RESUMEN
Feeding rumen-protected fat (RPF) can improve energy supply for dairy cows but it affects glucose metabolism. Glucose availability is a precondition for high milk production in dairy cows. Therefore, this study investigated endocrine regulation of glucose homeostasis and hepatic gene expression related to glucose production because of RPF feeding in lactating cows. Eighteen Holstein dairy cows during second lactation were fed either a diet containing RPF (mainly C16:0 and C18:1; FD; n = 9) or a control diet based on corn starch (SD; n = 9) for 4 wk starting at 98 d in milk (DIM). Feed intake and milk yield were measured daily and milk composition once a week. Blood samples were taken weekly for analyses of plasma triglyceride, nonesterified fatty acids (NEFA), ß-hydroxybutyrate, bilirubin, urea, lactate, glucose, insulin, and glucagon. At 124 DIM, an intravenous glucose tolerance test (GTT; 1g/kg of BW(0.75)) was performed after a 12-h period without food. Blood samples were taken before and 7, 14, 21, and 28 min after glucose administration, and plasma concentrations of glucose, insulin, and glucagon were measured. Glucose half-life as well as areas under the concentration curve for glucose, insulin, and glucagon were calculated. After slaughter at d 28 of treatment, liver samples were taken to measure mRNA abundance of pyruvate carboxylase, cytosolic phosphoenolpyruvate carboxykinase, glucose 6-phosphatase (G6Pase), and facilitative glucose transporter 2. Dry matter intake, but not energy and protein intake, was lower in FD than in SD. Milk yield during lactation decreased more in SD than in FD, and milk protein was lower in FD than in SD. Plasma concentrations of triglycerides and NEFA were higher in FD than in SD. Plasma insulin concentrations were lower and the glucagon:insulin ratios were higher in FD than in SD. Fasting glucose concentration before GTT was lower, and fasting glucagon concentrations tended to be higher in FD than in SD. In liver, fat content tended to be higher and G6Pase mRNA abundance was lower in FD than in SD. Lower hepatic G6Pase mRNA abundance was associated with reduced fasting plasma glucose concentrations, but the glucose-induced insulin response was not affected by RPF feeding. Hepatic G6Pase gene expression might be affected by DMI and might be involved in the regulation of glucose homeostasis in dairy cows, resulting in a lower hepatic glucose output after RPF feeding.
Asunto(s)
Bovinos/fisiología , Grasas de la Dieta/metabolismo , Glucosa/metabolismo , Lactancia/fisiología , Hígado/metabolismo , Leche/metabolismo , Rumen/metabolismo , Alimentación Animal , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Bovinos/metabolismo , Dieta/veterinaria , Ingestión de Alimentos/fisiología , Metabolismo Energético , Femenino , Insulina/sangreRESUMEN
Effects of dietary fat supplementation prepartum on liver lipids and metabolism in dairy cows are contradictory. Thus, we examined in 18 German Holstein cows (half-sib; first lactation 305-d milk yield >9,000 kg) whether dietary fat:carbohydrate ratio during the last trimester of gestation affects lipid metabolism and milk yield. The diets were formulated to be isoenergetic and isonitrogenous but differed in rumen-protected fat (FD; 28 and 46.5 g/kg of dry matter during far-off and close-up dry period; mainly C16:0 and C18:1) and starch concentration [carbohydrate diet (CD); 2.3 times as much starch as FD]. Diets were given ad libitum starting 12 wk before expected parturition. After parturition all cows were fed a single lactation diet ad libitum for 14 wk. With the FD treatment, dry matter intake was depressed prepartum, milk yield during first 4 wk of lactation was lower (36.9 vs. 41.0 kg/d), and postpartum energy balance during this period was more negative. During the first 4 wk, cows in the FD group had lower lactose percentage and yield but higher milk fat, whereas milk protein and fat yield as well as energy-corrected milk did not differ. Between wk 5 and 14, milk fat and milk protein percentage was lower in CD than in FD. Milk fat C14:0 was lower and C16:1 was higher in the FD group. For FD cows, plasma triacylglycerol, nonesterified fatty acids, and cholesterol concentrations were higher prepartum, whereas plasma beta-hydroxybutyrate and glucose concentrations were lower. During the first 10 d after parturition, plasma triacylglycerol concentration was higher in FD, and prepartum plasma glucose and cholesterol differences persisted during the first 14 wk of lactation. Irrespective of prepartum nutrient composition, concentrations of plasma leptin and subcutaneous fat leptin mRNA decreased between -10 d to +10 d relative to parturition, and liver lipids and glycogen reached maximum and minimal values, respectively, 10 d after parturition. Acetyl-coenzyme A carboxylase alpha mRNA abundance in subcutaneous fat decreased between -10 d to +1 d relative to parturition by 97%, whereas it was generally much lower in the liver and remained at a low level until wk 14 of lactation. In conclusion, feeding a diet containing rumen-protected fat during late lactation and dry period until calving negatively affected dry matter intake, energy balance, and milk yield during subsequent lactation, did not change acetyl-coenzyme A carboxylase alpha mRNA abundance in subcutaneous fat, and was not beneficial for liver lipid accumulation.
Asunto(s)
Bovinos/fisiología , Dieta/veterinaria , Grasas de la Dieta/metabolismo , Lactancia/fisiología , Rumen/metabolismo , Tejido Adiposo/anatomía & histología , Tejido Adiposo/metabolismo , Animales , Análisis Químico de la Sangre , Peso Corporal/fisiología , Bovinos/metabolismo , Industria Lechera , Ingestión de Alimentos/fisiología , Metabolismo Energético , Femenino , Hígado/metabolismo , Leche/metabolismo , Embarazo , Distribución AleatoriaRESUMEN
The objective of this study was to examine the effects of somatotropin (ST) on porcine reproductive and metabolic statuses during early pregnancy. Four pregnant crossbred gilts received 6 mg of recombinant porcine somatotropin (rpST) daily from days 10 to 27 after artificial insemination while six pregnant gilts served as controls. Blood samples were taken on days 8, 10, 12, 14, 18, 22, and 27 prior to rpST injections (8:00 h) and subsequently at 9:00, 10:00, 12:00, 14:00, 16:00, 18:00, and 20:00 h. On all remaining days of treatment, samples were taken once daily before injections (8:00 h). The samples were assayed for the metabolic hormones: ST, insulin-like growth factor I (IGF-I), insulin, thyroxine (T(4)), triiodothyronine (T(3)), and cortisol; for metabolites: free fatty acids (FFA) and glucose; and for the reproductive hormones: luteinizing hormone (LH), progesterone, estradiol-17beta, estrone sulfate, and prostaglandin F(2alpha). Delivery of rpST daily induced a 20- to 40-fold increase in plasma ST concentrations. Moreover, repeated administration of rpST resulted in a continuous increase in plasma IGF-I concentration (P < 0.001), from 191.0 +/- 22.3-340.0 +/- 15.3 ng/mL 24 h after initial injection to 591.3 +/- 46.8 ng/mL after final injections. Mean serum insulin tended to be greater in rpST-treated gilts. Blood concentrations of T(4) were reduced (P < 0.05) from day 14 of gestation in treated gilts while T(3) concentrations remained unchanged. Concentrations of both glucose and FFA were greater (P < 0.01) and cortisol concentrations were unchanged in treated gilts. Changes in reproductive steroid hormones were minimally affected. Circulating progesterone (P = 0.078), and estradiol-17beta (P = 0.087) concentrations tended to be lower in treated animals. These data show that treatment of pregnant gilts with rpST during early gestation mainly impacts metabolic rather than reproductive status.
Asunto(s)
Dinoprost/análogos & derivados , Estrona/análogos & derivados , Hormona del Crecimiento/farmacología , Preñez/sangre , Porcinos/fisiología , Glándulas Suprarrenales/metabolismo , Animales , Dinoprost/sangre , Estradiol/sangre , Estrona/sangre , Trompas Uterinas/metabolismo , Ácidos Grasos no Esterificados/sangre , Ácidos Grasos no Esterificados/metabolismo , Femenino , Glucosa/metabolismo , Hormona del Crecimiento/sangre , Hidrocortisona/sangre , Insulina/sangre , Factor I del Crecimiento Similar a la Insulina/metabolismo , Hormona Luteinizante/sangre , Masculino , Embarazo , Preñez/metabolismo , Progesterona/sangre , Receptores de Estrógenos/metabolismo , Receptores de Progesterona/metabolismo , Porcinos/metabolismo , Tiroxina/sangre , Triyodotironina/sangre , Útero/metabolismoRESUMEN
The objective of this study was to determine the effects of maternal treatment with porcine somatotropin (pST) during early gestation on embryonic survival, fetal development, and internal environment for fetal growth. Sixty-two crossbred gilts received daily injections of either 3 mL of a placebo (control, n = 31) or 6 mg of pST (n = 31) from d 10 to 27 of gestation. Representative gilts were slaughtered on d 28, 37, and 62 of gestation. The remaining gilts were allowed to farrow. It was found that embryonic survival was not influenced by pST treatment (P > 0.10). However, pST affected the growth and composition of the maternal (endometrium) and fetal (chorion) parts of the placenta. Thus, endometrial RNA concentration tended to be increased by pST at d 37 (P = 0.15), and it was increased at d 62 (P < 0.05) of gestation, which is indicative of increased capacity for protein synthesis. At birth, placental chorion weight (P < 0.10) and contents of DM and protein (P < 0.05) were increased due to pST treatment, but no effects were detectable up to d 62 of gestation. Maternal pST treatment was effective at increasing nutrient supply to the embryo as suggested from elevated glucose concentrations in amniotic and allantoic fluids (P < 0.05) at d 28 of gestation. With regard to prenatal growth, embryonic DNA concentration was slightly elevated at d 28 (P < 0.10), but pST did not induce any changes in average embryonic, fetal, or neonatal weights. However, within litters, the birth weights of piglets in the 25% lowest weight group (LW) were increased by pST treatment vs control LW pigs (1,241+/-55 vs 1,099+/-59 g, P < 0.10). Thirty-eight neonates from 15 litters divided among the three weight groups were examined for body composition. The weight of the intestinal tract was increased above average after maternal pST treatment (P < 0.01). Additionally, the amounts of tissues such as bone (P = 0.12) and s.c. fat (P = 0.06), and of protein, fat (P = 0.10), and ash (P < 0.05) were increased, whereas the relative body composition remained unchanged by pST (P > 0.10). On average, muscle protein concentration was elevated due to pST (P < 0.01), and, in LW piglets, plasma IGF-I concentration was increased (P < 0.10). The results suggest that maternal somatotropin is a critical factor in early pregnancy capable of influencing placental nutrient transfer and placental growth. It thereby selectively improves the growth conditions for the smaller littermates.
Asunto(s)
Composición Corporal/efectos de los fármacos , Desarrollo Embrionario y Fetal/efectos de los fármacos , Hormona del Crecimiento/farmacología , Preñez/efectos de los fármacos , Porcinos/fisiología , Alantoides/química , Líquido Amniótico/química , Animales , Constitución Corporal , ADN/química , Femenino , Factor I del Crecimiento Similar a la Insulina/metabolismo , Leptina/metabolismo , Masculino , Embarazo , Efectos Tardíos de la Exposición PrenatalRESUMEN
12-Methyltridecanal (MT) smelling tallowy, beef-like was formed from plasmalogens when beef was boiled. To clarify the origin of MT, its concentration was determined by a stable isotope dilution assay in bacteria and protozoa isolated from the rumen of bovine animals as well as in the plasma, erythrocytes, and other physiological samples. The highest amounts of MT were found in bacteria followed by protozoa. The MT content of the erythrocytes was small. The results support the hypothesis that microorganisms are the main source of MT of which a small amount is resorbed by the animal and transported to the muscular tissue where MT is incorporated into plasmalogens.
Asunto(s)
Aldehídos/análisis , Bacterias/aislamiento & purificación , Eucariontes/aislamiento & purificación , Rumen/química , Abomaso , Aldehídos/sangre , Alimentación Animal , Animales , Bacterias/química , Bovinos , Eritrocitos/química , Eucariontes/química , Cromatografía de Gases y Espectrometría de Masas/métodos , Contenido Digestivo/química , Contenido Digestivo/microbiología , Contenido Digestivo/parasitología , Intestino Delgado , Masculino , Rumen/microbiología , Rumen/parasitologíaRESUMEN
The effect of dietary n-3 fatty acids on the fatty acid composition and lipid peroxidation of different tissues in pigs were studied. 20 castrated male pigs were included in this investigation, one half was fed daily a diet containing 1.3 g n-3 fatty acids/kg diet (control) and 10 pigs were fed a diet containing 14 g n-3 fatty acids/kg diet (n-3 diet) at the growing-finishing period. The intake of dietary n-3 fatty acids increased the concentration of these fatty acids in backfat, and the neutral and polar fractions of skeletal muscle and heart homogenates. The polar fraction showed an increased relative concentration of n-3 fatty acids in comparison to control, while the n-6 fatty acid content was reduced. In heart homogenates there was an enlargement of n-3 fatty acids both in polar lipids and in neutral lipids whilst n-6 fatty acids were decreased. Feeding n-3 fatty acid enriched diet had no influence on meat quality parameters drip loss, meat colour or pH value. The lipid peroxidation (measured as malondialdehyde equivalents) was in the order liver > heart > skeletal muscle with higher values in the n-3 group. However, by stimulation of oxidation by Fe2+/ascorbate for 3 hours the order of oxidative products in the n-3 group was muscle > liver > heart, whereas in the control group the order was liver > heart = muscle. Summarized, feeding a highly n-3 fatty acid enriched diet caused an incorporation of these fatty acids and increased the susceptibility to peroxidation in all investigated tissues.
Asunto(s)
Tejido Adiposo/metabolismo , Ácidos Grasos Omega-3/metabolismo , Ácidos Grasos Omega-3/farmacología , Metabolismo de los Lípidos , Carne , Músculo Esquelético/metabolismo , Tejido Adiposo/química , Alimentación Animal , Animales , Aditivos Alimentarios , Peroxidación de Lípido , Lípidos/análisis , Masculino , Carne/análisis , Miocardio/metabolismo , Orquiectomía , PorcinosRESUMEN
A study was designed to determine the effects of triptorelin (Decapeptyl C.R.), a GnRH-agonist in a depot formulation, on androst-16-en-3-one (androstenone), LH, oestradiol and testosterone and on carcass composition and muscle structure in boars. Treatment with this highly potent GnRH analog ensured peptide release for 4 weeks when given to 18 animals at 135 days of age (group 1). Control animals (n = 20, group 2) received a saline injection. Blood samples (n = 10) were collected by venipuncture from each boar from 7 days before hormone treatment to 28 days after treatment. During the treatment period, three samples of back fat were taken by biopsy to determine the levels of androstenone and skatole. Testis size was determined at slaughter at 165 days of age. The treatment of boars with triptorelin increased concentrations of LH, oestradiol-17 beta, and testosterone for one day, followed by a decrease to base-line concentrations. The result of sensorial testing for boar taint detection at slaughter showed a slight reduction in this trait (0.76 vs. 0.99). The concentration of androstenone in the body fat of all treated animals was lower than the generally accepted limit of 0.5 microgram/g for the absence of boar taint, compared with the concentrations from 20 control animals among which 13 showed levels higher than this limit. The hormonal treatment significantly reduced the weight and size of the tests. There was no effect on skatole levels in backfat (0.141 vs. 0.150 microgram/g). The GnRH-agonist did not influence the carcass composition of treated boars. The muscle meat percentage was not significantly altered in the experimental group (51.39 vs. 50.50%). Overall, these results indicate that the use of this form of GnRH-agonist in a depot formulation offers a new possibility for reducing concentrations of androstenone which is mainly responsible for undesirable boar taint.
Asunto(s)
Tejido Adiposo/química , Composición Corporal/efectos de los fármacos , Glándulas Endocrinas/efectos de los fármacos , Músculo Esquelético/efectos de los fármacos , Porcinos , Pamoato de Triptorelina/farmacología , Secuencia de Aminoácidos , Androstenodiona/análisis , Animales , Glándulas Endocrinas/fisiología , Hormonas Esteroides Gonadales/sangre , Masculino , Músculo Esquelético/anatomía & histología , Sensación , Homología de Secuencia , Escatol/análisis , Testículo/efectos de los fármacos , Pamoato de Triptorelina/químicaRESUMEN
From theoretical considerations animals with a higher protein-fat ratio in the body should have a higher maintenance energy requirement (MEm). The literature on this problem shows a non-uniform picture with deviating results. From the results of a series of experiments it is possible to compare the heat production (HP) of male and female animals of the Vietnamese Sway-back breed pigs which vary quite widely in their body composition. The protein-fat ratio was 1.2 for the male and 0.2 for the female animals. In the experiments 4 male and 4 female animals in the live weight range of 20-33 kg and 33-42 kg, respectively, were involved. The HP measurements were carried out in climatized respiration chambers on two levels of energy intake at ambient temperatures of 6 degrees C, 12 degrees C, 18 degrees C, 24 degrees C, 30 degrees C, and 35 degrees C. The dependence of HP on the ambient temperature has been described by a cubic regression function. Thermoneutral temperatures are lower in the female animals caused by the better insulation effect of the backfat. The difference in HP which was expected by the large difference in body composition, was not found. The absolute protein mass determined the correlation to HP. Certainly the difference increased after lowering the ambient temperature. The influence of different factors on HP is discussed.
Asunto(s)
Composición Corporal , Regulación de la Temperatura Corporal , Ingestión de Energía , Metabolismo Energético , Porcinos/fisiología , Temperatura , Animales , Calorimetría Indirecta , Femenino , Masculino , Caracteres SexualesRESUMEN
Seventy eight growing-finishing pigs (male castrates and females) of the cross-breed Pietrain x (Large White x German Landrace) were used to investigate the effects of pST treatment on the chemical composition of the body, the growth of adipocytes, and the fatty acid profile of the backfat. Intramuscular injections (1 or 3 mg pST) were administered daily from an average weight of 65 kg up to slaughter. After pST treatment significant changes in all studied characteristics were observed in barrows, whereas the females exhibited very small responses. The pST caused an increase of water and protein contents and a simultaneous decrease of lipid content especially in body parts rich in fat. Furthermore, the proportion of unsaturated fatty acids increased and the fat cell diameter decreased in the backfat.
Asunto(s)
Tejido Adiposo/efectos de los fármacos , Composición Corporal/efectos de los fármacos , Hormona del Crecimiento/farmacología , Porcinos/crecimiento & desarrollo , Adipocitos/citología , Adipocitos/efectos de los fármacos , Tejido Adiposo/química , Animales , Agua Corporal , Ácidos Grasos/análisis , Hormona del Crecimiento/administración & dosificación , Inyecciones Intramusculares , Proteínas/análisisRESUMEN
The effects of long-term application of recombinant porcine somatotropin (pST) to Landrace pigs on the development of backfat thickness, fat cells and fatty acid composition were investigated from about the 116th to the 186th day of life. Biopsy samples from the backfat of 56 castrates were taken at the beginning of treatment and after 5 and 10 weeks. The daily injection of 2 or 4 mg of pST induced a considerable decrease in backfat growth compared to untreated controls. This was attributed to a decreased size (about 18-20%) and number (about 13-25%) of fat cells. The higher dose of 4 mg pST/day induced a greater restriction of fat growth. This was obviously based on differences in fat cell number. Furthermore, pST treatment delayed the normal decrease of unsaturated fatty acids (C 18:2; C 18:3) during the period of growth examined. Therefore, the percentages of unsaturated fatty acids increased, indicating changes in fat cell metabolism of pST treated pigs.
RESUMEN
Gas chromatography was used to study both the relative composition and level of nonesterified fatty acids in the blood of pigs, following target-oriented deflection of two hormonal systems, hypothalamus-pituitary gland-thyroid and hypothalamus-pituitary gland-adrenal cortex. The findings originally expected were not made. Percentual C-18 was increased, following long-time application of tri-iodothyronine/thyroxine, while c-12 was percentually lowered, as compared to the perchlorate group. Deflection of the hypothalamus-pituitary gland-adrenocortical system caused slight alteration in both the composition and overall concentration of blood-borne non-esterified fatty acids.