The main objective of the study was to determine the effect of farm to abattoir environmental conditions and their subsequent effects on behavioural and physiological responses, as well as the quality of meat from Nguni (NG) and non-descript (ND) beef steers reared extensively on natural pastures. The forty 16 – 19 months old steers (20 ND and 20 NG) used in the current study were grouped together, medically treated, allowed three weeks acclimatizing period and were used in this trial over a four-month period. The weather and periodical variations influence on time budgets and body weights of these steers were determined. Furthermore, the effects of on-farm successive handling on behavioural scores and physiological responses of the same steers were determined. Later in the trial, some pre-slaughter effects on response-behaviour, bleed-out times and selected blood physiological responses were determined. Finally, the effect of genotype, muscle type, lairage duration, slaughter order and stress responsiveness on pH24, temperature, colour (L*, a*, b*, C, HA), thawing (TL) and cooking (CL) losses and Warner Bratzler Shear Force (WBSF) of the meat harvested from the same steers were determined. The daily time budgets of steers in natural pastures changed with temperature, humidity, observation week and time of the day. The grazing behaviour was observed throughout the observation days (> 37 percent); though it was reduced (26.9±2.64 percent) on days with higher temperatures and low humidity. Higher proportions of drinking (1.5±1.04 percent) and standing (20.8±4.63 percent) behaviours prolonged in such weather conditions, which were mostly during midday. The avoidance-related behaviour of the steers during handling varies, with the steers showing more avoidance and aggression in other weeks than some. These variations could however be traced back to the events of that particular day/time of handling. Only Weighing Box (WBS) and stepping (SS) scores differed (P<0.05) with genotype; with more calm NG steers (> 40 percent) and not kicking than the ND steers that were more vocal (20–60 percent) and kicking (> 5 percent). In addition, the weekly behavioural responses were reflected (P<0.05) in the measured cortisol, glucose and lactate. However, regardless of the prominent negative behaviour seen over time, the levels of the measured blood constituents continued to drop. Furthermore, steers of different genotypes displayed similar (P>0.05) response to the identical pre-slaughter conditions they were exposed to. However, steers that were Transport Group 1 (TG1) showed more avoidance (63.2 percent) pre-slaughter than those in TG2 (23.9 percent). Furthermore, all the steers that were in slaughter Group 2 (SG2) showed less avoidance behaviour than those in other groups. Vocalization was observed only for ND steers (5 percent), in TG1 and SG2. Some connections between the observed pre-slaughter activities and some behavioural and physiological changes of these steers were established; with TG1 and SG1 steers showing higher cortisol (140±14.50 and 175.9±17.24 nmol/L, respectively) and lactate (12.4±0.83 and 13.5±1.12 mmolL) levels than the other groups. Lastly, the muscle type, genotype, lairage duration, slaughter order and stress responsiveness have an effect on some meat quality characteristics of the two genotypes; with the L. dorsi muscle having highest WBSF (38.0±1.35N) than the Superficial pectoral muscle (Brisket muscle) (30.7±1.35N). Additionally, steers lairaged for a shorter time produced a L. dorsi with higher WBSF (41.6±2.34N) and a Brisket with lower TL (2.7±0.24 percent). It can therefore be concluded that the conditions and activities at the farm, during transportation, lairaging and slaughter at the abattoir have an influence on some behavioural and physiological changes and the quality of beef harvested from the Nguni and non-descript steers that were extensively-reared in natural pastures. However, the relationship patterns between these different conditions are not clear.

Made available in DSpace on 2015-05-14T16:53:17Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-12-05Bitstream added on 2015-05-14T16:59:03Z : No. of bitstreams: 1 000829410.pdf: 511554 bytes, checksum: 8af199dd873a4a75c37c1be5aadce934 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O presente estudo teve por objetivos determinar a ocorrência de Streptococcus suis em funcionários (portadores sadios) e ambiente de abatedouros com SIF do estado de São Paulo, Brasil, descrever a distribuição dos diferentes tipos do agente e o perfil de suscetibilidade aos antimicrobianos das linhagens isoladas, bem como pesquisar os fatores de risco associados à ocorrência do patógeno. Suabes de tonsilas de 139 funcionários e 261 suabes ambientais foram coletados para detecção de S. suis e seus tipos através das técnicas de monoplex e multiplex PCR, respectivamente. Não houve detecção de funcionários portadores sadios. S. suis foi isolado de 27,03% das amostras coletadas no abatedouro A; 17,31% no abatedouro B; 15,31% no abatedouro C; e 36,36% no abatedouro D. Diferença estatisticamente significativa (p<0,05) foi observada para as ocorrências de S. suis entre os abatedouros e entre as áreas de risco baixo, médio e alto da etapa de matança no abatedouro A. Os tipos 4 (20,00%), 5 (20,00%), 12 (20,00%) e 29 (20,00%) foram os mais frequentes seguidos pelos tipos 21 (10,00%) e 31 (10,00%). Os antimicrobianos mais eficazes foram amoxicilina com clavulanato (100,00%), doxiciclina (100,00%), ceftiofur (93,75%), ampicilina (81,25%) e cefalexina (75,00%). Multirresistência foi observada em 100,00% das linhagens isoladas. Os abatedouros e as diferentes áreas da etapa de matança podem ser fatores de risco para a ocorrência de S. suis, consequentemente, para infecção humana pelo patógeno. No entanto, é importante ressaltar que todos os funcionários estão expostos à infecção. O presente trabalho é o primeiro estudo epidemiológico realizado no Brasil acerca dos fatores de risco associados à ocorrência de S. suis envolvendo grande número de indivíduos pertencentes ao principal grupo de risco / The present study aimed to determine the occurrence of Streptococcus suis in employees (healthy carriers) and environment of swine slaughterhouses with federal inspection service of the state of São Paulo, Brazil, to describe the distribution of the different types of the agent and the antimicrobial susceptibility profile of the isolated strains, as well as to research the risk factors associated with the occurrence of the pathogen. Tonsillar swabs of 139 employees and 261 environmental swabs were collected for detection of S. suis and its types by monoplex and multiplex PCR, respectively. There was no detection of healthy carriers employees. S. suis was isolated from 27.03% of the samples collected at slaughterhouse A; 17.31% at slaughterhouse B; 15.31% at slaughterhouse C; and 36.36% at slaughterhouse D. Significant statistical differences (p<0.05) were observed for the occurrence of S. suis among slaughterhouses and among areas of low, medium and high risk of the slaughterhouse A. The types 4 (20.00%), 5 (20.00%), 12 (20.00%) and 29 (20.00%) were the most frequent followed by types 21 (10.00%) and 31 (10.00%). The most effective antimicrobials were amoxicillin-clavulanate (100.00%), doxycycline (100.00%), ceftiofur (93.75%), ampicillin (81.25%) and cephalexin (75.00%). Multidrug resistance was observed in 100.00% of the isolates. The slaughterhouses and the different areas of the pig slaughtering may be risk factors for the occurrence of S. suis and, consequently, for human infection. However, it is noteworthy that all employees are exposed to S. suis infection. This project is the first epidemiological study in Brazil about the risk factors associated with the occurrence of S. suis involving a large numbers of individuals belonging to the main risk group / FAPESP: 2011/50787-1

Orientador: Antonio Carlos Paes / Banca: Jane Megid / Banca: Márcio Garcia Ribeiro / Banca: Sandra de Moraes Gimenes Bosco / Banca: Rogério Giuffrida / Resumo: O presente estudo teve por objetivos determinar a ocorrência de Streptococcus suis em funcionários (portadores sadios) e ambiente de abatedouros com SIF do estado de São Paulo, Brasil, descrever a distribuição dos diferentes tipos do agente e o perfil de suscetibilidade aos antimicrobianos das linhagens isoladas, bem como pesquisar os fatores de risco associados à ocorrência do patógeno. Suabes de tonsilas de 139 funcionários e 261 suabes ambientais foram coletados para detecção de S. suis e seus tipos através das técnicas de monoplex e multiplex PCR, respectivamente. Não houve detecção de funcionários portadores sadios. S. suis foi isolado de 27,03% das amostras coletadas no abatedouro A; 17,31% no abatedouro B; 15,31% no abatedouro C; e 36,36% no abatedouro D. Diferença estatisticamente significativa (p<0,05) foi observada para as ocorrências de S. suis entre os abatedouros e entre as áreas de risco baixo, médio e alto da etapa de matança no abatedouro A. Os tipos 4 (20,00%), 5 (20,00%), 12 (20,00%) e 29 (20,00%) foram os mais frequentes seguidos pelos tipos 21 (10,00%) e 31 (10,00%). Os antimicrobianos mais eficazes foram amoxicilina com clavulanato (100,00%), doxiciclina (100,00%), ceftiofur (93,75%), ampicilina (81,25%) e cefalexina (75,00%). Multirresistência foi observada em 100,00% das linhagens isoladas. Os abatedouros e as diferentes áreas da etapa de matança podem ser fatores de risco para a ocorrência de S. suis, consequentemente, para infecção humana pelo patógeno. No entanto, é importante ressaltar que todos os funcionários estão expostos à infecção. O presente trabalho é o primeiro estudo epidemiológico realizado no Brasil acerca dos fatores de risco associados à ocorrência de S. suis envolvendo grande número de indivíduos pertencentes ao principal grupo de risco / Abstract: The present study aimed to determine the occurrence of Streptococcus suis in employees (healthy carriers) and environment of swine slaughterhouses with federal inspection service of the state of São Paulo, Brazil, to describe the distribution of the different types of the agent and the antimicrobial susceptibility profile of the isolated strains, as well as to research the risk factors associated with the occurrence of the pathogen. Tonsillar swabs of 139 employees and 261 environmental swabs were collected for detection of S. suis and its types by monoplex and multiplex PCR, respectively. There was no detection of healthy carriers employees. S. suis was isolated from 27.03% of the samples collected at slaughterhouse A; 17.31% at slaughterhouse B; 15.31% at slaughterhouse C; and 36.36% at slaughterhouse D. Significant statistical differences (p<0.05) were observed for the occurrence of S. suis among slaughterhouses and among areas of low, medium and high risk of the slaughterhouse A. The types 4 (20.00%), 5 (20.00%), 12 (20.00%) and 29 (20.00%) were the most frequent followed by types 21 (10.00%) and 31 (10.00%). The most effective antimicrobials were amoxicillin-clavulanate (100.00%), doxycycline (100.00%), ceftiofur (93.75%), ampicillin (81.25%) and cephalexin (75.00%). Multidrug resistance was observed in 100.00% of the isolates. The slaughterhouses and the different areas of the pig slaughtering may be risk factors for the occurrence of S. suis and, consequently, for human infection. However, it is noteworthy that all employees are exposed to S. suis infection. This project is the first epidemiological study in Brazil about the risk factors associated with the occurrence of S. suis involving a large numbers of individuals belonging to the main risk group / Doutor

Thesis (MTech (Chemical Engineering))--Cape Peninsula University of Technology, 2017. / The poultry industry is one of the largest industries in the South African agricultural sector. To sustain their various operations, this industry utilises a large quantity of potable water to process slaughtered birds in order to satisfy hygiene and sanitation requirements in processing facilities. Thus, the consumption of potable water during poultry slaughterhouse operations results in the production of high-strength poultry slaughterhouse wastewater (PSW), which is laden with a variety of pollutants, including fats, oil and grease (FOG), carcass debris, feathers and organic matter, including proteins, that should be removed from the wastewater, or at least reduced in concentration, prior to the PSW being discharged into the environment. This is to avoid and/or minimise levies and non-compliance penalties from monitoring institutions in charge of controlling the quality of effluents in the area from which the PSW was collected for this study. Furthermore, the option of treating and recycling the PSW to address the current issue of water scarcity in the Western Cape (South Africa), and to minimise possible harmful effects on the environment, will reduce the overreliance on slaughterhouses in the region on potable/drinking water, thus also lessening running costs associated with water procurement for operations. Various technologies, involving physical, chemical or biological processes, have been evaluated for the treatment of PSW, with this study focusing on anaerobic treatment (part of the biological treatment) of PSW, using a high-rate anaerobic bioreactor system (HRABs), which provides for low production of sludge, the production of biogas as a source of energy and the provision of high performance in terms of organic matter removal. Moreover, HRABs are cheaper, when compared to other aerobic treatment technologies. However, numerous potential challenges were encountered when using HRABs, such as low production of biogas due to gas entrapment, head losses across the granular bed, sludge washout in upflow HRABs, uneven wastewater distribution, and thus poor dispersion of the organic matter, which impacts on the adequacy of treatment, poor release of toxic substances contained in the entrapped biogas (NH3 or H2S), clogging of the underdrain system for down-flow HRABs, or the formation of dead zones within the granular bed, resulting in short-circuiting.

Thesis (DTech (Chemical Engineering))--Cape Peninsula University of Technology, 2017. / The process of anaerobic digestion (AD) is one of the most cost-effective and environmentally sustainable technologies to treat wastewater in the agricultural sector. In South Africa, in some industries in the agricultural sector, such as the poultry industry in particular, slaughterhouses have the highest consumption of potable water, culminating in the production of a large quantity of high strength wastewater. This high consumption of potable water has become a concern in South Africa due to water scarcity and reduced rainfall attributed to global warming, including weather changes. Furthermore, the generation of a large volume of wastewater poses environmental pollution concerns. The wastewater from poultry slaughterhouses can be quite easily treated to a suitable quality for reuse, using various bioreactor systems that utilise low cost anaerobic digestion processes. However, as this wastewater contains a high quantity of biodegradable organic matter – with the primary pollutants being proteins, blood, fats, oil and grease (FOG) – selecting a suitable anaerobic reactor configuration (up-flow vs down-flow) plays an important role in achieving high reactor performance. In this study, both the up-flow, (i.e. Expanded Granular Sludge Bed Reactor) and the down-flow (i.e. Static Granular Static Granular Bed Reactor), were studied to quantitatively determine their performance in treating poultry slaughterhouse wastewater. Firstly, the feasibility of treating poultry slaughterhouse wastewater with an up-flow Expanded Granular Sludge Bed Reactor (EGSB) coupled with anoxic and aerobic bioreactors was investigated at an HRT of 7 (168 hr), 4 (96 hr) and 3 (72 hr) days using organic loading rates of 0.5, 0.7 and 1.0 gCOD/L.day. The averaged tCOD removal for the EGSB reactor was 40%, 57% and 55%, respectively, at the various OLRs and HRTs investigated. The overall tCOD removal of the system (EGSB-anoxic/aerobic) at high OLR of 1.0 gCOD/L.day was increased to 65%. The redundant performance of the up-flow EGSB reactor was attributed to the periodical sludge washout experienced during its operation due to high FOG and TSS concentrations in the influent. Due to the periodic sludge washout, the reactor required continuous re-inoculation resulting in the EGSB being operated for a short period (i.e. 26 days). As a result of such system deficiency, it was recommended that to improve the performance of the up-flow EGSB reactor in treating poultry slaughterhouse wastewater, a pre-treatment system – such as a Dissolved Air Floatation system (DAFs) or a FOG skimmer – is required to reduce the FOG and total suspended solids (TSS) load prior to the wastewater fed to the EGSB. This will minimise system failure and the need for a continuous re-inoculation of the system (see Appendix C for improved operation strategy of the EGSB reactor). Furthermore, a system redesign was recommended, thus the use of the SGBR. Secondly, after the EGSB system evaluation, the performance of a down-flow system (i.e. SGBR) for the new design, the following were deemed appropriate for improved system (SGBR) design: 1) reduced HRT for high wastewater treatment through-put rates; 2) the ability to adequately treat the wastewater with higher organic loading rates; and 3) reduction of the plant footprint by using a membrane filtration system (i.e. a single process unit) to effectively reduce process requirements needed for the anoxic/aerobic bioreactors (i.e. n=2 process unit) used with the EGSB. Similarly, for large-scale operations, it is advisable to have a backwash system to adequately handle declogging processes (i.e. these systems modifications were evaluated in the SGBR). The SGBR, coupled with an ultra-filtration (UF) membrane system, was then investigated for treating the poultry slaughterhouse wastewater at an HRT of 55 hrs and 40 hrs, including average OLRs of 1.01 and 3.14 gCOD/L.day, respectively. The average maximum performance of the SGBR in terms of tCOD, TSS and FOG removal was > 90% at the OLRs and HRTs investigated. The UF membrane system used as a post-treatment system further yielded a system performance improvement for tCOD, TSS and FOG of 64%, 88% and 60%, respectively. The overall performance of the combined system (SGBR and UF membrane system) in terms of tCOD, TSS and FOG removal was 98%, 99.8% and 92.4%, respectively. The highest performance for the down-flow SGBR was attributed to its ability to retain granulated sludge in the reactor while maximizing the digestion of the organic matter fed into the reactor, even at higher OLRs. Furthermore, for effective declogging, the implementation of a periodic backwash system to effectively remove dispersed fine sludge particles in the underdrain and excessive suspended solids entrapment was observed to ease the system operational deficiencies.

Thesis (MTech (Chemical Engineering))--Cape Peninsula University of Technology, 2017. / In the recent past, the poultry industry in South Africa has grown due to an increased demand of poultry products as a result of population growth and improved living standards. Furthermore, this has led to poultry slaughterhouses generating high strength wastewater which is laden with a high concentration of organic and inorganic pollutants from the slaughtering process and sanitation of equipment and facilities. As a result, South Africa has promulgated restrictions and a set of quality standards for effluent discharged into the environment to minimize ecological degradation and human health impact. Hence, there is a need for improved Poultry Slaughterhouse Wastewater (PSW) pre-treatment prior to either discharge into municipal wastewater treatment plants (WWTP) or on-site secondary treatment processes such as anaerobic digesters. Additionally, amongst the pre-treatment methods for Fats, Oil and Grease (FOG) laden wastewater, flotation remains the most popular with Dissolved Air Flotation (DAF) system being the most applied. However, modelling and optimization of a biological DAF system has never been attempted before in particular for a bioflocculant supported DAF (BioDAF) for PSW pre-treatment. Process modelling and optimization involves process adjustment to optimize influential parameters. In this study, Response Surface Methodology (RSM) was used to develop an empirical model of a BioDAF for pre-treatment of PSW, for which a bioflocculant producer including production conditions, flocculant type and its floc formation mechanism, were identified. Twenty-one (n = 21) microbial strains were isolated from the PSW and their flocculation activity using kaolin clay suspension (4g/L) was quantified, with a mutated Escherichia coli (mE.coli) [accession number LT906474.1], having the highest flocculation activity even in limited nutrient conditions; hence, it was used for further analysis in other experiments. Furthermore, the optimum conditions for bioflocculant production achieved using RSM were pH of 6.5 and 36°C conditions which induced instantaneous bioflocculant production with the highest flocculation activity. The bioflocculant produced by the mE.coli showed the presence of carboxyl/amine, alkyne and hydroxyl functional groups, which was indicative that the bioflocculant contained both polysaccharides and some amino acids.

Orientador: Helio Langoni / Banca: Antonio Carlos Paes / Banca: Márcio Garcia Ribeiro / Banca: Lisiane de Almeida Martins / Banca: Luiz Fernando Pita Gondim / Resumo: Toxoplasma gondii é um parasito de grande importância no contexto de produção animal e saúde pública, sendo importante patógeno oportunista em pacientes imunocomprometidos. Este estudo objetivou determinar a soroprevalência de toxoplasmose em ovinos de abatedouros do estado de São Paulo, e a variabilidade genotípica dos isolamentos obtidos. A presença de anticorpos para T. gondii foi pesquisada em 602 amostras de soro pela reação de imunofluorescência indireta (RIFI), aglutinação direta modificada (MAT), com antígeno fixado pelo metanol (AM) e formalina (AF). Bioensaio em camundongos e pesquisa do DNA do parasito pela reação em cadeia pela polimerase (PCR) do gene 529 pares de bases (pb), repetitivo 300 vezes no genoma do parasito, foi realizado com cérebro, pulmão e músculo ("pool" de diafragma e coração) dos ovinos soropositivos. Das amostras positivas à PCR realizou-se a genotipagem pelas técnicas de multilocus-, nested-PCR e polimorfismo de comprimento dos fragmentos de restrição (RFLP-PCR) em 12 loci (SAG1, 5'SAG2, 3'SAG2, alt-SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, Apico, CS3), adicionado de ROP18Del e ROP18UPS, além da confirmação do parasito pelo locus 18S rRNA, diferenciando de Hammondia hammondi, Neospora caninum, Sarcocystis neurona, S. moulei, S. miescheriana, S. hominis, S. capracanis e S. tenella. 66/602 (11,0%) amostras de soro foram positivas para algum teste sorológico, com maior sensibilidade da MAT-AF, utilizado como teste de triagem. Amostras teciduais de 20/66 (30,3%) animais foram positivas ao isolamento, sendo detectados cistos em 12, taquizoítos em quatro e somente sorologia positiva em outras quatro. Detectouse o DNA do parasito em amostras de 22/66 (33,3%) animais. O genótipo completo foi obtido em somente 13/22 (59,1%). Dez genótipos diferentes foram identificados, sendo seis novos genótipos... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Toxoplasma gondii is a parasite with high importance to the animal production and public health, being important opportunistic pathogen in immunocompromised patients. This study was aimed to determine the seroprevalence of toxoplasmosis in ovines in slaughterhouses from State of de São Paulo, and the genotypic variability of the obtained isolates. T. gondii antibodies were researched in 602 serum samples by indirect fluorescent antibody test (IFAT) and modified agglutination test (MAT), with methanol- (AM) and formalin-fixed antigen (AF). Bioassay in mice and the research of DNA by polymerase chain reaction (PCR) of gene 529 base pairs (bp), 300 times repetitive in parasite genome, was assayed with brain, lung and muscle ("pool" of diaphragm and heart) from seropositive ovines. Genotyping of the PCR positive samples was performed by multilocus-, nested-PCR and restriction fragment lenght polymorphism (RFLP-PCR) in 12 loci (SAG1, 5'SAG2, 3'SAG2, alt-SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, Apico and CS3), added of ROP18Del and ROP18UPS, beyond the confirmation by 18S rRNA locus, to differentiate Hammondia hammondi, Neospora caninum, Sarcocystis neurona, S. moulei, S. miescheriana, S. hominis, S. capracanis and S. tenella. 66/602 (11.0%) serum samples were positive to, at least, one serological test with high sensitivity to MAT-AF, used as screening test. Tissue samples of 20/66 (30.3%) animals were positive to the isolation, being detected cysts in 12, tachyzoites in four and in other four only positive result to the serology. DNA of the parasite was detected in samples of 22/66 (33.3%) animals. The complete genotype was detected in only 13/22 (59.1%). Ten different genotypes were identified, with six new genotypes. Two samples presented type II, isolated from Polwarth (Ideal) breed, bred extensively in Santana do Livramento and Uruguaiana, RS. Two other samples, from... (Complete abstract click electronic access below) / Doutor

The South African ostrich industry is presently characterised by a drastic decline in the slaughter price of slaughter birds, due to the drop in the price of meat as well as leather. As a result, the economic viability of ostrich farming is severely hampered by these developments, and many generally accepted industry practices have to be reviewed. Among the practices under review is the possibility of slaughtering ostriches at an earlier age than the traditional slaughter age of 12 - 14 months, in order to minimise feed costs and the incidence of damage to the skin. However, little information is available on the effect of the slaughter age on the yield and quality of the economically important end-products. The effect of slaughter age on production and the economic viability of a commercially intensive ostrich production system was consequently evaluated in a completely randomised experimental design involving two batches (n= 81 and n= 94) of ostriches. The experiments took place at Kromme Rhee experimental farm of the Elsenburg Research Centre near Stellenbosch. The birds were subject to experimental treatment at the age of 4 months (n= 81, from May 2004 to March 2005) and 6 months (n= 94, from August 2004 to August 2005) respectively. The ostriches were randomly divided into 10 groups of between 16 and 20 birds per group. Standard production practices, as applied in an intensive ostrich production unit, were implemented. Clean drinking water and self-mixed grower diet (min 15 percent crude protein, 0.68 percent lysine and 11.4 MJ ME per kg feed) and finisher diet (min 14 percent crude protein, 0.55 percent lysine and 9.8 MJ ME per kg feed) were provided ad libitum to the birds. Birds were slaughtered at the ages of 8.5, 10.5, 12.5, 14.5, and 16.5 months respectively. Data on feed intake and yields of cold carcass, crust skin size, skin grade and total feathers was recorded for birds slaughtered at the respective ages. Data was analysed according to the analysis of variances. Values for meat yield, skin size yield and feed intake were predicted by regression analysis based on experimental values. Industry figures and norms were used as proxy for other production inputs and costs. A gross margin type analysis was performed to evaluate the effect of different slaughter ages on the profitability of each production system. There was a positive correlation between age and feed intake (r2= 0.40), slaughter weight (r2= 0.97), cold carcass yield (r2= 0.48), skin surface area (r2= 0.39), skin grade (r2= 0.19) and total yield of feathers (r2= 0.29). The dry skin grade showed deterioration as slaughter age was prolonged. Highly significant differences (P< 0.01) in slaughter weight, cold carcass yield, skin surface area, dry skin grade and total feathers were detected at the different slaughter ages. There were no significant differences (P> 0.05) with respect to gender for slaughter weight, skin surface area and dry skin grade within the different age groups. Males had significantly higher (P< 0.05) cold carcass yield and total feather yield than their female counterparts. From this study it can be concluded that an increase in slaughter age significantly increases feed intake, slaughter weight, cold carcass yield, and skin surface area. It is also clear that an increase in slaughter age can be detrimental to dry skin grade. The relative income contribution of the three main products (skin: meat: feathers) occurred in a ratio of 47:53:0, 52:47:1, 47:50:3, 44:51:5, 39:56:5 at the respective slaughter ages. Total income revealed an increase of 26 percent from 8.5 to 10.5 months slaughtering, an increase of 4 percent between 10.5 and 12.5 months, and an increase of 11 percent between 12.5 and 14.5 months. The income dropped by 0.3 percent between 14.5 and 16.5 months slaughtering. Total costs increased with slaughter age, particularly feed costs which showed an increase (at a decreasing rate) between the different slaughter ages. The margin above specified cost per bird was the highest for birds slaughtered at the age of 10.5 months. The margin above cost showed a steady decline as birds were slaughtered at higher ages. Slaughtering at 16.5 months revealed a negative margin. To compare the effect of differences in time span on different slaughter age regimes, margin above costs for each system over 5 years were discounted to a present value. In this study, with current feed costs and income from end products, slaughtering at 10.5 months revealed the highest present value for the margin above cost. Furthermore, slaughtering at 16.5 months revealed a negative present value on the margin above cost after 5 years. Financial viability calculations are relevant and valid for data obtained in this case study. Financial viability is however case-specific and may vary between producers, depending on their individual management practices, production systems and cost structures. Results from this study may be of significant value to managerial decision-making in the ostrich industry.

Effects of pre-slaughter sheep handling and animal-related factors on Creatine Kinase levels and physico-chemical attributes of mutton By Chulayo Amanda Yucca The objective of the study was to determine the effects of pre-slaughter sheep handling and animal-related factors on Creatine kinase (CK) levels and physico-chemical characteristics of mutton from South African sheep breeds. One hundred and seventy-three castrated male sheep from four breeds (15 Dormer, 46 South African Mutton Merino, 77 Dorper and 35 Blackhead Persian) were used. The animals were grouped according to age categories. The grouping was as follows: Group 1 (6 ≤ 8 months), Group 2 (9 ≤ 12 months) and Group 3 (13 ≤ 16 months). Blood samples for CK determination were collected at exanguination using disposable vacutainer tubes. Representative samples of the Muscularis longissimuss thoracis et. lumborum (LTL) muscle were taken for the determination of ultimate pH (pHu), colour (L*-lightness, b*- redness and a*- yellowness), thawing and cooking losses and meat tenderness. Significant (P<0.01) breed effects were observed on CK levels with Dormer having the highest CK values. Significant linear relationships were observed between pre-slaughter condition and CK levels. There were positive correlations between colour coordinates L* and b* (r =+0.22) and between a* and b* (r =+0.63). Cooking loss and Warner Braztler Shear Force (WBSF) values were positively correlated (r =+0.29). The Principal Component Analysis (PCA) showed a significant variance for CK and between physico-chemical characteristics of mutton. There were no relationships between CK levels and physico-chemical characteristics of mutton. Significant breed and age effects on pHu, L, a*, b*, thaw %, CL and WBSF of mutton were observed. iv It was concluded that, pre-slaughter conditions affect CK levels and physico-chemical characteristics of mutton. However, there were no relationships between CK levels and physico-chemical characteristics of mutton.

The study was conducted to determine the effect of pre-slaughter stress of pigs on the levels of cortisol, creatine kinase (CK) and their subsequent relationship with pork quality. From our knowledge, there is paucity of information on transportation, lairage duration and sex effects on saliva cortisol and its relation with serum cortisol, urine cortisol and other meat quality traits. Stage one of the study assessed the effect of sex and time to slaughter (transport and lairage duration) on the levels of cortisol and CK in crossbred pigs. The second stage of the study evaluated the effect of sex and lairage duration on pork quality. The trials comprised of 60 22-weeks old commercial crossbred pigs [(30 boars vs. 30 gilts) with an average body weight of 76.9kg for gilts and 78.3kg for boars. Thirty pigs (15 Boars vs. 15 Gilts) were slaughtered on arrival after a 120km road journey and the other 30, after travelling the same road and distance, were slaughtered after having been in the lairage for 20 hours. Saliva samples were obtained during three time periods: between 07:00-10:00 on the day before the journey, on arrival at the abattoir and after lairage. Levels of cortisol in serum and urine and CK in serum samples collected at slaughter were determined. The samples (saliva and serum) were centrifuged at 20oC for 10 min at 3550 x g and stored at -20oC in separate vials until analysis. Pork quality was assessed using muscle pH, colour, thawing and cooking losses and Warner-Bratzler Shear Force. Correlations between cortisol levels in saliva, serum and urine and meat quality were assessed. The effect of sex and time to slaughter on saliva cortisol was significant. Statistical analysis showed significant interaction of sex by time to slaughter on serum cortisol. It was only the effect of sex that demonstrated higher (P <0.05) serum creatine kinase levels in gilts. Likewise, urine cortisol was influenced (P <0.05) only by time to slaughter. Saliva cortisol after transportation (r = 0.52) was correlated (P <0.05) with urine cortisol. The study suggests that there are greater responses of the Hypothalamic-pituitary-adrenal axis following time to slaughter (transport and lairage duration) between gilts and boars. This can be used in measuring cortisol in saliva, serum and urine, and serum creatine kinase to determine stress levels in pigs. Besides the lightness (L*) colour value which was significantly lower (P <0.05) in meat from gilts than from boars, the results of this study showed no interaction or individual effect (sex or lairage duration) on pH and other colour measurements. Meat cooking loss was affected (P <0.05) by gender x lairage interaction. Effect of lairage duration (as an individual effect) on the measured meat quality traits was not significant (P <0.05). Correlation analysis showed significant (P <0.05) negative relation between baseline saliva cortisol (r = -0.40) and the pork L* value. Saliva cortisol after lairage duration (r = -0.38 and r = 0.38) was correlated (P <0.05) with pH45 and pork a* value, respectively. Serum cortisol (r = -0.35) was negatively correlated (P <0.05) with pH45. Moreover, there were negative correlations (P <0.05) between saliva cortisol after transportation (r = -0.35), saliva cortisol after lairage duration (r = -0.44), serum cortisol (r = -0.40) and meat cooking loss. The study suggests that cortisol in saliva and serum can be used to determine effect of time to slaughter (transport and lairage duration) on meat quality traits from gilts and boars. Keywords: Boars; gilts; saliva cortisol; serum cortisol; serum creatine kinase; urine cortisol.