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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.
1

The effects of exogenous factors and post mortem interventions to improve beef quality of Sudanese Baggara cattle

Biraima, Ahmed Dayain Abdalla 18 November 2019 (has links)
This study investigated the effects of electrical stimulation (ES), age and weight at slaughter, breed type, post-freezing ageing, and the proteolytic extract of Solanum dubium (Gubbain) seeds on the carcass and meat quality of Sudanese Baggara cattle in Sudan. The study also assessed the microstructural and biochemical properties of Afrikaner x Bonsmara crossbred steer muscles treated with the Gubbain protease in South Africa. In order to achieve these goals, three trials were conducted. In the first trial, eighty Baggara cattle were selected according to breed type and age. The cattle (expermintal animals) were divided into two equal groups that were representative of the typical white Nyalawi breed type (n = 40) and typical red Mesairi breed type (n = 40). Each breed type was divided into two age groups: 20 bulls of about 5 to 5.5 years old, weighing between 280 and 310 kg; and 20 bulls of about 4 to 4.5 years old, weighing between 240 and 260 kg. The bulls were slaughtered and dressed according to the standard Halal method. Electrical stimulation (110 V for 30 seconds) was randomly applied to 50% of the carcasses in each group at 20 minutes post mortem (pm). The carcasses were stored in a chiller (2-4°C) within 45 minutes post mortem. Carcass pH and temperature were recorded at 0.17, 1, 3, 6, 9, 12, and 24 hours pm. Samples of m. longissimus dorsi (LD) were collected for meat analyses. Meat colour (L*, a*, b*, chroma, hue) was measured at 24 hours pm, and then each sample was labelled and put in a plastic bag and frozen at -20°C until processing. The frozen samples were thawed and cut into two equal steaks. Half of the steaks were immediately analysed, while the rest were aged at 4°C for seven days and then analysed. The samples were analysed for instrumental colour, water-holding capacity (WHC), cooking loss (CL), Warner-Bratzler shear force (WBSF) values, and sensory quality. The second trial was for exploratory purposes, while the third trial was for detailed analyses. In the second trial, thirty LD were sampled at 24 hours pm from two age groups of Sudanese Baggara bulls. The ultimate pH and instrumental colour were determined at 24 hours pm. The beef LD samples were each cut into two steaks and randomised into two treatments injected with the Gubbain protease extract (10 per cent muscle weight) and left as a control. The steaks were incubated at 4oC for 24 hours, after which they were analysed for pH, colour, CL, WBSF and sensory quality. The third trial was conducted on muscles from Afrikaner x Bonsmara crossbred steers to study the efficacy of the Gubbain protease extract injection in muscle tenderisation. Twelve m. longissimus thoracis et lumborum (LTL) steaks were sampled from both sides of several carcasses at 24 hours pm. Each steak was cut into two equal samples and then randomised for treatments (injection with Gubbain protease extract vs no injection). The steaks were incubated at 4oC for 24 hours. They were then analysed for colour, sarcomere length (SL), myofibril fragment lengths (MFLs), WBSF, collagen solubility, muscle fibre types, quantification meat degradation, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The results suggest that ES, animal age and weight affected meat quality attributes, while breed type had no significant effect. ES hastened the rate of pH decline significantly up to 24 hours pm. The ES of the Sudanese Baggara beef carcasses and the use of lighter and younger bulls showed higher L* values, lower a* values, higher hue values, and lower values for WBSF. The carcasses of the Mesairi breed type responded better to ES in terms of tenderness than those of the Nyalawi breed type. The meat from electrically stimulated carcasses resulted in lower WHC with no effect on CL, compared with non-electrical stimulation (NES) carcasses. The WHC of the meat improved as age and weight at slaughter increased. No risk of cold shortening was observed in any of the treatment groups. Although post-freezing ageing showed a negative influence on meat colour stability, it resulted in lower shear force values, which suggest more tender beef. Panellists did not recognise any variations in meat sensory quality between the two age groups. In contrast, the differences in sensory tenderness and overall acceptability due to post mortem interventions (ES and enzymatic protease) were detected. The meat injected with the Gubbain protease extract reduced the WBSF values by 62 to 65% compared with the non-injected samples. The Gubbain protease treatments increased b* values, cooking losses, and the sensory juiciness, tenderness, and overall acceptability of the beef. The injection with the protease extract showed better L* values compared with the control samples. Muscle samples treated with Gubbain protease had shorter MFLs (23.65 ± 3.22 vs 33.09 ± 2.33), probably due to the increased proteolytic activity, and also showed lower WBSF values (1.95 ± 0.70 vs 5.13 ± 1.01) than those samples from the control group. The muscles treated with the protease extract had a higher percentage of collagen solubility (36.30%) than the control muscles (18.40%). The muscle fibres from the treated samples with the Gubbain protease had more breaks and fractures than those from non-injected samples. The SDS-PAGE pattern of the LTL samples showed losses in the higher molecular weight fractions, accompanied by the appearance of many new lower molecular weight bands after treating the muscle with the Gubbain protease extract. The study has shown that there is potential to improve the quality of beef of Sudanese Baggara cattle types if certain interventions (ES, slaughtering younger and lighter bulls, post-freezing ageing, and injection with Gubbain protease) are used. The study also paved the way for a novel and promising meat tenderiser for the beef industry. / Thesis (PhD (Animal Science))--University of Pretoria, 2020. / University of Pretoria (UP) Postgraduate Research Support Bursary Prof. Webb’s meat science research fund at the University of Pretoria / Animal and Wildlife Sciences / PhD (Animal Science) / Unrestricted
2

Assay, Purification, and Characterization of a Pantetheine Hydrolyzing Enzyme from Pig Kidney

Wittwer, Carl Thomas 01 May 1982 (has links)
A microsomal glycoprotein hydrolyzing pantetheine to pantothenate and cysteamine has been solubilized and purified to homogeneity as determined by sodium dodecylsulfate electrophoresis. Four rapid, independent assays of pantetheine hydrolysis are described and compared along with a method for localizing enzymatic activity on polyacrylamide gels. The enzyme is solubilized on exposure to butanol and purified by heat treatment, (NH4)2SO4 fractionation, hydrophobic chromatography, and hydroxyapatite chromatography. The glycoprotein, purified 5600-fold in 22% yield, has a specific activity of 14 μmoles pantothenate produced/min/mg of protein, 35 times that previously reported. The enzyme has a pH optimum of 9.0-9.5 and a Km of 20 μM for D-pantetheine. Its molecular weight has been estimated by gel filtration (54,000) and sodium dodecylsulfate electrophoresis (60,000). Amino acid analysis indicates a high content of isoleucine (11.3 mole %) and phenylalanine (7.4 mole %) with an absorbancy index El%cm (280 nm) of 11 .3. Galactose, mannose, fucose, and glucose are present in decreasing concentrations totaling 90 μg of neutral hexoses per mg of protein. Galactosamine and sialic acid are also present. The enzymatic hydrolysis of various pantetheine analogs indicate the enzyme 1s specificity is high for the pantothenate moiety but low for the cysteamine portion. The enzyme should be useful in routine 11 total 11 pantothenate determinations in tissues.
3

The Antibody Production by Swine in Response to Sheep Red Blood Cells

Seymour, Deborah 01 July 1985 (has links)
Two experiments were conducted to study the antibody response of pigs challenged with the general antigen sheep red blood cells (SRBC). In one experiment SRBC's were injected at one of four sties: intramuscularly into the neck, intramuscularly into the ham, subcutaneously into the fore flank or rear flank. These treatments were repeated four weeks later. The antibody responses to the four treatments were determined by microtiter and analyzed statistically. No significant (P> 0. 10) differences were found among responses to the four treatments during the fourth and eighth weeks after injections, but a significant (P<0.05) difference was found during the fifth week among all four groups. Coefficients of correlation showed highly significant (P<.0.01) relationships between SRBC antibody titer during the fourth week after injections and increase in weight of test animals from the beginning of the study until slaughter. In a second experiment pigs were given intramuscularly either 2 milliliters of a 5% or 4 milliliters of a 10% SRBC suspension to determine the optimum dosage level. The difference between the antibody responses to these two treatments was not significant (P)0.10). Results of this study indicate that when challenging hogs with SRBC, any of the commonly used sites for injection is acceptable. The injection of 2 milliliters of a 5% SRBC suspension is sufficient to obtain antibody titers which differentiate among individuals. Coefficients of correlation indicate a relationship may exist between SRBC antibody titer and some economically important traits.
4

Swine Breed Differences in Agglutination Titers Following Vaccination with Sheep Red Blood Cells and Pasteurella Multocida (Serotype A)

Stalder, Kenneth 01 May 1992 (has links)
An investigation into the genetic differences in the humoral immune response of swine following vaccination with a sheep red blood cell solution (SRBC) and a commercially prepared Pasteurella multocida (serotype A) bacterin (PmA) was conducted on a total of 268 pigs from two individual trials. This study was also conducted to evaluate the humoral immune response of pigs to a non-pathogen (SPEC) and a known pathogen to swine (PmA). The pigs used in the first trial were from 22 litters born between January 1991 and July 1991. The pigs consisted of Hampshire x Yorkshire (n=114), purebred Yorkshire (n=70) and Hampshire (n=17). Individual pigs were vaccinated at five and eight weeks of age with 2 ml of a 5% SRBC solution and 1 ml of a killed PmA bacterin. AL 11 weeks of age 8 uE of blood was collected frun each animal and serum prepared to determine antibody titer levels against the two antigens by agglutination methods. Pigs utilized in the second study consisted of purebred Duroc (n=11), Haupshire (n= 10), Landrace (n=12) and Yorkshire (n=11) and crossbred Hampshire X Durcc (n= 12) and Yorkshire X Landxace (n=12). Results of trial 1 indicate that breed of pig affected the immune response against both PmA (P<.01) and SRBC (P<.01), with the Hampshire x Yorkshire crossbred pigs having higher titer levels against the PmA than either Hampshire or Yorkshire purebred pigs. The purebred Hampshire were not statistically different from either the purebred Yorkshire or the Hampshire x Yorkshire crossbred pigs in their antibody response to SRBC; however, the Hampshire x Yorkshire crossbred pigs were statistically higher than the Yorkshire pigs. Results from trial 2 indicate highly significant (P<.01) breed differences in the humoral immune response to PmA. Purebred Landrace pigs were superior to both Duroc and Hampshire purebred pigs in their immune response to PmA. Purebred Yorkshire and crossbred Yorkshire X Landrace pigs were superior to purebred Durtcs in their immune response to PmA. NO other significant differences among breeds of pigs occurred in trial 2. A low positive correlation of .22 was found between the pigs' antibody responses to PmA and SRBC in trial 1. Correlation differences among breeds were found between average daily gain while an test and the humoral immune response to both PmA and SRBC. Results suggest that further studies into breed differences of the immune response in swine are warranted. Results also suggest that further studies are needed to evaluate sheep /Ed blood cells as a suitable antigen When conducting research to analyze the humoral immune response in swine.
5

Understanding the formation of the grade B4 Beef in Alberta

Holdstock, Jamie H Unknown Date
No description available.
6

Comparison of Iron Supplements for the Prevention of Anemia in Young Pigs

Hieronymus, Steve 01 May 1977 (has links)
Crete Koate® product originally intended to be utilized for absorbing excess moisture and reducing knee abrasions of baby pigs raised in confinement, was tested as a hematinic for young pigs. Four treatments were studied: (1) T-NI, pigs receiving no iron; (2) T-IS, pigs receiving a 2 ml intramuscular injection of iron-dextran at 2 days of age; (3) T-CK, pigs raised in pens treated daily with Crete Koate; (4) T-ISCK, pics receiving an intramuscular injection of iron-dextran on day 2 whose pens received daily treatments of Crete Koate. Hemoglobin levels were used as an indicator of iron status in the body and weights were used as a measure of production. Blood samples taken at 14 days of age revealed differences (P<.01) in hemoglobin levels among treatments. Those treatments supplying iron, T-IS, T-CK, and T-ISCK, maintained higher (P>.01) hemoglobin levels than the control, T-NI. Weights did not significantly differ among treatment groups at either 14 or 28 days (P>.10). There was no observable difference in 'Knee scuffing among treatments. However, those pens receiving Crete Koate appeared to stay drier and cleaner. Results of this study suggest that Crete Koate may be capable of supplying iron for hemoglobin synthesis and production equivalent to that of iron-dextran.
7

Comparisons of Performance & Carcass Traits of Littermate Boars & Barrows

Hirano, Hiromi 01 May 1987 (has links)
The purpose of this study was to determine differences between littermate boars and barrows for performance and carcass traits in the Iowa and Northeast Iowa Swine Testing Stations. Data were obtained from 917 litters including 1,804 boars and 917 barrows. The data included 1,086 boars and 581 barrows from the Iowa Station at Ames, Iowa, and 718 boars and 336 barrows from the Northeast Iowa Station at New Hampton, Iowa. The Iowa Station data were obtained over a period of 12 seasons from the fall of 1979 through the fall of 1985, and the data from the Northeast Iowa Station were collected in eight seasons from the fall of 1981 through the spring of 1985. The spring testing season included pigs born from November through March, and the fall testing season included pigs born from May through September. Littermate boars and barrows from the following purebred breeds were used: Berkshire, Chester White, Duroc, Hampshire, Landrace, Poland China, Spotted, and Yorkshire. Boars grew .03 (2.21+/-.20 vs. 2.18+/-.21) and .10 (2.21+/-.18 vs. 2.11+/-.22) pounds/day faster (P<.01) than littermate barrows in the Iowa and Northeast Iowa Stations. Boars had .58 (.80+/-.08 vs. 1.38+/-.20) inches less (P<.01) backfat than littermate barrows (N=581) in the Iowa Station. In the Northeast Iowa Station, boars were significantly (P<.01) leaner than barrows when comparing average backfat of boars with carcass backfat measurements of Ilttermate barrows at the tenth rib (.76+/-.06 vs. 1.06+/-.21) or the average of three carcass backfat measurements (.75+/-.08 vs. 1.29+/-.18 and .79+/-.05 vs. 1.31+/-.19). Boars had .67 (5.49+/-.42 vs. 4.82+/-.67) and .66 (5.62+/-.28 vs. 4.96+/-.65) square inches larger (P<.01) loin eye areas than littermate barrows in the Iowa and Northeast Iowa Stations, respectively. The t test revealed no significant (P>.05) differences between boars and barrows for average daily gain among the eight major breeds in the Iowa Station. However, at the Northeast Iowa Station, the Duroc (2.39+/-.19 vs. 2.12+/-.21) and Hampshire (2.16+/-.17 vs. 2.07+/-.24) boars grew significantly faster (P<.01) than littermate barrows. The t test also revealed that boars averaged seven days (156.00+/-10.78 vs. 163.00+/-12.90) younger (P<.01) at 230 pounds than barrows in the Northeast Iowa Station. Although the sample size was small and the differences nonsignificant, there were some breeds in which barrows appeared to grow faster than boars. The I test for boar-barrow differences among breeds revealed that boars had significantly (P<.01) less average backfat than littermate barrows for eight major breeds in the Iowa Station and for seven breeds in the Northeast Iowa Station. For both stations, the differences in backfat thickness between boars and barrows was lowest for the Hampshire breed and the greatest differences were between boars and barrows in the Chester White, Yorkshire, Berkshire and Landrace breeds. The t test for loin eye area revealed that boars had significantly (P<.01 or .05) greater loin eye area than barrows for all breeds except Poland China in the Iowa Station and Landrace in the Northeast Iowa Station. The sex differences between littermate boars and barrows for backfat and loin eye area were significantly different (P<.01) for all years and seasons in the Iowa and Northeast Iowa Stations. The sex differences between littermate boars and barrows for backfat and loin eye area have been increasing in both stations with the largest increase occurring during the last five years. The differences between boars and barrows for days to 230 pounds were significantly different (P<.01) In all years and seasons for both stations. In comparing data for 1981 and 1985, both boars and barrows averaged ten days younger at 230 pounds In 1985 than in 1981. Coefficients of correlation for various measurements of performance and carcass cutability between littermate boars and barrows were determined. In general, there were positive associations between boar and barrow data; however, the correlations were relatively low. The predictive value of the barrow data appears to be of little use In estimating breeding values for boars. Although a limited number of Chester White pens were included in this study, the coefficients of correlation between littermate boars and barrows suggest that castration may have a different effect upon performance and carcass cutability of Chester White than for other breeds. Unfortunately for Chester White breeders, there appears to be a much higher positive correlation between average daily gain and beckfat thickness for Chester White boars and barrows than for other breeds. In other breeds, the correlation between growth rate and backfat is low enough to allow simultaneous progress for improving both traits. A similar desirable low correlation was found between growth rate and loin eye area for other breeds. The coefficients of correlation between backfat and loin eye area were greater for barrows than boars, suggesting that errors of measurement may have been prevalent in the boar data. Large errors In measurement of boar backfat could account for some or all of the increased difference in backfat thickness observed between littermate boars and barrows during recent years.
8

Long-term effects of different fat sources and vitamin E supplementation on growth performance, antioxidant status, carcass characteristics, meat quality, and immune capacity of pigs with heavy slaughter weight up to 150 kg

Wang, Ding 01 January 2019 (has links)
Two experiments were used to evaluate the potential interaction of fat source and vitamin E (VE) in heavy slaughter weight pigs. In Experiment 1, a total of 64 individually-fed pigs (28.41 ± 0.83 kg) were randomly assigned to 8 dietary treatments in a 4×2 factorial arrangement. Fat treatments included cornstarch (CS), tallow (TW), corn-oil (CO), and coconut-oil (CN). VE treatments were dietary α-tocopheryl acetate (ATA) at 11 and 200 ppm. In Experiment 2, a total of 72 individually fed pigs (28.55 ± 1.16 kg) were randomly assigned to 12 dietary treatments in a 2 × 6 factorial arrangement. Fat treatments were TW and CO. VE treatments included four levels of ATA (11, 40, 100, and 200 ppm) and two levels of mixed tocopherols (primarily γ-tocopherol; 40 and 100 ppm). VE deposition, growth performance, and meat quality were measured in both experiments. In both experiments, interaction between fat sources and VE were detected (P < 0.01) on plasma VE concentration, which increased (P < 0.01) with time and with increasing dietary VE, but increased faster (P < 0.05) in pigs fed with CN and TW compared to pigs fed CS and CO. Compared to CO, more saturated dietary fat sources (CN and TW) led to firmer belly (P < 0.01), which had more (P < 0.01) SFA and MUFA while less (P < 0.05) Feed/Gain in Phase 4 and Phase 5. In Experiment 2, increasing dietary ATA increased overall ADG (linear, P = 0.02), with an interaction (P < 0.05) with fat sources on cumulative ADG during Phase 1-4, wherein pigs fed CO, but not TW, had increased ADG with increasing dietary ATA. Increasing dietary ATA increased (quadratic, P < 0.05) liver SOD activity, and decreased (quadratic, P < 0.05) liver MDA content. The oxidative stability of loin was improved (P < 0.01) when dietary ATA increased over 40 ppm. In summary, both dietary fat source and VE supplementation affected the response measures.
9

IMPACT OF ALGAE SUPPLEMENTED DIETS COMBINED WITH ANTIOXIDANTS ON THE NUTRITIONAL PROFILE, QUALITY ATTRIBUTES, AND STORAGE STABILITY OF CHICKEN BREAST MEAT

Norcross, Rebecca G. 01 January 2015 (has links)
Consumers’ demands for ω-3 polyunsaturated fatty acids (PUFAs) are at all-time high. Algae, a common source of PUFAs, and antioxidants are both used as supplements in livestock feeds, are known to affect the overall quality of meat. To implement PUFA deposits into broiler meat, this study evaluated combining antioxidants and algae in broiler feed to enhance the breast meat quality. Broilers were fed diets supplemented with 50 IU Vitamin E or 200 g/ton EconomasE (EcoE, an antioxidant pack) plus 10 IU Vitamin E, with or without 0.5% algae extract (SP-1). The feed oil was partially oxidized soybean oil (POV: 86 mEq of O2/kg). The feed supplementation with combined SP-1 and EcoE increased meat lipid oxidation but had no effect on protein. This combination supplement substantially reduced (P < 0.05) meat exudation during refrigerated storage while no evident differences were seen on cooking loss or tenderness between diets. Meat from SP-1 supplemented diets was found less acceptable than meat from other diets due to detected off-flavors. The results indicate that EcoE at a supplementation level other than 200 g/ton may be required to overcome off-flavors of broiler meat due to feed incorporation of 0.5% SP-1 with oxidized oil.
10

Improving the meat quality of Blesbok (Damaliscus Dorcas Phillipsi) and Springbok (Antidorcas Marsupialis) through enhancement with inorganic salts

Du Buisson, Petro-Mare 03 1900 (has links)
Thesis (Msc (Animal Sciences))--University of Stellenbosch, 2006. / This research had a dual purpose, firstly to study five muscles (M. biceps femoris, M. longissimus et lumborum, M. rectus femoris, M. semitendinosus and M. supraspinatus) of the blesbok (Damaliscus dorcas phillipsi) and springbok (Antidorcas marsupialis) in terms of the physical and chemical meat quality characteristics, and secondly, to investigate the effects of inorganic salt enhancement on the physical, chemical and sensory meat quality characteristics. The muscles differed significantly for the investigated characteristics, with the exception of a* value, chroma, and ash percentage, which did not differ in either blesbok or springbok. Furthermore, no muscle differences were found in fat percentage in blesbok or protein percentage in springbok meat. Muscle differences were found in the stearic acid (C18:0) composition, the percentage saturated fatty acids (SF) and the polyunsaturated: saturated fatty acid ratio (P:S) of the blesbok. Only linoleic acid (C18:2) as a percentage of the total fatty acids differed significantly amongst the springbok muscles. The shear force values were found to be significantly lower in the enhanced samples (blesbok: 25.16 vs. 43.75 N/1.27cm; and springbok: 23.96 vs. 34.89 N/1.27cm), which means that the enhanced muscles were more tender. The enhanced muscles of both species were found to have lower values for all investigated colour characteristics. Moisture values were found to be higher in all the enhanced muscles (blesbok: 76.53% vs. 74.38%; and springbok: 75.34% vs. 73.37%). The lower fat and protein contents of the enhanced muscles can possibly be ascribed to a diluent effect caused by the water added as part of the inorganic salt injection (blesbok: fat, 1.86% vs. 2.22%, protein, 19.61% vs. 21.67%; and springbok: fat, 1.84% vs. 2.14%, protein, 21.23% vs. 23.26%). Major changes in the mineral contents were expected between the two treatments and in both species the enhanced muscles had higher phosphorus, potassium, sodium and copper values, but lower magnesium, iron and zinc levels than the untreated muscles. Analytical sensory analyses were performed on the M. biceps femoris and M. longissimus et lumborum samples of both species. Tenderness and juiciness were significantly higher in the enhanced muscles. Although salty taste was significantly higher in the enhanced muscles due to the addition of the inorganic salt solution, it remained acceptable. Analytical and consumer sensory analyses were performed on blesbok and springbok M. longissimus et lumborum samples prepared in a stock mixture. The outcome of the analytical sensory analysis was similar to the analytical results reported above. The consumer sensory analysis showed that consumers preferred the enhanced blesbok and springbok muscles, with a significant improvement in consumers’ likeness of enhanced vs. untreated meat. This study provides important insights into the muscle differences of two of the most common game species currently utilised in South African meat production. It confirms that both species can be marketed as a low fat organic red meat source well capable of filling the modern consumer’s nutritional and health needs. It also shows that enhancing game meat with an inorganic salt solution might be a very useful processing tool to use to further game meat acceptability in terms of tenderness and juiciness as game meat is often experienced as being dry and less tender because of its lower fat content and the use of incorrect preparation techniques.

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