Forage Nutritional Quality Research Articles

Genetic Variability for Mineral Element Concentrations of Wild Jerusalem Artichoke Forage

One of the potential uses of Jerusalem artichoke (Helianthus tuberosus L.) is as a forage crop. Information on inherent differences in forage nutritional quality is essential if the quality of the forage is to be improved through breeding. The objectives of this study were to determine the genotypic variability among and within wild Jerusalem artichoke populations for the concentration of N, P, Ca, Mg, K, and the Ca/P ratio in the forage at flowering, estimate the magnitude of genotype × environment interaction, and examine relationships among mineral concentrations in the forage. Nine wild Jerusalem artichoke populations grown in an irrigated field nursery at Bushland, TX, were evaluated for N, P, Ca, Mg, K, and the Ca/P ratio in the forage at flowering over a 2‐yr period. Population, year × population, and error variances were estimated to calculate the phenotypic variance. Estimates of the within‐population variances were also determined. The adequacy of Jerusalem artichoke forage at flowering for maintenance of a ruminant animal was classified as follows: N, Ca, Mg, and K as adequate, P inadequate, and the Ca/P ratio as excessive. There were genotypic differences among the nine populations for N, K, P, Ca, Mg, and the Ca/P ratio for both years and averaged across years. The magnitude of the genotypic variance components indicated that a substantial proportion of the total variation for these elements was due to genotype, indicating the possibility of improvement through hybridization and selection. Within‐population variation for N, Ca, and K was high, indicating potential for improvement with further selection within populations. Population variances for P and Mg were low, suggesting it will be difficult to improve these with selection. Unfortunately, P is inadequate in the forage to begin with, and our data indicated that selecting within populations for high P may not be very successful.

Nutritional Quality of Forages Used by Elk in Northern Idaho

The nutritional quality (digestible energy, crude protein, and minerals) of 7 known elk (Cervus elaphus Linnaeus) forages was assessed at 4 different time periods from May to November. Species evaluated were elk sedge (Carex geyeri Boott), Kentucky bluegrass (Poa pratensis Linnaeus), western goldthread (Coptis occidentalis Nuttall), clover (Trifolium repens Linnaeus), service-berry (Amelanchier alnifolia Nuttall), redstem ceanothus (Ceanothus sanguineus Pursh), and Scouler willow (Salix scouleriana Barratt). Mineral concentrations generally met estimated requirements for elk in all seasons, except sodium remained below requirements in all seasons. Crude protein in most plant species sampled was adequate for adult gravid or lactating cows throughout the year, although concentrations in graminoids fell below requirements during August. Forage provided adequate digestible energy for gravid or lactating cows only during May, indicating potential deficiencies in summer and autumn. Elk must be selective of plant parts, plant taxa, and foraging habitat to gain adequate nutrition. In this area, summer and fall forage quality may be critical to lactating cow elk. DOI:10.2458/azu_jrm_v55i3_alldredge

Nutritional quality of forages used by elk in northern Idaho

The nutritional quality (digestible energy, crude protein, and minerals) of 7 known elk (Cervus elaphus Linnaeus) forages was assessed at 4 different time periods from May to November. Species evaluated were elk sedge (Carex geyeri Boott), Kentucky bluegrass (Poa pratensis Linnaeus), western goldthread (Coptis occidentalis Nuttall), clover (Trifolium repens Linnaeus), service-berry (Amelanchier alnifolia Nuttall), redstem ceanothus (Ceanothus sanguineus Pursh), and Scouler willow (Salix scouleriana Barratt). Mineral concentrations generally met estimated requirements for elk in all seasons, except sodium remained below requirements in all seasons. Crude protein in most plant species sampled was adequate for adult gravid or lactating cows throughout the year, although concentrations in graminoids fell below requirements during August. Forage provided adequate digestible energy for gravid or lactating cows only during May, indicating potential deficiencies in summer and autumn. Elk must be selective of plant parts, plant taxa, and foraging habitat to gain adequate nutrition. In this area, summer and fall forage quality may be critical to lactating cow elk.

Potencial forrajero de poblaciones de maíz y relación entre atributos agronómicos con la calidad

The purposes of this study were to identify maize populations with high forage quality and to determine associations between agronomic and forage quality variables. Five genetic groups made up by 19 populations and six commercial hybrids were evaluated at Pabellon, Ags., and Torreon, Coah., Mexico, in split plot tests with three replications each and densities of 80,000 and 75,000 plants ha-1 respectively. Dry matter production (TDM), forage nutritive quality and estimated milk production per hectare were assessed. A significant interaction (P<0.01), was detected for populations within groups x locations only for ear dry matter percentage (EDMP), neutral detergent fiber (NDF), and in vitro digestibility (IVD); whereas all variables, except acid detergent fiber (ADF) were significant for groups. Hybrids had the highest TDM and estimated milk production with 20.3 and 12.5 t ha-1 respectively; while the earliest populations derived from highland germplasm showed the highest nutritive value with 49.7, 26.4 and 72.4 % of NDF, ADF and IVD respectively. The top populations for forage production and quality within groups were Pop 800, Lucio Blanco, Pop42 ETO IL, CPAB3, P3066WF2, A7597F2 and the hybrids Pantera and AS900. Days to harvest, NDF and ADF content, were the variables which showed stronger correlation (P<0.01) to IVD with coefficients of -0.74, -0.74 and -0.81 respectively; while TDM, EDMP and NDF showed more correlation to estimated milk production, with coefficients of 0.78, 0.84 and 0.55, respectively.

Suppression of Annual Bromes Impacts Rangeland: Vegetation Responses

Presence of invading annual bromes (Bromus spp.) can alter seasonal patterns of forage production and quality and require management changes for efficient use of infested rangelands in the Northern Great Plains. We studied biological impacts of the presence of brome by comparing brome infested rangeland to similar sites in which brome had been suppressed with autumn applications of atrazine [6-chloro-N-ethyl-N'-(1-methylethyl)- 1,3,5-triazine-2,4-diamine] at 0.56 kg ha(-1) in 1992 and 1993. Each treatment was randomly assigned to three, 12-ha pastures. Vegetation was measured for 5 months (May to September) each year from 1993 to 1995. Each pasture was stocked with 8 cross-bred steers (Bos taurus) from mid-May to mid-September 1993 and 1995 and to mid-August 1994. The forage base varied temporally by date and year, but generally was not less than 800 kg ha(-1). Brome suppression increased (P less than or equal to 0.05) crude protein concentration for western wheatgrass (Pascopyrum smithii Rydb. [Love]) in July (7.1 vs. 9.1%) and August (6.0 vs. 7.1%). With the variation in annual brome stands among years, as influenced by growing conditions, this experiment demonstrated that improvement in forage nutritional quality can be expected from suppression of annual bromes on semiarid rangelands. DOI:10.2458/azu_jrm_v54i6_haferkamp

Suppression of annual bromes impacts rangeland: Vegetation responses

Presence of invading annual bromes (Bromus spp.) can alter seasonal patterns of forage production and quality and require management changes for efficient use of infested rangelands in the Northern Great Plains. We studied biological impacts of the presence of brome by comparing brome infested rangeland to similar sites in which brome had been suppressed with autumn applications of atrazine [6-chloro-N-ethyl-N'-(1-methylethyl)- 1,3,5-triazine-2,4-diamine] at 0.56 kg ha(-1) in 1992 and 1993. Each treatment was randomly assigned to three, 12-ha pastures. Vegetation was measured for 5 months (May to September) each year from 1993 to 1995. Each pasture was stocked with 8 cross-bred steers (Bos taurus) from mid-May to mid-September 1993 and 1995 and to mid-August 1994. The forage base varied temporally by date and year, but generally was not less than 800 kg ha(-1). Brome suppression increased (P less than or equal to 0.05) crude protein concentration for western wheatgrass (Pascopyrum smithii Rydb. [Love]) in July (7.1 vs. 9.1%) and August (6.0 vs. 7.1%). With the variation in annual brome stands among years, as influenced by growing conditions, this experiment demonstrated that improvement in forage nutritional quality can be expected from suppression of annual bromes on semiarid rangelands.

Daily and Seasonal Forage Availability Under Rotational Grazing of a Mixed-Species Temperate Pasture

ABSTRACT Sustainable use of mixed species pastures under management intensive rotational grazing requires information on forage dry matter availability on a daily basis for feed budgeting purposes. Forage availability, forage nutritive quality, and species composition were measured during May to September in 1994 and 1995. Forage available for daily consumption declined in both years as the season progressed. However, the magnitude of this decline varied between years during summer (July to September), which was attributed to differences in soil moisture availability. Under adequate moisture conditions observed in 1994, forage was available at an average rate of 70, 68, 51, 66, 24, and 11 kg dry matter ha−1 d−1 during May, June, July, August, September, and October, respectively. Due to extended periods of dry weather in the summer of 1995, forage availability during the months of July, August and September was reduced to 26, 47, and 11 kg ha−1 d−1, respectively. Total forage consumed during 1994 and 1995 was 8580 and 6460 kg dry matter ha−1, respectively. Averaged over the two years, forage dry matter consumed during the grazing season contained 22% crude protein (CP), 45% neutral detergent fiber (NDF), and 24% acid detergent fiber (ADF). Averaged over die two years, forage cut at ground level was composed of 22% Kentucky Bluegrass (Poa pratensis L.), 33% of mostly smooth bromegrass (Bromus inermis Leyss.) and quack-grass (Elytrigia repens [L.] Nevski), 13% legumes (mostly white clover, Trifolium repens L.), 27% dead matter, and 5% of all other species. These fractions remained stable during the season, except under intense drought when dead matter increased as the bluegrass and white clover fractions declined. However, bluegrass and clover recovered quickly upon return of favorable moisture conditions. The results indicate that these pastures can provide significant amounts of forage under management intensive rotational grazing, but additional feed may be needed for a month or two under extended periods of water stress. While more years of data are needed to accurately assess the effects of rotational grazing on species composition, the limited set of data presented suggests that the pasture composition, a measure of pasture persistence, may remain fairly stable from year to year under the system of grazing management imposed, even though significant but transient changes were observed within a grazing season.

Landscape-Scale Foraging Decisions by Reintroduced Arabian Oryx

We evaluated landscape-level movements of reintroduced Arabian oryx (Oryx leucoryx) in relation to rainfall for 8 years (1982-89). For the first 4 years (1982-85), captive-bred oryx released into habitat devoid of conspecifics demonstrated a distinct shift in movement patterns as foraging conditions deteriorated. Based on mean monthly estimates, during the first 2 months after rain, oryx used large areas (297-724 km 2 ), exhibited low site fidelity (15-32%) overlap between consecutive months), high range expansion (45-62%) new area used each month), and undertook more long distance journeys than expected (P < 0.01). From 2 to 3 months after rainfall, oryx reduced the amount of area used by 86%, increased site fidelity by 72%, reduced range expansion by 29%, and gradually suspended long distance forays. We related this shift to the low nutritive quality of the oryx's primary forage species (Stipagrostis spp.). Once Stipagrostis declined to extremely low levels of crude protein, copper, and phosphorus, the oryx apparently suspended their nutritionally costly searching activities, and instead remained in areas where Stipagrostis was most palatable. In contrast, in years 6 through 8 following their release, the oryx responded to rain with no apparent shift in foraging patterns. Instead, they exhibited less variable and reduced levels of range expansion (10-42%) and area use (180-211 km 2 ). In addition, site fidelity was more consistent on a monthly basis (46-65% overlap),. and long distance movements were more random regardless of the influence of rainfall on the nutritive value or palatability of Stipagrostis. The changes in movement patterns over time were attributed to: (1) a reduction in the oryx's threshold of acceptance for low-quality Stipagrostis; (2) decreased consumption of Stipagrostis and a concomitant increase in browse consumption, and (3) greater knowledge of the landscape. Captive-bred oryx released in years 7 and 8 into the existing reintroduced population reacted to changes in forage nutritive quality caused by rain with a similar shift in foraging patterns as exhibited by the first releases during their first 4 years in the desert. This result emphasizes the relative importance of learned foraging behavior in explaining changes over time in the movement patterns of the oryx. Results of this study indicate that reintroductions of social herbivores should be implemented in ways that enhance the transfer of knowledge from experienced to naive individuals.

Rotational vs. Continuous Stocking of Beef Cows and Calves on Mixed Endophyte-Free Tall Fescue-Bermudagrass Pasture

Endophyte-free tall fescue (Festuca arundinacea Schreb.) furnishes better animal performance than endophyte- infected grass but is less persistent under grazing, especially in mixture with common bermudagrass [Cynodon dactylon (L.) Pers]. Rotational (RS), compared with continuous (CS), stocking of endophyte-free tall fescue may improve persistence when grown with an aggressive warm season perennial grass. Four 40-acre bermudagrass pastures no-till seeded witb endophyte-free 'AU Triumph' tall fescue were used, allowing two replications to compare CS and RS methods. Rotationally stocked pastures were divided into 12 paddocks to allow 2 d of grazing and 22 d of rest. Twenty Hereford (Bos taurus)x Brangus (B. indicus x B. taurus) beef cows/40-acre pasture were maintained year around for 3 yr with additional cows added in spring and summer to maintain similar forage availability. Grazing method had no effect on cow weight change, pregnancy rate, or calf weaning weight. Pasture stocking rate and calf weaning weight per acre were 38 and 37% higher (P < 0.10), respectively, and winter hay consumption was 31% lower from rotationally stocked pastures because of better tall fescue persistence and forage availability. Crude protein (CP) and in vitro dry matter digestibility of available forage generally exceeded 8 and 50%, respectively, throughout the year. Rotational stocking appears to be useful in maintaining stands of endophyte-free tall fescue in bermudagrass pastures.

Effects of Diet on Ungulate Excretion of Enterococcus spp., Streptococcus bovis, and Streptococcus equinus in Feces

AbstractWe compared fecal streptococci (FS) quantities and species composition excreted by native and domestic ungulates that were consuming various feed rations. Group 1 was comprised of elk (Cervus elaphus), white‐tailed deer (Odocoileus virginianus), and bighorn sheep (Ovis canadensis) fed alfalfa (Medicago sativa) hay. Group 2 consisted of elk, cattle (Bos spp.), mule deer (Odocoileus hemionus), domestic sheep (Ovis aries), and horses (Equus caballus) grazing separate grass paddocks of similar botanical composition. Group 3 had four subgroups of cattle each fed a different feed ration: (1) grain and silage; (2) hay, grain, and silage; (3) hay; and pasture. The FS were isolated from ungulate species in each group using the membrane filter technique. Filters were placed on KF streptococcus agar and all pink to red colonies were counted. The FS composition was determined by randomly selecting 20 colonies from each filter and then identified by using growth characteristics and C source utilization. Forage samples were analyzed for crude protein (CP) and neutral detergent fiber (NDF). Ungulates did exhibit some differences in FS quantities and composition, however, all FS species were present in most all ungulates and occurrences were highly variable. Nutritive quality of ungulate diets on grazed forage did not greatly affect the quantities and composition of FS excreted, but trends were difficult to discern because of the high variability of FS samples. Botanical composition of ungulate diets altered both FS quantities and composition. The FS quantities from cattle were greatest when cattle were fed grain rations and smallest when cattle consumed hay or pasture forage. Streptococcus bovis proliferated in feces of cattle fed grain and silage rations while S. equinus and Enterococcus durans dominated on pasture and hay diets. We concluded that the use of FS as indicators of fecal pollution from specific ungulates is unreliable in most cases because of the effects of forage nutritive quality and botanical composition.

Effects of the Timing of Multiple Grazings by Geese on Net Above-Ground Primary Production of Swards of Puccinellia Phryganodes

SUMMARY (1) The effects of the frequency and timing of multiple grazings (including faecal input) by captive goslings of the lesser snow goose on net above-ground primary production (NAPP) and shoot nitrogen content of swards of the forage grass, Puccinellia phryganodes were examined. The effects of clipping and addition of nitrogen on the growth in pots of individual tillers of this grass were also investigated in a factorial experiment designed to separate the effects of each treatment. The experimental design of both investigations was closely based on the foraging behaviour of wild geese on Puccinellia swards. (2) The clipping of leaves per se which mimicked the leaf demography of shoots grazed by wild birds had a detrimental effect on shoot growth and NAPP. Addition of nutrients ameliorated the adverse effects of clipping on shoot growth. Plants which received nutrients, but whose leaves were not clipped, produced the highest amount of above-ground biomass. (3) During the summer of 1987 plots of Puccinellia were either grazed once every 12 days (one to six occasions), or once every 24 days (two or three occasions), or on three occasions at intervals of 12 days late in the season after the wild geese had left the marsh. Plots grazed on three occasions at intervals of 12 days from late June to early August during the period of rapid growth of above-ground biomass most closely mimicked the foraging behaviour of the wild geese. (4) Seasonal cumulative NAPP in 1987 was significantly higher in plots grazed on three occasions than in ungrazed plots, plots grazed once, or plots grazed repeatedly throughout the season. In 1988 plots were not grazed and a similar trend in NAPP was obtained, except that the NAPP of plots grazed late in the season in 1987 was low. The departure of wild geese in early August may be necessary if swards are to recover from the effects of defoliation. (5) During the summer of 1987, forage quality (N content) and NAPP together were highest in plots grazed on three occasions at intervals of 12 days - the treatment closest to the foraging pattern of wild birds. In July of the following summer shoot nitrogen content did not differ among the exclosed plots, irrespective of the treatment in 1987, and all values were lower than that for shoots from adjacent swards which were grazed and fertilized by wild geese. (6) The results show that NAPP and the nutritional quality of forage are de

In vivo nutritional evaluation and feeding value of silage made from extensive pastures containing wildflowers and herbs

With the trend in agriculture to more extensive systems of production it is likely that less productive grasslands with lower inputs of fertilizer nitrogen will be used. However, there is a need to marry conservation orientated policies with profitable farming. It is therefore necessary to study the nutritional quality of forage from extensive pastures which will be used for animal production. The objectives of this experiment were to measure the digestibility in vivo of silages made from extensive pastures containing grasses, clovers, wildflowers and herbs and to investigate the feeding value of big bale silage from these pastures for feeding dairy heifer replacements for calving at two years of age.

Prediction of Leaf Fraction, Neutral Detergent Fiber, and Intake of Ground Forage Samples by Airflow Segregation1

Research on forage nutritional quality is facilitated by procedures that are fast and simple and that require only small samples. This is especially true for dry matter intake, which can now be accurately evaluated only by feeding trials. In order to evaluate airflow segregation as a method of forage analysis, oven dried forage samples, ground to pass a 2‐mm screen, were separated into coarse and fine portions using several airflow speeds in a seed cleaner. An airflow speed setting of 7 units gave the cleanest separation of leaf from stem material, but contamination of the coarse portion with leaf fragments and of the fine portion with stem fragments could be easily seen at 4✕ magnification. However, for alfalfa (Medicago sativa L.), actual leaflet fraction of the original herbage regressed on coarse portion of the separated material gave the equation Y = 1.669 – 2.665. X, n = 25,r2 = 0.99, and a root error mean square of 0.024. Neutral detergent fiber (NDF) and intake of alfalfa herbage were highly correlated to the coarse portion (r = 0.85 and ‐0.87, respectively), but this was not true when other forage species were considered. Airflow separation can be calibrated to predict leaf and NDF fractions of pure alfalfa samples, but a universal relationship was not found across a range of temperate forages.

Influence of Photoperiod and Nutrition on Pine Vole Reproduction

Two experiments were conducted to determine the relative influence of photoperiod and nutrition on reproduction and related characteristics of pine voles (Microtus pinetorum). In a laboratory experiment, adult voles fed a rabbit chow diet supplemented with fresh apples had more body fat and males had heavier testes than those fed only rabbit chow. Voles of both sexes on a 14L:I OD photoperiod had heavier reproductive organs than those on a naturally declining photoperiod. In a field study, the presence of apples as a food source during the autumn had little effect on vole body fat content. However, more females were pregnant and males had heavier testes and seminal vesicles and higher spermatoza counts in areas with apples. We conclude that both photoperiod and nutrition influence the extent of late autumn and winter breeding of pine voles and that their effects are additive. INTRODUCTION The pine vole, a pest that causes economic losses in apple orchards along the eastern seaboard (Byers et al., 1976), has a longer breeding season and higher reproductive rates in maintained orchards than in abandoned orhards (Noffsinger, 1976; Cengel et al., 1978). Cengel et al. (1978) hypothesized these differences arose from the higher nutritional quality of forage and greater availability of fallen apples in maintained orchards. Lochmiller (1980) demonstrated that forage biomass was higher in maintained orchards, and differences in habitat or supplemental feeding have been shown to cause higher rates of reproduction and growth in other microtine rodents (Krebs and DeLong, 1965; Andrzejewski, 1975; Cole and Batzli, 1978, 1979). There are few studies of the influence of photoperiod on reproduction in pine voles. Geyer and Rogers (1979) reported that exposure to low light intensity reduced the number of litters and number of young per litter in pine voles. However, Lepri and Noden (1984) reported that reproductive function was independent of photoperiod in adult male pine voles in North Carolina. Short photoperiod has been shown to reduce litter size, number of litters or reproductive organ weights in Microtus agrestis (Baker and Ransom, 1932a,b), M. pennsylvanicus (Imel and Amann, 1979) and M. californicus (Nelson et al., 1983). The additive effects of photoperiod and nutrition have been demonstrated in M. montanus (Pinter and Negus, 1965) and M. californicus (Nelson et al., 1983). In the present study, two experiments were conducted to determine the relative influence of nutrition and photoperiod on reproduction in pine voles. MATERIALS AND METHODS Laboratory experiment. -The objective of this experiment was to test the influence of nutrition and photoperiod on reproductive activity in adult pine voles under controlled conditions. The experiment was conducted in an unheated, metal frame building with translucent skylight panels. Three to 5 cm of soil were placed in the bottom of four concrete troughs (originally constructed as fish raceways) inside the building. Troughs were divided into 12 sections of 2.2 by 1.1 m each. Adult pine voles were trapped from an orchard near Roanoke, Virginia, in late July and immediately placed in the troughs. On 15 September, groups of two male and five female voles were formed at random and placed in each of the 12 sections. Half of these groups was fed ground Purina Rabbit Chow (C) ad lib. The other half was fed ad lib amounts of both sliced apple and ground rabbit chow (A). The six groups on each diet

COMPARISON OF GROWTH, FORAGE YIELD AND NUTRITIONAL QUALITY OF DIPLOID AND AUTOTETRAPLOID MAIZE SYNTHETICS

Three autotetraploid maize synthetics were compared with four diploid synthetics of similar adaptation in yield trials and growth analysis experiments at several southern Ontario locations, in order to assess the potential of tetraploid maize as a source of forage. No differences were observed among ploidy levels in productivity of whole-plant dry matter, or in nutritional quality of forage. Tetraploids appeared to be lower in dry matter content at harvest and through much of their period of growth.Key words: Silage corn, forage corn, autotetraploid, (Zea mays L.)

Yield and Nutritional Quality of Intermediate Wheatgrass Infested by Black Grass Bugs at Low Population Densities

An important question in the management of wheatgrass monocultures during recent years has been the effect of the grass bug Labops spp. (Hemiptera: Miridae) on forage yields, forage quality, and stand longevity. Grass bugs occur throughout the Intermountain and adjacent areas (Bohning and Currier 1967; Denning 1948; Todd and Kamm 1974) and have been reported to cause extensive damage to crested wheatgrass (Agropyron cristatum) and intermediate wheatgrass (A. intermedium) stands in some areas (Knowlton 1967; Haws et al. 1973). Their effect on nutritional quality of forage has remained virtually unknown, although Todd and Kamm (1974) inferred significant short-term losses in a recent Oregon study. The study reported here was initiated to determine the effects of relatively low population densities of black grass bugs (Labops hesperius) on yield and nutritional quality of intermediate wheatgrass.

The evaluation of forage nutritive quality by microdigestion

Ruminal microdigestion of test forage samples was run concurrently with conventional digestion trials in an experiment devised to evaluate microdigestion as a technique for assessing the nutritive quality of forages common to southern Australia. Microdigestion was found to be closely associated with in vivo digestibility. Significant variation in microdigestion estimates was attributed to basal diet, test forage, pouch fabric and individual sheep; microdigestion differences of the order of two to three units were detectable. It is suggested that the microdigestion technique offers potential scope for providing unbiased assessment of forage nutritive quality under field conditions.

Effect of Snow Depth on Mule Deer in Middle Park, Colorado

Effect of Snow Depth on Mule Deer in Middle Park, Colorado

Forage yield and nutritive quality of haulm from dual-purpose cowpea cultivars for dry season, livestock and feeding in Nigeria

The availability of high quality forage, especially during the dry season remains a major challenge to ruminant livestock production in Nigeria and many parts of West Africa. This study was conducted to evaluate forage yield and nutritive quality of haulm from selected dual purpose cowpea (Vigna unguiculata L. Walp.) cultivars in the humid rain forest zone of Nigeria. The forage and pod yields of twenty cultivars were evaluated at the Teaching and Research Farm of the Federal University of Technology, Owerri, Imo State, Nigeria. Subsequently, five dual-purpose cultivars, namely IT04K-334-2, IT07K-293-3, IT04K-194-3, IT04K-405-5, IT06K-147-2, were selected based on forage and pod yields from previous trial, for determination of chemical and fibre compositions. The results revealed significant (P&lt;0.05) differences in pod and forage yields among the twenty cowpea cultivars, with yields ranging from 0-1.5 t ha-1 and 0.1-4.5 t ha-1 for pod and forage, respectively. Cultivars IT07K-293-3, IT04K-405-5, IT06K-147-2, IT07K-194-3, IT04K-334-2, IT04K-267-8 and IT04K-339-1 recorded the highest fodder yields of at least 2715 t ha-1, with crude protein contents ranging from 10.49% in IT07K-194-3 to 13 .57 % in IT04K-405-5. Cultivars IT07K-194-3, IT07K-293-3, IT07K-220-1-9, IT06K-147-2, IT07K-187-55IT04K-332-1 recorded the highest pod yields (&gt;700 t ha-1). There were significant (P&lt;0.05) differences in crude protein, ether extract and non-fibre carbohydrates (NFC) contents among five cultivars selected from the top ten high yielding cultivars, based on mean ranking score. These selected cultivars are recommended as dual-purpose cowpea for the humid forest zone.

Range Management. Principles and Practices

(NOTE: Each chapter concludes with Range Management Principles and Literature Cited.) 1. Rangeland and Man. Rangeland Defined. Range Management Defined. Relationship of Range Management to Other Disciplines. The Importance of Rangelands to Humans. Desertification. Changes in the Amount of Rangeland. 2. Range Management History. The Origin of Range Science. Chronological History of Livestock Grazing. Government Land Policies. Development of Range Management in Other Countries. 3. Rangeland Physical Characteristics. Precipitation. Wind. Temperature. Humidity. Climate Types. Topography. Soils. Influence of Rangeland Physical Characteristics on Range Animals. 4. Description of Rangeland Types. Types of Rangeland. Rangelands of the United States. 5. Range Plant Physiology. Basic Concepts. Carbohydrate Reserves. Water Relations. Plant Morphology. Reproduction. Resistance to Grazing. Grazing Optimization Theories. 6. Range Ecology. Ecology Defined. Rangeland Ecosystem Components and Functions. Importance of Rangeland Ecosystem Services. Succession and Climax. Drought. Competition. Plant Succession and Range Management: A Conclusion. 7. Range Inventory and Monitoring. Vegetational Mapping. Determination of Vegetational Attributes. Grazing Surveys. Determining Grazing Intensity. Range Condition. Determining Trend. 8. Considerations Concerning Stocking Rate. Importance of Correct Stocking Rate. Influence of Stocking Rate on Forage Production. Flexible Versus Fixed Stocking Rates. Grazing Intensity Considerations. Setting the Stocking Rate. Adjustment for Distance from Water. Key-plant and Key-Area Principles. Forage Allocation to More Than One Animal Species. Conclusion. 9. Selection of Grazing Methods. Definition of Grazing System Terms. Considerations in Grazing System Selection. Grazing Systems for Riparian Zones. Grazing Systems for Developing Countries. Economic Advantages of Specialized Grazing Systems. 10. Methods of Improving Livestock Distribution. Factors Causing Poor Distribution. Better Livestock Distribution Methods. 11. Range Animal Nutrition. Nutritional Components of Grazing Animal Foods. Methods for Determining the Nutritional Value of Grazing Animal Diets. Diet and Nutritional Quality of Livestock on Different Ranges. Forage Intake of Grazing Animals. Comparative Nutritive Value of Plant Parts. Seasonal Effects on Forage Nutritional Quality. Grazing Intensity Effects on Forage Nutritional Quality. Comparative Nutritive Value of Range Forages. Comparative Nutrition of Grazing Animals. How Grazing Animals Cope with Periods of Low Forage Quality. Energy Expenditure by Grazing Animals. Supplementing Range Livestock. Range Livestock Nutritional Guidelines. 12. Range Management for Multiple Use. Herbage Residue and Multiple-Use Concepts. Rangeland Hydrology. Grazing Impacts on Watersheds. Manipulation of Water Yield. Timber Production and Grazing. Management Systems for Trees, Livestock, and Wildlife. Recreational Use of Rangelands. 13. Range Livestock Production. Economics of Range Livestock Production. Management of Reproductive Efficiency. Animal Selection. Common-Use Grazing. Livestock Management During Drought. Poisonous Plant Problems. 14. Range Wildlife Management. Trends in Rangeland Wildlife Populations. Basic Concepts Concerning Wildlife Habitat. Grazing Effects on Rangeland Wildlife. Grazing Methods for Wildlife Enhancement. Provision of Forage to Big Game. Impacts of Brush Control on Wildlife. Game Ranching. Wild Horses and Burros. Small Mammals. Insects. Predators. Threatened and Endangered Wildlife. 15. Manipulation of Range Vegetation. Rangeland Problems in the Western United States. Control of Unwanted Plants. Economic Considerations. Considerations in Seeding. Fertilization. Forage Conservation. 16. Range Management in Developing Countries. Challenges to African Pastoralism. Problems Relating to Livestock Numbers. Land Tenure and Communal Grazing. Problems Relating to Dry-Season Grazing. Drought. Development of Livestock Water. Range Burning. Range Problems in Latin America. Agricultural Versus Industrial Development. 17. Planning, Technology, and the Future. Range Management Planning. Technology and Computers. Systems Analysis. Virtual Reality. Economic Analysis. Computers and the Future. Index.