Thesis (M.S. Agric.)--University of Pretoria, 2002. / Includes bibliographical references (p. 81-84).

Thesis (M.Sc.(Agric.)(Meat Science)) -- University of Pretoria, 2009. / Summary in English and Afrikaans. Includes bibliographical references.

A Dissertation Submitted to the Faculty of Science of the University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the Degree of Master of Science. / Impala are an ancient and successful specdes whose biogeography differs from other bovids. A detailed electrophoretic investigation of genetic variability within and between subpopulations found six polymorphic loci, CK-C"', GPl"', MPr\ PEP-Jr, PGM-2'" and PROT-2'" in a sample of 464 impala collected from 10 localities in southern Africa. Average gene diversity was 0,047. Between-population gene diversity was normal for bovid species. Allele frequency differences and genetic distances revealed low levels of subdivision into three broad regions. Wright's FST (0,035) revealed a significant yet low level of population subdivision. The distributions of single-locus heterozygosities and allele frequencies were significantly different to those predicted during mutation-drift equi librium, indicating that non-equilibrium conditions may prevail and that the population may be recovering from a recent bottleneck. / AC 2018

Thesis (Ph. D.)--University of Wisconsin--Madison, 1966. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Ph.D. (Zoology) / Please refer to full text to view abstract

Thesis (MSc (Veterinary Science))--University of Pretoria, 2002. / Includes bibliographical references.

Thesis (MMedVet. (Veterinary Tropical Diseases, Veterinary Science))--University of Pretoria, 1999. / Also available in print format.

Please read the abstract in the 00front part of this document / Dissertation (MSc Agric)--University of Pretoria, 2007. / Animal and Wildlife Sciences / unrestricted

Thesis (MScAgric)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: Regardless of the extensive game eradication during most of the previous century, the game farming industry in South Africa has shown dynamic growth over the past few decades. Currently the approximately 8 000 game farms have a total income of more than R850 million per annum. Although there are various game species included in these farming enterprises, three of the most important species for commercial farming and meat marketing are springbok iAntidorcas marsupialisï, blesbok (Damaliscus dorcas phillipsiï and impala (Aepyceros melampus). Since nutrition is a key factor in the productivity of animals, any information on this subject is essential for the successful management of a game farm. However, apart from the general lack in applied research on game animals (due to the different approaches by biologists and agricultural researchers), there is also only limited information available on the nutritional requirements of game species or any of the aspects affected by nutrition. In order to address the above shortcomings in game animal nutrition, two separate studies were conducted. The purpose of the first study was to determine the physical body component and nitrogen (N) distribution in the springbok, blesbok and impala. The chemical composition of the three-rib cut was also compared with that of the carcass. Amino acid requirements for growth of the three game species were investigated in the second study according to the ideal protein concept. The essential amino acid (EAA) profile of the whole empty body of the three game species was compared with the EAA profile of the duodenal digesta in order to detect any imbalances for optimal growth. The same animals were used in both studies, namely eight of each of the three game species. Characterization of the physical body composition revealed that the dressing percentages (% of body weight; % of empty body weight) for the three game species were: springbok (57.1 ± 2.4 %; 64.0 ± 2.5 %), blesbok (50.2 ± 2.1 %; 62.8 ± 1.4 %) and impala (57.4 ± 2.2 %; 65.6 ± 2.0 %). The proportional distribution ofN between the carcass, external offal and internal offal was also determined. The mean carcass N concentration of the impala was higher (P<0.05) than that of the springbok and blesbok on a dry matter basis. According to the carcass chemical composition, the three game species seem to have a better potential for lean meat production (fat content of carcass 4.7-5.2 %) than domestic sheep (17-25 % fat). Male animals had a lower (P<0.05) fat and higher (P<0.05) moisture percentage in the carcass and threerib cut than the females. The fat correlation between the three-rib cut and the carcass on both an as-is and dry matter basis was significant across species and sexes. The protein content of the same cuts did, however, not yield a significant correlation on an as-is basis, and only the protein content of the springbok three-rib cut related (P<0.05) to that in the carcass on a dry matter basis. The second study concentrated on the nutritional requirements of springbok, blesbok and impala, and more specifically the EAA requirements. Differences (P<0.05) were found between the whole empty body EAA composition of the three game species. These differences were present whether protein quantity was included in the calculations (g AA/100 g crude protein) or not (expressed as % of lysine). The chemical scores indicated that the four most limiting amino acids (three for impala) in the duodenal digesta for whole empty body growth were: arginine, histidine, threonine and methionine (springbok); methionine, arginine, histidine and lysine (blesbok); and methionine, histidine and arginine (impala). Further disproportion of the amino acids in the duodenal digesta was present in excess levels of isoleucine (blesbok) and lysine, valine, leucine, threonine, isoleucine and phenylalanine (impala). The EAA:Lysine ratios of the whole empty body indicated a similar trend for the three game species. / AFRIKAANSE OPSOMMING: Die essensiële aminosuurbenodighede van springbok, blesbok en rooibok vir optimale groei: Ten spyte van die feit dat wild grootskaals uitgedun is gedurende die vorige eeu, het die wildboerdery-bedryf in Suid-Afrika oor die laaste paar dekades dinamiese groei getoon. Die totale inkomste van die ongeveer 8000 wildsplase beloop tans meer as R850 miljoen per jaar. Alhoewel daar verskeie wildspesies is wat by hierdie tipe boerdery ingesluit word, is die springbok (Antidorcas marsupialis), blesbok (Damaliscus dorcas phillipsi) en rooibok (Aepyceros melampus) van die belangrikste spesies vir kommersiële boerdery en vleisbemarking. Voeding IS 'n sleutelfaktor in die produktiwitieit van diere en daarom is emge inligting oor hierdie onderwerp noodsaaklik vir die suksesvolle bestuur van 'n wildsplaas. Afgesien van die algemene tekort aan toegepaste navorsing op wilde diere (as gevolg van die verskillende benaderings van bioloë en landboukundige navorsers), is daar ook slegs beperkte inligting beskikbaar oor die voedingsbehoeftes van wilde dierspesies of enige van die faktore wat deur voeding beïnvloed word. In 'n poging om bogenoemde tekortkominge in die voeding van wilde diere aan te spreek, is daar twee aparte studies uitgevoer. Die doel van die eerste studie was om die fisiese liggaamsamestelling en die stikstof (N) verspreiding in die springbok, blesbok en rooibok te bepaal. Die chemiese samestelling van die drie-ribsnit is ook met die van die karkas vergelyk. In die tweede studie is ondersoek ingestel na die aminosuurbehoeftes van die drie wildspesies deur van die ideale proteïen konsep gebruik te maak. Die bepaling van die essensiële aminosuurprofiel van die totale leë liggaam van die onderskeie drie wildspesies is bepaal en met die essensiële aminosuurprofiel van die duodenale-inhoud vergelyk, ten einde enige wanbalans vir optimale groei vas te stel. Dieselfde diere is in beide studies gebruik, naamlik ag springbokke, blesbokke en rooibokke. 'n Beskrywing van die fisiese liggaamsamestelling het aangetoon dat die uitslagpersentasies (% van liggaamsmassa; % van leë liggaamsmassa) van die drie wildspesies as volg was: springbok (57.1 ± 2.4 %; 64.0 ± 2.5 %), blesbok (50.2 ± 2.1 %; 62.8 ± 1.4 %) en rooibok (57.4 ± 2.2 %; 65.6 ± 2.0 %). Die proporsionele verspreiding van N in die karkas, uitwendige afval en inwendige afval is ook bepaal. Die gemiddelde N konsentrasie in die karkas van die rooibok was hoër (P<0.05) as die van die springbok en blesbok op 'n droë materiaal basis. Dit blyk vanaf die chemiese samestelling van die karkas dat die drie wildspesies 'n groter potensiaal het vir die produksie van maer vleis (vet-inhoud van karkas 4.7-5.2 %) as skape (17-25 % vet). Manlike diere het 'n laer (P<0.05) vetpersentasie en 'n hoër (P<0.05) vogpersentasie in beide die karkas en die drie-ribsnit teenoor die vroulike diere gehad. 'n Betekenisvolle korrelasie is tussen die persentasie vet in die drie-ribsnit en die karkas van al drie wildspesies en vir beide geslagte gevind, op beide 'n nat en droë materiaal basis. Die proteïeninhoud van dieselfde snitte was egter nie op 'n nat basis betekenisvol gekorreleerd nie, en slegs die proteïen-inhoud van die springbok se drieribsnit het verband gehou (P<0.05) met die in die karkas op 'n droë materiaal basis. Die klem van die tweede studie was op die voedingsbehoeftes van springbok, blesbok en rooibok, en meer spesifiek die essensiële aminosuurbenodighede. Daar is verskille (P<0.05) tussen die totale leë liggaam essensiële aminosuursamestelling van die drie wildspesies gevind. Hierdie verskille was aanwesig afgesien daarvan of die hoeveelheid proteïen in berekening gebring is (g aminosure /100 g ruproteïen) of nie (uitgedruk as % van lisien). Volgens die chemiese tellings was die vier mees beperkende aminosure (drie vir rooibok) in die duodenale-inhoud vir totale leë liggaamsgroei as volg: arginien, histidien, treonien en metionien (springbok); metionien, arginien, histidien en lisien (blesbok); en metionien, histidien en arginien (rooibok). Verdere wanbalanse in die armnosure van die duodenale-inhoud was aanwesig in die oormaat isoleusien (blesbok) en lisien, valien, leusien, treonien, isoleusien en fenielalanien (rooibok). Die verhouding van die essensiële aminosure tot lisien van die totale leë liggaam het by al drie wildspesies dieselfde tendens getoon.

Thesis (MSc)--Stellenbosch University, 2002. / ENGLISH ABSTRACT: The purpose of this study was to evaluate the effects of age, sex, region and cropping methodology on the meat quality of impala. Forty impala were cropped during separate day and night operations at the Mara Agricultural Development Centre. Carcass pH45 (measured in M. longissimus dorsi 45 minutes post mortem) was higher in night cropped animals (6.67 ± 0.111; P<0.05) compared to the day cropped animals (6.55 ± 0.236). The ultimate carcass pH (pHu) of animals cropped at night was lower (5.39 ± 0.081; P<0.05) compared to those cropped in the day (5.45 ± 0.108). Non-linear regression analysis showed that the rate of pH decline of the night cropped animals was slower than that of the day cropped animals (P<0.05). The cooling rate of the M. longissimus dorsi was twice as fast in the night cropped group (P<0.05). Shear force values and drip losses of the night cropped animals were both lower (19.11 ± 5.675 g/mm2 and 2.93 ± 1.597% respectively; PO.OS) compared to those of day cropped animals (23.42 ± 8.128 g/mm2 and 4.15 ± 2.339%). The results indicate that nighttime cropping has a beneficial effect on certain meat quality parameters compared to daytime cropping. A second group of impala was sampled at the Musina Experimental Farm in the Limpopo Province of South Africa. Live weights of the Mara animals (50.23 ± 9.32 kg) were higher (P<0.05) than the Musina animals (44.25 ± 10.81 kg). Impala sampled at Mara had significantly higher dressing percentages than those at Musina (P<0.05). Impala ewes from both regions had a higher lipid content (P<0.05), but the sex of the animal had no effect on the remaining chemical parameters. The crude protein content of impala at Musina (24.88 ± 1.044%) was higher (P<0.05) than the Mara animals (23.80 ± 0.840%). Regional differences (P<0.05) were found in the amounts of phosphorous and calcium in the meat. Female animals at Mara showed higher proportions (P<0.05) of saturated (SFA), and mono-unsaturated fatty acids than the male animals. Males from both regions showed higher proportions (P<0.05) of poly-unsaturated fatty acids. Myristic, palmitic and stearic acid formed the greatest proportion of the SFA component for males and females from both regions. Samples of the M. semi-membranosus (SM), M. deltoideus (D), M. longissimus dorsi et laborum (LO), and M. psoas major (PS) were analysed for citrate synthase (CS) and phosphofructo-kinase activities. MHC distribution varied significantly between 0, SM and LD (P<O.05). D expressed more MHC I, and less MHC lIa than the other three muscle groups. Positive correlations were found between age and MHC I in 0 (r=O.93; P<O.05) and CS and weight of the animal in D (r=O.76; P<O.05). The enzyme activities and MHC distribution indicate that energy in the impala is produced to a large extent via oxidative pathways. / AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om die invloed van ouderdom, geslag, area, en uitdunmetodes op die vleiskwalitiet van rooibokke te evalueer. Veertig rooibokke is gedurende afsonderlike dag en nag uitdunningsoperasies by die Mara Landboukundige Ontwikkelings Sentrum geoes. Karkas pH45 (gemeet in die M. longissimus dorsi 45 minute post mortem) was hoër (P<0.05) in nag-geoesde diere (6.67 ± 0.11) in vergelyking met die dag-geoesde diere (6.55 ± 0.23). Die finale pH (pHu) van diere wat in die nag geoes is (5.39 ± 0.08) was laer (P<0.05) in vergelyking met die wat in die dag geoes is (5.45 ± 0.11). Nie-lineêre regressie analise toon dat die tempo van pH-daling van die nag-geoesde diere merkbaar stadiger was as die dag-geoesde diere (P<0.05). Die afkoelings tempo van die M. longissimus dorsi et lumborum was twee keer vinniger in die nag geoesde groep (P<0.05). Die gemiddelde skeurkragwaarde en drupverlies was beide laer (P<0.05) vir nag geoesde diere (respektiewelik 19.11 ± 5.67 g/mm2 en 2.93 ± 1.59%) in vergelyking met diere wat in die dag geoes is (23.42 ± 8.12 g/mm2 en 4.15 ± 2.33%). Die resultate toon dat nag-uitdunning 'n voordelige effek op vleiskwaliteit gehad het, in vergelyking met dag-uitdunning. 'n Tweede groep van rooibokke is gemonster by die Musina Eksperimentele plaas in die Limpopo Provinsie in Suid-Afrika. Die gewigte van die Mara diere (50.23 ± 9.32 kg) was hoër (P<0.05) as die van die Musina diere (44.25 ± 10.81 kg). Die Mara groep het hoër uitslag persentasies (P<0.05) gehad. Vroulike diere in beide areas het 'n hoër vet inhoud (P>O.05) gehad. Die ru-proteien inhoud van die Musina diere (24.88 ± 1.04%) was hoër (P<0.05) as die van die Mara diere (23.80 ± 0.84%). Area verskille (P<0.05) is gevind in die fosfaat en kalsium inhoud in die vleis. Vroulike diere by Mara het 'n hoër proporsie (P<0.05) van versadigde en mono-onversadige vetsure in die weefsel as manlike diere gehad. Manlike diere van beide areas het 'n hoër proporsie (P<0.05) van poli-onversadige vetsure (P<0.05) as die vroulike diere getoon. Miristien, palmitien en stearien suur was kwantitatief die belangrikste vetsure in manlike en vroulike diere van beide areas. Monsters van die M. semi-membranosus (SM), M. deltoideus (D), M. longissimus dorsi et laborum (LO), en M. psoas major (PS), van die rooibokkarkasse is ontleed vir sitraatsintase (SS) en fosfofruktokinase aktiwiteite (FFK). MSK verspreiding het merkbaar varieer tussen 0, SM en LO (P<O.05). 0 toon meer MSK I en minder MSKlia as die ander drie spiergroepe (P<O.05). Postiewe korrelasies is bevind tussen ouderdom en MSK I in 0 (r=O.93; P<O.05), asook tussen SS en die gewig van die dier in o (r=O.76; P<O.05). Die ensiemaktiwiteite en MSK verspreiding toon dat energie in die rooibok tot 'n groot mate deur die oksidatiewe paaie geproduseer word.