Two trials were conducted simultaneously to evaluate the effects of energy supplementation for cattle grazing tropical pastures managed with different initial sward heights on DMI and ruminal fermentation of cattle grazing intensively managed tropical grass during the rainy season. Eight 24-month-old rumen-cannulated Nellore steers were used per trial (Trial 1: 300 kg BW ± 5.97, Trial 2: 343 kg BW ± 7.40) allocated in two 4x4 Latin squares. Treatments corresponded to 0 (mineral supplementation) and a 0.3 (0.3% of BW of ground corn as fed basis) combined with 2 pre-grazing sward heights (25 and 35 cm). The stubble height was 15 cm. In the second trial the level of supplementation was 0.6% BW of ground corn as fed basis. Steers were managed in 2 ha of Palisadegrass pasture (Brachiaria brizantha marandu). Pastures were fertilized with 120 kg nitrogen/ha and averaged 13.8 and 11.0% CP and 58.8 and 63.4% NDF, for 25 and 35 cm, respectively The forage and the diet DM and CP digestibility were greater (P<0.05) for 25 then for 35 cm grazing management. For both trials 1 and 2, cattle grazing the pastures with 25 cm initial sward height consumed more forage DMI, more total DMI and more energy (P<0.05) and at the same time steers spent less time grazing (P<0.05) and more time resting (P<0.05), presented greater bite rates (P<0.05), less steps per day and less steps between feeding stations (P<0.05), when compared with cattle grazing the 35 cm pastures. Rumen pH values were less (P<0.05 in trial 1; P<0.1 in trial 2) and concentrations of rumen N-NH3 and retention of N were greater (P<0.05) for cattle grazing the 25 cm pastures while rumen VFA and microbial synthesis were not affected (P>0.05) by pasture management. Supplementing energy at 0.3% (trial 1) increased (P<0.05) diet DM digestibility while feeding energy at 0.6% (trial 2) decreased forage CP digestibility, increased (P<0.05) forage NDF digestibility and increased diet DM (P<0.05) and diet NDF (P<0.1) digestibility. Supplementing energy at 0.3% (trial 1) or at 0.6% (trial 2) decreased forage DMI (P<0.05) and substitution rates were 1.63 and 0.72, respectively. The total DMI and energy intake were not increased (P>0.05) by supplementing energy at 0.3% while increasing energy supplementation to 0.6% was effective to increase total DMI and energy intake of cattle grazing tropical forage, independent of initial sward height. Energy supplementation decreased (P<0.05) grazing time, but it did not affect (P>0.05) any other grazing behavior parameter. Supplementing grazing cattle with 0.3% had no effect (P>0.05) on rumen pH, N retention and microbial synthesis, increased (P<0.05) rumen propionate and decreased (P<0.05) rumen N-NH3, rumen acetate and acetate:propionate ratio. Supplementing grazing cattle with 0.6% decreased (P<0.05) rumen pH, rumen N-NH3, rumen acetate and acetate:propionate ratio, while it increased (P<0.05) rumen propionate, N retention and microbial synthesis. Plasma glucose was not affected by treatments (P>0.05). The pre-grazing sward height of 25 cm and feeding energy supplement at 0.6% of BW were efficient strategies to increase energy intake of cattle grazing Palisadegrass. / Dois experimentos foram conduzidos simultaneamente, para avaliar o uso da suplementação energética para bovinos manejados em diferentes alturas de entrada na pastagem. Foram usados 8 novilhos Nelore canulados no rumen por experimento (Exp. 1: 300 kg de PC ± 5,97, Exp. 2: 343 kg PC ± 7,40) distribuídos em 2 quadrados latinos 4x4. Os tratamentos para o Exp. 1 foram 0 (suplementação mineral) e 0,3 (0,3% do PC em milho moído) combinados com 2 alturas de entrada (25 e 35 cm). A altura de saída foi 15 cm. No Exp. 2 o nível de suplementação foi 0,6% do PC em milho moído. Os animais foram manejados em 2 ha de Capim Marandu, os quais foram adubados com 120 kg de N/há, apresentando valores médios de 13,8 e 11,0% de PB e 58,8 e 63,4% de FDN para pastos de 25 and 35 cm, respectivamente. A DMS e DPB da forragem e da dieta foram maiores (P<0,05) para o manejo da pastagem de 25 cm do que 35. Em ambos os experimentos, o CMS de forragem, energia e total foi maior (P<0,05) para o tratamento de 25 cm, que ao mesmo tempo promoveu menor tempo de pastejo (P<0,05), maior tempo em ócio (P<0,05) e taxa de bocado (P<0,05), menor número de passos por dia e passos entre estações de pastejo (P<0,05), quando comparados com animais mantidos no tratamento de 35 cm. O pH ruminal foi menor (P<0,05 no Exp. 1; P<0,10 no Exp. 2), a N-NH3 ruminal e retenção do N foram maiores (P<0,05) para animais manejados na altura de entrada de 25 cm. Os AGVs e a síntese microbiana não foram afetados (P>0,05) pelo manejo da pastagem. A suplementação em 0,3% (Exp. 1) aumentou (P<0,05) a DMS da dieta, enquanto a suplementação de 0,6% (Exp. 2) reduziu a DPB da forragem (P<0,05), aumentou a digestibilidade da FDN da forragem (P<0,05) e a DMS (P<0,05) e da FDN da dieta (P<0,01). A suplementação em 0,3% (Exp. 1) ou em 0,6% (Exp. 2) reduziu o CMS de foragem (P<0,05) e as taxas de substituição foram 1.63 and 0.72, respectivamente. O CMS total e de energia não foram aumentados (P>0,05) pela suplementação em 0,3%, enquanto o nível de 0,6% foi efetivo em aumentar o CMS total e de energia de bovinos mantidos em pastagem tropical, independente do manejo da pastagem. A suplementação reduziu o tempo de pastejo (P<0,05). Animais suplementados com 0,3% não alteraram (P>0,05) o pH ruminal, a retenção de N e síntese microbia, mas aumentaram (P<0,05) propionato no rumen e diminuíram (P<0,05) N-NH3 ruminal, acetato e relação acetato:propionato. A suplementação com 0,6% diminuiu (P<0,05) o pH ruminal, N-NH3 ruminal, acetato e relação acetato:propionato no rumen, aumentaram (P<0,05) o propionato no rumen, a retenção de N e a síntese microbiana. A glicose plasmática não foi alterada (P>0,05). A altura de pré-pastejo de 25 cm e a suplementação energética de 0,6% do PC foram estratégias eficientes para aumentar o consumo de energia de bovinos mantidos em pastagens de Capim Marandu.

Thesis (MSc. (Animal Production)) -- University of Limpopo, 2016 / A study was conducted to determine the effect of shredded Colophospermum (C.) mopane wood inclusion as roughage on performance of fattening Nguni heifers weighing 200 ± 5kg. The four diets used were isocaloric and isonitrogenous but with different shredded C. mopane wood inclusion levels of 5 (F95M5), 8.5 (F91.5M8.5), 10 (F90M10) and 15 (F85M15) %. The heifers were randomly allocated to the treatments in a completely randomized design. A quadratic equation was used to determine the shredded C. mopane inclusion levels for optimal productivity of the heifers. Shredded C. mopane wood inclusion level had effect (P<0.05) on intake and feed conversion ratio (FCR). Diet DM, OM, CP, NDF and ADF intakes per metabolic weight and FCR of Nguni heifers were optimized at different shredded C. mopane wood inclusion levels of 11.0, 13.7, 8.0, 15.0, 14.0, 14.0 and 15%, respectively. However, shredded C. mopane wood inclusion level did not affect (P>0.05) diet in vitro digestibility, carcass weight, dressing percentage, meat pH, meat shear force values and meat colour intensities except for red colour intensity of rump steak. It was, thus, concluded that shredded C. mopane wood can be used as roughage without adversely affecting diet intake, FCR, and live weight of Nguni heifers. However, diet intake and FCR were optimized at different C. mopane wood inclusion levels.

Thesis (M. Dev.) -- University of Limpopo, 2017 / There is a gap in the literature about the role and relevance of Indigenous Knowledge and beef cattle welfare in many parts of the Limpopo province. This gap is relevant because many marginalised cattle owners use indigenous knowledge in their day to day management of beef cattle. The aim of the study is to investigate the use of IK methods on beef cattle husbandry in Tshebela village in the Capricorn district of the Limpopo province as a contribution to filling the void identified above. The objectives of the study were as follows:  -To investigate the IK methods used in beef cattle husbandry in the area of the study;  -To assess if beef farmers use IK to identify medicinal plants to cure beef cattle;  -To investigate farmers‘ perceptions and attitudes on the use of IKS on beef cattle husbandry in the area of study. A qualitative methodology that was used was primarily phenomenological in design. A purposive sampling technique was used and twenty seven (27) traditional beef farmers, two (2) local herbalists were recruited as participants. Data was collected through focus group discussions, key informant interviews, and observations. An interpretative phenomenological-based analysis was used to surface the role and relevance of indigenous knowledge in beef cattle husbandry. The findings suggest that indigenous knowledge is used by cattle owners alongside modern knowledge and that communal farming posed some challenges to the farmers.

Concentrations of trace minerals within the body are known to impact reproductive processes. Thus, the current study analyzed the effects of using an injectable trace mineral supplement containing selenium, zinc, copper, and manganese during a superovulation protocol on embryo outcomes in donor beef cows and further effects on pregnancy rate in recipient females. We hypothesized that an injectable trace mineral (TM) supplement provided to cows fed to meet known nutrient requirements would increase TM status and influence superovulation, embryo characteristics, and enhance pregnancy rates. Our findings indicate that the injectable TM increased concentration of Se within the liver. However, superovulatory response, embryo production, quality grade, and developmental stage were not influenced by TM status. In addition, embryo treatment did not influence pregnancy rate, gestation length, or calf body weight.

Best management practices are methods that have been determined to be the most effective and practical means of preventing or reducing pollution. Best Management Practices (BMPs) relating to surface water pollution abatement for North Dakota beef cow operations are of particular importance due to the importance of the agriculture industry in North Dakota. North Dakota has yet to address the use of voluntary BMPs to address potential surface water pollution regulations. Probit models were used to estimate the likelihood of North Dakota beef cow operators adopting specific production practices to reduce potential surface water pollution through the use of BMPs. The six BMPs discussed in this research include nutrient management, rotational grazing, filterstrjps, riparian buffers, streambank fencing, and streambank bridging/crossing. Number of beef cows on operation, education, awareness of cost share programs, contact with extension service, ownership structure, debt level, record keeping method, and pasture season usage were found to be significant in the likelihood of adopting a BMP.

<p>Fat supplementation has potential to improve reproductive performance and increase pregnancy rates in cattle by increasing the energy density of the diet. However, some of the positive effects of fat seem to be influenced by the type of fatty acid fed. Supplementation of omega-3 (n-3) fatty acids increase uptake of n-3 fatty acids into tissue phospholipids and can mitigate immune and inflammatory responses in favor of pregnancy maintenance in cattle. However, n-3 fatty acid supplementation in ruminants has been associated with a decrease in circulating PGF_2α, which may delay CL regression, extend an animal’s time in diestrus, and prevent ovulation. Prostaglandin F_2α is a series 2 prostaglandin, synthesized from omega-6 (n-6) fatty acids, which is inhibited by production of series 3 prostaglandins from n-3 fatty acids. Docosohexaenoic acid (DHA, 22:6n-3) and eicosapentaenoic acid (EPA, 20:5n-3) are long-chain n-3 poly-unsaturated fatty acids (PUFA) that have important biological effects on reproduction through their involvement in hormone and series 3 prostaglandin synthesis. Ruminant tissues are naturally almost devoid of n-3 long-chain PUFA, specifically EPA and DHA. Fish oil is the most common ration additive used to provide very long chain n-3 fatty acids to ruminants. However, marine fish do not synthesize n-3 fatty acids; they consume microscopic algae or other algae-consuming fish to obtain n-3 fatty acids. Algae biomass provides a consistent source of DHA and EPA that could be fed to alter hormonal profiles and improve reproduction of beef heifers. Eighty-eight Angus × Simmental heifers (427 ± 1.8 kg) were blocked by BW and allotted to 2 treatments (44/treatment, 4 pens/treatment, 11 heifers/pen). Control heifers were fed a diet that contained (DM basis) 52.8% mixed grass silage, 32% corn silage, and 15.2% concentrate. DHAgold™ (49% fat; 21.8% DHA; DSM Inc.) was included in the algae diet at 1.65% of DM, replacing equal parts of corn and DDGS. Diets were formulated to contain 12% CP and 0.79 Mcal/kg NEg. Heifers were fed treatment diets from 54 d prior to the breeding season through the first trimester. Follicular fluid was collected on day 47 for hormonal analysis. Artificial insemination (AI) was from d 55 to 98, after which open heifers were removed to 1 control and 1 algae pen and placed with a bull. The study ended on d 180. Performance data were analyzed using the MIXED procedure and conception data were analyzed using the GLIMMIX procedure of SAS. Dominant follicle diameter and follicular estrogen concentration were unaffected by treatment (<i>P</i>≥0.12). Follicular insulin-like growth factor-1 was greater in algae compared to control heifers (<i>P</i>=0.03). During the pre-breeding period, algae supplemented heifers had lesser DMI (<i>P</i>=0.006), and greater ADG (<i>P</i>=0.03) during the breeding period, while BW tended to be greater compared to control heifers on d 98 and 180 (<i>P</i>≤0.07). First service conception rate did not differ between treatments (<i>P</i>=0.67); however, second service tended (<i>P</i>=0.08) and overall conception was (<i>P</i>=0.03) lesser in algae compared to control heifers. These data suggest supplementing DHA-rich algae improved growth, but decreased conception rates of primiparous beef females.</p>

Orientador: Reinaldo Fernandes Cooke / Resumo: Este estudo avaliou os efeitos da administração oral de meloxicam nas respostas metabólicas, inflamatórias e de fase-aguda em bovinos de corte recebendo um desafio de lipopolissacarídeo (LPS) bacteriano (Exp. 1; d -1 a d 6) ou vacina contra patógenos respiratórios (Exp. 2; d 7 a d 21). Vinte e um novilhos (n=11) e novilhas (n=10) foram alocados em baias individuais no d -15 e receberam água, mistura de sais minerais e vitaminas, e feno de alfafa ad libitum até d 21. No d -1, os animais foram classificados por sexo e peso corporal (PC) e designado para um dos três tratamentos a seguir: 1) Administração via oral de Meloxicam (1mg/Kg PC, diariamente; Carlsbad Technologies Inc., Carlsbad, CA, EUA) do d -1 até d 6 (MEL8); 2) Administração via oral de Meloxicam (1mg/Kg PC; Carlsbad Technologies Inc., Carlsbad, CA, EUA) no d 0 e de monoidrato de lactose (1mg/Kg PC; Avantor Performance Materials, Center Valley, PA, EUA) no d -1 e do d 1 até d 6 (MEL1); ou 3) Administração via oral de monoidrato de lactose (1mg/Kg PC, diariamente; Avantor Performance Materials, Center Valley, PA, EUA) do d -1 até d 6 (CON). Para o Experimento 1, no d 0, os animais receberam infusão intravenosa de LPS (0,5 μg/Kg PC; Escherichia coli 0111:B4, Sigma-Aldrich, St. Louis, MO, EUA) simultaneamente à administração do tratamento. Temperatura retal (RTEMP) foi medida, e amostras de sangue coletadas nas horas −2, 0, 2, 4, 6, 8, 12, 16, 24, 36, 48, 60, 72, 96, 120, e 144 h relativa à administração de LPS. Não foram detectados efeitos de tratamentos (P ≥ 0,36) para RTEMP, concentração sérica de Fator de Necrose Tumoral Alfa (TNFα), concentrações plasmáticas de haptoglobina, cortisol, insulina e leptina, assim como para expressão de RNAm sanguíneo para TNFα e ciclooxigenase-2 (COX2), contudo todas as variáveis se elevaram (P < 0,01) dentre os... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This study evaluated the effects of oral meloxicam administration on metabolic, inflammatory, and acute-phase responses of beef cattle receiving a lipopolysaccharide (LPS) challenge (Exp. 1; d −1 to 6) or vaccinated against respiratory pathogens (Exp. 2; d 7 to 21). Twenty-one Angus steers (n = 11) and heifers (n = 10) were housed in individual pens on d −15 and were offered free-choice water, mineral-vitamin mix, and hay until d 21. In Exp. 1, cattle were ranked on d −1 by sex and BW and assigned to 1) oral meloxicam administration (1 mg/kg BW daily) from day −1 to 6 (MEL8), 2) oral meloxicam administration (1 mg/kg BW) on d 0 and oral lactose monohydrate administration (1 mg/kg BW) on d −1 and from d 1 to 6 (MEL1), or 3) oral lactose monohydrate administration (1 mg/ kg BW daily) from d −1 to 6 (CON). On d 0, cattle received an intravenous LPS bolus (0.5 μg/kg BW) concurrently with treatment administration. Rectal temperature (RTEMP) was assessed, and blood samples were collected at −2, 0, 2, 4, 6, 8, 12, 16, 24, 36, 48, 60, 72, 96, 120, and 144 h relative to LPS administration. No treatment effects were detected (P ≥ 0.36) for RTEMP, concentrations of serum tumor necrosis factor α (TNFα), plasma haptoglobin, cortisol, insulin, and leptin, as well as blood mRNA expression of TNFα and cyclooxygenase-2, although all variables increased (P < 0.01) across treatments after LPS administration. In Exp. 2, cattle received the same treatments that they were assigned to in Exp. 1 from d 7 to d 13 and were vaccinated against respiratory pathogens concurrently with treatment administration on d 8. Blood samples were collected, and RTEMP was assessed as in Exp. 1 in addition to 168, 240, and 336 h relative to vaccination. No treatment effects were detected (P ≥ 0.26) for RTEMP, the same plasma and serum variables evaluated in Exp. 1, and serum concentrations of antibodies against... (Complete abstract click electronic access below) / Mestre

Orientador: João Guilerme de Camargo Ferraz Machado / Resumo: A pecuária de corte se destaca como atividade do agronegócio em um cenário competitivo com escala produtiva ascendente e expressiva na participação nas exportações e formação das riquezas geradas. O processo da rastreabilidade destaca-se por garantir a eficiência e diminuição dos custos dos processos produtivos, dinamizar as estruturas organizacionais dos estabelecimentos produtores, bem como promover acesso a mercados exigentes demandantes de segurança e qualidade dos alimentos; além de agir como “ponte” suprindo o mercado consumidor de informações acerca de todo processo produtivo, armazenamento e distribuição da carne bovina. Nesse aspecto o Sistema Brasileiro de Identificação Individual de Bovinos e Búfalos (SISBOV), contribui potencialmente como ferramenta de controle de gestão e manejo de animais, além de possibilitar o acesso dos estabelecimentos rurais a denomina “Lista Trace” que por meio de auditoria de certificadoras de protocolos de adesão ao sistema, ficam aptas a exportação a mercados exigentes de segurança e qualidade como a União Europeia. Destaca-se ainda a informação e os fluxos informacionais formais gerados tanto no processo em si da rastreabilidade como da adesão ao sistema, atuando como ativos nas organizações, sendo considerados como recursos estratégicos nas tomadas de decisões, ressaltando que os fluxos informacionais tácitos como relevantes na construção das ações organizacionais. Nesse contexto busca se responder se a gestão da informação e os fluxo... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Beef cattle stands out as an agribusiness activity in a competitive scenario with an upward and significant production scale in participation in exports and formation of the wealth generated. The traceability process stands out for ensuring efficiency and lowering the costs of production processes, streamlining the organizational structures of producing establishments, as well as promoting access to demanding markets that demand food safety and quality; in addition to acting as a “bridge” supplying the consumer market with information about the entire production process, storage and distribution of beef. In this respect, the Brazilian System for the Individual Identification of Bovines and Buffaloes (SISBOV), potentially contributes as a tool for animal management and management control, in addition to allowing access by rural establishments to the so-called “Lista Trace” which, through the audit of certifiers protocols for joining the system, they are suitable for export to demanding safety and quality markets such as the European Union. Also noteworthy is the information and formal information flows generated both in the process itself of traceability and adherence to the system, acting as assets in organizations, being considered as strategic resources in decision making, emphasizing that tacit information flows as relevant in construction of organizational actions. In this context, it seeks to answer whether information management and informational flows are considered in... (Complete abstract click electronic access below) / Mestre

Orientador: Telma Teresinha Berchielli / Resumo: O objetivo deste estudo foi avaliar a influência da suplementação ou não com proteína não degradável no rúmen (PNDR) sobre o consumo, metabolismo e desempenho de bovinos Nelore na fase da recria, durante o período das águas. Os animais foram mantidos em pastagem de Urochloa brizantha cv. Xaraés (PB = 12,3%), sob pastejo contínuo e método put and take. Dois experimentos foram realizados simultaneamente e as seguintes suplementações foram avaliadas: suplementação mineral (SM), suplementação proteica de 3 g/kg PC de glúten de milho 60 (GLU) ou farelo de soja protegido (FSP). As médias dos tratamentos foram comparadas utilizando contrastes ortogonais (SM vs. PNDR; e GLU vs. FSP). O experimento de desempenho (Exp1) teve duração de 112 dias, utilizou-se 96 tourinhos jovens da raça Nelore com peso corporal inicial médio de 240 ± 19,72 kg, distribuídos em um delineamento em blocos ao acaso. A suplementação com PNDR promoveu aumento no ganho médio diário (GMD; P <0,01), com ganho adicional de 205 g/dia para GLU e FSP em relação ao SM, sem diferenças entre as fontes de proteicas suplementadas. O experimento de metabolismo (Exp2) teve duração de 84 dias e foram utilizados 9 novilhos da raça Nelore, castrados, canulados no rúmen e duodeno, com aproximadamente 350 ± 78,51 kg de peso corporal inicial. Os animais foram distribuídos em 3 quadrados latinos simultâneos 3 x 3. Não foram observadas alterações no consumo de matéria seca (CMS kg e %PC), consumo de matéria orgânica e de forragem (P... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aim of this study was to evaluate the effect of ruminal undegradable protein (RUP) supplementation on intake, metabolism and, performance of Nellore cattle on the growing phase, during the rainy season. The animals were kept on pasture of Urochloa brizantha cv. Xaraes (CP = 12.3%), in continuous grazing, and put and take method. Two experiments were carried out simultaneously, and the supplements evaluated were: mineral supplementation (MS), protein supplementation of 3 g/ kg BW of corn gluten 60 (CG) or protected soybean meal (PSM). The treatment means were compared using orthogonal contrasts (MS vs. RUP; and CG vs. PSM). The performance experiment (Exp1) lasted 112 days, using 96 young Nellore bulls with average initial body weight of 240 ± 19.72 kg, assigned in a randomized block design. RUP supplementation promoted an increase in average daily gain (ADG; P <0.01), with an additional gain of 205g/ day for CG and PSM compared to MS, with no differences between supplemented protein sources. The metabolism experiment (Exp2) lasted 84 days and 9 Nellore steers, castrated, cannulated in the rumen and duodenum, with approximately 350 ± 78.51 kg initial body weight were used. The animals were assigned in 3 simultaneous 3 x 3 Latin squares. There were no changes in dry matter intake (DMI kg, and % BW), organic matter intake, and forage intake (P ≥ 0.11). Supplementation with CG, and PSM increased the crude protein (CP), nitrogen (N), metabolizable energy intake (P <0.01), and ... (Complete abstract click electronic access below) / Mestre

No description available.