, 61.1 and 66.2 g DM/(kg W^0.75) per day for L, M and S) and reduced mean retention time (MRT) of the undigested residues (sheep MRT: 54.6, 52.9 and 45.9 h for L, M and S) and digestive efficiency (sheep DM digestibility: 0.524, 0.522 and 0.493 for L, M and S) with the reduction in forage particle size. The respective responses of goats (feral crosses) were not modified with forage staple length (goat DMI: 68.1, 65.9 and 67.3 g DM/(kg W^0.75) per day for L, M and S); (goat MRT: 38.7, 39.3 and 41.1 h for L, M and S); (goat DM digestibility: 0.495, 0.475 and 0.480 for L, M and S). However, both species had similar intakes of digestible dry matter (DDMI) on all staple lengths (mean DDMI: 32.0 and 32.6 g DDM/(kg W^0.75) per day for sheep and goats). On the longer staple lengths (L and M) goats masticated the fibre into smaller particles than did sheep and had (P<0.01) a greater proportion of small particles in their boli (mean: 0.45 and 0.30 for goats and sheep). The selection of components within the forage offered was different for the two species. Goats consumed forage of lower nitrogen (N) (P<0.01) and in vitro organic matter digestibility (OMD) (P<0.05) and higher neutral detergent fibre (NDF) (P<0.01) contents than sheep. This was associated with the residues from sheep having a coarser texture than those of goats. When the forages of different staple lengths were offered in pairs to the animals, there was no evidence for selection of forage types by either species. It would appear that the greater ability of goats to chew efficiently provides a reason for the different responses to staple length in intake, digestibility and MRT by the two species.     

Diet and food preferences of the endangered Bearded Vulture Gypaetus barbatus: a basis for their conservation

The Bearded Vulture Gypaetus barbatus population in the Pyrenees is managed using feeding stations to increase breeding success and reduce mortality in the pre-adult population. Nevertheless, very little quantitative and qualitative information has been published on such basic aspects of the species' ecology as feeding habits and dietary preferences. This study investigated both aspects through direct and unbiased observation of breeding Bearded Vultures during the chick-rearing period. Bearded Vulture diet comprises mammals (93%), birds (6%) and reptiles (1%), with medium-sized ungulates (mainly sheep/goats) the most important species in the diet (61%, n  = 677). Prey items were not selected in proportion to their availability, with the remains of larger species (cows and horses) being avoided, probably due to the variable cost/benefit ratios in handling efficiency, ingestion process and transport. There is no relationship between the proportion of sheep limbs in the diet and the proximity of feeding stations, suggesting that these sites are probably less important for breeding adults than for the pre-adult population. On the other hand, diet specificity seems related to productivity, with territories with greater trophic breadth being those with higher fecundity. Bearded Vultures prefer to eat limbs, although meat remains (provided principally by small mammals) can play an important role in guaranteeing breeding success during the first few weeks after hatching. The management of carrion provided by animals that die naturally in extensive livestock practices and the remains of wild ungulates which have died naturally or by human hunting, are important conservation tools for the Bearded Vulture and other carrion-eating species.     

Creatinine and inulin clearance at the different nitrogen and energy intake in sheep

1. Renal creatinine and inulin clearances were compared between sheep fed (a) high nitrogen and high energy diet; (b) low nitrogen and high energy diet and (c) low nitrogen and low energy diet. 2. Inulin clearance was significantly lower in sheep on both low nitrogen diets vs the group with high nitrogen intake. Differences were not ascertained between the groups on low nitrogen diets. 3. No significant differences were found in the creatinine clearance. The creatinine inulin clearance ratio was higher when animals were fed low nitrogen diets, vs the group on a high nitrogen diet. 4. Results suggest that the endogenous creatinine is not suitable for the GFR measurement in sheep under the different conditions of nutrition.     

Digesta Passage Time,Digestibility, and Total Gut Fill in Captive Japanese Macaques (<Emphasis Type="BoldItalic">Macaca fuscata</Emphasis>): Effects Food Type and Food Intake Level

Digestion is an important process in understanding the feeding ecology of animals. We examined digesta passage time, digestibility, and total gut fill in Japanese macaques (Macaca fuscata; n = 4) under 4 dietary conditions representing the seasonal and regional variations in the diets of wild populations to determine the effects of food type and food intake on these digestive features. Food type is associated with mean retention time (MRT), digestibility, and total gut fill. Dry matter intake (DMI) of food correlates positively with total gut fill but not with MRT or digestibility. Conversely, indigestible DMI affected MRT negatively. Thus, when Japanese macaques consume high-fiber foods, MRT becomes shorter and digestibility is lower than when eating low-fiber foods. Moreover, macaques experience increases in total gut fill when they consume high-fiber diets or a large amount of food. Japanese macaques may excrete difficult-to-digest food components quickly; they nevertheless buffer an increase in food intake by an increase in gut fill. Our study offers new insights into the relationship between feeding ecology and nutritional physiology in primates by simultaneously examining the effects of food type and intake level on MRT and digestibility.     

The intake and digestion of a range of temperate forages by sheep and fibre-producing goats

The voluntary intake, digestibility and mean retention time of six temperate forages differing in their chemical composition by 12 adult castrated male Scottish blackface sheep, aged 15 months, and fibre-producing castrated male goats, aged 27 months, and of similar live weight, 40 kg, were described. The creation of a range of chemical compositions was effected through the use of barley straw, and a low- and high-digestibility hay, and the use of ammonia treatment of these forages. A wide range of voluntary intakes (42–78 g DM/kg W^0.75/day), digestibility of dry matter (0.46–0.60) and mean retention times of undigested residues (36–72 h) was achieved through feeding the six forages. Across all the forages fibre-producing goats had higher voluntary intakes, expressed on a metabolic live weight basis, and lower digestibility values than sheep, whereas the mean retention time of the undigested residues was similar for the two species. Within forages goats selected a diet of potentially higher nutritive value, as predicted from chemical composition, with a smaller particle size than sheep. It was concluded that the differences in intake and digestion of temperate forages between sheep and fibre-producing goats are broadly similar to those observed in other experiments between sheep and goats ingesting tropical forages.     

Comparative plasma pharmacokinetics of meloxicam in sheep and goats following intravenous administration

Meloxicam, a novel cyclooxygenase-2 selective nonsteroidal anti-inflammatory drug (NSAID), has been used extensively in humans and recently in some domestic animal species. Although it is an attractive NSAID for use in small ruminants, meloxicam pharmacokinetics have not been investigated in sheep and goats and this information is essential for rational therapeutic use of the drug in these species. In this investigation, comparative pharmacokinetic properties of meloxicam were studied in sheep and goats after a single intravenous dose of 0.5 mg kg(-1) body mass. Blood samples were collected via jugular venepuncture into heparinised tubes at predetermined times after drug administration. Plasma concentrations of meloxicam were determined by reversed-phase high performance liquid chromatography. The plasma concentrations of meloxicam were detectable in sheep and goats up to 72 and 48 h, respectively. The plasma concentration versus time data of meloxicam in both sheep and goats were adequately described by a two-compartment open model. The values obtained for sheep and goats for distribution half-life, volume of distribution at steady state and volume of the central compartment were almost similar in sheep and goats. The elimination half-life (t(1/2beta)), area under the plasma concentration-time curve (AUC), mean residence time (MRT) and total systemic clearance (Cl(B)) in sheep were significantly different from those of goats. The mean+/-S.E. values of t(1/2beta), MRT, AUC and Cl(B) in sheep were 10.85+/-1.21 h, 15.13+/-1.67 h, 31.88+/-2.97 microg h mL(-1) and 0.016+/-0.002 L h(-1) kg(-1), respectively whereas the respective values in goats were 6.73+/-0.58 h, 9.37+/-0.83 h, 19.23+/-2.23 microg h mL(-1) and 0.03+/-0.01 L h(-1) kg(-1). The results indicate that elimination kinetics of meloxicam differ significantly between sheep and goats and the elimination of the drug tends to be faster in goats compared to sheep.     

Effects of particle size and moisture levels in mixed rations on the feeding behavior of dairy heifers

Two experiments on replacement heifers (175±12 days of age) assessed the effects of forage particle length and moisture on feeding behavior. Both experiments used a replicated 3×3 Latin square design, with nine heifers per replication and three periods of 9 days each. Each group of nine heifers was housed in one pen with access to three electronic feed bins. In Experiment 1, hay chopped at different lengths was incorporated into three total mixed rations (TMR) all having the same ingredient and nutrient composition but differing in the percentage of long particles (>19 mm): 60% (Short), 64% (Medium) and 72% (Long). In Experiment 2, heifers were fed a TMR with the same ingredient and nutrient composition but differing in moisture content: 65% DM (Dry), 50% DM (Moderate), and 35% DM (Wet). In both experiments, feeding behavior during the last 5 days of each period was analyzed using a mixed model accounting for the fixed effects of treatment and period, and the random effects of replication and animal. In Experiment 1, dry matter intake (DMI) and eating rate (DMI/min) tended to increase, whereas daily eating time decreased as the feed particle size decreased. Heifers fed the Long diet selected in favor of long particles (>19 mm) and against Short (1.18 to 8 mm) and fine (<1.18 mm) particles; heifers fed the Short diet selected against long particles and in favor of short and fine particles. Heifers fed the Medium diet showed a preference for medium particles with no preference for the other particle sizes. In Experiment 2, heifers fed the Dry diet tended to consume more feed than those fed the Moderate and Wet diets, with no differences in feeding behavior or sorting activity. In conclusion the Medium diet minimized sorting without reducing eating rates and intake, and adding water to TMR to achieve a dry matter less than 65% tended to decrease DMI without reducing sorting.     

Digestive Retention Times in Forest Guenons (Cercopithecus spp.) with Reference to Chimpanzees (Pan troglodytes)

Because the length of time food is maintained in the gut influences fermentation rates and its overall digestibility, information on digestive passage rates is critical to explain the overall feeding and foraging strategy of a species. I present results from digestive passage experiments conducted on captive Cercopithecus ascanius, C. mitis, C. neglectus, Miopithecus talapoin, and Pan troglodytes. I recorded several measures of digestive passage time, including transit time (time of first marker appearance; TT), mean retention time of markers (MRT), and time of last appearance of a marker (TLA). I conducted 4 trials on each of the 10 subjects. A trial consists of the administration of 20, non-toxic colored plastic markers. Overall, the 5 species varied in digestive times (p < 0.01), but there is no difference between Cercopithecus neglectus and Pan troglodytes (p = 0.131) or between C. mitis and C. ascanius (p = 0.661). When the effect of body size is removed (by computing the ratio y/x, where x = body mass, and y = MRT), Pan troglodytes exhibits a low ratio, suggesting relatively slow retention times in the 4 cercopithecines. My findings and other published digestive passage rates suggest that lengthy digestive retention times may be characteristic of cercopithecines. These data may help to interpret how the smaller-bodied guenons are able to consume a higher percentage of fiber than that of chimpanzees, a specialized frugivore. Small body size, in combination with long digestive passage times may be an adaptation on the part of Cercopithecus species to consume a high fiber diet, while maintaining a greater capacity to detoxify secondary metabolites.     

The role of time of food intake on upcoming liver disease in male Wistar rat

Interventions against obesity, are mainly around changing calorie intake and energy expenditure. Recently, some studies focused on the influence of circadian time of food intake on metabolic status. Here, we compare the role of calorie restriction and time restricted feeding followed by high-fat diet started post weaning, First, 52 male Wistarrats (3 weeks old) were divided into two groups: the high-fat diet (HFD, n = 42) and the control group (CON1, n = 11). After 17 weeks, five rats were randomly selected from each group for sample preparation. In the second phase, the animals in HFD group were assigned into four groups (n = 9): (1) 30% calorie restriction (CR), (2) day intermittent fasting (DIF), (3) night intermittent fasting (NIF), (4) adlibitum food intake (AL), (5) remained animal from the first phase control (CON2). Seventeen weeks of HFD started post-weaning did not cause fatty liver but it caused a significant difference in the body and the adipose tissue weight (P0.05). The results showed that longtime HFD did not lead to liver steatosis while the incorrect time of food intake predisposes the animal to the upcoming liver disease. This data indicate a significant role of timing of food intake rather than nutrition composition itself.     

Effect of method of processing foliage of Acacia mangium and inclusion of bamboo charcoal in the diet on performance of growing goats

Two experiments were conducted to examine the effect of including charcoal and of different processing methods of foliage from Acacia mangium in the diet on intake and performance of goats. In experiment 1, four male goats were used in a Latin square arrangement. The treatments were: control, no bamboo charcoal, and 0.5, 1.0 or 1.5 g bamboo charcoal per kg body weight (BW). The diet consisted of 10 g/kg initial BW dry matter (DM) of concentrate and Para grass, respectively. Acacia was fed ad libitum at a level of 130% of the individual fresh intake the previous day. The time for each period was 21 days with the last seven days for data collection. Adding bamboo charcoal to the diet did not increase DM intake of Acacia, total DM intake or neutral detergent fiber or acid detergent fiber digestibilities, but had a significant effect on DM, organic matter (OM) and crude protein (CP) digestibilities and nitrogen (N) retention higher values being obtained in treatments 0.5 and 1.0, significantly higher than in the control or 1.5 treatments.

In experiment 2, 42 goats were randomly allotted to 6 different treatment groups. The treatments were three different methods of processing Acacia: fresh foliage, wilted foliage or dried foliage. Each method was tested with or without adding bamboo charcoal (0.5 g charcoal/kg BW). The diet was the same as in Exp. 1. The experimental time was 12 weeks. The goats fed the diet with bamboo charcoal consumed similar amounts of total DM and DM of Acacia as the goats fed the diet without bamboo charcoal and grew significantly faster (53 and 44 g/day, respectively, with and without charcoal). The processing method of Acacia foliage had a significant effect on total DM intake and DM intake of Acacia. The highest total DM intake was obtained by goats fed wilted Acacia, significantly different from fresh and dried Acacia. The weight gain of goats fed wilted or dried Acacia was higher than that of goats fed fresh Acacia, but this difference was not significant. In conclusion, the value of Acacia mangium as a feed for goats can be improved by wilting the foliage and feeding 0.5 to 1 g/kg BW of bamboo charcoal per day