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  • 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.
31

Nutrient content and carcass composition of South African mutton with a focus on bioavailability of selected nutrients

Sainsbury, Jeanine 30 November 2009 (has links)
South Africans frequently consume red meat as part of their diet. However the nutrient content of South African sheep meat is derived from other countries. The Red Meat Industry considered it essential to have more reliable data and thus the nutrient content of A2 South African lamb was recently determined and published. This is the next phase of the study in which the right sides of C2 mutton carcasses were used to determine the nutrient and physical (carcass) composition of each raw cut as well as the whole carcass by calculation. Eighteen mutton carcasses of the most commonly consumed breeds, namely Dorper and Merino, in South Africa were selected. The carcasses were obtained from large abattoirs form three mutton producing regions in South Africa namely Ermelo, the Karoo and Kalahari. Chilled carcass sides were subdivided into ten primal cuts. Three cuts (shoulder, loin and leg) from the left side were cooked in order to determine the nutrient composition thereof. The cuts were dissected into meat which consists of muscle and intramuscular fat, intermuscular - plus subcutaneous fat and bone in order to determine the physical composition per cut and for the whole carcass. Meat compromise of 63.2% of the carcass, with bone contributing to 20.5% and fat to 16.9%. Results showed differences in the physical composition of South African C2 mutton as it contains on average 47% less fat and 19% more lean muscle, when compared to previous published composition data. Three cuts (shoulder, loin and leg) from the left side were cooked in order to determine the nutrient composition thereof. Cooking resulted in an increase in the protein and cholesterol concentrations of the cooked cuts. Iron content was higher in the cooked loin and leg but decreased in the cooked shoulder. According to nutrient density, a 100g edible portion of the leg, loin and shoulder have a nutrient density higher than one for protein, iron, zinc and vitamin B12 indicating that these cuts are a good source of these specific nutrients. A 100g edible portion of the loin cut contained higher fat quantities than the cooked shoulder and leg cuts. The loin cut also had a higher cholesterol content at 70.8mg compared the 58.5mg cholesterol content in the shoulder and 57.9mg in the leg cut. However, these values were calculated with all associated subcutaneous fat and it is known that many consumers trim on plate, especially the loin cut. Considering the fact that significant differences were apparent between the current study and previous data derived from other countries, it emphasizes the importance of determining the nutrient composition of South African food products in order to increase the validity of the SA food composition tables. Food-based approaches targeting the relief of micronutrient deficiency usually encourage the consumption of animal foods together with the consumption of green leafy vegetables (GLV). The inclusion of GLV and red meat, two micronutrient rich foods, can be a strategy based on mutual supplementation to combat nutritional deficiencies as it has the potential to alleviate numerous micronutrient deficiencies including iron and vitamin A deficiency. / Dissertation (MSc)--University of Pretoria, 2009. / Food Science / unrestricted
32

Factors affecting the composition and physical properties of pig adipose tissue triacylglycerols

Dziubajlo, Maria January 1991 (has links)
No description available.
33

Effect of Moringa Oleifera and probiotic inclusion on growth performance carcass characteristics and cost benefit analysis in broiler chicken production

Ramathithi, Tshilidzi 11 August 2020 (has links)
MSCAGR (Animal Science) / One of the ways to minimise cost and promote health in humans and animals is to use natural feed additives instead of antibiotics. Moringa oleifera (Moringa) is a phytobiotic which possess anti-microbial and immune-modulatory properties and contains high levels of nutrients and it can be used as a feed additive. Probiotics are feed additives which consist of living microorganisms that have beneficial effects on the physiology and health of other organisms. The objective of the study was to determine the effect of various levels of Moringa oleifera and probiotics inclusion on growth performance, carcass characteristics and cost benefit analysis for broiler chicken production. Moringa oleifera leaf powder was purchased from Bethel Farm No:683 Bethel mission Gucksdadt Vryheid in Zululand district AbaQulusi municipality. The study was a 5x2 factorial design with five levels of Moringa and two levels of probiotic. Six hundred (600) Ross 308-day old chicks were received and fed commercial starter. The experimental treatments were randomly divided into five levels of Moringa with and without probiotics introduced through drinking water at grower to finisher phase. The diets were supplemented with different inclusion levels of Moringa (Mo) as follows: 0g/kg (M0), 0.6g/kg (M3), 1.2g/kg (M6), 1.8g/kg (M9), 2.4g/kg (M12) of Moringa oleifera leaf meal (MOLM) and probiotic at P0 (0ml/bird/week), P1 (1 ml/bird/week) of a commercial probiotic administered in water for the first three weeks (starter phase). The experiment had three replications with 20 birds per replicate. MOLM and PRB interaction had no significant effect (P>0.05) on any of growth parameters and same findings with MOLM. Probiotics treatments had significantly reduced (P < 0.05) mortality rate (MTRT) in the grower phase. MOLM×PRB had significant effect on (P<0.01) feed intake (FI), MOLM had significantly reduced (P< 0.05) average bodyweight gain (ABWG) and FI in finisher phase. MOLM and PRB interaction had significant effect (P< 0.05) on dressed weight only and non-significant effect (P>0.05) on the rest of carcass parameters. MOLM inclusion levels did not significantly affect (P>0.05) back fat weight. However, MOLM inclusion level significantly reduced (P< 0.05) dressed weight, shank length, wing weight, drum and thigh weight, back weight and breast muscle weight. PRB inclusion in the diets significantly increased (P< 0.01) shank size and drum + thigh weights (P<0.05). MOLM and PRB inclusion level had no significant effect (P>0.05) on giblets parameters. MOLM and PRB interaction had significant effect on (P<0.05) water holding capacity (WHC) and hardness. MOLM had significant effect (P<0.05) on pH and dripping loss. A significant effect between (MOLM×PRB) Moringa oleifera leaf meal and probiotics (P<0.01) was observed on CD, C* and b*. MOLM had significant effect (P<0.01) on CD, C*, a*, b*, L*, PRB had significant effect (P<0.01) on h*(increased) and a*(reduced) on colour parameters. MOLM fed at P0 resulted in higher mortality at grower stage. It is concluded that MOLM can be added up to 12% with or without PRB without affecting growth performance at finisher phase and carcass characteristics. Inclusion of MOLM up to 12% had good impact on hardness and water holding capacity in the meat. PRB presence improved the growth performance of birds supplemented with MOLM up to 12% inclusion level. MOLM diets were not economically profitable compared to control diet due to high price level of Moringa oleifera powder supplemented in the diets and no best return weight gain per rand invested amongst the diets. / NRF
34

The effect of two levels of dietary ractopamine hydrochloride (Paylean®) supplementation on growth performance, feed efficiency and quantitative carcass traits in finisher gilts

Teague, Paul David January 2016 (has links)
Ractopamine hydrochloride (RAC) has been used in the pig production industry for over 30 years. RAC is a beta-adrenergic agonist which is supplemented in the feed during the last 28 days prior to harvesting in finisher pigs to modify the pig's metabolism such that nutrients are redirected to favour muscle accretion rather than adipose deposition, and hence improve growth efficiencies, feed utilisation and carcass revenues. The objective of this study was to investigate the effect of dietary ractopamine (Paylean®) supplementation at levels of 0, 5, and 10 mg.kg-1 (hereafter referred to as 0-RAC, 5-RAC, and 10-RAC respectively) on animal growth performance, efficiency and carcass characteristics including daily voluntary feed intake, feed efficiency, absolute daily growth rate (ADG) and daily live weight gain, and backfat thickness for the last 27 days in finishing gilts. In this 27-day study, a homogenous group of 71 grower gilts (LW = 43 ± 1 kg) were pre-selected at a source farm. The gilts were then housed in similar and equally sized group pens at the Hatfield experimental facility of the University of Pretoria and fed a standard maize-soya oilcake based grower ration formulated to contain 0.94% standardised ileal digestible Lys (1.05% total Lys) and 14.01 MJ ME kg-1 during the 28 day pre-adaptation phase. From these gilts, individuals were weighed and 58 gilts selected (average LW = 68.7 ± 4.3 kg), and placed into individual pens and the same diet for 7 days (adaptation phase), afterwhich they were assigned to 1 of 3 treatments in a completely randomized block design with 19, 19, and 20 replicate pens per treatment. The pigs were then fed a standard maize-soya oilcake finisher (treatment) diet containing either 0-RAC, 5-RAC or 10-RAC for 27 d before harvesting. All treatment diets were formulated to contain 1.02% standardised ileal digestible Lys (1.13% total Lys) and 13.96 MJ ME kg-1. Individual pig LW, P2 thickness and pen feed disappearance were recorded weekly to determine LW changes, ADG, ADFI, and G:F. After 27 d on trial, gilts were slaughtered and carcass measurements were recorded at 24 h post-mortem. Overall, RAC supplementation did not affect ADFI or P2 (P > 0.05) but did influence LW (P = 0.049) and overall G:F (P = 0.012) after d27. At d15-d21 and d22-27, only a tendency (P = 0.169, 0.104 respectively) for a linear decrease in G:F with RAC supplementation was found. RAC also affected HCY (P= 0.045) and CCY (P = 0.045) but not fat depth, meat depth or fat % (P > 0.05). These results indicate that RAC may have small but beneficial effects in modern pig production, but further research is required to optimize concentrations and duration of supplementation in modern lean pig genotypes. / Dissertation (MSc (Agric))--University of Pretoria, 2016. / Animal and Wildlife Sciences / MSc (Agric) / Unrestricted
35

A Procedure for Developing a Carcass Merit Program for the Pork Industry

Burrow, James Allen 01 May 1989 (has links)
A stratified sample of 420 market hogs representing the seven 10- pound incremental carcass weight classes from 140 lbs. to 210 lbs. , and the nine last rib back fat classes from less than .8 inches to 1.5 inches, or greater, within each weight class were analyzed to determine carcass value and yield of wholesale cuts. Simple correlation coefficients were calculated between each of the carcass measurements. The carcass yield data were manipulated by multiple regression procedures to achieve a series of equations for predicting the weights of the primal cuts. The benefits of being able to predict the weights of the primal cuts were discussed. A procedure for developing a premium/discount matrix was explained . The fo rmulae for developing the matrix were explained. The necessary assumptions were also explored. A procedure for evaluating a premium/discount matrix was developed. The impact of an industry-wide carcass merit program was discussed.
36

The effects of feeding a ground raw soybean diet on reproductive performance and carcass quality of prepubertal gilts

Sykes, Daniel Jason 02 May 2009 (has links)
The administration of raw soybeans to the diet of prepubertal gilts had no effect (p>0.05) on age to puberty, number of corpora lutea, or embryos present. Also, the number of pigs farrowed live and 28d litter weights did not differ between gilts consuming the raw soybean diet and gilts consuming the control diet. There was a reduction (p<0.05) in the number of pigs weaned in the group consuming the raw soybeans but no differences (p>0.05) in weaning weights. Gilts fed the raw soybean diet had a reduction (p=0.05) of hot carcass weights compared to gilts consuming the control diet but exhibited no differences for other carcass parameters measured. Thermal imaging was able to differentiate gilts in estrus versus diestrus. Gilts in estrus had greater (p<0.05) surface area temperatures than gilts in diestrus.
37

Growth Performance, Carcass Traits, and Reproductive Characteristics in Boars Fed Diets Supplemented With an Organic Source of Selenium

Speight, Susan Michelle 14 December 2010 (has links)
The objectives of this study were to assess growth and reproductive performance of boars fed a diet supplemented with organic selenium (Se). Crossbred boars received one of three treatments: I. basal diet with no supplemental Se, II. basal diet supplemented with 0.3 ppm organic Se (Sel-Plex), and, III. basal diet supplemented with 0.3 ppm sodium selenite. Nursery (n = 13 pens/treatment) boar performance was not affected (P > 0.1) by diet and only grow-finish (n = 11 pens/treatment) G:F was greater (P < 0.06) for Sel-Plex (0.378) compared with selenite (0.368) or control (0.363) boars. At 15-mo of age semen was collected from boars (n = 10/treatment) over 5-d. Semen quality declined over time, but the negative impact day had on sperm motility was less pronounced with Sel-Plex boars. Effects of treatment x day were detected for progressively motile (P = 0.02) and rapidly moving (P = 0.03) spermatozoa, sperm path velocity (VAP; P = 0.05), and average velocity (VSL; P = 0.05). At 17-mo of age, semen was collected from boars (n = 10/treatment), extended and stored over 10-d. Although semen quality decreased over time, sperm from Sel-Plex boars resisted the negative effects of day on sperm motility and pH. Effects of treatment x day were detected for percent motile spermatozoa (P < 0.01), static spermatozoa (P < 0.01), VAP (P = 0.06), amplitude of head displacement (ALH; P = 0.02), straightness (P = 0.01), and pH (P < 0.01). At 23-mo of age, semen was collected (day 0) from boars (n = 6/treatment), extended, stored and evaluated at d 1 and 8 using in vitro fertilization. Dietary Se treatment failed to affect (P < 0.05) in vitro fertilizing rates of boars. In summary, dietary supplementation with Sel-Plex enhanced G:F in grow/finish boars. Dietary Sel-Plex supplementation may decrease the effects that stressors, such as intensive semen collection or semen storage, have on boar sperm characteristics such as sperm motility. The mechanisms for these responses remain to be elucidated. / Ph. D.
38

Use of ultrasound technology in the genetic improvement of U.S. lamb composition

Emenheiser, Joseph Carl 22 February 2009 (has links)
Ultrasound technology allows in vivo estimation of carcass composition. Successful genetic evaluation of ultrasonic measures depends upon technician certification guidelines and a viable common-endpoint adjustment strategy for field data. Four technicians and three image interpreters ultrasonically evaluated 172 lambs to determine accuracy and repeatability of loin eye area (LEA), backfat thickness (BF), and body wall thickness (BW) estimations. Correlations between ultrasonic and carcass measurements were 0.66, 0.78, and 0.73 for LEA, BF, and BW, respectively. Performance was similar among technicians and interpreters. Mean bias ranged from -1.30 to -2.66 cm2, -0.12 to -0.17 cm, and 0.14 to -0.03 cm, for LEA, BF, and BW, respectively; prediction standard errors ranged from 1.86 to 2.22 cm2, 0.12 to 0.14 cm, and 0.35 to 0.38 cm, respectively. Repeatability standard errors ranged from 1.61 to 2.45 cm2, 0.07 to 0.11 cm, and 0.36 to 0.42 cm for LEA, BF, and BW, respectively. Changes in ultrasonic measurements were evaluated using seven serial scans on 24 growing Suffolk ram lambs. All equations had similar goodness of fit. Equations were tested on other populations, including similarly-managed rams across breeds and years and ewe lambs fed for slower gain. Correlations between predicted and actual measures ranged from 0.78 to 0.87 for BF and 0.66 to 0.93 for LEA in winter-born rams, were only slightly lower in fall-born rams, and ranged from 0.72 to 0.74 for BF and 0.54 to 0.76 for LEA in ewe lambs. Of the equations tested, linear and allometric forms appear best for general use. / Master of Science
39

Lietuvoje skerdžiamų kiaulių kai kurių skerdenų kokybės rodiklių palyginamasis įvertinimas / Comparison valuation concerning some carcass quality measures of fattened pigs in Lithuania

Matijošaitytė, Gintarė 19 April 2007 (has links)
The consumers of nowadays market can find various products of pork, but in accordance with a higher step of living standards and a lower one of the physical work concerning to human habitual changes, the EU and world market go to the demand for muscle pork. Due to the new price regulation of May 2002, every specialized enterprise has to run the accountance for meat accordingly to new valuation of prices, where the main criteria are as follows: carcass mass, muscularity (quantity of red meat) and thickness of bacon. The muscle-meat with thin slices of bacon is becoming even the higher rating. Therefore the meat corporations have to breed the more muscled fattened-pigs. The mass-production of pork have to run this obligation through a large complex of measures: best of fattening food, optimal micro-climat condition in piggery, consequent use of breeding methods as well as a systematic promoted selection. The aim of work is both to compare some carcass of quality measures of fattened-pigs in agricultural companies and corporate complexes (in connection with carcass weight/kg, bacon thickness/mm, muscularity/% (FOM), muscularity class) and to compare the average measures of carcass of fattened pigs in Lithuania with the average measures of carcass of fattened-pigs in Poland. Research results. The research was completed in 7 agricultural companies “A”, “B”, “C”, “D”, “E”, “F”, “G”, as well as in the corporate complexes: “H”, “I”, “J”, “K”, “L”, “M”, “N”. There were gathered... [to full text]
40

Carcass and eating quality of sheep grazing saltbush based saline pasture systems

k.pearce@murdoch.edu.au, Kelly L Pearce January 2006 (has links)
Forage halophytes such as saltbush (Atriplex spp) are being widely used to revegetate Australian saline land and can also provide a medium quality fodder source. There is widespread anecdotal evidence that sheep grazing on saltbush are leaner, tastier and juicer. This thesis investigated the potential to produce a high quality carcass with improved eating quality from grazing sheep on saltbush on saline land. The first experimental chapter in this thesis details an animal house experiment investigating the carcass, eating and wool quality and physiological responses of sheep ingesting a 60:40 dried saltbush (Atriplex nummularia):barley grain (S+B), ration verses a 33:25:42 lupin grain:barley grain:oaten hay ration (Control, C) for 10 weeks prior to commercial slaughter (Chapter 4). Subsequently, two field experiments were conducted to examine the effects of grazing saltbush on saline land compared to dry senesced pasture on carcass and eating quality of lambs (Goomalling 2003) and hoggets (Wickepin 2004) (both chapter 6) for 14 weeks. Both chapters demonstrated that the ingestion of saltbush resulted in significantly less fat and in the 2 field experiments the ingestion of saltbush resulted in more lean on the carcass compared to sheep grazing a stubble/pasture (control) ration. These are positive findings for processors as costs of fat denudation are high so the lower the fat content and for farmers because less fat is deposited on the carcass per unit of liveweight gain. The decreased deposition of fat was attributed to the higher protein:energy ratio available for production, secondary compounds in saltbush and lower circulating insulin and higher growth hormone of the S+B fed sheep compared to the control fed sheep. Further work is needed to determine if these beneficial improvements in carcass composition can be achieved without compromising animal production. The long term grazing of saltbush did not result in commercially desirable hot carcass weights unless the sheep were supplemented with a high energy source such as barley. The low growth rates are attributed to a decreased availability of energy substrates, low feed intake and increased energy output of sheep fed high salt diets. The low energy intake of the S+B fed sheep also resulted in an a significantly lower percentage of unsaturated fat and unchanged levels of saturated fat in the fat depots compared to the C treatment. Consumer taste tests conducted on meat from experiments in both chapter 4 and 6 indicated no difference between the treatments for any of the eating quality traits assessed. This can be considered a positive result as sheep can be finished on saltbush without any detriment to eating quality. High vitamin E levels in the meat may have also prevented the development of rancid flavours and aroma. It can be speculated that saltbush does not impart beneficial flavour and aroma volatiles as previously thought; instead the high vitamin E levels inhibit off-flavour and aroma development compared to meat from sheep grazed on dry pasture. The long term ingestion of saltbush also resulted in significantly lower urine specific gravity (USG), muscle dry matter and higher urine weights suggesting that the saltbush fed sheep had a better hydration status compared to control fed sheep. However, this finding did not correspond with higher hot carcass weight or dressing percentages. The increases in muscle fluid content of the saltbush fed sheep were attributed to changes in body composition. The saltbush fed sheep had a higher lean and lower fat content which corresponded with a greater body fluid content as found in the animal house study. Under conditions where the body composition of sheep remains the same, the use of short term strategic feeding of components of saltbush was investigated (mimicked in the form of salt and betaine) to reduce dehydration and subsequent reductions in carcass weight and dressing percentages (Chapter 7). Salt and or betaine were fed for 1 week either prior to a 48 h period of water deprivation or prior to 48 h commercial slaughter process where water was available in lairage from 24-48 h. Under both scenarios the diets did not result in improved dressing percentages, hot carcass weights, muscle dry matter or muscle weights. The ingestion of high salt diet prior to slaughter, did increase fluid retention in the extracellular spaces prior to slaughter however by 48 h both groups were at a similar physiological and therefore similar hydration status. Therefore similar levels of fluid were present in the muscles and no difference in carcass weight or dressing percentage could be expected. An important observation from the second experiment was that the high salt group drunk more water than the low salt fed sheep but the low salt group consumed fluid in lairage also. The low salt fed sheep may have been encouraged to drink water after observing the frequent drinking patterns of the high salt group. This thesis has also shown that saltbush contains high levels of vitamin E (á-tocopherol) (193 mg/kg dry matter). As a result the concentration of á-tocopherol in plasma, liver and muscle of the saltbush fed sheep was elevated compared to those grazing dry pasture. The high muscle concentrations of vitamin E in the saltbush-grazed sheep resulted in improved meat colour stability. The high vitamin E levels did not influence the drip and cooking loss of the meat despite a decrease in the muscle dry matter of the meat. The browning of meat and increased drip loss results in large losses to the meat industry due to value deterioration at the supermarket. There is also great potential for the high vitamin E content in saltbush to be used for the prevention of nutritional myopathy instead of using expensive and labour intensive synthetic supplements. In conclusion, this thesis has provided an insight into the carcass and eating quality of sheep grazed on saltbush based saline pasture systems. The most significant findings were that

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