• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 6
  • 5
  • 5
  • 5
  • 5
  • 5
  • 5
  • Tagged with
  • 11
  • 11
  • 11
  • 6
  • 6
  • 6
  • 6
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Foods and habitat of four anatinids wintering on the Fraser Delta tidal marshes

Burgess , Thomas Edward January 1970 (has links)
The Fraser delta tidal marshes are important for migrating and wintering ducks, in particular, Mallard, Pintail, Widgeon, and Green-winged Teal. Agricultural, residential, and industrial development threaten the tidal marshes with destruction and quality loss. In order to preserve and protect the most valuable areas, and perhaps improve the characteristics which attract ducks, it was considered necessary to determine areas of most value, and the environmental characteristics which could be improved. A study of the occurrence and food habits of ducks on the tidal marshes was considered to be the best means of determining the importance of each unit. The relative importance of the tidal marshes for loafing and feeding habitat was indicated from a synthesis of all available information on duck use of the entire delta area. Aerial censuses conducted throughout two winters provided data on the distribution and abundance of Mallard, Pintail, Widgeon, and Green-winged Teal on the foreshore and adjacent upland. It was found that an annually variable population of ducks was present from September until May, with the largest numbers occurring during fall and spring migrations. The tidal marshes attracted approximately one-half the ducks on the deltas— with the largest proportions occurring in September, early October, late March, April, and May.. All four census units of the tidal marsh attracted similar winter totals of ducks although the relative number at each unit varied throughout the winter. As all of the tidal marshes appeared important to ducks, the features of all of them were studied. Area was determined from aerial photographs, and topographical relationships were determined from known tide levels. Composition and distribution of vegetation was determined from line transects. Relative production of seeds was determined from line transects and seed samples. The tidal marshes were found to cover approximately 3,733 acres, sloping from the approximately thirteen foot to the seven foot tide level. A six to eighteen inch "drop-off", which usually occurred near the ten foot tide level, separated the tidal marsh into an upper and lower zone, each with a different vegetative composition. Fourteen plant species were found, of which five Cyperaceae species, Scirpus americanus , Carex lyngbyei , Eleocharis macrostachya , Scirpus paludosus , and Scirpus validus composed ninety-three percent of all plants. The first two species, dominant on the lower and upper zones respectively, formed seventy percent of all plants. Distribution appears to be determined by the degree of tidal flooding, the degree of local drainage, and possibly by undemonstrated differences in soil and water salinity. Seed production varied annually, and was related to the degree of tidal flooding. Scirpus validus and Carex Lyngbyei produced the most seeds, followed next by Scirpus americanus. Ducks were collected on the tidal marshes and adjacent agricultural areas. Analysis of their stomach contents revealed that Carex Lyngbyei, Scirpus validus and Scirpus americanus were the most important- tidal marsh food items. Polygonum lapathifolium and P. persicaria were the most important seed foods taken on the agricultural areas. Although Mallard, Pintail, and Green-winged Teal consumed mostly seeds, Widgeon consumed primarily green vegetation, including winter rye, Lolium sp., and several Gramineae species. A synthesis of the available information indicates that the tidal marshes were most important as loafing areas from October until January, while during the remainder of the period, from September until May, they were also important for the provision of food. The control of water levels, by diking and pumping, appears to be essential for the improvement and protection of the tidal marshes. / Science, Faculty of / Zoology, Department of / Graduate
2

Nutritional evaluation of industrial food wastes in ducks diets

Farhat, Antoine G. January 1997 (has links)
Six hundred day-old Pekin and Muscovy male ducklings were raised on diets based exclusively on food wastes to market ages of 7 and 11 weeks, respectively. Three dietary treatments were offered to the birds: commercial pellets (control), feeds consisting partially of food waste, and feeds consisting entirely of food waste. The two experimental treatments each had a dry pelleted diet and a wet mash diet. Twenty-four carcasses from each breed were analyzed to determine the effects of the experimental diets compared to those of the control (commercial pellets). In addition to corn and soybean meal, a total of nine food waste ingredients were tested. The precise-feeding technique was performed to establish DM, fat, and fibre digestibility as well as N retention, AME, AMEn, TME, TMEn values for the 11 feedstuff ingredients. The results of this study provide reliable data for formulation of duck diets using the tested food waste ingredients as well as corn and soybean meal in both Pekin and Muscovy ducklings at 2 different ages during growth. (Abstract shortened by UMI.)
3

Application of ultrasound technology for selection and production of lean Pekin ducks

Lavallée, Sophie. January 1998 (has links)
Knowledge of carcass merit will help the meat duck breeder identify superior stock and accelerate genetic improvement. Selection for leanness will enhance product acceptance by the consumer. Heritability values for carcass traits are in the medium-high range. Feed intake level during rearing is critical for reproduction. The objectives were to evaluate (1) the response of breast muscle thickness of the F1 progeny from parent breeders selected for maximum muscle thickness at market age and (2) the effect of 2 levels of feed restriction during development for subsequent egg production. In a commercial flock, 4842 Pekin ducks (Brome Lake Ducks Ltd.) were individually weighed and measured by ultrasound for breast muscle thickness (MT, mm) at 47 days of age. Three groups of 120 females and 25 males each were selected and allocated to the following groups: (1) control (CT), randomly selected; (2) maximum body weight (BW), and (3) maximum MT. From 7 to 23 wk old, one half of breeders followed a conventional restriction (CR) at 67 g feed/kg body weight daily, the other half were slightly more restricted following a Macdonald restriction (MR) at the same intake as CR but with a weekly skip-a-day feeding. (Abstract shortened by UMI.)
4

Nutritional evaluation of industrial food wastes in ducks diets

Farhat, Antoine G. January 1997 (has links)
No description available.
5

Application of ultrasound technology for selection and production of lean Pekin ducks

Lavallée, Sophie. January 1998 (has links)
No description available.
6

Growth and IGF-I response to breast muscle selection by ultrasound and dietary protein programs in Pekin ducks

Farhat, Antoine G. January 1999 (has links)
No description available.
7

Growth and IGF-I response to breast muscle selection by ultrasound and dietary protein programs in Pekin ducks

Farhat, Antoine G. January 1999 (has links)
Four experiments were conducted to determine the reproductive, metabolic, growth and IGF-I response to ultrasound selection for increased breast muscle thickness (MT) in Pekin ducks. Selection for body weight had a negative ( P < 0.05) effect on the reproductive performance while the selection for greater breast muscle thickness resulted in egg production, fertility and hatchability similar to those of the control line (C). Males from the MT line reached market weight at 6 wk but the breast muscle thickness improved from 6 to 7 wk. Compared to females from the C line, MT females had higher (P < 0.05) carcass yield, plasma glucose, and body protein; lower fat and plasma uric acid; and no difference (P > 0.05) in plasma triglycerides and total cholesterol. Males responded more efficiently to increasing dietary protein than females, and males selected for greater MT can be slaughtered at an earlier age when a high protein feeding program (HP) was followed. Males receiving HP had greater (P < 0.05) pectoralis muscles yield, longer keel bone, and lower breast skin and total skin fat yields. Female dissection data show similar (P > 0.05) effects of high and medium protein programs. Increasing dietary protein reduced (P < 0.05) carcass fat and increased (P < 0.05) crude protein (CP). In vivo breast muscle measurement correlated positively (P < 0.05) with body weight, pectoralis yield, and keel bone length. Birds with higher pectoralis yield tended to have more CP and less fat in their carcasses. A low correlation (r = 0.19) was found for the caliper measurement of breast skin plus fat thickness and carcass fat. We determined the metabolic differences between lean and fat male and female ducks, associated metabolic parameters and body composition, and assessed the difference between two feeding solutions for the determination of metabolic endogenous losses. There was a positive correlation between breast muscle:total breast muscle thickness ratio (MT/TO
8

Recycling of agro-industrial food wastes into feed for Pekin duck meat production towards a sustainable agriculture in the province of Quebec

Normand, Luc. January 1997 (has links)
Two experiments were carried out to assess the nutritional potential of food wastes to be transformed into duck meat. In both experiments, 600 day-old unsexed White Pekin ducklings were randomly distributed into 6 different dietary treatment groups. / In both experiments, the ducks receiving food wastes had significantly ($ rm P<0.05$) more total body fat than did the control. This was most likely due to the quantity of dietary fat ingested by the ducks. The results reported in this thesis indicate that it is possible to raise Pekin ducks to market weight using food wastes as the only source of feed. To meet the consumer demand of leaner carcasses, the food wastes with a high fat content should be included in a limited amount in the ration. The recycling of industrial food wastes into animal products could be considered an important step toward a sustainable agriculture system in Quebec. (Abstract shortened by UMI.)
9

Recycling of agro-industrial food wastes into feed for Pekin duck meat production towards a sustainable agriculture in the province of Quebec

Normand, Luc. January 1997 (has links)
No description available.
10

Economic feasibility of processing food waste and incorporating processed food waste products in least cost duck feeds

Budu, Ben Asare. January 2001 (has links)
The focus of this thesis was to analyze the least cost of producing rations for ducks in three age categories from a mixture of conventional feed ingredients and three different processed food waste products and to examine the financial and economic feasibility of establishing an industrial plant to produce these food waste products in the Montreal region. The first part of the thesis was investigated through the use of a linear programming model. The effect of recognizing the variability of protein levels in the various feed ingredients was examined through the use of chance-constrained programming. / The second part of the thesis was examined using economic and financial analyses for the investment. The basic plant requirements to produce the three processed food waste products were the same, however energy costs were different for the three products. Revenue was generated from tipping fees and the sale of the three processed food waste products. (Abstract shortened by UMI.)

Page generated in 0.0916 seconds