Manejo de neonatos caninos prematuros / Management of premature neonatal puppies

Dentre as mais importantes causas de morbidade neonatal na prematuridade, destacam-se os distúrbios respiratórios, complicações infecciosas, instabilidade crítica da termorregulação, inabilidade para homeostase energética e falhas na transferência de imunidade passiva. Dentre os problemas de origem pulmonar intimamente relacionados à prematuridade, destaca-se a imaturidade pulmonar por deficiência de surfactante, evoluindo para diminuição da capacidade pulmonar, hipoxemia, hipercapnia e acidose. Os neonatos caninos prematuros apresentam baixa vitalidade, hipotermia, bradipnéia, irregularidade do padrão respiratório, reduzido tônus e responsividade neuro-muscular. As áreas do parênquima pulmonar para efetuar trocas gasosas são limitadas em filhotes prematuros, culminando em alterações do equilíbrio ácidobase. Além disto, os recém-nascidos prematuros apresentam instabilidade energética e falha de transferência de imunidade passiva. Como medida preventiva à morbidade do neonato prematuro, indicase a corticoterapia pré-natal 48 horas antes do parto em cadelas gestantes, induzindo a maturidade funcional do pulmão fetal, além de melhorar a vitalidade e evolução clínica neonatal. Ademais, a corticoterapia antenatal estimula a transferência placentária de imunoglobulinas e absorção de imunoglobulinas colostrais, bem como aumenta a capacidade glicogênica. Nos casos emergenciais, preconiza-se medidas intensivas aos recém-nascidos prematuros, as quais incluem: reanimação respiratória, controle da hipotermia, reposição glicêmica na hipoglicemia e controle imunológico da falha de transferência imune passiva.(AU)

Among the most important causes of neonatal morbidity in prematurity, respiratory disorders, infectious complications, critical instability of thermoregulation, inability for energy homeostasis and failures in the transfer of passive immunity stand out. Among the problems of pulmonary origin closely related to prematurity, pulmonary immaturity due to surfactant deficiency stands out, evolving to decreased lung capacity, hypoxemia, hypercapnia and acidosis. Premature canine neonates have low vitality, hypothermia, bradypnea, irregular breathing pattern, reduced tone and neuromuscular responsiveness. The areas of the lung parenchyma to carry out gas exchange are limited in premature pups, culminating in changes in acid-base balance. In addition, premature newborns have energetic instability and failure to transfer passive immunity. As a preventive measure against premature neonate morbidity, prenatal corticosteroid therapy is indicated 48 hours before delivery in pregnant bitches, inducing functional maturity of the fetal lung, in addition to improving neonatal vitality and clinical evolution. Furthermore, antenatal corticosteroid therapy stimulates the placental transfer of immunoglobulins and the absorption of colostral immunoglobulins, as well as increasing the glycogenic capacity. In emergency cases, intensive measures are recommended for premature newborns, which include: respiratory resuscitation, hypothermia control, glycemic replacement in hypoglycemia and immunological control of passive immune transfer failure.(AU)

Blood parameters of lactating cows fed calcium salts as energetic source

Background: The negative energetic balance of lactating cows that occurs during the few weeks postpartum shifts the hormonal profile of the animal. These alterations may lead to metabolic disturbance as ketosis and lipid infiltration. Hypocalcemia is another metabolic problem that occurs in the peripartum period, it is characterized by the reduction in blood levels of calcium (Ca2+) near birth. Blood parameters illustrates the nutritional status of milking cows. The serum levels of glucose, β-hydroxybutyrate (BHB) and cholesterol are parameters that reveal liver condition and it is very important for the metabolism of milking cows. The objective of this study was to evaluate three additives in the form of a calcium salts on blood parameters of lactating cows.Materials, Methods & Results: Two Latin square 4x4 were used, whereas one comprehended of early lactation cows and the other of mid lactation cows. Animals of 2nd and 3rd parity were used only. Parity was distributed evenly among groups. The trial consisted of 4 groups with 4 treatments as follow: T1: 300 g of calcium acetate, T2: 200 g of calcium propionate, T3: 200 g of calcium salts of fatty acids, and T4: control without any calcium additive. Blood samples were collected for analysis of serial calcium, glucose, β-hydroxybutyrate (BHBA) and cholesterol. The calcium levels were higher in T1 than T3 in early lactation. There was no significant difference of glucose levels between groups. Groups T1 and T2 had lower amounts of BHBA. Cholesterol was higher in T3 and T1 in the early lactation and just in T3 was higher in the mid lactation.[...]

Blood parameters of lactating cows fed calcium salts as energetic source

Background: The negative energetic balance of lactating cows that occurs during the few weeks postpartum shifts the hormonal profile of the animal. These alterations may lead to metabolic disturbance as ketosis and lipid infiltration. Hypocalcemia is another metabolic problem that occurs in the peripartum period, it is characterized by the reduction in blood levels of calcium (Ca2+) near birth. Blood parameters illustrates the nutritional status of milking cows. The serum levels of glucose, β-hydroxybutyrate (BHB) and cholesterol are parameters that reveal liver condition and it is very important for the metabolism of milking cows. The objective of this study was to evaluate three additives in the form of a calcium salts on blood parameters of lactating cows.Materials, Methods & Results: Two Latin square 4x4 were used, whereas one comprehended of early lactation cows and the other of mid lactation cows. Animals of 2nd and 3rd parity were used only. Parity was distributed evenly among groups. The trial consisted of 4 groups with 4 treatments as follow: T1: 300 g of calcium acetate, T2: 200 g of calcium propionate, T3: 200 g of calcium salts of fatty acids, and T4: control without any calcium additive. Blood samples were collected for analysis of serial calcium, glucose, β-hydroxybutyrate (BHBA) and cholesterol. The calcium levels were higher in T1 than T3 in early lactation. There was no significant difference of glucose levels between groups. Groups T1 and T2 had lower amounts of BHBA. Cholesterol was higher in T3 and T1 in the early lactation and just in T3 was higher in the mid lactation.[...](AU)

Diferentes fontes energéticas durante o período de transição de vacas primíparas e os seus efeitos sobre metabólitos sanguíneos e hormônios / Different energy sources during the primiparous dairy cow transition period and its effects on blood metabolites and hormones

Objetivou-se com este estudo comparar os efeitos do fornecimento de dietas glicogênicas ou lipogênicas sobre metabolitos sanguíneos e hormônios em vacas primíparas (n=40) durante o período de transição. Os animais foram aleatoriamente distribuídos em quatro tratamentos: controle, sais de cálcio de ácidos graxos poli-insaturados (Megalac-E, 100g pré-parto e 250g pós-parto), soja tostada (400g pré-parto e 800g pós-parto) e propilenoglicol (300ml pré e pós-parto). Os suplementos foram fornecidos individualmente. Foram realizadas coletas de sangue para determinação das concentrações plasmáticas de insulina, glicose, ácidos graxos não esterificados (AGNE) e IGF-I. As concentrações de insulina e de glicose foram maiores nos animais do tratamento com sais de cálcio de ácidos graxos poli-insaturados. A maior concentração de AGNE foi observada no grupo controle. A concentração plasmática de IGF-I foi mais elevada para os animais do tratamento que receberam suplementos lipogênicos. A adição de sais de cálcio de ácidos graxos poli-insaturados a dieta foi capaz de amenizar as mudanças hormonais e metabólicas características do período de transição.(AU)

The aim of this study was to compare the effects of glycogenic supply or lipogenic diets on blood metabolites and hormones in primiparous dairy cows (n=40) during the transition period. The animals were randomly assigned to four treatments: control, calcium salts of polyunsaturated fatty acids (Megalac-E, 100g prepartum and 250g postpartum), roasted soybeans (400g prepartum and 800g postpartum) and propylene glycol (300ml pre- and postpartum). The supplements were provided individually. Blood samples were taken to determine plasma concentrations of insulin, glucose, non-esterified fatty acids (NEFA) and IGF-I. The glucose and insulin concentrations were higher in calcium salts of polyunsaturated fatty acids treatment. The highest concentration of NEFA was observed in the control group. The plasma concentrations of IGF-I were higher for the treatments with lipogenic supplements. Adding calcium salts of polyunsaturated fatty acids diet was able to ease the hormonal and metabolic changes of the transition period features.(AU)

Diferentes fontes energéticas durante o período de transição de vacas primíparas e os seus efeitos sobre metabólitos sanguíneos e hormônios / Different energy sources during the primiparous dairy cow transition period and its effects on blood metabolites and hormones

Objetivou-se com este estudo comparar os efeitos do fornecimento de dietas glicogênicas ou lipogênicas sobre metabolitos sanguíneos e hormônios em vacas primíparas (n=40) durante o período de transição. Os animais foram aleatoriamente distribuídos em quatro tratamentos: controle, sais de cálcio de ácidos graxos poli-insaturados (Megalac-E, 100g pré-parto e 250g pós-parto), soja tostada (400g pré-parto e 800g pós-parto) e propilenoglicol (300ml pré e pós-parto). Os suplementos foram fornecidos individualmente. Foram realizadas coletas de sangue para determinação das concentrações plasmáticas de insulina, glicose, ácidos graxos não esterificados (AGNE) e IGF-I. As concentrações de insulina e de glicose foram maiores nos animais do tratamento com sais de cálcio de ácidos graxos poli-insaturados. A maior concentração de AGNE foi observada no grupo controle. A concentração plasmática de IGF-I foi mais elevada para os animais do tratamento que receberam suplementos lipogênicos. A adição de sais de cálcio de ácidos graxos poli-insaturados a dieta foi capaz de amenizar as mudanças hormonais e metabólicas características do período de transição.(AU)

The aim of this study was to compare the effects of glycogenic supply or lipogenic diets on blood metabolites and hormones in primiparous dairy cows (n=40) during the transition period. The animals were randomly assigned to four treatments: control, calcium salts of polyunsaturated fatty acids (Megalac-E, 100g prepartum and 250g postpartum), roasted soybeans (400g prepartum and 800g postpartum) and propylene glycol (300ml pre- and postpartum). The supplements were provided individually. Blood samples were taken to determine plasma concentrations of insulin, glucose, non-esterified fatty acids (NEFA) and IGF-I. The glucose and insulin concentrations were higher in calcium salts of polyunsaturated fatty acids treatment. The highest concentration of NEFA was observed in the control group. The plasma concentrations of IGF-I were higher for the treatments with lipogenic supplements. Adding calcium salts of polyunsaturated fatty acids diet was able to ease the hormonal and metabolic changes of the transition period features.(AU)

Icterícia em gatos: estudo retrospectivo e prospectivo.

Foram necropsiados 44 felinos domésticos (Felis catus) com icterícia, no período de junho de 2014 a dezembro de 2019. Os gatos eram provenientes da região metropolitana de Belo Horizonte, Minas Gerais (n= 31) e de Teresina, Piaui (n= 13). Desses 44 felinos, 34,1% eram fêmeas, 56,8% eram machos e em 9,1% não havia informações sobre o sexo do animal. As idades variavam de seis meses a 13 anos. Destes, cinco eram adultos, e em 11 gatos a idade não foi informada. A maioria dos gatos examinados eram sem raça definida (35/44). As raças especificadas foram Angorá (2/44), Oriental Short Hair (1/44) e Persa (1/44), e em cinco gatos, a raça não foi informada. Todos os animais tinham icterícia, com intensidade que variavam de leve a acentuada. Dos 44 animais, 39 foram diagnosticados com anemia leve a acentuada. A classificação do tipo de icterícia (pré-hepática, hepática e pós-hepática) foi baseada nos achados macroscópicos e microscópicos. Dos 44 animais, 10 foram classificados com icterícia pré-hepática, 33 com icterícia hepática e sete com icterícia pós-hepática. Contudo, em alguns gatos foram encontrados dois tipos de icterícia, dos quais cinco apresentaram icterícia pré-hepática e icterícia hepática e um caso de icterícia hepática e icterícia pós-hepática. De acordo com os achados macroscópicos e microscópicos, a causa da icterícia pré-hepática foi a anemia hemolítica idiopática. Para a icterícia hepática, a causa mais frequente foi a lipidose hepática (26/44), em seguida peri-hepatite e hepatite compatível com o vírus da peritonite felina, linfoma, degeneração glicogênica, colangiocarcinoma e um diagnóstico sugestivo de leucemia mieloide. Nos animais com icterícia pós-hepática as causas foram colangite devido a infecção por Platynosomum spp., colangioma do ducto hepático comum e colangite crônica.

Forty-four domestic cats (Felis catus) with icterus were necropsied from June 2014 to December 2019. The cats were from the metropolitan region of Belo Horizonte Minas Gerais (n = 31) and Teresina, Piaui (n = 13). Of these 44 cats, 34.1% were females, 56.8% were males and for 9.1% there was no information about the gender. Ages ranged from six months to 13 years. Of these, five cats were adults and, in 11 cats, the age was not informed. Most of the cats examined were mixed breed (35/44). Other breeds were Angora (2/44), Oriental Short Hair (1/44) and Persian (1/44); in five cats the breed was not informed. All animals had icterus, with intensity ranging from mild to severe. Of the 44 animals, 39 had mild to severe anemia. The classification of the type of icterus (pre-hepatic, hepatic and post-hepatic) was based on macroscopic and microscopic findings. Of the 44 animals, 10 were classified as pre-hepatic icterus, 33 with hepatic icterus and seven with post-hepatic icterus. Nevertheless, in some cats, two types of icterus were found, of which five cases were classified with pre-hepatic and hepatic icterus, and one case with hepatic and post-hepatic icterus. According to gross and microscopic findings, the cause of pre-hepatic icterus was idiopathic hemolytic anemia. For hepatic icterus, the most frequent causes were liver lipidosis (26/44), followed by peri-hepatitis and hepatitis compatible with feline peritonitis virus infection, lymphoma, glycogenic degeneration, cholangiocarcinoma and myeloid leukemia. In animals with post hepatic icterus, the causes were colangitis due Platynosomum spp. infection, cholangioma of the common hepatic duct and chronic cholangitis.

FONTES DE ENERGIA ASSOCIADAS A UM HEPATOPROTETOR NA DIETA DE VACAS EM LACTAÇÃO CONFINADAS

Objetivou-se com este estudo avaliar os efeitos de fontes de energia associadas a um hepatoprotetor sobre o desempenho e o metabolismo de vacas em lactação confinadas. Foram realizados dois estudos, os quais utilizaram 16 vacas mestiças Holandês x Gir no terço médio da lactação, com peso corporal médio de 553 ± 85 kg, distribuídas em delineamento experimental quadrado latino 4x4 quádruplo em arranjo fatorial 2x2. Os tratamentos consistiram de dieta com ou sem a inclusão do hepatoprotetor comercial, e variação de milho moído ou polpa cítrica como fontes de energia. No primeiro estudo, o qual avaliou o desempenho e a partição de nutrientes em vacas lactantes observou-se que: o consumo de matéria seca, a produção de leite, o leite corrigido para 4% de gordura foram maiores (P=0,001) nas dietas com milho moído como fonte de energia. O teor de gordura do leite foi maior (P=0,049) nas dietas com a polpa cítrica. Houve redução (P<0,05) no teor de proteína bruta no leite das vacas que receberam o hepatoprotetor na dieta. O hepatoprotetor favoreceu maior (P=0,038) balanço de nitrogênio nas vacas. No segundo estudo, o qual avaliou o status metabólico de vacas em lactação constatou-se que: o milho moído como fonte de energia proporcionou maiores (P<0,05) concentrações séricas de glicose, colesterol-HDL e globulinas. Enquanto, o -hidroxibutirato (BHB), ácidos graxos não esterificados (AGNE), colesterol total, albumina e aspartato aminotransferase (AST) apresentaram as maiores concentrações (P<0,05) nas dietas com a polpa cítrica. Houve interação (P=0,004) entre o tempo e a inclusão do hepatoprotetor na concentração plasmática de colesterol-LDL. No entanto, ambos os estudos não verificaram interação entre as fontes de energia e o hepatoprotetor para as variáveis de desempenho, partição de nutrientes e status metabólico. O milho como fonte de energia na dieta impulsionou a produção de leite e a síntese precursores glicogênicos. Enquanto, a polpa cítrica alterou a status lipídico e a composição do leite por meio do incremento do teor de gordura. O hepatoprotetor afetou o teor de proteína no leite, melhorou o balanço de nitrogênio e contribuiu para incremento pós-prandial das concentrações séricas do colesterol-LDL em vacas lactantes confinadas.

The aim of this study was to evaluate the effects of energy sources associated with a hepatoprotector on the performance and metabolism of confined lactating cows. Two studies were carried out, which used 16 crossbred Holstein x Gir cows in the middle third of lactation, with an average body weight of 553 ± 85 kg, distributed in a quadratic quadruple 4x4 experimental design in a 2x2 factorial arrangement. The treatments consisted of a diet with or without the inclusion of the commercial hepatoprotector, and variation of ground corn or citrus pulp as energy sources. In the first study, which evaluated the performance and nutrient partitioning of lactating cows, it was observed that: dry matter consumption, milk production, 4% fat-corrected milk were higher (P= 0,001) in corn diets ground as a source of energy. The fat content of milk was higher (P= 0,049) in diets with citrus pulp. There was a reduction (P<0,05) in the crude protein content in the milk of cows that received the hepatoprotector in the diet. The hepatoprotector favored a higher (P=0,038) nitrogen balance in cows. In the second study, which evaluated the metabolic status of lactating cows, it was found that: ground corn as an energy source provided higher (P<0,05) serum concentrations of glucose, HDLcholesterol and globulins. Whereas, -hydroxybutyrate (BHB), non-esterified fatty acids (AGNE), total cholesterol, albumin and aspartate aminotransferase (AST) presented the highest concentrations (P<0,05) in diets with citrus pulp. There was an interaction (P= 0,004) between time and the inclusion of the hepatoprotector in the plasma LDLcholesterol concentration. However, both studies did not find an interaction between energy sources and the hepatoprotector for the variables of performance, nutrient partition and metabolic status. Corn as a source of energy in the diet boosted milk production and the synthesis of glycogenic precursors. Meanwhile, the citrus pulp changed the lipid status and the composition of the milk by increasing the fat content. The hepatoprotector affected the protein content in milk, improved the nitrogen balance and contributed to postprandial increase in serum LDL-cholesterol concentrations in confined lactating cows.

UTILIZAÇÃO DE GLICERINA COMO SUPLEMENTO ENERGÉTICO EM OVELHAS MORADA NOVA: EFEITO DA FORMA E TEMPO DE ADMINISTRAÇÃO SOBRE A DINÂMICA FOLICULAR, ESTRESSE OXIDATIVO E RESPOSTA OVARIANA

O glicerol, presente na glicerina adotada na alimentação animal, é considerado um aditivo glicogênico de grande valia que promove alterações metabólicas que elevam as concentrações plasmáticas de glicose, favorecendo as reservas energéticas dos animais. Assim, o objetivo deste trabalho foi avaliar o efeito das estratégias de fornecimento de glicerina em diferentes protocolos de suplementação ultra-curta sobre a dinâmica folicular e a taxa ovulatória de ovelhas da raça Morada Nova. Dezoito ovelhas Morada Nova foram sincronizadas por meio da administração de um análogo da prostaglandina (PGF2) seguindo protocolo intercalado de 7 dias. A dieta foi fornecida método de ração mista total (TMR) e as ovelhas dos grupos-tratamento foram suplementadas com 150 mL de glicerol na forma de solução de glicerina, diariamente por três (Drench3d e TMR3d) ou sete (Drench7d e TMR7d) dias. O monitoramento da dinâmica folicular foi realizado por ultrassonografia e os níveis de glicose plasmática e glutationa peroxidase foram medidos na terceira administração de PGF2. A taxa ovulatória de todos os grupos foi avaliada seis dias após a dose final de prostaglandina por laparoscopia. Observou-se maiores níveis de glicose nos grupos tratamento em relação à dieta controle. Nos grupos TMR3d, Drench7d e TMR7d houve maior proporção (P < 0,001) de folículos grandes ( 3 < 5 mm); com observação de folículos com tamanho superior a 5mm. Nos mesmos grupos pode-se registrar na terceira dose PGF2, um número maior (P < 0,001) de folículos em crescimento (> 3 mm), e um maior tamanho do maior folículo (P < 0,001). Nos grupos onde a glicerina foi adicionada durante 7 dias (Drench7d e TMR7d) a taxa ovulatória apresentou um aumento de 30%, em relação ao grupo controle, sendo observado também uma redução de 38% nos níveis de glutationa peroxidase. Com base em nossos achados, o uso de glicerina na suplementação energética de curta duração para ovelhas Morada Nova foi bem sucedido quando fornecida por sete dias.

Glycerol, present in glycerin adopted in animal feed, is considered a glycogenic additive of great value that promotes metabolic changes that increase plasma glucose concentrations, favoring the energy reserves of animals. Thus, the objective of this work was to evaluate the effect of glycerin supply strategies in different ultra-short supplementation protocols on follicular dynamics and ovulation rate of Morada Nova sheep. Eighteen Morada Nova sheep were synchronized through the administration of a prostaglandin analogue (PGF2) following a 7-day interleaved protocol. The diet was provided with total mixed feeding method (TMR) and the sheep of the treatment groups were supplemented with 150 mL of glycerol in the form of glycerine solution, daily for three (Drench3d and TMR3d) or seven (Drench7d and TMR7d) days. Follicular dynamics monitoring was performed by ultrasonography and plasma glucose and glutathione peroxidase levels were measured in the third administration of PGF2. The ovulatory rate of all groups was evaluated six days after the final dose of prostaglandin by laparoscopy. Higher glucose levels were observed in the treatment groups compared to the control diet. In groups TMR3d, Drench7d and TMR7d there was a higher proportion (P < 0.001) of large follicles ( 3 < 5 mm); with observation of follicles with size greater than 5 mm. In the same groups a higher number (P < 0.001) of growing follicles (> 3 mm), and a larger size of the larger follicle (P < 0.001) can be registered in the third dose PGF2. In the groups where glycerin was added during 7 days (Drench7d and TMR7d) the ovulation rate showed an increase of 30% in relation to the control group, being also observed a reduction of 38% in the levels of glutathione peroxidase. Based on our findings, the use of glycerin in short term energy supplementation for Morada Nova sheep was successful when supplied for seven days.

PROTEIN SUPPLEMENTATION IN LATE GESTATION FOR BEEF COWS AFFECTS MATERNAL SKELETAL MUSCLE GENE EXPRESSION AND PLASMA CIRCULATING AMINO ACIDS

No final da gestação de vacas de corte, as exigências de nutrientes aumentam para atender à taxa de crescimento do concepto e estas matrizes podem alterar o metabolismo no tecido esquelético, hepático e modificar os níveis plasmáticos circulantes de aminoácidos (AA) em função da suplementação de proteína bruta (PB). Quarenta e três vacas Nelore gestantes de fetos machos, [idade média = 6 anos; peso médio = 500 kg] em 193 ± 30 (SD) dias (d) de gestação foram divididas em oito grupos (unidades experimentais, com 4 a 5 vacas cada). Os tratamentos foram 1) Controle (CON, n = 4), dieta baseada em pastagem sem suplementação de proteína bruta (PB) e 2) Suplemento (SUP, n = 4), dieta baseada em pastagem acrescida da suplementação de 2 g / kg de peso corporal de suplemento proteico. Foram coletadas através de biópsia, amostras de fígado e músculo para a análise de expressão relativa de RNAm e amostras de sangue para níveis de AA plasmáticos circulantes. Vacas do grupo CON apresentaram tendência (P = 0.057) para maiores níveis de AA circulantes em comparação ao SUP. Níveis de AA glicogênios foram maiores (p = 0.035) no grupo CON em relação ao SUP. Vacas do grupo CON apresentaram maiores concentrações de Histidina (P = 0.015), Metionina (P = 0.007) e Alanina (P = 0.036) em relação ao grupo SUP. Ambos grupos, CON e SUP não apresentaram diferenças significativas gliconeogênese, transporte de ácido graxo e eixo somatotrófico. As vacas CON tenderam a apresentar maiores valores para marcadores relacionados a síntese de tecido muscular esquelético, p7056k (P = 0.060) e GSK3B (P = 0.096). Não foi encontrado diferenças significativas para marcadores relacionados a degradação de tecido muscular esquelético. A suplementação de proteína bruta para vacas de corte no terço final da gestação e mantidas em pastagens altera o perfil de aminoácidos circulantes no plasma e a síntese no tecido muscular esquelético.

In late pregnancy of beef cows, nutrients requirements increase to meet the growth rate of conceptus and dams may alters metabolism in liver and skeletal tissue, and modify the circulating plasma levels of amino acids (AA) in function of crude protein (CP) supplementation. Fourty tree pregnant Nellore cows gestating male fetuses, [average age = 6 years; average weight = 500 kg] at 193 ± 30 (SD) days (d) of gestation were divided into eight groups (experimental units, with 4 to 5 cows each). Treatments were 1) Control (CON, n = 4), pasture-based (PB) diet without crude protein (CP) supplementation and 2) Supplemented (SUP, n = 4), PB diet supplemented with 2 g/kg of body weight of CP supplement. Liver and muscle biopsies for relative mRNA expression, and circulating plasma levels of AA were recorded. The CON-fed cows tended to have greater (P = 0.057) total circulating AA than SUP-fed cows. Circulating glycogenic AA was greater (p = 0.035) in CON than in SUP cows. CON cows was greater for Histidine (P = 0.015), Methionine (P = 0.007) and Alanine (P = 0.036) than SUP cows. CON and SUP-fed shown no significant differences for gluconeogenesis, fatty acid transport and signaling axis. CON cows tended to be greater than SUP cows in mRNA expression of markers related to Skeletal muscle synthesis, p7056k (P = 0.060) and GSK3B (P = 0.096). No significant differences were found for mRNA expression of markers related to Skeletal muscle degradation. Crude protein supplementation for late pregnant beef cows in a pasture-based diet change the profile of plasma circulating AA and synthesis of skeletal muscle tissue.

Increasing ovulation quota: more than a matter of energy

Background: Nutritional supplementation before breeding (Flushing) has become a common practice and is a reliable method to improve lambing and twining rates in sheep. The improvement of the body condition of a ewe is reflected in a higher number of ovulatory follicles and is termed "static effect of nutrition". Shorter periods of nutritional supplementation can also affect follicular development in the absence of changes in the body condition and weight of the animal, which is known as "acute effect of nutrition". Studies of follicular development in small ruminants have shown that 4 to 5 follicular waves occur during the estrous cycle, and that waves emerge every 5 to 7 days. However, the selection phase of the follicular wave occurs within 3 to 4 days, thus the length of flushing could last merely the time needed to push follicles over the selection threshold. Review: Here we examined the evidence produced by our research on the minimum length and appropriate timing of nutrient supplementation needed to enhance ovulation rate and prolificacy in sheep. Ewes have follicles ready to reach ovulatory size at any time of the estrous cycle and, when a follicular phase is induced, most show estrus and ovulate within 60 to 80 h. Hence, ovulatory follicles should commit for ovulation shortly after the decline in progesterone if they are to achieve ovulatory competence. We showed that an ultrashort flushing (USF) given as a single administration of a glycogenic substance at the time of prostaglandin-induced luteolysis (Control =1.6 ± 0.06 vs. USF= 2.08± 0.06) or progestin withdrawal (Control =1.64 ± 0.07 vs. USF= 2.41± 0.09) increased ovulation rate (P < 0.01). This increase was associated with elevated glucose and insulin concentrations for 12 h after USF (P < 0.01). However, the diameter of the three largest follicles did not change between the day of flushing and the day of estrus and did not differ between the control and the USF (P > 0.10). The USF could act either by advancing follicle maturation, or by affecting the feedback loop between the ovaries and gonadotrophin secretion. Therefore, we measured mRNA abundance for LH receptor (LHr), 3ß-hydroxysteroid dehydrogenase (3ß-HSD) and P450 aromatase at 0, 12, 24 and 48 h after the start of luteolysis in ewes treated or not with USF. Aromatase mRNA decreased in large follicles 12 h after USF (P < 0.01), with no changes on mRNA for LHr or 3ß-HSD. Further, we observed that the in vitro rumen fermentation and the in vivo glucose plasma concentrations in response to an isoenergetic (1470.83 kcal) single oral drench of glycerol, propylene glycol or molasses differed. The longer time to begin fermentation of glycerol allows for its absorption and its direct use for glucose production in the liver. Molasses was preferably fermented to butyrate, whereas propylene glycol was preferably fermented to propionic acid thus serving as glycogenic substrate. Glycerol and propylene glycol increased glucose and insulin concentrations in vivo, whereas molasses did not, thus the later may not be suitable for the USF. An increase in ovulation rate and prolificacy was also obtained with treatments that cause nutrient redistribution in the animal such as beta adrenergic receptor agonists and bovine somatotropin. Conclusions: We have developed an ultrashort flushing with glycogenic solutions that when applied at luteolysis will increase ovulation rate in sheep. This hyper-acute effect of nutrition caused a reduction in mRNA for P450 aromatase 12 hours after the glycogenic drench. In addition, from our results we can infer that ovine follicles can develop ovulatory capacity within 48 h after being selected when coinciding with the follicular phase.