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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.
391

Optimal risk management strategies for a cattle backgrounding operation in the Peace River area

Klee, Felix Wilhem Peter 05 1900 (has links)
Backgrounding cattle is risky. Large amounts of short-term capital are required to buy feeders and feedstuffs, and a ten month cost-revenue gap makes financial planning difficult. In addition, finished cattle prices are volatile and, frankly, unknown at the time the management places its feeders. Income risk and financial risk must be addressed by the management. Several strategies are available to reduce return risk, including anticipatory hedging with cattle futures contracts, placing custom feeders, placing feeders at different months and investing off-farm. This study developed a shot-term decision making model for a backgrounding operation that addresses the interaction between feeder ownership options, the feeder placement month, cash flow requirements, hedging alternatives, off-farm investments, the line of credit and the management's degree of risk-aversity. The following backgrounding issues were examined: (1) whether participation in a classical hedging program with Feeder and Live Cattle contracts would result in lower farm return variability and would increase owned feeder placements, (2) whether managements would be deterred from using hedging strategies if a gradually increasing downward BIAS was introduced, (3) whether managements would be deterred from using hedging strategies if margin calls had to be deposited during the hedging period and (4) to what extent cash flow constraints would affect the management's decision set. The literature of decision making under uncertainty was reviewed to determine the approach which would best accommodate the backgrounding management's risk concerns. The Expected Value-Variance analysis was identified to formulate these management concerns in a mathematical programming context. A quadratic programming model was chosen to derive the expected return and return standard deviation frontiers (risk-efficient frontiers). The participation in an anticipatory hedging program provided a compelling risk management tool for reducing the backgrounding operation's return variability. Compared to the no-hedging case, the standard deviation of returns was almost cut by half for the hedging case. The introduction of a downward BIAS reduced hedging ratios drastically, whereas margin calls hardly effected the use of hedging. Custom feeders proved themselves essential in closing the typical cost-revenue gap in backgrounding and, despite offering the lowest returns, enabled the backgrounder to engage in more risky activities.
392

Suplementação de ácidos graxos poli-insaturados protegidos no desempenho e respostas imunológicas de bovinos nelores confinados

Sarti, Luís Marcelo Nave [UNESP] 20 January 2014 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:32:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-01-20Bitstream added on 2014-06-13T18:44:40Z : No. of bitstreams: 1 sarti_lmn_dr_botfmvz.pdf: 586571 bytes, checksum: 1ac7284e05a3eca975e4a50d8f0bcde2 (MD5) / O objetivo neste estudo foi avaliar os efeitos da adição de fontes de lipídeos naturais e protegidos da degradação ruminal na dieta de bovinos Nelore durante o período pré-condicionamento e confinamento no desempenho e características de carcaça. Foram utilizados cento e vinte bovinos, machos, não castrados, da raça Nelore (366,9 ± 28,7 kg) de aproximadamente 24 meses, provenientes de sistema de recria em pasto. O delineamento experimental foi inteiramente casualizado, composto por três dietas caracterizando os tratamentos: (CONTR) sem fonte adicional de lipídeo, (GDESP) com fonte de lipídeo natural a base de coprodutos do algodão (torta de algodão), e (GPROT) com fonte de lipídeo protegido rico em ácidos graxos poli-insaturados. O estudo foi dividido em duas fases: pré-condicionamento, 30 dias antes do transporte, com os animais mantidos em pasto recebendo suplementação a base de grãos com adição ou não de fonte de lipídeo conforme os tratamentos; e confinamento. Antes do embarque, os animais foram pesados e logo depois transportados por aproximadamente 16 horas. No confinamento, os animais foram mantidos em 24 baias com cinco animais por baia, sendo que cada tratamento foi composto por oito baias, consideradas as unidades experimentais, e pesados a cada 21 dias. O uso de torta de algodão (GDESP) proporcionou maiores ganhos de peso na fase de pré-condicionamento. Contudo, os animais suplementados com lipídios protegidos (GPROT) durante o período de confinamento apresentaram desempenho semelhante (peso vivo final, ganho de peso diário, conversão e eficiência alimentar)... / The aim of this study was to evaluate the effects of adding sources of natural lipids and rumen-protected PUFA to the diet of Nellore cattle in the preconditioning and feedlot periods on performance and carcass characteristics. One hundred and twenty 24-mo-old Nellore yearling bulls were used (366.9 ± 28.7 kg), coming from rearing on pasture system. The experimental design was completely randomized, consisting of three diets according to the treatments: (CONTR) without additional source of lipid, (GDESP) with source of natural lipid based on co-products from cotton (cottonseed cake), and (GPROT) with rumen-protected lipid source rich in polyunsaturated fatty acids. The study was divided into two phases: pre-conditioning, 30 days before shipping, the animals were kept on pasture receiving supplement just described with or without lipid source according to the treatments; and feedlot. Prior to shipment, the animals were weighed and transported approximately for 16 hours. In feedlot, animals were kept in 24 pens with five animals per pen, 8 pens per treatment, which were considered the experimental units, and weighed every 21 days. The use of cottonseed cake (GDESP) led to greater weight gains during preconditioning. However, animals supplemented with GPROT during the feedlot period presented similar performance (final body weight, average daily gain, feed conversion and efficiency) to animals that consumed GDESP treatment, but lower intake of dry matter was observed in the GPROT treatment compared GDESP. The fat sources did not influence carcass characteristics... (Complete abstract click electronic access below)
393

Effects of live yeast, monensin and concentrate level in dairy cattle diets on gas and volatile fatty acids production

Mokatse, Brenda 14 September 2015 (has links)
Two meta-analysis of effects of yeast culture and monensin in lactating dairy cows were first performed. Secondly, two experiments were performed to evaluate the effects of live yeast (LY) or monensin (M) or both (LY+M) on gas production and fermentation by rumen micro-organisms in vitro in low (40 %) and high (60 %) concentrate diets of dairy cows. Rumen contents were collected from one cannulated lactating Holstein cow. Gas production was measured from 0 to 48 h of incubation. Volatile fatty acids and ammonia nitrogen concentrations were measured after 48 h. Meta-analysis of monensin indicated decrease dry matter intake (DMI) and increasing milk yield, consequently improving feed efficiency. Meta-analysis of yeast culture did not show improved performance. These results highlighted the importance of the meta-analysis as a useful tool that can be employed to both summarize effects across studies and to investigate factors explaining potential heterogeneity of response. The batch fermentation showed that in high concentrate diet, M significantly increased ammonia nitrogen, decreased acetate, but tended to increase propionate concentration (7.9, 63.2, 18.6 vs. 6.3, 66.8, 14.2 mmol/l; respectively). Addition of LY increased acetate concentration (64.2 vs 66.8 mmol/l). Supplementation with M, LY and LY+M reduced total gas production by 37.1, 22.5 and 26.9 %, respectively, compared to control at 48 h. In low concentrate diet, M and LY+M decreased and increased acetate (60.1 and 69.7 vs. 7.1 mmol/l; respectively). Adding LY and LY+M produced 8.6 % less gas, and M treatment 3.4 % more gas than the control. Overall, at 48 h, high concentrate resulted in less gas than low concentrate diets. High concentrate diets showed increased ammonia (7.9 and 6.4 vs. 5.21 and 4.7 mmol/l) decreased acetate (63.0 and 63.2 vs. 67.0 and 69.7 mmol/l) with a tendency to increased propionate (18.6 and 18.9 vs. 14.6 and 14.1 mmol/l) compared to low concentrate in M and LY+M treated diets. These results indicate that the effects of M and LY on rumen fermentation are substrate dependent, the high-concentrate diet showing the greatest response / Agriculture / M. Sc. (Agriculture)
394

Suplementação de ácidos graxos poli-insaturados protegidos no desempenho e respostas imunológicas de bovinos nelores confinados /

Sarti, Luís Marcelo Nave, 1982. January 2014 (has links)
Orientador: Mário de Beni Arrigoni / Coorientador: Cyntia Ludovico Martins / Banca: Danilo Domingues Millen / Banca: Rodrigo Dias Lauritano Pacheco / Banca: Paulo Roberto de Lima Meirelles / Banca: Reinald Fernandes Cooke / Resumo: O objetivo neste estudo foi avaliar os efeitos da adição de fontes de lipídeos naturais e protegidos da degradação ruminal na dieta de bovinos Nelore durante o período pré-condicionamento e confinamento no desempenho e características de carcaça. Foram utilizados cento e vinte bovinos, machos, não castrados, da raça Nelore (366,9 ± 28,7 kg) de aproximadamente 24 meses, provenientes de sistema de recria em pasto. O delineamento experimental foi inteiramente casualizado, composto por três dietas caracterizando os tratamentos: (CONTR) sem fonte adicional de lipídeo, (GDESP) com fonte de lipídeo natural a base de coprodutos do algodão (torta de algodão), e (GPROT) com fonte de lipídeo protegido rico em ácidos graxos poli-insaturados. O estudo foi dividido em duas fases: pré-condicionamento, 30 dias antes do transporte, com os animais mantidos em pasto recebendo suplementação a base de grãos com adição ou não de fonte de lipídeo conforme os tratamentos; e confinamento. Antes do embarque, os animais foram pesados e logo depois transportados por aproximadamente 16 horas. No confinamento, os animais foram mantidos em 24 baias com cinco animais por baia, sendo que cada tratamento foi composto por oito baias, consideradas as unidades experimentais, e pesados a cada 21 dias. O uso de torta de algodão (GDESP) proporcionou maiores ganhos de peso na fase de pré-condicionamento. Contudo, os animais suplementados com lipídios protegidos (GPROT) durante o período de confinamento apresentaram desempenho semelhante (peso vivo final, ganho de peso diário, conversão e eficiência alimentar)... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aim of this study was to evaluate the effects of adding sources of natural lipids and rumen-protected PUFA to the diet of Nellore cattle in the preconditioning and feedlot periods on performance and carcass characteristics. One hundred and twenty 24-mo-old Nellore yearling bulls were used (366.9 ± 28.7 kg), coming from rearing on pasture system. The experimental design was completely randomized, consisting of three diets according to the treatments: (CONTR) without additional source of lipid, (GDESP) with source of natural lipid based on co-products from cotton (cottonseed cake), and (GPROT) with rumen-protected lipid source rich in polyunsaturated fatty acids. The study was divided into two phases: pre-conditioning, 30 days before shipping, the animals were kept on pasture receiving supplement just described with or without lipid source according to the treatments; and feedlot. Prior to shipment, the animals were weighed and transported approximately for 16 hours. In feedlot, animals were kept in 24 pens with five animals per pen, 8 pens per treatment, which were considered the experimental units, and weighed every 21 days. The use of cottonseed cake (GDESP) led to greater weight gains during preconditioning. However, animals supplemented with GPROT during the feedlot period presented similar performance (final body weight, average daily gain, feed conversion and efficiency) to animals that consumed GDESP treatment, but lower intake of dry matter was observed in the GPROT treatment compared GDESP. The fat sources did not influence carcass characteristics... (Complete abstract click electronic access below) / Doutor
395

Sistemas de terminação e pesos de abate de bovinos leiteiros visando à produção de carne de vitelão / Finishing systems and slaughter weights of dairy cattle in order to produce rosé veal meat

Santos, Priscila Vincenzi dos 26 February 2013 (has links)
Fundação Araucária; CAPES / O trabalho foi desenvolvido na Universidade Tecnológica Federal do Paraná, Câmpus Dois Vizinhos, com o objetivo de avaliar as características e a composição física da carcaça e carne de bezerros holandeses terminados em pastagem com suplementação ou confinamento e abatidos com diferentes pesos. Foram utilizados 43 animais, da raça Holandesa, com peso inicial ao desmame de 57 kg e 58 dias de idade, distribuídos em dois sistemas de terminação e em quatro pesos de abate pré- estipulados: 140; 180; 220 e 260 kg de peso corporal. Vinte e três animais foram confinados em baias individuais recebendo dieta constituída de silagem de milho, como volumoso e concentrado comercial com relação 40:60. Os vinte animais restantes foram terminados em pastagem de aveia branca (Avena sativa) consorciada com azevém comum (Lolium multiflorium), estrela africana (Cynodon nlemfuensis) e milheto (Pennisetum glaucum) e receberam suplementação diária com o mesmo concentrado a 1% do peso corporal. A terminação em confinamento possibilitou redução da idade de abate em comparação à pastagem, proporcionando maior cobertura de gordura e melhor conformação de carcaça, no entanto, o rendimento de carcaça foi semelhante entre os sistemas de terminação. As características de carcaça melhoraram com o aumento do peso de abate. Animais terminados à pasto apresentaram maior percentagem de músculo, menor percentagem e quantidade de gordura em relação aos animais do confinamento. A medida que aumentou o peso de abate houve incremento na quantidade total de músculo, osso e gordura, relação músculo/osso e relação porção comestível/osso, palatabilidade e suculência da carne para ambos os sistemas. O percentual de osso e a cor da carne decresceram com o aumento do peso de abate. Os animais terminados em pastagem apresentaram melhor textura da carne com o aumento do peso de abate. / The work was developed at Federal Technological University of Paraná, Campus Two Neighbors, with the objective of evaluating the characteristics and physical carcass composition and meat Holstein calves finished on pasture with supplementation or confinement and slaughtered at different weights. We used 43 animals, Holstein, with an initial weight of 57 kg at weaning and 58 days old, divided into two finishing systems and slaughter weights in four pre-stipulated: 140, 180, 220 and 260 kg of body weight . Twenty-three animals were housed individually fed a diet consisting of corn silage as forage and concentrate commercial about 40:60. The twenty remaining animals were terminated on oat (Avena sativa) intercropped with ryegrass (Lolium multiflorium), African Star (Cynodon nlemfuensis) and millet (Pennisetum glaucum) and received daily supplementation with concentrated even 1% of body weight . The feedlot finishing enabled reduction of slaughter age compared to pasture, providing greater fat cover and better carcass conformation, however, carcass yield was similar between finishing systems. Carcass traits improved with increasing slaughter weight. Animals finished on pasture had a higher percentage of muscle, lower percentage and amount of fat in relation to animal confinement. As slaughter weight increased there was an increase in the total amount of muscle, bone and fat, muscle / bone ratio and ratio edible portion / bone, palatability and juiciness for both systems. The percentage of bone and flesh color decreased with increasing slaughter weight. The animals finished on pasture had better meat texture with increasing slaughter weight.
396

Sistemas de terminação e pesos de abate de bovinos leiteiros visando à produção de carne de vitelão / Finishing systems and slaughter weights of dairy cattle in order to produce rosé veal meat

Santos, Priscila Vincenzi dos 26 February 2013 (has links)
Fundação Araucária; CAPES / O trabalho foi desenvolvido na Universidade Tecnológica Federal do Paraná, Câmpus Dois Vizinhos, com o objetivo de avaliar as características e a composição física da carcaça e carne de bezerros holandeses terminados em pastagem com suplementação ou confinamento e abatidos com diferentes pesos. Foram utilizados 43 animais, da raça Holandesa, com peso inicial ao desmame de 57 kg e 58 dias de idade, distribuídos em dois sistemas de terminação e em quatro pesos de abate pré- estipulados: 140; 180; 220 e 260 kg de peso corporal. Vinte e três animais foram confinados em baias individuais recebendo dieta constituída de silagem de milho, como volumoso e concentrado comercial com relação 40:60. Os vinte animais restantes foram terminados em pastagem de aveia branca (Avena sativa) consorciada com azevém comum (Lolium multiflorium), estrela africana (Cynodon nlemfuensis) e milheto (Pennisetum glaucum) e receberam suplementação diária com o mesmo concentrado a 1% do peso corporal. A terminação em confinamento possibilitou redução da idade de abate em comparação à pastagem, proporcionando maior cobertura de gordura e melhor conformação de carcaça, no entanto, o rendimento de carcaça foi semelhante entre os sistemas de terminação. As características de carcaça melhoraram com o aumento do peso de abate. Animais terminados à pasto apresentaram maior percentagem de músculo, menor percentagem e quantidade de gordura em relação aos animais do confinamento. A medida que aumentou o peso de abate houve incremento na quantidade total de músculo, osso e gordura, relação músculo/osso e relação porção comestível/osso, palatabilidade e suculência da carne para ambos os sistemas. O percentual de osso e a cor da carne decresceram com o aumento do peso de abate. Os animais terminados em pastagem apresentaram melhor textura da carne com o aumento do peso de abate. / The work was developed at Federal Technological University of Paraná, Campus Two Neighbors, with the objective of evaluating the characteristics and physical carcass composition and meat Holstein calves finished on pasture with supplementation or confinement and slaughtered at different weights. We used 43 animals, Holstein, with an initial weight of 57 kg at weaning and 58 days old, divided into two finishing systems and slaughter weights in four pre-stipulated: 140, 180, 220 and 260 kg of body weight . Twenty-three animals were housed individually fed a diet consisting of corn silage as forage and concentrate commercial about 40:60. The twenty remaining animals were terminated on oat (Avena sativa) intercropped with ryegrass (Lolium multiflorium), African Star (Cynodon nlemfuensis) and millet (Pennisetum glaucum) and received daily supplementation with concentrated even 1% of body weight . The feedlot finishing enabled reduction of slaughter age compared to pasture, providing greater fat cover and better carcass conformation, however, carcass yield was similar between finishing systems. Carcass traits improved with increasing slaughter weight. Animals finished on pasture had a higher percentage of muscle, lower percentage and amount of fat in relation to animal confinement. As slaughter weight increased there was an increase in the total amount of muscle, bone and fat, muscle / bone ratio and ratio edible portion / bone, palatability and juiciness for both systems. The percentage of bone and flesh color decreased with increasing slaughter weight. The animals finished on pasture had better meat texture with increasing slaughter weight.
397

Optimal risk management strategies for a cattle backgrounding operation in the Peace River area

Klee, Felix Wilhem Peter 05 1900 (has links)
Backgrounding cattle is risky. Large amounts of short-term capital are required to buy feeders and feedstuffs, and a ten month cost-revenue gap makes financial planning difficult. In addition, finished cattle prices are volatile and, frankly, unknown at the time the management places its feeders. Income risk and financial risk must be addressed by the management. Several strategies are available to reduce return risk, including anticipatory hedging with cattle futures contracts, placing custom feeders, placing feeders at different months and investing off-farm. This study developed a shot-term decision making model for a backgrounding operation that addresses the interaction between feeder ownership options, the feeder placement month, cash flow requirements, hedging alternatives, off-farm investments, the line of credit and the management's degree of risk-aversity. The following backgrounding issues were examined: (1) whether participation in a classical hedging program with Feeder and Live Cattle contracts would result in lower farm return variability and would increase owned feeder placements, (2) whether managements would be deterred from using hedging strategies if a gradually increasing downward BIAS was introduced, (3) whether managements would be deterred from using hedging strategies if margin calls had to be deposited during the hedging period and (4) to what extent cash flow constraints would affect the management's decision set. The literature of decision making under uncertainty was reviewed to determine the approach which would best accommodate the backgrounding management's risk concerns. The Expected Value-Variance analysis was identified to formulate these management concerns in a mathematical programming context. A quadratic programming model was chosen to derive the expected return and return standard deviation frontiers (risk-efficient frontiers). The participation in an anticipatory hedging program provided a compelling risk management tool for reducing the backgrounding operation's return variability. Compared to the no-hedging case, the standard deviation of returns was almost cut by half for the hedging case. The introduction of a downward BIAS reduced hedging ratios drastically, whereas margin calls hardly effected the use of hedging. Custom feeders proved themselves essential in closing the typical cost-revenue gap in backgrounding and, despite offering the lowest returns, enabled the backgrounder to engage in more risky activities. / Land and Food Systems, Faculty of / Graduate
398

Growth performance, carcass characteristics and meat quality of Nguni, Bonsmara and Angus steers raised on natural pasture

Muchenje, Voster January 2007 (has links)
The objective of the current study was to compare tick loads, growth, carcass characteristics and meat quality of Nguni, Bonsmara and Angus steers raised on natural pasture. A total of 30, 7-month old steers each of Bonsmara and Angus, and 40 Nguni steers were kept at the University of Fort Hare Farm till slaughter at 18 months. Monthly weights of the steers were recorded. Carcasses were electrically stimulated. The m. longissimus thoracis et lumborum was sampled for the measurement of meat colour, pH, drip loss, sarcomere length (SL), water holding capacity (WHC), cooking losses, myofibrillar fragmentation length (MFL), Warner Bratzler shear force (WBSF), fatty acid profiles and sensory characteristics of the steers. Urine samples were collected at the slaughter line for the determination of stress hormone concentrations. The Nguni had the lowest tick load (P < 0.05) while the Angus had the highest tick load (P < 0.05). Tick load did not affect the growth rate and carcass characteristics of the steers. Bonsmara and Angus steers had higher (P < 0.05) carcass weight and dressing percentage than the Nguni steers. Meat quality characteristics were similar (P > 0.05) among all the breeds, except that Nguni meat was darker (L*) (P < 0.05) than meat from the other two breeds. The Bonsmara had the highest (P > 0.05) concentrations while the Nguni had the lowest (P > 0.05) concentrations of stress hormones. There were significant (P < 0.05) correlations between WB values of meat aged for two and 21 days in Nguni and Bonsmara, but not in Angus. The correlations among stress responsiveness hormones and meat quality were breed-dependent. Except monounsaturated fatty acids (MUFA) and the n-6/n-3 ratio, fatty acid profiles among the breeds were similar (P > 0.05). Cholesterol levels among the breeds were similar (P > 0.05). The Nguni had the best (P < 0.05) sensory characteristics, such as flavour and tenderness. It can be concluded that while the Nguni is a small framed breed, its meat quality is similar to that of Bonsmara and Angus and has the best meat taste when raised on natural pasture.
399

Manure production and nutrient management in pasture-based dairy production systems

Svinurai, Walter January 2010 (has links)
Manure production and nutrient management in pasture-based dairy production systems by Walter Svinurai The effect of dietary treatments on nutrient excretion was determined and an attempt to improving the retention of excreted nitrogen in stored manure using Aloe ferox leaf gel (AFLG) and pine bark was conducted at a pasture-based dairy farm. The animal mass-balance method was used to determine nutrient excretion by cows fed on three dietary treatments, Lolium perrene-based treatment (LP), Lolium multiforium-based treatment (LM) and Lolium perenne- Trifolium repens -based treatment (LTF). In separate experiments, slurry from dairy cows fed LM was amended with AFLG and pine bark at concentrations of 25, 50, 75 and 100 g/l and stored under anaerobic conditions for 16 days. The highest and lowest excretions of N, P and K were observed in LM and LP treatments, respectively. Increasing dietary N improved K and N retention in milk and, consequently increased milk urea nitrogen (MUN) and N excretion (P < 0.05). The concentrations of AFLG affected N and P retention in manure (P < 0.05). The highest retention in total Kjeldahl nitrogen (TKN) of the initial was 42% AFLG at 25g/l inclusion rate. Ammonium nitrogen (AMN) concentration increased significantly due to the interactive effect of AFLG inclusion rate and time. Pine bark powder significantly improved N and P retention in manure at all concentrations. The retention in TKN was higher (P < 0.05) at 25g/l pine bark powder than other concentrations. The interaction effect of inclusion rate and time increased iii AMN (P < 0.05). Dietary treatments significantly affected nutrient excretion, and AFLG and pine bark considerably improved N retention in stored slurry. Findings from the filed trial suggest the need for more attention on managing dietary nutrients in the post-rainy and cool-dry season when growth of pasture influenced choice of dietary treatments that led to high nutrient excretion. Field simulation of the additives to determine their efficacy and environmental hazards was recommended.
400

Development of an immunoglobulin-fortified milk replacer and a purified, injectable immunoglobulin solution as alternative methods of achieving passive immunity in colostrum-deprived neonatal calves

Crowley, Margaret L. January 1990 (has links)
An immunoglobulin-fortified milk replacer and a subcutaneous (SC) injectable solution of immunoglobulins (Ig) were examined as methods of achieving passive immunity in neonatal calves. Bovine Ig, from abattoir blood, were purified by polyphosphate fractionation and ion-exchange chromatography. In experiment 1, carried out at Agriculture Canada Research Station, Agassiz, 37 colostrum-deprived Holstein-Friesian bull calves were allotted to one of four treatments. Col/WM calves were fed colostrum on day 1 and whole milk, days 2 - 42. MR-Nolg calves (control) were fed milk replacer with no Ig, days 1-42. MR-Hi/Lo calves were fed milk replacer with Ig at 50 mg/ml on day 1, and at 10 mg/ml, days 2 -21. MR-Hi/No calves were fed milk replacer with Ig at 50 mg/ml, day 1,'and with no Ig, days 2 - 21. From days 2 2 - 42, MR-Hi/Lo and MR-Hi/No treatment calves received milk replacer with no Ig. In experiment 2, carried out at the University Research Farm at Oyster River, 24 colostrum-deprived Holstein-Friesian bull calves were allotted to one of three treatments. The first two treatments were the same as for experiment 1, Col/WM and MR-Nolg fed for days 1-21. MR-Lo Inj calves were fed milk replacer with Ig at 10 mg/ml, days 1-21, and were also given a SC injection of Ig solution within the first 6 hours of life. For days 2-42, calves were fed WM or MR-Nolg, as per experiment 1. For both experiments, blood samples and calf weights were taken at birth, 24 & 48 hours of age, day 7 and weekly thereafter for six weeks. Diarrhea (scours) levels, rectal temperatures and general health of calves were recorded daily for the first three weeks as well. Experiment 1 survival at 6 weeks of age was 11 out of 11 calves for Col/WM treatment, 8 out of 8 calves for MR-Hi/Lo treatment, 7 out of 8 calves for MR-Hi/No and a significantly lower (P>0.05) 7 out of 9 calves for MR-Nolg. In experiment 2, survival was 7 out of 8 calves for both Col/WM and MR-Lo-Inj treatments and a significantly lower (P>0.05) 4 out of 8 calves for MR-Nolg treatment. Calves on MR-Hi/No had significantly higher diarrhea levels than the other three treatments over weeks one and four in experiment 1. In experiment 2, calves which did not receive any Ig had significantly higher diarrhea levels over weeks three and four than calves which received Ig. Experiment 1 average daily gains (ADG) were significantly higher for calves on Col/WM, MR-Hi/Lo and MR-Hi/No treatments than for calves on MR-Nolg at six weeks of age. In experiment 2, six week ADG were significantly higher for calves on Col/WM and MR-Lo Inj treatments than for MR-Nolg. For both experiments, serum Ig levels of calves on Col/WM were significantly higher than calves on the other treatments at 24 and 48 hours of age. MR-Hi/Lo, MR-Hi/No and MR-Lo Inj calves trended to higher serum Ig levels than MR-Nolg calves but were not significantly different. Calves which received Ig, from colostrum, the Ig-fortified milk replacer or a subcutaneous Ig injection, had higher survival rates, lower diarrhea levels, less antibiotic treatment and higher average daily gains than calves hot receiving any Ig. It was concluded that immunoglobulins, administered either orally or parenterally, are an effective, alternative method, for providing passive immunity in neonatal calves. / Land and Food Systems, Faculty of / Graduate

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