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Virginiamycin (V) and Ionophores, such as Poulcox (active ingredient monensin sodium), are antimicrobial feed additives approved for use in cattle to improve performance. The effect of virginiamycin on Gram positive bacteria is similar to that of monensin (M) although the modes of actions differ. Very little information is available on the potential synergistic effects of V and M, especially in dairy cattle diets. The objectives of this study were to investigate the effect of combinations of V and M on the performance of dairy cows. Forty high producing Holstein cows were blocked according to previous milk production and randomly allocated to one of the following lucerne based total mixed diets: 1) Control, no medication (C); 2) Control plus 20 ppm virginiamycin (V); 3) Control plus 15 ppm monensin (M); 4) Control plus 20 ppm virginiamycin and 15 ppm monensin (V+M). The experimental period was from 21 days prepartum until 60 days postpartum. Data were analysed according to a randomized block design, using the model GLM procedure (SAS, 2001). Dry matter intake varied from 23.6 kg/d to 25.4 kg/d and did not differ between treatments (P>0.10). Milk production was higher (P<0.10) for cows receiving V+M (41.2 kg/d) when compared to cows receiving only V (36.6 kg/d), but did not differ from other treatments (P>0.10). Milk fat % was lower for cows receiving M (3.42 %) and the control (3.62 %) when compared to treatment V+M (3.86 %) (P<0.10). Milk protein and MUN did not differ. Body weight loss for the period from calving until day 60 postpartum, tended (P<0.15) to be less for cows receiving V+M (-8.1 kg) when compared to the control (-34.2 kg) and M (-31.9 kg) treatments. Both treatments M and V respectively, decreased blood BHBA and treatment M increased blood glucose (P<0.10) when compared to the control diet. Results suggest a complementary effect between the two additives monensin and virginiamycin when supplemented to early lactation cows. / Dissertation (MSc(Agric))--University of Pretoria, 2008. / Animal and Wildlife Sciences / unrestricted

These projects were conducted to determine the digestibility of forage diets with differing CP levels in llamas and alpacas. The Utah study was designed to compare llama and alpaca nutritional parameters to determine if nutritional recommendations for llamas can be directly extrapolated to alpacas. The first study evaluated the effects of forage quality on blood metabolites and nitrogen balance in mature, intact male llamas (n = 4, 36 ± 4.4 months, 87 ± 17 kg) at high altitude in Letanias, Bolivia (4,267 m = aprox.14,000 ft above sea level). A second experiment was conducted with eight adult gelded camelids (n = 8; 4 llamas, 24-36 months, 90 ± 10.7 kg; 4 alpacas, 24-36 months, 50 ± 4 kg) at Brigham Young University, Provo, UT (altitude 1370 m). Animals were randomly fed barley hay (B) and 80% barley/20% alfalfa hay (BA). A fresh cut grass pasture (P) was included as the third forage for Bolivian llamas. Animals were housed in metabolism crates and diets were fed for a 7 d adjustment period followed by a 5 d collection period. Feed, feed refusal, feces and urine were collected, dried and N content determined by combustion analysis. Venous blood samples were collected on d 12 at 30 min intervals over a 6 h period. Plasma was harvested and analyzed for electrolytes (Na, K, Cl, Ca, Ca++, P, Mg) and metabolites (glucose, non- esterified fatty acids (NEFAs), urea N, creatinine, albumin, total protein (TPP), osmolality (Osm)). Llamas and alpacas demonstrated differences with respect to nitrogen metabolism when consuming forage diets with differing protein concentration. Llamas showed a N maintenance requirement of 0.75 g crude N/ W0.75. Using the standard CP to digestible protein (DP) conversion factor of 0.8, llamas required 0.60 digestible N/W0.75. When consuming the same high protein barley alfalfa diet, llamas had a much greater increase in N retention than alpacas. These species differences indicate that alpacas have a higher N requirement to meet metabolic needs, and extrapolations with respect to nitrogen requirements and balance are not valid between llamas and alpacas. In the Bolivian llama trial, locally grown and harvested hycrested and Siberian wheat grass pasture (P), barley (B), and barley80%/alfalfa20% (BA) hays were fed. The Bolivian llamas were in negative N balance when fed the B and P diets. Dry matter digestibility was greater with the B and BA than P forage, and N digestibility was significantly higher with BA than either the B or P forages. Nitrogen maintenance requirement for Bolivian llamas at 4,267 m was 0.58 compared to 0.75 g crude N/W0.75 for Utah llamas, an increased digestive efficiency and a lower N maintenance requirement at higher altitude.

The nutritional status, especially circulating amino acid (AA) levels, can drastically change during a non-infectious (i.e., LPS) or infectious (e.g., Salmonella) challenge. Thus, study 1 examined the effect of LPS treatment (N = 9, 26.9 ± 1.07 kg BW) on plasma AA and metabolite levels in pigs. Data were used to generate prediction equations establishing mathematical relationships between plasma AA levels and numerous blood metabolites (e.g., total lipid, LDL, HDL, blood urea nitrogen, etc). These equations have the potential to improve the nutritional treatment and recovery of acute and chronically ill patients. Study 2 (19.1 ± 0.37 kg) was a continuation of study 1 except the sampling time was increased from 12 to 24 h. One-half of the pigs in study 2 were treated with LPS (N=15) and the other one-half were saline treated control animals (N = 16). This design allows for monitoring changes in plasma AA and their catabolism in response to endotoxemia. Area under the curve (AUC) was calculated for a selected AA to report AA balances. During the induction phase of an acute challenge (t = -2 to 12 h), analyzed AA were in a negative balance indicating heavy AA catabolism. However, during the recovery phase (t = 12 to 24 h) half of the AA were in a positive balance while the other half were still negative. The ability of equations to accurately predict AA concentrations was tested. Results indicate poor performance possibly due to heavy term biases. Thus, it was concluded that equations need to be revisited and non-linear terms need to be evaluated. Nonetheless, routine clinical blood metabolites can be used to estimate plasma AA levels during immune activation. We successfully established a porcine Salmonella enterica serovar Typhimurium model. Pigs infected with Salmonella had a febrile response for 4 d and exhibited marked changes in their fecal bacterial populations Finally, we investigated plasma changes in N-τ-methyl histidine (NτMH) in healthy and LPS-treated pigs. NτMH— is a post-translationally modified AA that has historically been used as an indirect marker of muscle protein breakdown in rodents and humans. However, the major form (i.e., free or acetylated) of NτMH in pig plasma was unknown. Results indicate that only 15% of plasma NτMH is in the free form and the remainder is acetylated. Furthermore, LPS treated pigs had increased acetylated and total NτMH fractions while free NτMH did not change. Therefore, to accurately monitor plasma changes in NτMH as an indicator of muscle proteolysis, plasma samples must be subjected to acid hydrolysis. / Ph. D.

Propolis as natural dietary additive can be used to manipulate rumen fermentation towards less methane (CH4) and it may affect animal reproductive and productive performance. To study the application of propolis, three studies were conducted. The first study aimed to evaluate the in vitro nutritive value of two types of propolis (Brazilian red propolis (BRP) and Egyptian brown propolis (EBP) for their anti-methanogenic activity, ruminal fermentation and degradability. Propolis extracts were prepared using 70% ethanol and added to a 50:50 Tifton hay to concentrate diet at three levels [0 (negative control, CTL), 25, 50 and 100 micrograma / 0.5 g substrate]. Each propolis were compared with monensin as positive control. Both BRP50 micrograma and EBP25 micrograma showed similar significant effects on CH4 production as monensin; on average 14.2 ml/TDOM g compared with CTL (19.3 ml/TDOM). Monensin supplementation increased (P<0.001) the propionate concentration and decreased the acetate/propionate ratio, while BRP and EBP enhanced (P<0.001) the individual and total volatile fatty acids concentrations and reduced (P<0.002) protozoa count compared to CTL. The objective of the second study was to evaluate the oral administration of BRP extract to Santa Inês ewes during and after flushing period on the reproductive performance and animal health (hormonal profiles, hematological, biochemical and parasites responses). Thirty adult grazing ewes (40±2.0 kg BW) were divided into two dietary treatments, control (basal diet) and BRP (basal diet plus 3.0g of BRP/ewe/day) for 21 days. Blood and fecal samples were collected weekly for eight weeks. Oral administration of BRP did not affect (P>0.05) any of the observed reproduction traits, but there was promising improvement on the number of services per conceptions and hormones levels: increased (P<0.01) progesterone, decreased cortisol (P<0.05) and thyroxin (T4) (P<0.01) without significant changes in triiodothyronine (T3). Propolis resulted in increasing (P<0.01) of total leukocyte while there were no significant differences observed for other hematological parameters. Propolis increased (P<0.01) total protein and globulin but reduced (P<0.01) triglycerides, glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT) and fecal egg counts (P<0.05) compared with control. The third study was conducted to evaluate the oral administration of BRP extract to Santa Inês ewes from 25±3 day pre-partum through 48 d post-partum on milk yield, milk composition and lamb performance. Twenty Santa Inês ewes (60 ± 2.0 kg BW) were divided into two groups: control (basal diet) and BRP (basal diet plus 3.0g of BRP/ewe/day for 21 days). Milk samples were collected weekly for seven weeks. Propolis fed group showed increasing (P<0.05) milk yield, fat content, fat yield, protein yield, lactose yield and energy corrected milk while somatic cell counts was decreased (P<0.05). Propolis increased (P<0.05) ewes body condition score. Lambs average daily gain and milk conversion ratio were improved (P<0.05) by propolis treatment. The studies highlight the potential of propolis to handle the ruminal fermentation in order to reduce the production of CH4, as well as improved the health of ewes during the breeding season, besides increasing milk production and performance of lambs / Própolis, aditivo natural, pode ser usada para manipular a fermentação ruminal e diminuir a produção de metano (CH4), podendo afetar o desempenho dos animais. Foram conduzidos estudos visando avaliar a aplicação da própolis em ovinos. O primeiro experimento foi realizado com o objetivo de avaliar o valor nutritivo in vitro de dois tipos da própolis (Vermelho Brasileiro (PVB) e Marrom Egípcio (PME)), através da atividade antimetanogênica, fermentação ruminal e degradabilidade. Os extratos da própolis foram preparados usando etanol e adicionados a um substrato base (50:50 feno Tifton x concentrado) em quatro concentrações [0 (controle, CTL), 25, 50 e 100 micrograma / 0,5 g de substrato]; sendo comparadas com a monensina como controle positivo. As própolis PVB50 micrograma e PME25 micrograma apresentaram redução na produção de CH4 similar à monensina, sendo menores que o CTL. A monensina aumentou (P < 0,001) a concentração de proprionato e diminuiu (P < 0,001) a proporção de acetate / propionate, enquanto as própolis aumentaram (P < 0,002) as concentrações dos ácidos graxos voláteis e reduziram (P < 0,001) os protozoários. O segundo estudo objetivou avaliar a administração de extrato de PVB em ovelhas durante o período de \"flushing nutricional\" sobre o desempenho e a saúde dos animais durante a estação de reprodução. Trinta ovelhas (40 ± 2,0 kg PV) foram divididas em dois grupos, controle (dieta basal) e PVB (dieta basal com suplementação de 3,0 g de PVB / ovelha / dia) e suplementadas durante 21 dias. Amostras de sangue e fezes foram coletadas semanalmente durante oito semanas. Administração do PVB não afetou nenhuma característica reprodutiva, mas houve melhora (P < 0.01) no número de serviços por concepção, e aumento (P < 0,01) no teor de progesterona, diminuição (P < 0,01) nas concentrações de cortisol e tiroxina (T4), sem efeito na concentração de tri-iodotironina (T3). Própolis resultou apenas em aumento (P < 0,01) no número de leucócitos dentre os parâmetros hematológicos. A própolis aumentou (P < 0,01) a concentração de proteina total e de globulina, e reduziou (P < 0,05) os teores de triglicerídeos, transaminase oxalacética (TGO), transaminase glutamato piruvato (TGP) e contagem de ovos nas fezes quando comparado com o controle. O terceiro estudo foi conduzido para avaliar a administração do extrato de PVB para as ovelhas desde 25 ± 3 dias pré-parto até 48 dias pós-parto sobre a produção e composição do leite e desempenho dos cordeiros. Vinte ovelhas (56 ± 2,0 kg PV) foram divididas em dois grupos e suplementadas conforme descrito no segundo estudo: controle e PVB durante 21 dias. Amostras de leite foram coletadas semanalmente durante sete semanas. Própolis aumentou (P < 0,05) a produção de leite, conteúdo de gordura, rendimentos de gordura, proteína e lactose e leite corrigido para energia, enquanto diminuiu (P < 0,05) a contagem de células somáticas, mas aumentou (P < 0,05) a condição corporal. O ganho em peso médio diário dos cordeiros e taxa de conversão de leite foram melhoradas (P < 0,05) pelo tratamento com própolis. Os estudos destacam o potencial da própolis para manipular a fermentação ruminal visando redução na produção de CH4, assim como melhorar a saúde de ovelhas durante a estação de reprodução, além de aumentar a produção de leite e desempenho dos cordeiros

O estudo envolveu dois experimentos com o objetivo de avaliar o efeito de estratégias de alimentação sobre o estresse oxidativo, consumo, metabólitos sanguineos, a evolução da produção e composição do leite de vacas de diferentes composições raciais durante o período de transição. Estudo 1:Foi utilizado o delineamento inteiramente casualizado, com medidas repetidas no tempo e 24 vacas da raça Jersey foram distribuídas nos tratamentos controle - sem a adição de extratos vegetais (CON), adição de 10 gramas/dia de extrato de orégano (EO) e adição de 5,0 g/dia de extrato de chá verde (ECV).O fornecimento de extrato de orégano melhorou a eficiência alimentare a produção de leite em relação ao extrato de chá verde. A adição de extratos vegetais na dieta reduziu o radical livre(ROS) DCFE, contribuindo para redução do estresse oxidativo. Estudo 2:Foi utilizado o delineamento experimental inteiramente casualizado, em arranjo fatorial 2x2 (duas composições raciais e dois planos nutricionais no pré parto) com seis repetiçõese medidas repetidas no tempo. Durante 21 dias pré parto, novilhas Girolando F1 (½ Holandês ½ Gir) e Holandês receberam a mesma dieta total misturada (TMR), variando somente a quantidade ofertada (plano nutricional): 1,69 ou1,89% do peso corporal(PC) de matéria seca No pós parto, os animais receberam dietas semelhantes formuladas conforme as recomendações do NRC (prevista para raça Holandês). O plano nutricional de 1,89% do PC aumentou a concentração de ácidos graxos não esterificados (AGNE) no pré parto,a concentração de glicose no pós parto e o estresse oxidativo durante todo o período experimental em relação ao plano nutricional 1,69% do PC. Os animais da raça Girolando F1apresentaram os maior ECC durante todo o período experimental, menor ingestão de matéria seca no pré e pós parto e menor consumo de energia metabólica no pós parto;aumento da concentração de creatinina e AGNE no pré parto e maior concentração de glicose no pós parto; menor produção de leite, menor concentração de lactose em relação a animais Holandês.Diferenças metabólicas como as concentrações de AGNE, creatinina e glicose entre as composições raciais podem ter influenciado as variáveis indicativas de estresse oxidativo. O plano nutricional 1,89% do PC durante o período seconão deve ser oferecido, independentemente da composição racial. Animais Girolando F1 devem ser manejados de forma distinta de animais Holandês durante o período de transição, pois apresentam diferenças de consumo e metabolismo. / The study was performed based on two trialsand aimed of evaluating the effect of feeding strategies on oxidative stress, consumption, blood metabolites, milk production and milk composition of cows of different racial compositions during the transition period. Trial 1: we used a completely randomized design, with repeated measures along the time, where 24 Jersey cows were distributed in two diets: control - without the addition of plant extracts (CON), addition of 10 grams per day of oregano extract (OE) and addition of 5.0 grams per day of green tea extract (GTE). The supply of OE improvedfeed conversion during the postpartum period and milk production compared to GTE. The addition of plant extracts in the diet reduces the free radical (ROS) DCFE, contributing to the reduction of oxidative stress. Trial 2: A completely randomized experiment design was used, in a 2x2 factorial arrangement (two racial compositions and two nutritional plans in prepartum), with time-repeated measures (during days), with four treatments and six repetitions (heifers) in each treatment. For 21 day before of prepartum, nuluparous females Girolando F1 (½ Holstein ½ Gir) and Holstein received the same total mixed diet (TMR), varying only the amount offered (nutritional plan): 1.69 and 1.89% of (BW) of dry matter. In the postpartum the animals received the same basal diet formulated according to the recommendations of the NRC (predicted for Holstein) The nutritional plane of 1.89% showed a higher concentration of calcium and non-esterified fatty acids (NEFA) in the prepartum, higher concentration of glucose in the postpartum period and greater oxidative stress throughout the experimental period in relation to the nutritional plane 1,69% of the PC. The animals Girolando F1 had the highest ECC during the experimental period, lower intake of dry matter in the pre and postpartum, and lower metabolic energy consumption in the postpartum period; increased creatinine concentration and NEFA in prepartum and higher postpartum glucose concentration; lower milk yield, lower lactose concentration in relation to Hostein animals. Metabolic differences such as the concentrations of NEFA, creatinine and glucose among racial compositions may have influenced the variables indicative of oxidative stress. The nutritional plan 1.89%CP supply during the dry period should not be indicated. Girolando F1 animals should be handled differently from Holstein animals during the transition period, as they exhibit differences in intake and metabolism.

O estudo envolveu dois experimentos com o objetivo de avaliar o efeito de estratégias de alimentação sobre o estresse oxidativo, consumo, metabólitos sanguineos, a evolução da produção e composição do leite de vacas de diferentes composições raciais durante o período de transição. Estudo 1:Foi utilizado o delineamento inteiramente casualizado, com medidas repetidas no tempo e 24 vacas da raça Jersey foram distribuídas nos tratamentos controle - sem a adição de extratos vegetais (CON), adição de 10 gramas/dia de extrato de orégano (EO) e adição de 5,0 g/dia de extrato de chá verde (ECV).O fornecimento de extrato de orégano melhorou a eficiência alimentare a produção de leite em relação ao extrato de chá verde. A adição de extratos vegetais na dieta reduziu o radical livre(ROS) DCFE, contribuindo para redução do estresse oxidativo. Estudo 2:Foi utilizado o delineamento experimental inteiramente casualizado, em arranjo fatorial 2x2 (duas composições raciais e dois planos nutricionais no pré parto) com seis repetiçõese medidas repetidas no tempo. Durante 21 dias pré parto, novilhas Girolando F1 (½ Holandês ½ Gir) e Holandês receberam a mesma dieta total misturada (TMR), variando somente a quantidade ofertada (plano nutricional): 1,69 ou1,89% do peso corporal(PC) de matéria seca No pós parto, os animais receberam dietas semelhantes formuladas conforme as recomendações do NRC (prevista para raça Holandês). O plano nutricional de 1,89% do PC aumentou a concentração de ácidos graxos não esterificados (AGNE) no pré parto,a concentração de glicose no pós parto e o estresse oxidativo durante todo o período experimental em relação ao plano nutricional 1,69% do PC. Os animais da raça Girolando F1apresentaram os maior ECC durante todo o período experimental, menor ingestão de matéria seca no pré e pós parto e menor consumo de energia metabólica no pós parto;aumento da concentração de creatinina e AGNE no pré parto e maior concentração de glicose no pós parto; menor produção de leite, menor concentração de lactose em relação a animais Holandês.Diferenças metabólicas como as concentrações de AGNE, creatinina e glicose entre as composições raciais podem ter influenciado as variáveis indicativas de estresse oxidativo. O plano nutricional 1,89% do PC durante o período seconão deve ser oferecido, independentemente da composição racial. Animais Girolando F1 devem ser manejados de forma distinta de animais Holandês durante o período de transição, pois apresentam diferenças de consumo e metabolismo. / The study was performed based on two trialsand aimed of evaluating the effect of feeding strategies on oxidative stress, consumption, blood metabolites, milk production and milk composition of cows of different racial compositions during the transition period. Trial 1: we used a completely randomized design, with repeated measures along the time, where 24 Jersey cows were distributed in two diets: control - without the addition of plant extracts (CON), addition of 10 grams per day of oregano extract (OE) and addition of 5.0 grams per day of green tea extract (GTE). The supply of OE improvedfeed conversion during the postpartum period and milk production compared to GTE. The addition of plant extracts in the diet reduces the free radical (ROS) DCFE, contributing to the reduction of oxidative stress. Trial 2: A completely randomized experiment design was used, in a 2x2 factorial arrangement (two racial compositions and two nutritional plans in prepartum), with time-repeated measures (during days), with four treatments and six repetitions (heifers) in each treatment. For 21 day before of prepartum, nuluparous females Girolando F1 (½ Holstein ½ Gir) and Holstein received the same total mixed diet (TMR), varying only the amount offered (nutritional plan): 1.69 and 1.89% of (BW) of dry matter. In the postpartum the animals received the same basal diet formulated according to the recommendations of the NRC (predicted for Holstein) The nutritional plane of 1.89% showed a higher concentration of calcium and non-esterified fatty acids (NEFA) in the prepartum, higher concentration of glucose in the postpartum period and greater oxidative stress throughout the experimental period in relation to the nutritional plane 1,69% of the PC. The animals Girolando F1 had the highest ECC during the experimental period, lower intake of dry matter in the pre and postpartum, and lower metabolic energy consumption in the postpartum period; increased creatinine concentration and NEFA in prepartum and higher postpartum glucose concentration; lower milk yield, lower lactose concentration in relation to Hostein animals. Metabolic differences such as the concentrations of NEFA, creatinine and glucose among racial compositions may have influenced the variables indicative of oxidative stress. The nutritional plan 1.89%CP supply during the dry period should not be indicated. Girolando F1 animals should be handled differently from Holstein animals during the transition period, as they exhibit differences in intake and metabolism.

Propolis as natural dietary additive can be used to manipulate rumen fermentation towards less methane (CH4) and it may affect animal reproductive and productive performance. To study the application of propolis, three studies were conducted. The first study aimed to evaluate the in vitro nutritive value of two types of propolis (Brazilian red propolis (BRP) and Egyptian brown propolis (EBP) for their anti-methanogenic activity, ruminal fermentation and degradability. Propolis extracts were prepared using 70% ethanol and added to a 50:50 Tifton hay to concentrate diet at three levels [0 (negative control, CTL), 25, 50 and 100 micrograma / 0.5 g substrate]. Each propolis were compared with monensin as positive control. Both BRP50 micrograma and EBP25 micrograma showed similar significant effects on CH4 production as monensin; on average 14.2 ml/TDOM g compared with CTL (19.3 ml/TDOM). Monensin supplementation increased (P<0.001) the propionate concentration and decreased the acetate/propionate ratio, while BRP and EBP enhanced (P<0.001) the individual and total volatile fatty acids concentrations and reduced (P<0.002) protozoa count compared to CTL. The objective of the second study was to evaluate the oral administration of BRP extract to Santa Inês ewes during and after flushing period on the reproductive performance and animal health (hormonal profiles, hematological, biochemical and parasites responses). Thirty adult grazing ewes (40±2.0 kg BW) were divided into two dietary treatments, control (basal diet) and BRP (basal diet plus 3.0g of BRP/ewe/day) for 21 days. Blood and fecal samples were collected weekly for eight weeks. Oral administration of BRP did not affect (P>0.05) any of the observed reproduction traits, but there was promising improvement on the number of services per conceptions and hormones levels: increased (P<0.01) progesterone, decreased cortisol (P<0.05) and thyroxin (T4) (P<0.01) without significant changes in triiodothyronine (T3). Propolis resulted in increasing (P<0.01) of total leukocyte while there were no significant differences observed for other hematological parameters. Propolis increased (P<0.01) total protein and globulin but reduced (P<0.01) triglycerides, glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT) and fecal egg counts (P<0.05) compared with control. The third study was conducted to evaluate the oral administration of BRP extract to Santa Inês ewes from 25±3 day pre-partum through 48 d post-partum on milk yield, milk composition and lamb performance. Twenty Santa Inês ewes (60 ± 2.0 kg BW) were divided into two groups: control (basal diet) and BRP (basal diet plus 3.0g of BRP/ewe/day for 21 days). Milk samples were collected weekly for seven weeks. Propolis fed group showed increasing (P<0.05) milk yield, fat content, fat yield, protein yield, lactose yield and energy corrected milk while somatic cell counts was decreased (P<0.05). Propolis increased (P<0.05) ewes body condition score. Lambs average daily gain and milk conversion ratio were improved (P<0.05) by propolis treatment. The studies highlight the potential of propolis to handle the ruminal fermentation in order to reduce the production of CH4, as well as improved the health of ewes during the breeding season, besides increasing milk production and performance of lambs / Própolis, aditivo natural, pode ser usada para manipular a fermentação ruminal e diminuir a produção de metano (CH4), podendo afetar o desempenho dos animais. Foram conduzidos estudos visando avaliar a aplicação da própolis em ovinos. O primeiro experimento foi realizado com o objetivo de avaliar o valor nutritivo in vitro de dois tipos da própolis (Vermelho Brasileiro (PVB) e Marrom Egípcio (PME)), através da atividade antimetanogênica, fermentação ruminal e degradabilidade. Os extratos da própolis foram preparados usando etanol e adicionados a um substrato base (50:50 feno Tifton x concentrado) em quatro concentrações [0 (controle, CTL), 25, 50 e 100 micrograma / 0,5 g de substrato]; sendo comparadas com a monensina como controle positivo. As própolis PVB50 micrograma e PME25 micrograma apresentaram redução na produção de CH4 similar à monensina, sendo menores que o CTL. A monensina aumentou (P < 0,001) a concentração de proprionato e diminuiu (P < 0,001) a proporção de acetate / propionate, enquanto as própolis aumentaram (P < 0,002) as concentrações dos ácidos graxos voláteis e reduziram (P < 0,001) os protozoários. O segundo estudo objetivou avaliar a administração de extrato de PVB em ovelhas durante o período de \"flushing nutricional\" sobre o desempenho e a saúde dos animais durante a estação de reprodução. Trinta ovelhas (40 ± 2,0 kg PV) foram divididas em dois grupos, controle (dieta basal) e PVB (dieta basal com suplementação de 3,0 g de PVB / ovelha / dia) e suplementadas durante 21 dias. Amostras de sangue e fezes foram coletadas semanalmente durante oito semanas. Administração do PVB não afetou nenhuma característica reprodutiva, mas houve melhora (P < 0.01) no número de serviços por concepção, e aumento (P < 0,01) no teor de progesterona, diminuição (P < 0,01) nas concentrações de cortisol e tiroxina (T4), sem efeito na concentração de tri-iodotironina (T3). Própolis resultou apenas em aumento (P < 0,01) no número de leucócitos dentre os parâmetros hematológicos. A própolis aumentou (P < 0,01) a concentração de proteina total e de globulina, e reduziou (P < 0,05) os teores de triglicerídeos, transaminase oxalacética (TGO), transaminase glutamato piruvato (TGP) e contagem de ovos nas fezes quando comparado com o controle. O terceiro estudo foi conduzido para avaliar a administração do extrato de PVB para as ovelhas desde 25 ± 3 dias pré-parto até 48 dias pós-parto sobre a produção e composição do leite e desempenho dos cordeiros. Vinte ovelhas (56 ± 2,0 kg PV) foram divididas em dois grupos e suplementadas conforme descrito no segundo estudo: controle e PVB durante 21 dias. Amostras de leite foram coletadas semanalmente durante sete semanas. Própolis aumentou (P < 0,05) a produção de leite, conteúdo de gordura, rendimentos de gordura, proteína e lactose e leite corrigido para energia, enquanto diminuiu (P < 0,05) a contagem de células somáticas, mas aumentou (P < 0,05) a condição corporal. O ganho em peso médio diário dos cordeiros e taxa de conversão de leite foram melhoradas (P < 0,05) pelo tratamento com própolis. Os estudos destacam o potencial da própolis para manipular a fermentação ruminal visando redução na produção de CH4, assim como melhorar a saúde de ovelhas durante a estação de reprodução, além de aumentar a produção de leite e desempenho dos cordeiros

O estudo envolveu dois experimentos com o objetivo de avaliar o efeito de estratégias de alimentação sobre o estresse oxidativo, consumo, metabólitos sanguineos, a evolução da produção e composição do leite de vacas de diferentes composições raciais durante o período de transição. Estudo 1:Foi utilizado o delineamento inteiramente casualizado, com medidas repetidas no tempo e 24 vacas da raça Jersey foram distribuídas nos tratamentos controle - sem a adição de extratos vegetais (CON), adição de 10 gramas/dia de extrato de orégano (EO) e adição de 5,0 g/dia de extrato de chá verde (ECV).O fornecimento de extrato de orégano melhorou a eficiência alimentare a produção de leite em relação ao extrato de chá verde. A adição de extratos vegetais na dieta reduziu o radical livre(ROS) DCFE, contribuindo para redução do estresse oxidativo. Estudo 2:Foi utilizado o delineamento experimental inteiramente casualizado, em arranjo fatorial 2x2 (duas composições raciais e dois planos nutricionais no pré parto) com seis repetiçõese medidas repetidas no tempo. Durante 21 dias pré parto, novilhas Girolando F1 (½ Holandês ½ Gir) e Holandês receberam a mesma dieta total misturada (TMR), variando somente a quantidade ofertada (plano nutricional): 1,69 ou1,89% do peso corporal(PC) de matéria seca No pós parto, os animais receberam dietas semelhantes formuladas conforme as recomendações do NRC (prevista para raça Holandês). O plano nutricional de 1,89% do PC aumentou a concentração de ácidos graxos não esterificados (AGNE) no pré parto,a concentração de glicose no pós parto e o estresse oxidativo durante todo o período experimental em relação ao plano nutricional 1,69% do PC. Os animais da raça Girolando F1apresentaram os maior ECC durante todo o período experimental, menor ingestão de matéria seca no pré e pós parto e menor consumo de energia metabólica no pós parto;aumento da concentração de creatinina e AGNE no pré parto e maior concentração de glicose no pós parto; menor produção de leite, menor concentração de lactose em relação a animais Holandês.Diferenças metabólicas como as concentrações de AGNE, creatinina e glicose entre as composições raciais podem ter influenciado as variáveis indicativas de estresse oxidativo. O plano nutricional 1,89% do PC durante o período seconão deve ser oferecido, independentemente da composição racial. Animais Girolando F1 devem ser manejados de forma distinta de animais Holandês durante o período de transição, pois apresentam diferenças de consumo e metabolismo. / The study was performed based on two trialsand aimed of evaluating the effect of feeding strategies on oxidative stress, consumption, blood metabolites, milk production and milk composition of cows of different racial compositions during the transition period. Trial 1: we used a completely randomized design, with repeated measures along the time, where 24 Jersey cows were distributed in two diets: control - without the addition of plant extracts (CON), addition of 10 grams per day of oregano extract (OE) and addition of 5.0 grams per day of green tea extract (GTE). The supply of OE improvedfeed conversion during the postpartum period and milk production compared to GTE. The addition of plant extracts in the diet reduces the free radical (ROS) DCFE, contributing to the reduction of oxidative stress. Trial 2: A completely randomized experiment design was used, in a 2x2 factorial arrangement (two racial compositions and two nutritional plans in prepartum), with time-repeated measures (during days), with four treatments and six repetitions (heifers) in each treatment. For 21 day before of prepartum, nuluparous females Girolando F1 (½ Holstein ½ Gir) and Holstein received the same total mixed diet (TMR), varying only the amount offered (nutritional plan): 1.69 and 1.89% of (BW) of dry matter. In the postpartum the animals received the same basal diet formulated according to the recommendations of the NRC (predicted for Holstein) The nutritional plane of 1.89% showed a higher concentration of calcium and non-esterified fatty acids (NEFA) in the prepartum, higher concentration of glucose in the postpartum period and greater oxidative stress throughout the experimental period in relation to the nutritional plane 1,69% of the PC. The animals Girolando F1 had the highest ECC during the experimental period, lower intake of dry matter in the pre and postpartum, and lower metabolic energy consumption in the postpartum period; increased creatinine concentration and NEFA in prepartum and higher postpartum glucose concentration; lower milk yield, lower lactose concentration in relation to Hostein animals. Metabolic differences such as the concentrations of NEFA, creatinine and glucose among racial compositions may have influenced the variables indicative of oxidative stress. The nutritional plan 1.89%CP supply during the dry period should not be indicated. Girolando F1 animals should be handled differently from Holstein animals during the transition period, as they exhibit differences in intake and metabolism.

Although U.S. commercial catfish aquaculture ponds are in temperate regions and experience cool to cold temperatures during the winter, few studies have investigated the effects of low temperatures on catfish physiological processes. Therefore, growth, metabolism, swimming performance, and blood variables were compared between channel (Ictalurus punctatus), blue (I. furcatus), and hybrid (I. furcatus x I. punctatus) catfish at 10 and 20°C. Accelerometers were also used to evaluate relationships among acceleration, metabolism, and tail beat frequency (TBF) during swimming performance tests. Channel catfish experienced the greatest growth, yet growth was diminished across all fish types at 10°C. Metabolic processes, swimming performance, and related blood variables were also diminished at 10°C. Relationships among acceleration, metabolism, and TBF were found indicating cold temperatures inhibit maximum production in catfish and provide initial steps for creating holistic bioenergetic models for further application.