Master of Science / Department of Animal Sciences and Industry / James S. Drouillard / Three trials were conducted using dried distiller's grains with solubles (DDGS) to evaluate effects on feedlot performance, carcass characteristics, ruminal fermentation, and diet digestibility in cattle fed steam-flaked corn-based diets. In trial 1, crossbred yearling heifers were used in a finishing trial to evaluate interactions between corn-DDGS feeding levels and roughage source (alfalfa hay vs corn silage) in terms of impact on feedlot performance and carcass characteristics. Experimental diets were based on steam-flaked corn and contained 0% DDGS with 6% alfalfa hay (AH), 0% DDGS with 10% corn silage (CS), 25% DDGS with 6% AH, or 25% DDGS with 10% CS (DM basis). Results indicated no interaction between levels of DDGS and roughage source. Heifers fed DDGS as a partial replacement for steam-flaked corn had similar growth performance and carcass merit compared to heifers fed diets without DDGS. Corn silage and alfalfa hay were comparable roughages when a portion of steam-flaked corn was replaced with DDGS. The second trial was a companion metabolism study in which ruminal fermentation characteristics and diet digestibility were examined in 12 cannulated Holstein steers fed steam-flaked corn finishing diets with or without DDGS, using alfalfa hay or corn silage as roughage sources. Diets were similar to those fed in the performance study and consisted of steam-flaked corn with 0 or 25% DDGS (DM basis) and 6% AH or 10% CS (DM basis). Feeding DDGS decreased ruminal pH and ruminal ammonia concentrations, and digestion of DM and OM were less compared to diets without DDGS. The decrease in digestibility was largely attributable to poorer digestion of CP and, to a lesser extent, a reduction in starch digestion. The third study was designed to investigate effects of pH (5.0, 5.5, and 6.0) on in vitro fermentative activity by ruminal microorganisms from cattle adapted to a finishing diet containing 25% DDGS (DM basis). Higher pH led to greater dry matter disappearance in vitro (P < 0.01). DDGS can be an effective substitute for steam-flaked corn. Efforts to address low ruminal pH and low ruminal ammonia may prove beneficial for improving value of DDGS as cattle feed.

O objetivo deste trabalho foi a avaliação metabólica de dietas contendo níveis de inclusão de bagaço de cana-de-açúcar in natura (0, 3, 6, 9% da MS da dieta) associados a milho grão inteiro ou floculado (360g/L), perfazendo um total de cinco tratamentos. Foram utilizados cinco bovinos machos castrados da raça Nelore, com peso médio inicial igual a 479,2kg; contendo cânulas no rúmen, distribuídos em um delineamento Quadrado Latino 5x5. Tratamentos aplicados: MI-0: milho inteiro sem inclusão de BIN (bagaço de cana-de-açúcar in natura); MI-3: milho inteiro com 3% de BIN; MI-6: milho inteiro com 6% de BIN; MI-9: milho inteiro com 9% de BIN; MF-6: milho floculado com 6% de BIN. O método de processamento não alterou o consumo de MS e nutrientes (p>0,05) e não houve efeito de nível de inclusão de BIN (p>0,05), exceto para o consumo de FDN que aumentou linearmente (p=0,0145) com a inclusão de BIN. Os coeficientes de digestibilidade não diferiram entre os métodos de processamento e nem entre os níveis de BIN (p>0,05), apesar do efeito positivo da inclusão de BIN no pH ruminal (p=0,0001). O milho duro utilizado no presente estudo quando fornecido inteiro para bovinos Nelore em dietas com altos teores de concentrado apresentou ao redor de 96% da concentração de ELm e de ELg (2,12 e 1,44 Mcal/Kg de MS) em relação ao valor tabular do NRC (1996) para milho dentado (2,18 e 1,50 Mcal/Kg de MS). Os maiores teores de BIN na dieta ocasionaram maiores tempos gastos na atividade de ingestão (p<0,05) e mastigação (p<0,05) e, também, houve uma tendência (p=0,0702) para maior tempo de alimentação à medida que o teor de BIN foi aumentando. O método de floculação não alterou os VfCF e VfCNF, no entanto, diminuiu a KdCF e aumentou a KdCNF e o lag time. / The objective of this study was to evaluate diets containing levels of fresh sugar cane bagasse (0, 3, 6, 9% DM) associated with whole or steam flaked corn grain (360g/L) in metabolic parameters of cattle. Five rumen cannulated Nellore steers, weighing 479.2 kg at the beginning of the experiment, were distributed in five treatments in a 5x5 Latin Square design. Experimental treatments were the following finishing diets: WC-0: whole corn with no addition of sugar cane bagasse (SCB); WC-3: whole corn with 3% SCB; WC-6: whole corn with 6% SCB, WC-9: whole corn with 9% SCB; SFC-6: steam flaked corn with 6% SCB. Despite the increased in vitro Kd of non-fibrous carbohidrates (NFC), steam flaked corn did not improve the nutritional value of corn grain in comparison with whole grain based on in vivo metabolic assay. The inclusion of dietary SCB did not improve DM intake and digestibility of nutrients, but resulted in positive effects on ruminal pH. The addition of whole flint corn used in the present study in the diet of Nellore steers fed high concentrate finishing diets, had approximately 96% of NEm and NEg concentrations (2.11 and 1.44 Mcal / kg DM) in comparison to tabular values from (1996) for dent corn (2.18 and 1.50 Mcal / kg DM), for DM intake restricted to 85% of potential intake.

Os efeitos do fornecimento de dietas contendo glicerina bruta foram avaliados em quatro experimentos com ovinos de diferentes categorias. Experimento 1: Quarenta cordeiros foram usados para avaliar os efeitos da inclusão de glicerina bruta sobre o desempenho, as características de carcaça e da carne e a concentração de enzimas hepáticas. As rações experimentais foram isonitrogenadas, sendo que o ajuste proteico foi realizado pela inclusão de ureia e farelo de soja. Os teores de inclusão de glicerina bruta foram: 0, 5, 10 ou 15% na MS. A adição de glicerina bruta causou efeito quadrático no CMS, CFDN, CPB, GMD e peso final. A inclusão de glicerina causou efeito quadrático para peso corporal ao abate, PCQ e PCF. Foi observado efeito quadrático para os ácidos graxos mirístico, palmítico, palmitoleico, linoleico e rumênico. A glicerina bruta demonstrou ser um bom substituto do milho em dietas com alto teor de concentrado, melhorando o desempenho e as características da carcaça dos animais quando incluída até 10% na MS. Experimento 2: Cinquenta cordeiros(as) foram usados para avaliar os efeitos da inclusão de glicerina bruta em rações com alta proporção de concentrado, sobre o desempenho, características de carcaça e parâmetros enzimáticos. As rações experimentais foram isonitrogenadas, sendo o ajuste proteico realizado pela inclusão de farelo de soja. Os teores de inclusão de glicerina bruta foram: 0, 5, 10, 15 e 20% na MS. A inclusão de glicerina bruta não afetou as variáveis de desempenho analisadas. Houve apenas efeito linear para o CMM. A glicerina bruta pode substituir o milho em até 20%, mantendo o desempenho dos animais e as características de carcaça. Experimento 3: Cinco borregos canulados no rúmen foram utilizados para avaliar os efeitos da glicerina bruta sobre os parâmetros ruminais, a digestibilidade das dietas e o metabolismo de nitrogênio. As dietas foram isonitrogenadas e os teores de inclusão de glicerina bruta foram: 0, 5, 10, 15 ou 20% na MS. Houve redução linear na ingestão de FDN e aumento linear na ingestão de MM. Houve efeito linear crescente para a digestibilidade da MS e MO. A inclusão de glicerina bruta causou redução linear no acetato, relação C2:C3, AGCC total, e aumento linear no pH ruminal. A glicerina bruta pode substituir até 20% do milho em dietas de borregos, melhorando a digestibilidade da MS e MO. Experimento 4: Cento e dezoito ovelhas com 90 dias de prenhez foram utilizadas para avaliar a inclusão de glicerina bruta em dietas de gestação e lactação. Os teores de inclusão foram 0 ou 10%. Da segunda a oitava semana foi mensurado o CMS e produção de leite das ovelhas e a ingestão de concentrado inicial dos cordeiros. A inclusão de glicerina bruta aumentou o CMM e reduziu a porcentagem de gordura no leite. A adição da glicerina bruta na dieta das ovelhas diminuiu a concentração sérica de AGNE. A inclusão de 10% de glicerina bruta na dieta de ovelhas durante a gestação e lactação não prejudica o desempenho dos animais e reduz a possibilidade de ocorrência de toxemia da gestação. / The effects of feeding diets with crude glycerin were evaluated in 4 trials using different categories of sheep. Experiment 1: Forty Santa Inês ram lambs were used to determine the effects of partial replacement of corn by crude glycerin on growth, hepatic enzymes, carcass and meat characteristics of lambs fed high-concentrate diets. The diets were isonitrogenous and the protein was adjusted by increasing urea and soybean meal. Increasing levels of crude glycerin were: 0, 5, 10 or 15%. There was quadratic effect for DMI, NDFI, CPI. ADG and final weight. There was a quadratic effect for slaughter BW and dressing percentage, but no difference on longissimus muscle area, backfat thickness and body wall thickness. There was quadratic effect for myristic, palmitic, palmitoleic, linoleic and rumenic acid. Crude glycerin is a good substitute of corn in high-concentrate diets, improving performance and carcass characteristics when included until 10% of the diet DM. Experiment 2: Fifty lambs were used to determine the effects of partial replacement of corn by crude glycerin on growth, carcass characteristics and hepatic enzymes of lambs fed high concentrate diets. The diets were isonitrogenous and the protein adjusted was performed with increased soybean meal. Increasing levels of crude glycerin were: 0, 5, 10, 15 or 20%. There was an increased in mineral matter intake. Crude glycerin can be used as a substitute for corn in high concentrate diets of ram lambs without affecting performance and carcass characteristics. Experiment 3: Five Santa Inês ram lambs, cannulated in the rumen, were used to determine the effects of using crude glycerin on ruminal constituents, diet digestibility and nitrogen metabolism. The diets were isonitrogenous and crude glycerin was included in the ration at 0%, 5%, 10%, 15% or 20% in the DM. There was linear decreased on NDF intake and a linear increase in ash intake. Feeding crude glycerin increased DM and OM digestibility. Crude glycerin decreased acetate, acetate:propionate ratio, total SCFA and showed a linear increase on pH. Replacing corn by crude glycerin up to 20% of dietary DM increased DM and OM digestibility, maintained propionate and decreased acetate and total SCFA. When soybean meal was used to adjust the diet protein level, there were no changes on nitrogen metabolism. Experiment 4: One hundred and eighteen 90 d pregnant ewes were used to determine the effects of feeding crude glycerin on performance, NEFA concentration and lamb growth. Diets were isonitrogenous and crude glycerin levels were zero or 10%. From the second until de eighth week of lactation DM intake of the ewes and starter of the lambs were measured. There was an increase on ash intake for the glycerin fed ewes. There was a decrease in milk fat percentage. Crude glycerin fed ewes showed a decrease on blood NEFA. The inclusion of 10% of crude glycerin in the diets of sheep during pregnancy and lactation had no detrimental effect on performance of ewes and lambs. Using 10% of crude glycerin decreases the chances of pregnancy toxemia in ewes.

Bovine viral diarrhoea virus infection is an important viral infection affecting the cattle industry today. The prevalence of this infection in South African feedlots is unknown. Ear notch biopsies were collected from animals entering feedlots which appeared unthrifty, chronic poor doers, and animals entering the hospital pen with respiratory disease for the first time. One thousand and seventy four (1074) samples were collected from the first two categories and 616 samples from animals entering the hospital pen. Samples were processed with routine immunoperoxidase protocol. Serum samples were also collected when possible. The first aim of this study was to determine the prevalence with the use of immunoperoxidase staining on ear notch biopsies. Overall 49 animals tested positive, 43 from the 1074 group and 6 from the 616 group. The prevalence of persistently infected cattle entering the feedlots was determined as 2.9%, which is higher than the rule of thumb that 0.5% of infected animals enter feedlots. Four percent were positive in the group of 1074 animals and one percent in those entering the hospital pen for the first time. It was proposed by the author that persistently infected animals are at a greater risk to develop respiratory disease in the feedlot, but this was not supported by the data collected. There was thus no clear increase in respiratory disease in persistently infected animals. The reliability of the immunoperoxidase stain as a diagnostic method to identify persistently infected animals was also evaluated. This diagnostic method proved to be reliable, but the pathologist needs to be aware of non-specific staining. During the course of the research it became apparent that in some cases mast cells in the dermis stain positive with both DAB and NovaRED stains. Positive staining in keratinocytes and hair follicle epithelium was not present and these cases were proven as negative for persistent infection. The specific cause of positive staining of mast cell granules remains unclear. Only ten positive cases had serum samples on which ELISA tests for antigen and antibody were performed. All tests correlated well with the immunoperoxidase method except in four cases, where the animals were incorrectly diagnosed as positive due to the non-specific staining as described above. Immunoperoxidase staining on ear notch biopsies is thus a reliable diagnostic method to identify persistently infected animals with BVDV, but the pathologist must be aware of non-specific positive staining. / Bees virus diarree infeksie is ‘n belangrike virale infeksie wat die bees industrie van vandag beinvloed. Die prevalensie van die infeksie in Suid Afrikaanse voerkrale is onbekend. Oorknip biopsies is geneem van verdagte diere met aankoms by die voerkraal, chroniese swak beeste en diere wat vir die eerste keer in die hospitaal kraal weens respiratoriese siekte opgeneem is. Een duised vier en sewentig (1074) monsters is van die eerste twee kategoriee geneem en 616 monsters van diere wat in die hospitaal kraal opgeneem is. Monsters is op roetiene wyse vir immunoperoksidase kleuring geprosesseer. Serum monsters is waar moontlik ook versamel. Die eerste doel van die studie was om die prevalensie van permanente besmette draers te bepaal met behulp van immunoperoksidase kleuring op oorknip biopsies. Nege-en-veertig diere in totaal het positief getoets, 43 vanuit die eerste groep en 6 vanuit die tweede groep. Die prevalensie van permanente besmette draers wat in voerkrale opgeneem word is was 2.9% wat hoër is as die verwagte 0.5% wat deur die literatuur aangedui word. Vier persent was positief in die 1074 groep en 1% in die groep wat vir die eerste keer in die hospitaal kraal opgeneem is. Dit is deur die navorser voorgestel dat permanente besmette draers ‘n groter risiko het om met respiratoriese siektes in die hospitaal kraal opgeneem te word, maar dit is nie deur die data bevestig nie. Daar was dus geen verhoging in die teenwoordigheid van respiratoriese siektes in geaffekteerde diere nie. Die betroubaarheid van immunoperoksidase kleuring om permanente besmette diere met BVD te identifiseer is ook geevalueer. Die metode is betroubaar gevind, maar die patoloog moet bewus wees van nie-spesifieke kleuring. Gedurende die navorsing het dit aan die lig gekom dat mastselle in die dermis positief kleur met DAB en NovaRED kleuring. Positiewe kleuring was nie in die epidermis of haarfollikel epiteel teenwoordig nie en die die gevalle was negatief vir permanente besmetting. Die spesifieke rede vir positiewe kleuring in mastselle is steeds onduidelik. Slegs 10 positiewe gevalle het serum monsters gehad vir ELISA teenliggaam en antigeen toetse. Die resultate het goed gekorrelleer met die immunoperoksidase kleuring, behalwe in 4 gevalle waar gevalle verkeerd as positief gediagnoseer is as gevolg van nie-spesifieke positiewe kleuring soos beskryf. Immunoperoksidase kleuring is dus ‘n sensitiewe metode om permanente besmette draers met BVDV te identifiseer, mits die patoloog bewus is van nie-spesifieke kleuring wat mag voorkom. / Dissertation (MMedVet)--University of Pretoria, 2010. / Paraclinical Sciences / unrestricted

No description available.

Doctor of Philosophy / Department of Biological & Agricultural Engineering / Ronaldo G. Maghirang / Emissions of particulate matter (PM) are an increasing concern for large open beef cattle feedlots. Research is needed to develop science-based information on PM emissions and abatement measures for mitigating those emissions. This research was conducted to (1) measure PM concentrations emitted from large cattle feedlots, (2) compare different samplers for measuring concentrations of PM with equivalent aerodynamic diameter of 10 µm or less (PM10), (3) evaluate the relative effectiveness of pen surface treatments in reducing PM10 emissions, and (4) predict PM control efficiency of vegetative barriers. Concentrations of PM with equivalent aerodynamic diameter of 2.5 µm or less (PM2.5), PM10, and total suspended particulates (TSP) upwind and downwind of two large cattle feedlots (KS1, KS2) in Kansas were measured with gravimetric samplers. The downwind and net concentrations generally decreased with increasing water content (WC) of the pen surface; for effective control of PM emissions from feedlots, it appears that pen surface WC should be at least 20% (wet basis). Three types of samplers for measuring PM10 concentrations in feedlots KS1 and KS2 were compared: Tapered Element Oscillating Microbalance™ (TEOM), high-volume (HV), and low-volume (LV) PM10 samplers. Measured PM10 concentration was generally largest with the TEOM PM10 sampler and smallest with the LV PM10 sampler. A laboratory apparatus was developed for measuring the PM10 emission potential of pen surfaces as affected by surface treatments. The apparatus was equipped with a simulated pen surface, mock cattle hooves that moved horizontally across the pen surface, and PM10 samplers that collected emitted PM10. Of the surface treatments evaluated, application of water (6.4 mm) and hay (723 g/m2) exhibited the greatest percentage reduction in PM10 emission potential (69% and 77%, respectively) compared with the untreated manure layer. Computational fluid dynamics (CFD) was applied to predict airflow and particle collection by a row of trees (2.2 m high × 1.6 m wide). Predicted particle collection efficiencies generally agreed with published data and ranged from less than 1% for 0.875-µm particles to approximately 32% for 15-µm particles.

Master of Science / Department of Animal Sciences and Industry / James S. Drouillard / Christopher D. Reinhardt / The effects of supplementing forms of flaxseed on plasma and longissimus muscle (LM) fatty acid (FA) composition, finishing performance, and carcass characteristics were evaluated in five studies. In study 1, steers were fed diets with soy oil (SO), ground flaxseed (Flaxseed), or urea formaldehyde condensation polymer treated flaxseed (UFCP). In study 2, steers were fed diets with SO, linseed oil (LO), or a combination of flaxseed and field peas that was extruded (LinPro). Feeding flaxseed products increased (P < 0.01) α-linolenic acid (ALA), omega-3 FA, and decreased (P < 0.01) n-6:n-3 in LM compared to cattle fed SO. Feeding LinPro increased (P < 0.01) ALA, omega-3 FA, and decreased (P < 0.01) n-6:n-3 in LM compared to steers fed SO or LO. In studies 3 and 4, steers were fed diets with and without Flaxseed and implanted or not. Implanting improved (P ≤ 0.05) DMI, ADG, feed efficiency, HCW, and LM area compared to cattle not implanted. In study 4, cattle fed Flaxseed had increased (P < 0.01) ALA and omega-3 FA, and decreased (P < 0.01) n-6:n-3 in LM compared to cattle fed SO. In study 5, heifers were fed diets with 0% or 5% linseed meal, and administered with or without exogenous hormones (NHTC). Administering exogenous hormones improved (P ≤ 0.02) DMI, ADG, G:F, and HCW compared to NHTC cattle. Omega-3 FA increased in LM when cattle were supplemented with flaxseed products. Cattle fed LinPro achieved the highest levels of ALA and omega-3 FA. Flaxseed products did not interact with implants as a natural growth promoter in finishing cattle.

Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: The aim of this study was to investigate the effect of feedlot production on the growth and carcass characteristics, as well as the distribution of the main tissues (muscle, fat and bone) and meat quality of Merino, South African Mutton Merino (SAMM) and Dorper lambs. The Merino and SAMM 2008 outperformed (P<0.05) the 2007 SAMM and both Dorper production groups in terms of average daily gain, while the Merino and both SAMM production groups achieved the best feed conversion ratio (P<0.05). The highest percentage A2 graded carcasses was achieved after 42 days under feedlot conditions by the Merino and both Dorper production groups, but it took only 21 days in the feedlot for the SAMM lambs to achieve the same result. Slaughter weight, carcass weight and dressing percentage all increased significantly with an increase in the number of days under feedlot conditions for all three breeds, while a decrease in the percentage head, trotters and red offal was also documented. The fatter retail cuts (thick rib, flank, prime rib and loin) increased (P<0.05) in percentage with an increase in the number of days under feedlot conditions. A significant decrease in the percentage leaner retail cuts (raised shoulder and hind-quarters) was found when the amount of days under feedlot conditions increased. The highest profit is obtained by the prime rib, loin and hind-quarters in a lamb carcass. For the Merino and Dorper lambs these three cuts, or a combination of the three showed the highest combined percentages after 42 and 63 days under feedlot conditions, respectively. The late maturing SAMM lambs achieved the highest percentages for these three cuts after 63 and 84 days under feedlot conditions in 2007 and 2008 respectively. Visceral and renal fat deposition increased throughout the production period for all breeds. The Dorper lambs attained the highest subcutaneous fat depth, and also produced the heaviest, but fattest carcasses. For A2-graded carcasses, Dorper lambs had the highest dressing percentage and lowest subcutaneous fat depth, followed by the SAMM and then Merino breed. A decrease in the percentage muscle and bone was found with an increase in the number of days under feedlot conditions, whilst an increase in the percentage fat was found under the same conditions. Meat quality was mostly affected by the 48h post mortem pH. This pH value is affected by the cooling rate of the carcasses, which in turn is affected by the level of carcass fatness. Carcass fatness increased with an increase in the number of days under feedlot conditions, resulting in a low 48h post mortem pH. A low 48h post mortem pH is accompanied by higher percentages of cooking and drip loss, as well as a high a*-colour reading for all three breeds. / AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om die effek van voerkraalproduksie op die groeivermoë, karkaseienskappe, verspreiding van spier, been en vet, en vleiskwaliteit van Merino, Suid-Afrikaanse Vleismerino (SAVM) en Dorperlammers te bepaal. Die Merino en SAVM 2008 produksiegroepe het hoër (P<0.05) gemiddelde daaglikse toenames getoon as die SAVM 2007 en beide Dorper groepe, terwyl die Merino en beide SAVM produksiegroepe die beste voeromset verhoudings bereik het (P<0.05). Die hoogste persentasie A2 gegradeerde karkasse is na 42 dae in die voerkraal deur die Merino en beide Dorper produksiegroepe geproduseer, terwyl dit slegs 21 dae onder dieselfde toestande vir die SAVM groepe geneem het om dieselfde resultaat te lewer. Daar is ‘n betekenisvolle verhoging in slagmassa, karkasmassa en uitslagpersentasie vir al drie die rasse gevind met ‘n toename in die aantal dae in die voerkraal, terwyl ‘n afname in die persentasie kop, pote en haarslag gevind was. Die persentasie vetter groothandelsnitte (dikrib, dunrib, ribtjop en lendesnit) het toegeneem (P<0.05) met ‘n toename in die aantal dae in die voerkraal. ‘n Betekenisvolle afname in die persentasie van die maerder groothandelsnitte (blad en boude) is gevind met ‘n toename in die aantal produksie dae in die voerkraal. Die hoogste inkomste van ‘n lamkarkas is afkomstige van die ribtjop, lende snit en boude. ‘n Kombinasie van hierdie drie snitte was die hoogste vir die lammers van die Merino en beide Dorper groepe na 42 en 63 dae in die voerkraal onderskeidelik. Die laat volwasse SAVM lammers het die hoogste persentasie van hierdie drie snitte bereik na 63 en 84 dae in die voerkraal vir die SAVM 2007 en SAVM 2008 onderskeidelik. Die neerlegging van pensvet en niervet het voortdurend toegeneem deur die produksieperiode vir al drie rasse. Die Dorperlammers het die hoogste onderhuidse vetneerlegging getoon, maar het ook die swaarste en vetste karkasse geproduseer. Dorperlammers het die hoogste uitslagpersentasie en laagste onderhuidse vetneerlegging vir A2 gegradeerde karkasse gehad, gevolg deur die SAVM en Merino. ‘n Afname in die persentasie spier en been in karkasse is waargeneem namate die lammers langer in die voerkraal was, terwyl ‘n toename in die persentasie vet onder dieselfde omstandighede waargeneem is. Die 48h post mortem karkas pH affekteer die meeste vleiskwaliteit eienskappe. Hierdie pH waarde word weer deur die tempo van karkasafkoeling beϊnvloed, wat op sy beurt deur die vetheidsgraad van die karkas bepaal word. Die vetheid van karkasse het toegeneem met ‘n toename in die aantal dae in die voerkraal, wat ‘n lae pH waarde 48h post mortem tot gevolg gehad het. ‘n Lae 48h post mortem pH waarde het gelei tot hoër persentasies kook- en dripverliese en hoë a* kleurlesings vir al drie rasse.

O caroço de algodão é uma semente oleaginosa e sua inclusão na alimentação de ruminantes pode aumentar os níveis de ácidos graxos insaturados na carne, melhorando os benefícios potenciais da carne vermelha para a saúde. Contudo, como o tipo de dieta pode influenciar o sabor e aroma e a qualidade da carne produzida é possível que a utilização do caroço de algodão em diferentes níveis na dieta de ovinos confinados altere esses parâmetros. Neste experimento objetivou-se estudar o efeito da adição de diferentes níveis de caroço de algodão e do aquecimento do mesmo no desempenho e características da carcaça e da carne de cordeiros confinados após a desmama. Foram utilizados 36 cordeiros cruzados, 16 machos e 16 fêmeas, em um delineamento de blocos casualizados. O aquecimento do caroço de algodão não causou deterioração lipídica na semente. A utilização de caroço de algodão resultou em maior eficiência alimentar e menor ingestão de matéria seca. As dietas experimentais não alteraram as características de carcaça, a maciez objetiva, a cor e as características organolépticas da carne. Quanto ao perfil de ácidos graxos da carne, o caroço de algodão aumentou o teor saturados e diminuiu os monoinsaturados. O colesterol da carne não foi inflenciado pelos tratamentos alimentares. / Whole cottonseed is an oil seed and its inclusion on ruminants diets could alter meat unsaturated fat levels, thereby improving potential health benefits for the consumer. However, diet type could affect taste, flavour and meat characteristics, and there is a possibility of alteration of these parameters when whole cottonseed is included in different levels on the diet. The aim of this experiment was to evaluate the effects of the inclusion of whole cottonseed in different levels in the diet or the heating of this feed, on the performance, meat and carcass characteristics of lambs after weaning. Thirty-six crossbred lambs, sixteen males and sixteen females, were assigned to a ramdomized block design. The heating of the whole cottonseed failed to induce lipidic deterioration of the seed. Whole cottonseed utilization increased feed efficiency and decreased dry matter intake. Meat characteristics like color, objective tenderness, carcass characteristics and sensory qualities were not affected by treatments. Whole cottonseed increased meat saturated fatty acids and decreased monounsaturated fatty acids. Meat cholesterol were not affect by diets.

Foram conduzidos dois experimentos no confinamento experimental do Departamento de Zootecnia da ESALQ/USP com o objetivo de estudar os efeitos de diferentes aditivos em dietas para bovinos terminados em confinamento. As dietas continham 78,1% de milho moído fino, 12% feno de Tifton-85, 6% melaço de cana, 2,5% mineral, 1,4% uréia e os respectivos aditivos. No experimento 1 foram utilizados 134 tourinhos da raça Nelore com 24 meses de idade e 330 kg de peso corporal médio inicial, alocados em 24 baias por 102 dias. Os tratamentos foram: 1) Controle (sem aditivo), 2) Monensina (30 ppm), 3) Monensina (20 ppm) + Virginiamicina (15 ppm), 4) Monensina (30 ppm) + Virginiamicina (15 ppm), 5) Virginiamicina (17 ppm), 6) Salinomicina (13 ppm) + Virginiamicina (15 ppm). No experimento 2 foram utilizados 93 tourinhos da raça Nelore com 24 meses de idade e 320 kg de peso corporal médio inicial, alocados em 16 baias por 109 dias. Os tratamentos foram: 1) Controle (sem aditivo), 2) Monensina (30 ppm), 3) Levedura (Saccharomyces cerevisiae; 109 UFC/g) 10g/animal/dia, 4) Combinação dos microrganismos probióticos Bifidobacterium bifidum (3,33 x 106 UFC/g), Lactobacillus acidophilus (3,33 x 106 UFC/g), Lactobacillus plantarum (1,66 x 106 UFC/g), Enterococcus faecium (1,66 x 106 UFC/g) e Saccharomyces cerevisiae (3,33 x 105 UFC/g) FLORAFORT® na dosagem de 3g/animal/dia. No experimento 1, a suplementação com monensina sódica exclusiva e em combinação com virginiamicina reduziu (P<0,1) a ingestão de MS (9,89; 9,20; 9,29; 8,98; 9,76; 9,85). O ganho de peso diário dos animais (1,33; 1,33; 1,39; 1,44; 1,45; 1,49) não foi afetado pelos tratamentos (P>0,05). Em comparação com o tratamento controle, a suplementação com Monensina (30 ppm) + Virginiamicina (15 ppm) aumentou a eficiência alimentar dos animais (P<0,05). O uso de aditivos antibióticos foi efetivo (P<0,05) para aumentar os valores de energia líquida de ganho das dietas (1,05; 1,14; 1,17; 1,26; 1,15; 1,16). No experimento 2, a monensina sódica reduziu a ingestão de MS (P<0,1) em comparação com os demais tratamentos (9,35; 8,25; 9,33; 9,20). O ganho de peso diário, a eficiência alimentar e a densidade energética das dietas não foram afetados pela monensina sódica e pelos probióticos testados (P>0,05). / Two trials were conducted at the ESALQ/USP Animal Science Department experimental feedlot to evaluate the effect of different feed additives in feedlot finished cattle. The animals were fed with 78.1% ground corn, 12% Tifton hay, 6% sugarcane molasses, 2.5% mineral, 1.4% urea and the respective additives. The first trial had 134 Nellore bulls with an average of 24 months and 330 Kg of initial body weight, allocated in 24 pens for 102 days. Treatments were: 1) Control (without additive), 2) Monensin (30 ppm), 3) Monensin (20 ppm) + Virginiamycin (15 ppm), 4) Monensin (30 ppm) + Virginiamycin (15 ppm), 5) Virginiamicyn (17 ppm), 6) Salinomicyn (13 ppm) + Virginiamicyn (15 ppm). The second trial had 93 Nellore bulls with an average of 24 months and 320 Kg of initial body weight, allocated in 16 pens for 109 days. Treatments were: 1) Control (without additive), 2) Monensin (30 ppm), 3) Yeast (Saccharomyces cerevisiae) 10g/animal/day 109 UFC/g, 4) Combination of probiotic microorganisms: Bifidobacterium bifidum (3.33 x 106 UFC/g), Lactobacillus acidophilus (3.33 x 106 UFC/g), Lactobacillus plantarum (1.66 x 106 UFC/g), Enterococcus faecium (1.66 x 106 UFC/g) and Saccharomyces cerevisiae (3.33 x 105 UFC/g) FLORAFORT® 3g/animal/day. In the first trial, the results showed that monensin alone or in combination with virginiamycin decreased (P<0.1) dry matter intake (9.89; 9.20; 9.29; 8.98; 9.76; 9.85). The average daily gain(1.33; 1.33; 1.39; 1.44; 1.45; 1.49) was not affected by the treatments (P>0.05). In comparison to the control diet, the monensin (30 ppm) + virginiamycin (15 ppm) supplementation increased feed efficiency (P<0.05). The use of antibiotic additives was effective (P<0.05) to increase the diet energy values (1.05; 1.14; 1.17; 1.26; 1.15; 1.16). In the second trial, monensin decreased dry matter intake (P<0.1) in comparison to the other treatments (9.35; 8.25; 9.33; 9.20). Average daily gain, feed efficiency and diet energy density were not affected by monensin and probiotics (P>0.05).