3 resultados para meat nutritional quality

em Brock University, Canada


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In the past ten years, many researchers have focussed their attention on parasites regarding the role they may play in causing variations in male secondary sexual traits and subsequent effects on female choice. Male age has also been suggested to be an important factor in female choice if old age reflects superior genes. This study investigated the effects that gregarine gut parasites, age, and diet have on the calling and mating behaviour of the male Texas field cricket, Gryllus integer. Male calling songs were recorded in the laboratory using a Digital Signal Processing Network. The song parameters measured were: pulse rate, pulse width, burst duration, pulses per burst, interburst interval, and percent missing pulses. The effects of parasite load and age on the various calling song parameters was investigated in crickets that were fed two different diets varying in nutritional quality. None of the calling song parameters were affected by either parasite load or age in either diet grou p. Courtship behaviour was ob served and recorded using an Eventlog recorder on an IBM computer in the laboratory. Females mated equally with paras(tized and unparasitized males and with old and young males The total duration and proportion of time spent performing each of 9 courtship displays were recorded for males on each diet. Only one display was affected by parasite load. Highly parasitized males fed the nutritionally inferior diet juddered for a proportionately shorter time than males with low parasite loads. Also, older males performed juddering and shaking antennae proportionally longer and juddering and raising wings for longer durations than younger males. Males that successfully mated were observed for performance of 8 post-copulatory guarding behaviour displays. None of the guarding behaviours were affected by parasite load. However, one display was affected by age, with older males performing guard turning for shorter durations than younger males. Results are discuss,ed in terms of the influence of parasites and age on female choice.

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The Meat Packers Council of Canada was originally founded in 1919 in an effort to encourage farmers to produce better quality livestock. Originally known as the Industrial and Development Council of Canadian Meat Packers, charter members included Harris Abattoir Co. Ltd.; William Davies Co. Ltd.; Swift Canadian Co. Ltd.; Gunns Ltd.; Canadian Packing Co. Ltd.; Puddy’s Ltd.; F.W. Fearman Co.; Ingersol Packing Co. Ltd.; Whyte Packing Co. Ltd.; Gallagher-Holman & Lafrance Co. Ltd.; Gordon – Fronside and Fares Packers Ltd.; Wilson Canadian Co. Ltd.; and Armour & Co. Most of these firms were based in Ontario, but the Council’s operations were soon expanded with the opening of a western and eastern field office. The Council was incorporated in 1961. In 1980, the name changed to the Canadian Meat Council.

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The article was published in the journal Meat Science, Vol. 46, No.4. The focus is data collected for cattle temperament and the quality of meat produced.