Development In Swine Research Articles

Effects of exogenous progesterone and estrone on conceptus development in swine.

Administration of progesterone (P4, .55 mg/kg) and estrone (E1, .275 micrograms/kg) during discrete periods in early gestation was found to have beneficial effects on conceptus development in gilts. Three trials were conducted, with each trial examining two hormone treatment groups and one control group. In all trials, P4-E1 supplementation for either one or both of the time periods examined resulted in larger (P less than .05) placentas at d 50 of gestation. Administration of exogenous P4-E1 from either d 20 to 30 (trial 1) or d 25 to 30 (trial 3) of gestation resulted in the greatest augmentation in placental development. In all three trials, exogenous P4-E1 elicited beneficial effects on areolae formation and development. In all nine groups examined (both P4-E1-treated and controls), a positive uterine artery minus uterine vein difference in progesterone concentration was found. This suggests that the conceptus is metabolizing progesterone to metabolites that may have a local effect within the pregnant uterus. It is suggested that augmentation of placental growth, as demonstrated in this study, may reduce secondary fetal death losses in latter gestation (i.e., post-d 70) due to placental insufficiency.

Adrenocorticotropin administration during early gestation on conceptus development in swine

The purpose of this study was to examine the effect of exogenous adrenocorticotropin (ACTH), administered to gilts during early stages of gestation, upon fetal survival and various maternal and conceptus parameters. Forty-eight gilts of approximately 6–7 months of age were bred by means of artificial insemination after detection of the second estrus and randomly allotted to one of 12 treatment-period groups. Treatment consisted of a daily intramuscular injection of 0, 40 or 80 U.S.P. units of a long acting ACTH preparation for a period of five days. The injection periods were 1–5, 6–10, 11–15 or 16–20 days of gestation with day one corresponding to 48 hours post-estrus detection. All gilts were slaughtered at approximately 37 days of gestation. Forty-two of the 48 inseminated gilts conceived. Conception rate was not different (P>.10) among the 12 treatment-period combinations. Percent fetal survival was greater (P<.09) in gilts receiving 80 U.S.P. units of ACTH (82 ± 4.3%; X ± SEM ) than in gilts receiving 40 U.S.P. units of ACTH (68.8 ± 4.5%). The percent fetal survival in the control group (71.7 ± 3.9%) was not different (P>.10) from either of the two ACTH treatment groups. A significant (P<.05) treatment by period interaction for percent fetal survival was observed. The lowest percent fetal survival (48.0 ± 9.0%) was observed in gilts receiving 40 U.S.P. units of ACTH on day 11–15 of gestation. No significant (P>.10) differences were detected among the 12 treatment-period combinations for any of the maternal or conceptus parameters measured.

Effect of weaning age and feeding method on digestive enzyme development in swine from birth to ten weeks.

Effect of weaning age and feeding method on digestive enzyme development in swine from birth to ten weeks.

Husbandry components in prenatal and perinatal develooment in swine.

The biological data support the conclusion that healthy pigs undersized at birth are equal to their littermates in production capacities. Dedication and consistent perserverance are required at farrowing and during the early post-natal period. Utilization of knowledge of the role of genetics, health status, nutrition and non-nutritive substances and husbandry requirements during both gestation and post-natally are required for maximum success. As long as 35 to 45% of the ovulated eggs fail to be represented by live pigs at birth and 20 to 30% of the live pigs at birth die before weaning, husbandry techniques that improve perinatal development and survival will continue to offer a means by which production can be improved and profits increased.

Reproductive Performance and Progeny Development in Swine as Influenced by Protein Restriction during Various Portions of Gestation

Reproductive Performance and Progeny Development in Swine as Influenced by Protein Restriction during Various Portions of Gestation

Effect of Excess Levels of Dietary Crude Protein on Carcass Development in Swine

Effect of Excess Levels of Dietary Crude Protein on Carcass Development in Swine

Reproductive Performance and Progeny Development in Swine as Influenced by Feed Intake During Pregnancy

First-litter gilts (nearly equal numbers of purebred Hampshires, purebred Yorkshires and crossbreds) were used to study effects of gestation-diet intake on reproductive performance and progeny development. From breeding to farrowing, gilts were fed 0.9, 1.4, 1.9, 2.4 or 3.0 kg/day of a diet which was designed to be adequate to superadequate in all nutrients when fed at 1.9 kg. All gilts received this diet ad libitum during a 3-week lactation period. Farrowing percentage (number farrowing as a percentage of those mated) was less for gilts fed 0.9 kg/day than for those fed more, and was less for purebreds than for crossbreds. Gestation-diet intake did not affect the number of pigs farrowed (total or live) or weaned, but crossbreds farrowed and weaned more pigs than purebreds. Birth weight and weaning weight of offspring increased as gestation-diet intake increased; birth weight plateauing at 1.9 kg and weaning weight plateauing at 2.4 kg. As gestation-diet intake increased, weight gain of gilts increased quadratically during gestation but decreased linearly during lactation. Birth weight per pig decreased 43 g for each additional pig in the litter.

The Relationship of the Dam's Feeding Regimen, Breed, and Individuality to Fetal Development in Swine

The Relationship of the Dam's Feeding Regimen, Breed, and Individuality to Fetal Development in Swine

The Effect of Feeding Sodium Fluoride and Rock Phosphate on Bone Development in Swine

The feeding of either 2 parts rock phosphate (containing approximately 3.5 per cent fluorine) or 100 grams sodium fluoride in 100 pounds of a basal ration to pigs resulted in decreased gains, increased feed requirements, and a marked decrease in the breaking strength of the femurs over lots receiving the same basal ration supplemented with either limestone, steamed bone meal, or smaller amounts of sodium fluoride or rock phosphate. It was observed that the fluorine content of the femurs was directly proportional to the amount present in the feed.