Some aspects of progeny testing Southdown rams : a thesis presented in part fulfilment of the requirements for the degree of Master of Agricultural Science in Massey University of Manawatu, New Zealand

Recent changes that have taken place in the preparation and presentation of New Zealand lamb for marketing have been discussed by Barton (1964). Probably the most important of these changes is the increasing amount of lamb that is being displayed and sold as cuts. This is to some extent, the result of, and has definitely contributed to, the growing interest shown by the consumer in meat quality over the last decade. Such interest has been further amplified by increases in the general standard of living of people in many countries, and by the growing consumer aversion to animal fats. Indications of consumer preferences in any particular area may be obtained by surveys, and although these have been carried out extensively for beef, not many have been made concerning lamb. An example however, is that conducted by Marsh (1960), who, by sending questionnaires to members of the middle and working classes of Leeds, showed that the leg was the most popular cut, and that the most favoured quality characteristics in order of popularity were: economy in price and use, leanness, and absence of bone. Results such as these give an indication of the consumers' concept of meat quality, and it is the function of a grading system to integrate this concept with the aims of the lamb producer (Kiehl, 1957; Brayshaw and DeLoach, 1963). These aims will basically be to maximize his profit per unit time, and in order to do this he must produce the greatest possible weight of top grade carcasses in the shortest possible time. Grading of lamb in New Zealand which is carried out subjectively on the whole carcass, is based mainly on conformation and fat cover (Smith-Pilling, 1959), and it has been shown that the carcasses of the top grade contain more fat and less meat or bone, than those of the lowest grade (Barton, 1960). If, as it seems, present grading standards are not a true reflection of consumer preferences, then they can offer no real guidance or incentive to farmers who are interested in planning their management and breeding policies, so as to produce the type of lamb that the consumer wants, and for which he is prepared to pay the highest price. For the same reason there would be no real incentive to improve carcass quality through progeny testing. However, considerable interest has been shown in the grading of meat in recent years, both overseas (e.g., Brayshaw and DeLoach, 1963) and in New Zealand, where the Meat Export Grades Investigation Committee of the New Zealand Meat Producers Board is currently investigating the situation. It is assumed (in order to justify the conducting of the experiment reported herein) that the findings of the above Committee will eventually result in consumer preferences being represented more effectively in lamb grading criteria; thereby providing the producer to some extent with the required guidance and incentives. It has been shown (Morley, 1952) that greater genetic gains can be made through the selection of rams than ewes, and in the case of carcass quality characteristics, where killing of the animal is often necessary for measurement, progeny testing of rams is the obvious selection aid to use

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Refrigeration Requirements for Precooling and Fermentation Control in Wine Making

A database is provided which can be used as a guide to determine the maximum refrigeration capacity required during wine making (precooling and fermentation control). Factors such as maximum daily grape intake, temperature of the grapes, precooling period, fermentation rate, heat gain in the fermentation building, heat gain in the refrigerated water distribution system as well as the efficiency of refrigeration systems are considered. Graphs, as well as equations, are provided from which the maximum refrigeration capacity required for grape intakes varying from 25 t - 1 000 t per day can be determined in kJ/h. Provision is made for three different precooling periods. Separate graphs are provided from which the influence of the temperature of the grapes, as well as the influence of heat gain in refrigerated water distribution systems on the overall refrigeration capacity required, can be determined respectively. The database cannot replace thorough detailed refrigeration system design and engineering. However, it provides wine makers with a simple guide whereby designs can be checked, or the use of the capacity of existing systems managed more effectively

Sources of variability in the analysis of meat nutrient coenzyme Q10 for food composition databases

Coenzyme Q(10) (CoQ(10)) or ubiquinone (2,3-dimethoxy-5-methyl-6-multiprenyl-1,4-benzoquinone) is an endogenous hydroxybenzoquinone liposoluble compound which plays important physiological roles that makes it to be considered as a bioactive compound that may be used for clinical practices and as food supplement. The purpose of this work was to analyse CoQ(10) in three muscles with different oxidative patterns and determine its variability in different animal species (pork, beef, lamb and rabbit). The content of CoQ(10) ranged from 4.3 to 30.9 mu g/g meat with the highest content in those muscles with oxidative pattern. So, more specific data on type of meat cut and proportion of muscles must be given for this nutrient when reporting its content in food composition databases. (C) 2014 Elsevier Ltd. All rights reserved.Grant PROMETEO/2012/001 from Conselleria d'Educacio, Formacio i Ocupacio of Generalitat Valenciana (Spain) is fully acknowledged. Work prepared within the Unidad Asociada IAD (UPV)-IATA (CSIC) framework.Reig Riera, MM.; Aristoy, M.; Toldra, F. (2015). Sources of variability in the analysis of meat nutrient coenzyme Q10 for food composition databases. Food Control. 48:151-154. https://doi.org/10.1016/j.foodcont.2014.02.009S1511544

A Model to Evaluate Buying and Selling Policies for Growing Lambs on Pasture

In pastoral sheep finishing systems, farmers aim to maximize profitability by deciding on when and how many animals to buy and/or sell, while taking into account feed availability and current prices. This paper describes a stochastic lamb growth simulation model with a set of heuristic rules, which has been developed to financially evaluate different management strategies for growing lambs on pasture

Sensitivity Analysis of a Growth Simulation for Finishing Lambs

A stochastic lamb growth simulation model with a set of heuristic rules has been developed to evaluate management strategies for a solely pastoral grazing system in New Zealand (Morel et al., 2005). In the present paper the results of a sensitivity analysis for this model are presented

Energy balance of biogas production from microalgae: Effect of harvesting method, multiple raceways, scale of plant and combined heat and power generation

A previously-developed mechanistic energy balance model for production of biogas from the anaerobic digestion of microalgal biomass grown in open raceway systems was used to consider the energetic viability of a number of scenarios, and to explore some of the most critical parameters affecting net energy production. The output demonstrated that no single harvesting method of those considered (centrifugation, settlement or flocculation) produced an energy output sufficiently greater than operational energy inputs to make microalgal biogas production energetically viable. Combinations of harvesting methods could produce energy outputs 2.3–3.4 times greater than the operational energy inputs. Electrical energy to power pumps, mixers and harvesting systems was 5–8 times greater than the heating energy requirement. If the energy to power the plant is generated locally in a combined heat and power unit, a considerable amount of ‘low grade’ heat will be available that is not required by the process, and for the system to show a net operational energy return this must be exploited. It is concluded that the production of microalgal biogas may be energetically viable, but it is dependent on the effective use of the heat generated by the combustion of biogas in combined heat and power units to show an operational energy retur

Muscularity and leg composition in lambs of different genotypes and ages at slaughter

Foram avaliadas as características morfológicas da carcaça, musculosidade e composição tecidual da perna de cordeiros criados em regime de pasto, provenientes de ovelhas Romney, acasaladas com três raças paternas (Romney, East Friesian x (Finn x Texel) e Finn x Poll Dorset). Aos 150 e 300 dias de idade, os cordeiros foram abatidos em dois lotes, cada um com 15 animais de cada raça paterna, num total de 90 animais. O grupo oriundo de animais East Friesian x (Finn x Texel) apresentou maior quantidade de músculo na perna (1.975 g) e, em comparação ao grupo Romney, semelhante musculosidade da perna (0,45) e maior relação músculo:osso (7x6,69). A musculosidade da perna nos animais descendentes de Finn x Poll Dorset foi menor (0,44), quando comparada à dos demais grupos. Cordeiros abatidos mais tardiamente apresentaram carcaças mais longas e magras, provavelmente pelas condições adversas do verão e do outono, em que são típicas a menor taxa de crescimento e a qualidade inferior de forragem. O genótipo e a idade de abate influem nas características morfológicas da carcaça, no índice de musculosidade e de composição tecidual da perna dos cordeiros.Carcass morphologic characteristics, muscularity and leg tissue composition of pasture fed lambs (Limestone Downs farm, New Zealand) born to Romney ewes and sired by Romney, East Friesian x (Finn x Texel), and Finn x Poll Dorset were evaluated for carcass composition and meat quality. Animals were slaughtered in two age groups (150 and 300 days), each group containing 15 animals of each sire breed, comprising a total of 90 animals. The East Friesian x (Finn x Texel) sired group presented the highest weight-adjusted percentage of leg muscle (1,975 g), and relatively to the Romney group, it had similar leg muscularity (0.45), but higher muscle to bone ratio (7x6.69). Finn x Poll Dorset sired group presented less leg muscularity (0.44) than the other genotypes. Lambs slaughtered at the older age had longer and leaner carcasses at the same weight, probably because of summer-autumn adverse conditions, typically with slower pasture growth rates and herbage quality. Both genotype and slaughter age influence carcass morphologic characteristics, muscularity and leg tissue composition of lambs