Analysis Of Crop Contents Research Articles

Prospects of quality protein maize as feed for indigenous chickens in Zimbabwe: A review

Indigenous chickens (IC) play an important role in African rural household settings, particularly in improving their livelihoods. However, IC production is characterised by low productivity due to poor quality and quantity of feed, compounded by poor management practises. This dire situation is aggravated by the fact that IC are raised under extensive systems, supplemented with meagre grain supplements. They are a hardy poultry species and as a result most farmers assume that their nutritional requirements can be met through scavenging. To the contrary, analysis of crop contents has shown that IC nutritional intake levels are often below optimum for production. To enhance the productivity of IC, there is urgent need to explore the use of alternative nutritionally rich feed stuffs. One of such ingredients is Quality Protein Maize (QPM). Quality protein maize contains elevated levels of lysine and tryptophan, compared to non-QPM. The objective of this article is to review the prospects of QPM as feed for IC, through a strengths, weaknesses, opportunities and threats analysis. Due to its superior nutritional quality, QPM has the potential to enhance growth rate, carcass characteristics and immunity of indigenous chickens. However, QPM is still a new technology in Zimbabwe; most farmers are not aware of its existence. There is, therefore, need for policies and infrastructural adjustments to promote its widespread adoption. Furthermore, there is need for feeding trials as they provide concrete evidence of the benefits of this kind of maize.Key words: Carcass quality, quality protein maize, supplementary feed

Diet of Chinese Grouse (Tetrastes sewerzowi) during Preincubation

Abstract The endemic Chinese Grouse (Tetrastes sewerzowi) inhabits subalpine coniferous forests. Little is known about its diet in the breeding season, especially while birds feed on the ground. Analysis of crop contents indicated that willow (Salix spp.) was the primary food of males (>98% wet weight, n = 4), whereas Dragon spruce (Picea asperata) seeds and willow were the primary foods of females (both >40% wet weight, n = 2). Dragon spruce seeds, invertebrates (mainly ants), and forbs were frequently consumed by females, but seldom by males, possibly to meet the nutrient constraints of egg formation. We suggest the different diets of males and females of this monogamous species may be the result of females allocating more time to searching for scarce, nutritious food, whereas males spend more time in vigilance behavior.

Surface Sterilization of a Maggot Using Bleach Does Not Interfere with Mitochondrial DNA Analysis of Crop Contents

Mitochondrial DNA analysis of a maggot crop can identify the corpse a maggot has been feeding on. Analysis of the crop could be useful in a criminal investigation if maggots are found at a suspected crime scene in the absence of a body, or if there is a question of whether a maggot used in postmortem interval estimations moved onto the corpse from another food source. Such analysis can also resolve a chain of custody dispute if it has been suggested that larval samples have been switched. When recovering DNA from a maggot crop, the analyst must be careful to avoid external contamination. We investigated the effects of three simple wash methods developed to reduce external contamination. Maggots raised on pig liver and intentionally contaminated with cow blood were washed using water, 20% bleach, or a solution containing the enzyme DNase. Only washing the maggots in 20% bleach reduced the amount of vertebrate DNA amplified from the maggots' exteriors. No wash method affected the ability to recover DNA from the maggot crops.

Effects of Organophosphorus Insecticides on Sage Grouse in Southeastern Idaho

Die-offs of sage grouse (Centrocercus urophasianus) were verified in southeastern Idaho in 1981. We captured 82 apparently healthy grouse to quantify the effects of organophosphorus insecticides (OP's) and other pesticides on sage grouse in sagebrush (Artemisia spp.) bordering agricultural lands in July 1985 and 1986. Grouse were fitted with radio collars and tracked through part of each summer. At least 18% of 82 radio-tagged grouse in 1985-86 subsequently occupied fields at the time they were sprayed with OP insecticides dimethoate or methamidophos. Cholinesterase (ChE) assays of brains and residue analysis of crop contents indicated that 5 and 16% of the marked sample died from OP's in 1985 and 1986, respectively. Approximately 200 sage grouse were present in a block of alfalfa sprayed with dimethoate; 63 of these were later found dead and ChE activity in 43 brains suitable for assay were depressed >50%. Maximum residues in crop contents of dead grouse were 18 Ag/g methamidophos and 30 g/g dimethoate. Intoxicated or dead grouse were observed in or near 6 fields sprayed with dimethoate or methamidophos in 1985-86. Twenty of 31 intoxicated grouse radiotagged after being found in dimethoate-sprayed (1986) alfalfa died. Our study indicates that certain pesticides have the potential for adversely affecting grouse populations. J. WILDL. MANAGE. 53(4): 1139-1146 Replacement of organochlorine insecticides (OC's) with shorter-lived chemicals such as organophosphorus (OP), carbamate, and other compounds alleviated many problems with persistence and bioaccumulation of lipid-soluble OC's (Blus 1982, Wiemeyer et al. 1984). Additional research revealed that serious effects, resulting from different modes of action, are also associated with use of the newer compounds, particularly from a short-term perspective where acute or subacute toxicity (Hill and Fleming 1982, Grue et al. 1983, Henny et al. 1985) and reduction in the food base are major concerns (Rands 1985, Potts 1986). Initial evidence that OP's caused mortality of sage grouse was noted in 1981 when a die-off occurred near a potato field sprayed with methamidophos. Brain ChE activity of 5 sage grouse collected when intoxicated (sick, immobile, and showing signs of OP poisoning) and later sacrificed ranged from normal to 61% inhibition (E. F. Hill, Fish and Wildl. Serv., pers. commun.). Data collected in 1983 indicated depression of 40 to 65% in brain ChE activity of grouse collected in a potato field shortly after spraying with methamidophos. These preliminary findings and previous unverified reports of die-offs suggested a potentially serious situation and led to radio-telemetry studies in southeastern Idaho in 1985-86. The purpose of our study was to determine and quantify effects of OP's on a population of sage grouse. We thank K. L. Stromborg, D. H. White, and B. A. Rattner for reviewing the manuscript; the many individuals assisting with field work including C. R. Breckenridge, M. C. Mondecar, and R. K. Sherwood; and J. W. Connelly, Jr. and other members of the Idaho Department of Fish and Game for ideas and assistance. This study was partially funded by the U.S. Environmental Protection Agency (Interagency Agreement DW89931370-01). STUDY AREA AND METHODS The study area was located in southeastern Idaho near Mud Lake, Monteview, Hamer, and Camas in Jefferson County and Arco in Butte County (Fig. 1). This area provided summer range for sage grouse (Gates 1983, Connelly et al. 1988). Major agricultural crops included small ' Present address: Oak Ridge National Laboratory, P.O. Box 2567, Grand Junction, CO 81502.

Chaoborus populations: response to food web manipulation and potential effects on zooplankton communities

Chaoborus populations were studied in two lakes in which fish predation was experimentally reduced, and in a reference lake. In Tuesday Lake, major reduction of fish predation led to substantial increases in density of Chaoborus punctipennis. Analysis of crop contents and estimates of consumption rates suggested that C. punctipennis caused declines of rotifer and copepod populations following the manipulations. In Peter Lake, lesser changes in fish predation caused no major change in density of Chaoborus flavicans, perhaps because food limitation compensated for effects of reduced predation. In both Peter Lake and the reference lake, Paul Lake, C. flavicans preyed heavily and selectively on Daphnia less than about 1.4 mm in total length. Bioenergetic calculations indicated that up to 46% of the daphnids were consumed daily. At some times of the year, certain zooplankton populations (especially noncolonial rotifers, small copepods, and small cladocerans) were strongly influenced by Chaoborus predation.

Seasonal Fluctuations in the Numbers of Rufous Turtle Dove Streptopelia orientalis Using Cultivated Fields, in Relation to Feeding Conditions

(1)Rufous Turtle Doves Streptopelia orientalis using the cultivated fields and forest aroundthe National Agriculture Research Center, Tsukuba were counted from April to November in 1983 and 1984. The number of doves often increased in plots where wheat, barley and corn had just been harvested. On the other hand, the number of them in forests did not show such marked fluctuation.(2) An analysis of crop contents from seven doves showed that they were almost exclusively vegetarian with the seeds of wheat and barley making up more than 80% of the contents.(3) The materials available to dove's foods were collected from quadrats placed in forest floor and cultivated fields. There was a little vegetable materials in the forest floor, but a large amount of seeds was collected in the plots where crops had just been harvested.(4) These results suggest that doves leave their foraging sites where foods had become scarce and aggregate in the sites with a planty of foods, such as plots where crops had just been harvested.

Productivity of herded ducks in West Java

Throughout Indonesia, ducks are kept primarily for egg production. Particularly in Java and Bali, a large proportion of the flocks are kept under a traditional form of management whereby they are herded through recently harvested rice fields for feeding. Observations were made on two flocks of Tegal-type ducks in West Java, emphasis being given to factors influencing egg production. The average egg production was 41.3% and 26·9% (average per duck per day calculated from total production for all ducks for one year). The rate of production through the year varied widely and only rarely reached the level obtained when the same breed is well managed under intensive conditions. The feed obtained by ducks from rice fields was predominantly rice and snails. The average composition of the diet, obtained from an analysis of crop contents, was rice, 77.2%; snails, 17.4%; insects, 1.0%; grasses,, 0.5%; small frogs, 0.2%: crustacea, 0.1% and unidentified materials, 3.6%. No supplementary feed was provided. Both availability and composition of the diet were important factors affecting productivity. In addition, such factors as the effect of transporting birds to a new feeding area and the experience and diligence of the herdsman all significantly influence the actual or potential egg production of fully herded flocks.

Instar and species‐specific diets in two species of Chaoborus1

Analysis of crop contents of chaoborid larvae from Eunice Lake, British Columbia, revealed seasonal changes and instar‐specific differences in the food composition of two coexisting species—Chaoborus americanus and Chaoborus trivittatus. Diel vertical migration played an important role in determining the diet and time of feeding of C. trivittatus. Prey size, abundance, and distribution were used to interpret larval diets. Prey size determined the diet of the first three larval instars, which had difficulty handling large prey. In the fourth larval instar the diet was determined largely by the spatial availability of prey.

The Food of the Grey Field Slug (Agriolimax reticulatus (Muller)) in Woodland

The grey field slug, Agriolimax reticulatus (Muller), widely distributed in a variety of habitats (Quick 1960), is probably the most numerous species and the most important slug pest (Runham & Hunter 1970), although its status as a pest of permanent grassland is not known. South (1965) found average populations on pasture in Northumberland of over 60 per m2, aggregated in association with tufts of Dactylis glomerata L. No detailed investigation has been made of basic food requirements of this species and feeding in natural habitats has only so far been investigated in woodland (Pallant 1967, 1969, 1970). The diet of Agriolimax reticulatus, on grassland neighbouring on the woodland previously studied, was investigated by the analysis of crop contents. Prat (1932), Davies (1959) and Metcalfe (1960) used epidermal characteristics in the taxonomic study of grasses but Davies concludes that the distribution of differentiated cells over the leaf is of limited value for identifying a single leaf of a vegetative shoot and could only provide a 'broad analysis' of grass constituents of animal food. However, with a limited number of grass species available, it has been found possible to distinguish between them (Martin 1955, 1964; Croker 1959; Stewart 1967; Pollard & WaltersDavies 1968; Watts 1968; Bernays & Chapman 1970).