Digestibility of a high-fiber biscuit-based diet by black and white colobus (Colobus guereza)

The acceptability and digestibility of a high-fiber biscuit-based diet was investigated using two adult male Colobus guereza animals. Although the animals were initially reluctant to accept the biscuit, it was eventually readily consumed. Apparent digestion coefficients for the diet (average composition, dry matter basis: 16% crude protein, 25% neutral detergent fiber (NDF), 9.5% acid detergent fiber (ADF), 1.2% acid lignin) determined by total fecal collection were 0.871 for dry matter, 0.813 for NDF, 0.693 for ADF, and 0.208 for acid lignin. Fiber digestive capabilities in C. guereza generally exceeded those reported in ruminant species based on predictive equations. Use of acid lignin and Cr₂O₃ as markers underestimated dry matter digestibility by 3.9 and 6.0%, respectively.     

Effect of season on chemical composition and in situ degradability in cows and in adapted and unadapted goats of three Mexican browse species

Browse foliages from Lysiloma acapulcencis, Quercus laeta and Pithecellobium dulce, native to the subtropical region of southern México, were harvested during the dry season (DS) and rainy season (RS) to determine in situ degradability using ruminal inoculum from fistulated cows as well as goats previously adapted (AG) or not adapted (UG) to browse species fed in their daily diet. Browse leaf samples were incubated in the rumen of each group for 48 h. The crude protein (CP) content of browse was considerably higher in RS (P<0.001). P. dulce had the lowest neutral detergent fiber (NDFom) and acid detergent fiber (ADFom) in the two seasons; L. acapulcencis had the highest values and Q. laeta values were intermediate, with an overall increase in fiber fractions in DS browse foliage (P<0.001). The lowest in situ degradability values were in L. acapulcencis and Q. laeta had intermediate values during both seasons. Season of harvest (RS or DS), and ruminal inoculum (cows, UG, and AG) affected (P<0.001) dry matter degradability (DMD), crude protein degradability (CPD) and fiber fractions of browse. Nutrient degradabilities in all species were higher (P<0.001) in DS than RS. Goats previously exposed to these browse species (AG) had higher (P<0.001) in situ degradability of the browse species than cows or goats in UG fed diets without browse. Overall, goats had higher (P<0.001) nutrient in situ degradability than cows. Our results suggest higher potential of these browse species as forages for ruminants during the dry period in semi-arid regions, but goats previously exposed to diets supplemented with the browse species had a better ability to degrade them than cows or goats in UG. P. dulce has the highest potential as a feed protein source in small ruminants during the dry period.     

Seasonal diet preferences of black rhinoceros in three arid South African National Parks

Black rhinoceros diet and browse availability was investigated in Augrabies Falls (AFNP), Karoo (KRNP) and Vaalbos National Parks (VNP) in South Africa. Rhino tracks were followed and 18,804 standard bite volumes recorded. Browse availability of each plant species was recorded by measuring 14,800 plants and calculating reachable browse volume. The diet comprised 51, 53 and 41 plant species in AFNP, KRNP and VNP, respectively, but three species accounted for more than 65% of the diet in each park, making diet less diverse than available browse in AFNP and KRNP. Browse availability explained 14%, 15% and 52% of diet selection in AFNP, KRNP and VNP, with consumption of most plant species significantly different from availability. A few plant species were so highly preferred that browsing intensities were unsustainable, while some common species were totally rejected. Pressure on the eaten browse averaged 4.4%, 14.5% and 1.3% annually of the volume in AFNP, KRNP and VNP. In the dry season, there was a two to sevenfold increase in browsing pressure on species with actively photosynthesizing tissues. A few key species, including Monechma and Zygophyllum species, were identified as potential early warning indicators of black rhino browsing impact.     

Forage quality of native pastures in a Mediterranean area

Three field sites in the Hyblean region of Sicily were studied for their forage quality and botanical composition. A total of 70 plant species were analyzed. Another 36 were rare and of insufficient quantity for analysis. Forty-three bulk samples combining all existing species were also prepared and analyzed. The chemical analyses included were dry matter, ash, neutral-detergent fiber (NDF), acid-detergent fiber (ADF), lignin, total nitrogen, nonprotein nitrogen (NPN), soluble nitrogen and degradable protein. Quality varied over the growing season declining with forage maturity. The nutritional quality was high overall. Nongrass nonlegume species dominated. The most abundant species of high quality was a Compositae, Calendula arvensis, which represented approximately 22.8% of the available forage.     

Energy supply of the okapi in captivity: intake and digestion trials

In the nutrition of browsing ruminants in captivity, adequate nutrient digestibility and energy content of diet is debated. Problems related to energy‐provision and low forage intake have been reported for the okapi and other browsers like the giraffe, particularly during winter. High‐fiber concentrates like unmolassed beet pulp have some potential to improve the nutritional management of these species. Using a total of six okapis in captivity, seven feeding trials were carried out at two facilities (A+B) on a structured but opportunistic base. Three trials (A₁, A₂, B₁) were conducted when animals were fed their regular diet including grain based energy concentrates, fruits and vegetables, and alfalfa (Medicago sativa) hay. Two trials (A₅, B₂) examined the effect of unmolassed beet pulp, and two (A₃,₄) examined the effect of unmolassed beet pulp+fresh browse. Daily intake and feces production were quantified over 8–12 days. Samples were analyzed for dry matter, crude ash, neutral detergent fiber (NDF)/acid detergent fiber (ADF)/acid detergent lignin (ADL), crude protein, and gross energy. Metabolizable energy content of diets was estimated via a factor (0.83) from digestible energy. The proportion of beet pulp in diets was 13% (A₃), 24% (A₄), 20% (A₅), and 21% (B₂). Browse proportion was 11% (A₃) and 32% (A₄). Daily feed intake ranged between 1.5–1.7% of body weight (BW), digestibility of organic matter between 61–74%. Digestibility of fiber (NDF) was higher in beet pulp diets (A₃=39%, A₄=60%, A₅=54%, B₂=61%) than in the others (A₁=48%, A₂=33%, B₁=48%). Supply of metabolizable energy (ME) ranged between 0.50–0.70 MJ ME/(kg BW^0.75*day), meeting energy requirements of okapis of 0.50–0.53 MJ ME/(kg BW^0.75*day) in general. Diets with beet pulp+browse were not found to be highest, but in the upper level of the range of forage proportions of this study. Palatable browse species were preferred over all other feedstuff offered. The use of unmolassed beet pulp as energy‐concentrate for browsing ruminants like the okapi can be recommended because diets high in this high‐fibre feedstuff resulted in adequate energy intakes. Zoo Biol 0:1–14, 2006. © 2006 Wiley‐Liss, Inc.     

Intake,utilization, and composition of browses consumed by the Sumatran rhinoceros (Dicerorhinus sumatrensis harissoni) in captivity in Sabah,Malaysia

The significant threats to the fewer than 30 wild Dicerorhinus sumatrensis harrissoni, the Bornean sub‐species of the Sumatran rhinoceros, are obvious and include poaching, habitat loss, and environmental changes. Subtle effects on population survival, however, include nutritional or other diseases, which affect morbidity and reproductive success. To address these issues and focus on animals within their natural range, this feeding trial and analysis characterizes the diet fed to the only three captive D. s. harissoni in the world housed at the Sumatran Rhino Breeding Center (SRBC) in Sabah, Malaysia. The study provides an indication of the variance in nutrient composition in local browse, and a comparison with other captive feeding studies. Mean dry matter intake (DMI), comprising ∼90% native browse species, equaled 3.55% (range=2.8–4.1%) of body mass, with a dry matter digestibility averaging 82%. The mean crude protein content of native browses (n=8 spp.) averaged 11.2% (DM basis; range=5–23%, depending on plant part), with available protein measured at 7.8%. Leaves contained significantly (P<0.001) more crude protein, and less (P<0.001) fiber (neutral detergent fiber, acid detergent fiber, and lignin) than twig fractions analyzed, but animals consumed both fractions rather non‐selectively. Of minerals quantified, Na and P were potentially limiting in native browses compared to equid nutrient requirements, and Se may have been marginal. Ca, K, and Fe levels in particular were high in most native browses. Specifically, iron ranged from 45–1,400 mg/kg (mean=230 mg/kg DM), with only three preferred species containing this nutrient at <100 mg/kg. Excess dietary iron has been linked with health issues in browsing rhinos. Additionally, high levels of other minerals (for example Mn, with a mean of 382 mg/kg DM in this study), can precipitate deficiencies in crucial elements such as calcium. In view of the structural and chemical variations of the different parts of the same plants, dietary guidelines should be developed and incorporated into the basic husbandry of these animals that include increasing the number and combinations of species of browse offered daily to adjust for variance in protein, fiber, other nutritional components and food preference, to increasing the quantity of food offered per day based on desired weight gain and reproductive status. This, combined with information on the free‐ranging rhinoceros diet composition, and additional intake and digestibility trials (with concurrent serum analysis to evaluate nutritional status) should greatly assist in providing optimal diets for this highly endangered species. Zoo Biol 0:1–15, 2006. © 2006 Wiley‐Liss, Inc.     

Nutritional content of savanna plant foods: implications for browser/grazer models of ungulate diversification

Models of herbivore diversification rely heavily on adaptations that reflect the nutritional quality of foods consumed. In particular, browsers and grazers are expected to show dichotomous adaptations to deal with high quality (concentrate) browse-based and poor quality grass-based diets, respectively. In this study, we test the widespread assumption that browse represents a higher quality food source than grass. We analyzed plants from a South African savanna, collected over one dry and one wet season across several habitat types, for percent nitrogen (%N), neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid detergent lignin (ADL) to compare variations in nutritional value of different food types. Results show consistently higher %N and lower NDF and ADF of tree foliage and forbs compared to monocots, but the former have consistently higher ADL, implying a higher fiber digestibility in grass compared with browse. Some fruit species have a high NDF and ADL content, implying poorer nutritional value than is commonly assumed. Our findings are in agreement with several other studies depicting relatively poor digestibility of browse (tree foliage and fruit) compared to grass. Reference to browse as high quality foods is therefore misleading, and models of herbivory that rest on this assumption require revision. The more efficient fiber digestibility recorded in grazers compared to browsers cannot be treated as an adaptation to poor quality diets, but rather to maximize benefits of higher fiber digestibility of grass. Spatio-seasonal variations in plant nutritional seem to reflect seasonal and spatial diet changes expected for grazers and intermediate (mixed) feeders. We propose that future studies require further detail on variations in diet, diet quality, and digestive efficiency to properly understand mechanisms of adaptation.     

Effects of browse availability and quality on black rhino (Diceros bicornis michaeliGroves 1967) diet in Nairobi National Park,Kenya

Investigations were conducted to study the effects of browse availability and quality on black rhinoceros (Diceros bicornis michaeliGroves 1967) diet in Nairobi National Park, Kenya, between September 1994 and February 1995. Line intercept method was used to assess availability of browse. The ratios of browsed crowns to the total crown were applied in the estimate of browse use. Proximate analysis and extraction methods were used, respectively, to appraise browse nutritional quality and phytochemical status of twelve species. Thirty‐four plant species were identified as potential black rhino browse, whose availability differed significantly (P < 0.001). Lippia javanica (20.581 ± 3.101, n = 544) and Lannea cornuta (0.963 ± 0.529, n = 544) were the most and least available species, respectively. Only 32 species, however, were utilized, as L. cornuta and Rhynchosia hirta did not show any level of rhino feeding activity. Browse use was found to vary significantly (P < 0.001) during the study period. Grewia similis was most (20.564 ± 2.764, n = 544) and Commelina africana least (0.974 ± 0.974, n = 544) exploited, respectively. Differences in total alkaloids and phenols, crude fibre, crude protein and total ash contents among species investigated were highly significant (P < 0.001). Ether extract values were similar (P= 0.0933) across plant taxa. The study shows that the black rhino is a selective browser feeding on plants with low phenol and alkaloid contents and high fibre values. Of the nutritionally similar species, browsing was driven by availability. These findings suggest that a key habitat factor important in black rhinoceros conservation include diverse plant species with low levels of phenols and alkaloids.     

The analytical and biological accuracy of estimating the dry matter digestibility of different legume species

A comparison was made of the accuracy of 7 laboratory techniques for estimating dry matter digestibility in vivo of 5 legume species represented by 32 samples of known digestibility in vivo. The legumes studied were Desmodium spp., Lablab purpureus, Macroptilium atropurpureum, Vigna sinensis and Medicago sativa. Regressions were calculated relating digestibility in vivo to the laboratory analysis, and the residual standard deviation (RSD) of these regressions was used to calculate the error in predicting digestibility in vivo.For regressions based on all 32 samples the RSD's were: modified acid detergent fibre ± 2.1, acid detergent fibre ± 2.2, dry matter digestibility in vitro ± 2.7, crude fibre ± 3.7, feed nitrogen ± 4.0, Christian's lignin ± 2.8, and Van Soest's Lignin ± 3.7 digestibility units. The cause of the high RSD of these regressions was discussed and it was concluded that it was mainly associated with differences between legume samples grown in different ways, analytical error being only ± 0.5 percentage units or less and the estimation of digestibility in vivo ± 0.7 percentage units.It was concluded that the error in predicting digestibility in vivo from a laboratory analysis is best expressed as the RSD of regressions relating digestibility in vivo to the laboratory analysis, and that this error will not be materially altered by increased replication.     

Nutrition of captive lowland anoa (Bubalus depressicornis): a study on ingesta passage,intake, digestibility,and a diet survey

Members of the Bovini genus are classified as grazers. Smaller species of ruminants are not expected to be able to digest particularly fibrous diets and are more often classified as intermediate feeders or browsers. Anoas (Bubalus spp.) are interesting in this respect as they are the smallest representatives of the Bovini, being only 10–20% of the body weight of other species of the same genus. A feeding trial was carried out with four lowland anoas (Bubalus depressicornis) at London Zoo, investigating diet digestibility by total fecal collection and passage rates by the simultaneous administration of a fluid (Co‐EDTA) and a particle (Cr‐mordanted fibre <2 mm) marker. The diet consisted of legume hay, dairy cow pellets, browse, fruits, and vegetables. The achieved digestibility coefficients averaged 70±4% for dry matter and 57±7% for cell walls (NDF). Mean retention times for the total gastrointestinal tract were 25±4.1 hr for fluid and 39±6.7 hr for particles, respectively. The ratio of forestomach particle:fluid retention was 2.14±0.40. Additional information regarding anoa diets in captivity was collected through a survey targeting all institutions that have anoas in their collection currently. Suitability of the provided diet was evaluated using the ratio of unstructured:structured feeds (unstructured feeds pellets, grains, produce; structured feeds=roughage, browse) on a dry matter basis and an assumed complete consumption of offered unstructured diet items, with only the remaining intake capacity being met by structured items. The use of this ratio reliably predicted one facility that reported chronic diet‐related problems. As other ruminants, anoas should receive a diet with restricted amounts of concentrates and fruits. The comparatively high fibre digestibility and the high selective particle retention in the forestomach suggest a classification of an intermediate/grazing ruminant. Zoo Biol 24:125–134, 2005. © 2005 Wiley‐Liss, Inc.     

Intake,digestibility, and passage of a commercially designed diet by two propithecus species

The digestibility and passage of an experimental diet was used to compare the digestive physiology of two Propithecus species: P. verreauxi and P. tattersalli. Though both animals have a similar feeding ecology, the captive status of P. verreauxi is considered more stable than that of P. tattersalli. The test diet included a local tree species, Rhus copallina, at 15% of dry matter intake (DMI) and Mazuri Leafeater Primate Diet at 85% of DMI. The chemical composition of the diet (dry matter basis) was 25% crude protein, 34% neutral detergent fiber (NDF), and 22% acid detergent fiber (ADF) with a gross energy of 4.52 kcal/g. After a 6 week acclimation to the experimental diet, animals were placed in research caging. After a 7 day adjustment period, animals were dosed with chromium mordant and Co‐EDTA as markers for digesta passage and all feed refusals and feces were collected at timed intervals for 7 days. Digestibility values, similar for both species, were approximately 65% for dry matter, crude protein, and energy, and 40% and 35% respectively, for NDF and ADF. Transit times (17–18.5 hr) and mean retention times (31–34 hr) were not significantly different between species, and there was no difference between the chromium mordant and Co‐EDTA. Serum values for glucose, urea, and non‐esterified fatty acids (NEFA) were obtained during four different time periods to monitor nutritional status. While there was no change in serum glucose, serum urea increased over time. The NEFAs increased across all four time periods for P. verreauxi and increased for the first three periods then decreased in the last period for P. tattersalli. Results obtained indicate no difference in digestibility nor digesta passage between species, and that both Propithecus species were similar to other post‐gastric folivores. Am. J. Primatol. 48:237–246, 1999. © 1999 Wiley‐Liss, Inc.     

Small ruminants: Digestive capacity differences among four species weighing less than 20 kg

Small ruminants are generally classified as either browsers or frugivores. We compared intake and digestion in one browsing species, the pudu (Pudu pudu), body weight 9 kg, and three frugivorous species, the red brocket (Mazama americana), 20 kg, the bay duiker (Cephalophus dorsalis), 12 kg, and Maxwell's duiker (C. maxwellii), 9 kg. Rations comprised: a commercial grain and alfalfa pellet, a small amount of vegetables, and mixed hay. Across species, neutral-detergent fiber (insoluble fiber) consumed averaged 34.2 ± 2.6% of dry matter (DM) while the crude protein consumed averaged 16.1 ± 0.5% DM. Apparent DM digestion was similar in pudu (75.2 ± 4.7%), brocket (73.2 ± 1.1%), and Maxwell's duikers (73.0 ± 2.8%), and significantly lower (P = 0.0167) in bay duikers (67.1 ± 4.3%). There were significant differences among species in digestibilities of neutral-detergent fiber, hemicellulose, and cellulose, but they did not follow body size differences, since larger species were expected to show higher digestion coefficients for fiber compared to smaller species. The type of fiber fed may have influenced these results. Frugivores may be adapted to a diet of soluble fibers, as might be found in wild fruits, instead of the insoluble fibers in the diet fed. Passage trials were conducted on the two smallest species. The mean transit time for pudu was 29.9 ± 0.8 hr, and for the Maxwell's duiker was 42.2 ± 6.4 hr. © 1996 Wiley-Liss, Inc.     

The effect of white-rot basidiomycetes on chemical composition andin Vitro digestibility of wheat straw

Five white-rot basidiomycetes were evaluated for their potential to improve ruminal degradation of wheat straw.Polyorus brumalis, Lyophyllum ulmarium III,Trametes gibbosa, Pleurotus ostreatus, and aPleurotus ostreatus mutant were incubated on wheat straw for 30 d at 28°C. Detergent fiber, crude protein andin vitro dry matter digestibility (IVDMD) were determined. The results showed increasing crude protein and ash contents in fungus-treated straw. IVDMD values were increased in straws treated withP. ostreatus, P. ostreatus mutant andT. gibbosa only. Relative to untreated wheat straw the detergent fiber content—neutral detergent fiber (NDF), and acid detergent fiber (ADF) was reduced in fungus-treated straw and out of three fractions—hemicellulose, cellulose and lignin, hemicellulose showed the largest proportionate loss whereas lignin the smallest one in all 5 samples of fungus treated straw.     

ELEPHANT ECOLOGY IN THE QUEEN ELIZABETH NATIONAL PARK, UGANDA

1. Aerial and ground counts in the Queen Elizabeth National Park from 1963 to 1969 indicate that the number of elephants has more than doubled. The increase appears to be the result of immigration rather than reproduction. 2. Elephant food habits were studied for 10 months in two areas of the Park. In the short-grass/thicket area, browse intake rose markedly whenever the rainfall fell below 50 mm/month. In the tall-grass area without thicket, herbs were eaten frequently during the rains and Cymbopogon grass bases in the dry season. 3. Food availability had an important influence on the diet of elephants. Sometimes, however, elephant were very selective, e.g. for Panicum maximum, Azima tetracantha, Securinega virosa, and Tribulus terrestris. Certain grass inflorescences were selected during the rains, and bases in the dry season. 4. Most browse was consumed in the thicket area during the dry season and most grass was eaten in the tall-grass area of the Park. 5. Stomach and faecal samples gave a similar result and indicated that the diet in the tall-grass area was comparable to that of elephant in Murchison Falls National Park. 6. Analyses of important plant species showed that, in general, tall-grass had a lower crude protein content than short-grass, herbs and browse. Browse leaves had a relatively high crude-protein content in the dry season. Differences were less marked in the rains. 7. Ether extract, or fat content, was high in browse leaves and in Cymbopogon, in particular its bases. These may have been selected in the dry season for this reason. 8. Grass and browse stems were very fibrous and this may have contributed to their being avoided. 9. High carbohydrate levels probably enhanced the palatability of grass bases and browse leaves. 10. Grasses were very siliceous, in particular their bases when contaminated with soil. Elephant took considerable trouble to remove soil. Browse leaves had little silica but were rich in other minerals, and this may have contributed to their greater palatability. 11. Studies of woodland dynamics show a decline in large trees which corresponds to the increase in elephants. In some cases trees have been almost eliminated. Damage to trees indicates that a most important factor in their decline is the elephant. There is some evidence that the trees are eliminated selectively. 12. In the tall-grass area there has been an increase of 46.3% in elephant numbers, but a decline of 80.3 % in buffalo, over the past 15 years. An overall decline in combined biomass of 36.9 % is calculated. Estimates of energy utilization of the annual vegetation production by elephant and buffalo indicates a decline from 6.1 % to 3.9% over this period.     

Preferences among four species of local browse offered to Colobus guereza kikuyuensis at the Central Park Zoo

The objective of this study was to document the browse preferences of five adult Colobus monkeys (one male and four females, fed a nutritionally sound diet) among four local and readily available temperate browse types at the Central Park Zoo. The four browse species used in part A of the study were nasturtium (Tropaeolum majus), mulberry (Morus alba), Russian olive, (Elacagnus angustifolia), and weeping willow (Salix babylonica). During a second trial (part B), weeping willow was replaced by purpleosier willow (Salix purpurea). The Bradley‐Terry categorical model for paired comparisons using the LOGISTIC procedure was used to analyze the data with the SAS System for Windows, version 8.2. Individual preferences and group data were examined. The results of this preference study show that the majority of the Colobus troop preferred browse that was relatively low in fiber fractions. The male's preferences differed from those of the females. Nasturtium, which contained the least amount of lignin, was generally favored by the females but was the male's lowest choice in both trials. Zoo Biol 0:1–8, 2005. © 2005 Wiley‐Liss, Inc.     

Dietary generalists and nutritional specialists: Feeding strategies of adult female blue monkeys (Cercopithecus mitis) in the Kakamega Forest,Kenya

Generalist primates eat many food types and shift their diet with changes in food availability. Variation in foods eaten may not, however, match variation in nutrient intake. We examined dietary variation in a generalist‐feeder, the blue monkey (Cercopithecus mitis), to see how dietary food intake related to variation in available food and nutrient intake. We used 371 all‐day focal follows from 24 adult females (three groups) in a wild rainforest population to quantify daily diet over 9 months. We measured food availability using vegetation surveys and phenology monitoring. We analyzed >700 food and fecal samples for macronutrient content. Subjects included 445 food items (species‐specific plant parts and insect morphotypes) in their diet. Variation in fruit consumption (percentage of diet and total kcal) tracked variation in availability, suggesting fruit was a preferred food type. Fruits also constituted the majority of the diet (by calories) and some fruit species were eaten more than expected based on relative availability. In contrast, few species of young leaves were eaten more than expected. Also, subjects ate fewer young leaves (based on calories consumed) when fruit or young leaves were more available, suggesting that young leaves served as fallback foods. Despite the broad range of foods in the diet, group differences in fiber digestibility, and variation that reflected food availability, subjects and groups converged on similar nutrient intakes (grand mean ± SD: 637.1 ± 104.7 kcal overall energy intake, 293.3 ± 46.9 kcal nonstructural carbohydrate, 147.8 ± 72.4 kcal lipid, 107.8 ± 12.9 kcal available protein, and 88.1 ± 17.5 kcal structural carbohydrate; N = 24 subjects). Thus, blue monkeys appear to be food composition generalists and nutrient intake specialists, using flexible feeding strategies to regulate nutrient intake. Findings highlight the importance of simultaneously examining dietary composition at both levels of foods and nutrients to understand primate feeding ecology.     

The effects of Goami No. 2 rice, a natural fiber-rich rice, on body weight and lipid metabolism

Objective : Increased intake of dietary fiber reduces the risk of obesity and type 2 diabetes. We assessed the effects of a fiber‐rich diet on body weight, adipokine concentrations, and the metabolism of glucose and lipids in non‐obese and obese subjects in Korea, where rice is the main source of dietary carbohydrates. Research Methods and Procedures : Eleven healthy, non‐obese and 10 obese subjects completed two 4‐week phases of individual isoenergetic food intake. During the control diet phase, subjects consumed standard rice; during the modified diet phase, subjects consumed equal proportions of fiber‐rich Goami No. 2 rice and standard rice. We used a randomized, controlled, crossover study design with a washout period of 6 weeks between the two phases. Results : After the modified diet phase, body weight was significantly lower in both the non‐obese and obese subjects (non‐obese, 57.0 ± 2.9 vs. 56.1 ± 2.8 kg, p = 0.001; obese, 67.7 ± 2.1 vs. 65.7 ± 2.0 kg, p < 0.001 for before vs. after). The BMI was significantly lower in obese subjects (26.9 ± 0.5 vs. 26.0 ± 0.6 kg/m², p < 0.001). The modified diet was associated with lower serum triacylglycerol (p < 0.01), total cholesterol (p < 0.01), low‐density lipoprotein cholesterol (p < 0.05), and C‐peptide (p < 0.05) concentrations in the obese subjects. Discussion : These results indicate that fiber‐rich Goami No. 2 rice has beneficial effects and may be therapeutically useful for obese subjects.     

Nutritive value and voluntary feed intake by goats of three browse fodder species in the Sahelian zone of West Africa

Browsing ruminants have access to different biomass, depending on how high they can reach. Foliage consisting of leaves and green pods from Acacia senegal, Pterocarpus lucens and Guiera senegalensis, was collected according to height above ground accessible to either sheep (0.90 m), goats (1.65 m) or cattle (1.50 m). There was a significant variation in the chemical composition of the biomass between species. The crude protein (CP) content was 114, 157 and 217 g/kg dry matter (DM) and the neutral detergent fiber (aNDF) content 604, 534 and 412 g/kg DM for G. senegalensis, P. lucens and A. senegal, respectively. There was no significant variation in chemical composition according to the height accessible by cattle, sheep or goats. The voluntary intake was studied using eight goats per diet. The six diets consisted of the three browse leaves and two pods (A. senegal and P. lucens) and a control. The leaves were fed combined with hay of Schoenefeldia gracilis (maximum 30%) and the control was pure hay. Apparent digestibilities of the same diets, with the exception of G. senegalensis, were measured using five goats per diet. All browse fodders used in the feeding and digestibility trials were high in CP (105–170 g/kg DM) and lignin (164–234 g/kg DM except A. senegal leaves) and low in fiber (322–590 g/kg DM of NDF) compared to the hay (31 g/kg DM of CP and 755 g/kg DM of NDF). The highest intake was of the P. lucens diet (864 g) and the lowest of the G. senegalensis diet (397 g). The intake of pods from A. senegal was higher (1033 g) than from P. lucens pods (691 g). The apparent digestibility of OM and CP in the browse leaves was 0.63 and 0.57 and 0.63 and 0.64 for A. senegal and P. lucens, respectively, higher than for the hay, which showed higher digestibility of NDF. A. senegal pods had higher digestibility for all nutrients than P. lucens pods. Based on the high CP content and the intake and digestibility characteristics, P. lucens leaves and A. senegal leaves and pods can be recommended as protein supplements to low quality diets.     

Untersuchungen zur Methodik der Stoffwechselversuche an Kälbern

The digestible (DE) and metabolizable energy (ME) of full‐fat and defatted rubber seed meals (FRS and DRS) were determined with weanling albino rats fed diets in which the meals replaced either 20 or 40% glucose monohydrate in the reference diet. The nutritive value of both FRS and DRS included at 10, 20 and 30% of the diet as substitutes for groundnut meal and yellow maize was studied with 56, 28‐day‐old albino rats of the Wistar strain. The trial lasted 28 days. Nutrient digestion and nitrogen retention were studied at the end of the second week on test. The DE and ME for FRS were on average 24.7±1.30 and 21.7±0.80 hy/g dry matter and those for DRS were 15.3±0.97 and 13.8 ±0.46 hy/g dry matter.

Incorporation of rubber seed meals at increasing levels in the diet significantly depressed gains and worsened feed/gain ratio (P< 0.01), the diet containing 30% FRS or 20 and 30% DRS being significantly iferior to the control and the diet with 10% FRS or DRS. Significantly (P < 0.01) superior gains but not feed intake and efficiency were obtained for FRS compared to DRS.

Percent intake ‐N retained also decreased with increasing rubber seed levels in the diet. Except for the significantly (P < 0.05) higher crude fibre digestibility of the control diet compared with those containing 20 or 30% FRS or DRS, the digestibilities of other nutrients were not significantly different.     

Seasonal variations in the chemical composition and dry matter degradability of exclosure forages in the semi-arid region of northern Ethiopia

The present study was conduced at two sites (Tembien and Wukro) in the semi-arid region of Tigray in northern Ethiopia to investigate the seasonal dynamics in the chemical composition and dry matter digestibility of grass and browse species of exclosures. The browse species studied in Tembien and Wukro had a mean crude protein (CP) value of 166 and 117 g/kg dry matter (DM), respectively. The mean in vitro dry matter digestibility (IVDMD) coefficient and predicted metabolizable energy (ME) density of the browse species were 0.72 and 9.83 MJ/kg DM, respectively at Tembien, 0.62 and 8.38 MJ/kg DM, respectively, at Wukro. Neutral detergent fibre (NDF) and acid detergent fibre (ADF) values of the browse species varied from 192 to 437 and 127 to 391 g/kg DM, respectively. Acid detergent lignin (ADL) values ranged from 36 to 190 g/kg DM. The mean CP of the grass species in Tembien and Wukro during the long rainy season was 76 and 73 g/kg DM, respectively and values declined below a critical maintenance level during the dry and short rain seasons. Mean IVDMD and ME values for the two sites were 0.41 and 0.47, and 5.38 and 6.11 MJ/kg DM, respectively. The NDF, ADF, and lignin values of the grass species were generally above 700, 400, and 70 g/kg DM, respectively. The CP, IVDMD and ME values of the mixed grass samples differed (P<0.05) among harvesting months and values ranged from 20 to 103 g/kg DM, 0.47 to 0.72 MJ/kg DM, and 6.16 to 9.91 MJ/kg DM, respectively. The browse species could be used as useful dry season protein supplements to the N deficient native grass species. Especial emphasis should be given to propagate Maerua angolensis and Cadaba farinosa at community nursery sites. Harvesting in September, rather than the current extended harvest period that took place in October and November, can considerably improve the feeding value of native grass hay for smallholder ruminant production systems.