RESUMEN
Two hundred and twenty-four pigs (112 boars, 112 gilts) housed in pens of seven pigs per pen were used in a 2 x 2 x 2 factorial design, with the factors of vaccination with a gonadotropin-releasing factor (GnRF) vaccine (Improvac; 0 or 2 mL at 13 and 17 wk of age), porcine somatotropin (pST; 0 or 5 mg/d from 17 wk of age), and gender. Pigs were weighed and feed intake was measured from 17 wk of age until slaughter at 21 wk of age. Body composition was estimated by dual-energy X-ray absorptiometry in two focus pigs per pen at 17 and 21 wk of age. Testes and ovary weights at slaughter were decreased by Improvac treatment (P < 0.001), but were not altered by pST treatment (P > 0.44). Daily gain was lower for gilts than boars (1,128 vs. 1,299 g/d, P < 0.001) and was increased by pST (1,172 vs. 1,255 g/d, P = 0.003) and Improvac (1,150 vs. 1,276 g/d, P < 0.001) treatments. Feed intake (as-fed basis) was lower in gilts than in boars (2,774 vs. 3,033 g/d, P = 0.002), was decreased by pST (3,037 vs. 2,770 g/ d, P = 0.002), and was increased by Improvac treatment (2,702 vs. 3,105 g/d, P < 0.001). As a result of the differences in feed intake and daily gain, feed conversion efficiency (gain:feed) was lower for gilts than for boars (0.403 vs. 0.427 P = 0.025), was improved by pST (0.385 vs. 0.452, P < 0.001), but was unchanged by Improvac treatment (0.423 vs. 0.410, P = 0.22). Carcass weight was lower in gilts than in boars (75.3 vs. 77.0 kg, P = 0.012), was unchanged by pST treatment (75.9 vs. 76.4 kg, P = 0.40), and was increased by Improvac treatment (75.1 vs. 77.2 kg, P = 0.003). Lean tissue deposition rate was lower in gilts than in boars (579 vs. 725 g/d, P < 0.001), was increased by pST (609 vs. 696 g/d, P < 0.001) and by Improvac treatment (623 vs. 682 g/d, P = 0.014). Fat deposition rate tended to be lower in gilts than in boars (214 vs. 247 g/d, P = 0.063), decreased by pST treatment (263 vs. 198 g/d, P < 0.001), and increased by Improvac treatment (197 vs. 264 g/d, P < 0.001). For pigs treated with both pST and Improvac, daily gain and lean tissue deposition rate was greater than for pigs that received either treatment alone, whereas fat deposition rate and feed intake did not differ from untreated control pigs. In conclusion, Improvac increased growth rate through increased lean and fat deposition, but concomitant use of Improvac and pST increased lean gain above either alone, while negating the increase in fat deposition in pigs treated with Improvac.
Asunto(s)
Composición Corporal/efectos de los fármacos , Hormona Liberadora de Gonadotropina/inmunología , Hormona del Crecimiento/administración & dosificación , Inmunización/veterinaria , Porcinos/crecimiento & desarrollo , Absorciometría de Fotón/veterinaria , Tejido Adiposo/crecimiento & desarrollo , Animales , Composición Corporal/fisiología , Sinergismo Farmacológico , Femenino , Masculino , Distribución Aleatoria , Maduración Sexual , Vacunas/administración & dosificación , Aumento de Peso/efectos de los fármacosRESUMEN
Two experiments were conducted to determine apparent ileal digestibility of amino acids (AIDAA) and nitrogen (AIDN) in cottonseed meal (CSM) and soyabean meal (SBM) fed to growing pigs. In the first experiment, twenty-four male pigs (37.3 (SE 2.7) kg) were individually penned and randomized to either CSM or SBM diets. The diets contained 40% of the protein meal (either CSM or SBM) in a wheat starch-sucrose (1:1, w/w) base containing vitamins and minerals, and Cr2O3 as an indigestible marker. Pigs were acclimated to the experimental diets over a 3 d period and on day 4 through to day 14 were offered 1800 g/d of the diet. Diets were offered in three meals/d from day 4 to day 11 and in eight meals/d from day 12 to day 13. After the eighth hourly-meal on day 14, twelve pigs were anaesthetized with halothane while the remaining twelve pigs were CO2-stunned and processed using commercial slaughter procedures. Ileal digesta were collected from a 1500 mm portion of the terminal ileum of each pig and subsequently analysed for amino acids, N, organic matter and Cr. Results indicated that AIDAA of CSM and SBM were lower when digesta were collected following CO2-stunning than when digesta were obtained under halothane anaesthesia. Consistently, AIDN in CSM (0.51 v. 0.56) and SBM (0.55 v. 0.71) were lower (P < 0.05) in CO2-stunned pigs than in halothane-anaesthetized pigs. Furthermore, when digesta collection was conducted under halothane anaesthesia, AIDN of CSM was lower (P < 0.001) than that of SBM. In the second experiment, six male pigs (45 (SE 2.6) kg) were fitted with T-piece cannulas implanted in the terminal ileum, housed individually in metabolism cages, and randomly allocated to either CSM or SBM diets in a single reversal arrangement. Ileal digesta were collected for AIDAA and AIDN determination. Although statistical comparisons could not be made between the two experiments, the AIDAA and AIDN data obtained via cannulated pigs were similar to those values obtained using the halothane-anaesthesia method. Overall, the CO2-stunning method is not recommended for studies of amino acid or nitrogen ileal digestibilities, but may be useful for the study of other dietary constituents.
Asunto(s)
Aminoácidos/metabolismo , Alimentación Animal , Contenido Digestivo/química , Íleon/metabolismo , Nitrógeno/metabolismo , Porcinos/metabolismo , Anestésicos por Inhalación , Animales , Dióxido de Carbono , Aceite de Semillas de Algodón , Disección , Halotano , Masculino , Distribución Aleatoria , Glycine max , Porcinos/crecimiento & desarrolloRESUMEN
Merino ewes were given a prostaglandin synthetase inhibitor, Finadyne (50 mg flunixin meglumine ml-1), on days 14-16 of the oestrous cycle (day of oestrus = day 0), Finadyne on days 14-16 plus PGF2 alpha on days 15-16, or progesterone on days 14-17 plus PGF2 alpha on days 15-16. Blood samples were taken once a day on days 10-14 and three times a day on days 15-16 for progesterone measurement. The concentrations of oxytocin receptors were measured in the endometrial (pooled caruncular and intercaruncular) tissues collected on day 17. Treatment of ewes with Finadyne resulted in the maintenance of high plasma concentrations of progesterone and a small, but nonsignificant, reduction in the concentrations of endometrial oxytocin receptors. Co-administration of PGF2 alpha reversed this effect of Finadyne. Treatment with both progesterone and PGF2 alpha increased the concentrations of progesterone in plasma and significantly reduced the concentrations of endometrial oxytocin receptors compared with those in the control ewes. These data indicate that withdrawal of progesterone from the circulation as a result of spontaneous luteolysis or by a PGF2 alpha-induced luteolysis caused an increase in the concentrations of oxytocin receptors. However, maintenance of plasma progesterone concentrations over the period of normal luteolysis only partially inhibited the concentrations of endometrial oxytocin receptors. There results suggest that the increase in the concentrations of oxytocin receptors at luteolysis in the naturally cycling ewes may be due to the loss of the inhibitory effects of progesterone on uterine oxytocin receptors.
Asunto(s)
Endometrio/metabolismo , Luteólisis/fisiología , Oxitocina/metabolismo , Progesterona/fisiología , Receptores de Vasopresinas/metabolismo , Ovinos/fisiología , Animales , Clonixina/análogos & derivados , Clonixina/farmacología , Inhibidores de la Ciclooxigenasa/farmacología , Dinoprost/farmacología , Femenino , Progesterona/sangre , Progesterona/farmacología , Receptores de Oxitocina , Receptores de Vasopresinas/efectos de los fármacos , Ovinos/sangreRESUMEN
Ovariectomized ewes were treated with progesterone and oestradiol to induce oestrus (day of expected oestrus = day 0) and with progesterone on days 1 to 12. The concentrations of endometrial oxytocin receptors and the 13,14-dihydro-15-keto prostaglandin F2 alpha (PGFM) response induced by oxytocin were measured on days 12, 14, 16 and 18 after the cessation of progesterone treatment on day 12, by a receptor binding assay and direct radioimmunoassay, respectively. During the period of treatment, the concentrations of plasma progesterone were high and remained above 2 ng ml-1 until day 13 when they dropped rapidly to less than 0.5 ng ml-1 by day 14. The concentrations of oxytocin receptors in endometrium of control ewes were high (820.7 +/- 91.7 (SEM) fmol mg-1 protein). Treatment with progesterone significantly (P < 0.01) reduced the concentrations of the receptors on days 12 and 14 (144.1 +/- 65.0 and 200.4 +/- 45.4 fmol mg-1 protein, respectively). The receptor concentrations then increased to relatively high values on day 16 (1021.4 +/- 216.6 fmol mg-1 protein) and remained high until day 18 (677.7 +/- 103.4 fmol mg-1 protein).(ABSTRACT TRUNCATED AT 250 WORDS)