ABSTRACT The objective of this study was to determine the impact of metabolic changes occurring in induced subclinical gestation toxaemia in ewes on metabolic parameters and vigour in the first 72 h of their lambs’ life. Fifty-one adult Corriedale ewes of known gestation date and fed on a natural pasture were randomly divided into four groups at day 145 of gestation. Group A (ewes with single pregnancies) and group C (ewes with twin pregnancies) were fed on a natural pasture throughout the trial; group B (ewes with single pregnancies) and group D (ewes with twin pregnancies) were subjected to 75% feed restriction for three days until they reached glycaemia and β-hydroxybutyrate (BHB) values indicative of subclinical gestational toxaemia. The birth-to-first station and birth-to-first suckling times of the born lambs were studied. Within the first hour after parturition and at 24, 48, and 72 h, glycaemia and BHB concentrations were determined in the blood of lambs, and body temperature and body weight were assessed at the same time. Relative weight gain at 72 h of age was calculated for all lambs. The BHB concentration determined at all times studied showed no difference among the groups. Subclinical gestation toxaemia induced in ewes subjected to feed restriction causes a decrease in the glycaemia of their lambs in the first hour of life; however, it does not cause an increase in ketone bodies. The metabolic changes induced in the mothers do not have negative effects on the vigour of the lambs at birth, as the weight, temperature, and the time it took for lambs to stand and suckle are not affected. However, they have a negative effect on relative weight gain in the critical period of the first 72 h of life.

ABSTRACT The objective of this work was to determine the repercussion of the metabolic changes that occur in induced subclinical pregnancy toxemia in single- or twin-bearing ewes on the duration of gestation, type and length of lambing, and placental expulsion time. Fifty-one adult Corriedale ewes with a known gestation date and fed in the wild were randomly divided at day 145 of gestation into four groups. Group A included single-bearing ewes, and C twin-bearing ewes, all of which were fed ad libitum . Group B was composed of single-bearing ewes, and D of twin-bearing ewes, all subjected to a 75% feed restriction until glycemic values were compatible with subclinical pregnancy toxemia. Metabolic parameters were determined in all ewes from day 145 of gestation to 72 h postpartum. Likewise, the duration of gestation, type of lambing (eutocic/dystocic), labor length, and placental expulsion time were recorded. Glycemia and β-hydroxybutyrate values compatible with subclinical pregnancy toxemia were achieved after 48 h of feed restriction, being 30.67±2.37 mg/dL and 1.87±0.12 mmol/L in single-bearing ewes and 28.40±3.39 mg/dL and 2.21±0.42 mmol/L in twin-bearing ewes, respectively. It is concluded that subclinical pregnancy toxemia induced by feed restriction at the end of gestation, frequent situation that occurs in flock management, produces mild metabolic changes, which return to normal values after the delivery. These metabolic changes registered before lambing do not modify the gestation length, do not increase the percentage of dystocical deliveries, nor influence labor length or placental expulsion time.

Abstract Reticular groove closure in ruminants is a primary mechanism, almost exclusive of lactating animals, which makes the passage of food from the orifice of cardia to the abomasum possible, thus avoiding unwanted fermentations in rumen and reticulum. In this review It is described some anatomical and physiological aspects of the reticular groove, given its embryonic and postnatal development, its topographic location, structure, innervation, blood circulation and histology. Also describing the techniques used to study its functioning, both direct and indirect methods. Finally there is a concentrate on handling techniques to manipulate closing reflex of reticular groove and its veterinary applications, in both the stimulation and inhibition, since the possibility to control this reflex is of great interest in the oral administration of various drugs, the treatment of certain diseases, as well as a better utilization of some types of food.

Resumen El cierre del surco reticular en los rumiantes es un mecanismo primario, casi exclusivo de los animales lactantes, que hace posible el paso de los alimentos desde el orificio del cardias al abomaso, evitando las fermentaciones no deseadas en el rumen y el retículo. En esta revisión se describen algunos aspectos anatómicos y fisiológicos del surco reticular, teniendo en cuenta su desarrollo embrionario y postnatal, su localización topográfica, se estructura, su inervación, su circulación sanguínea y su histología. También se describen los métodos directos e indirectos utilizados para el estudio de su funcionamiento. Finalmente, la revisión se concentra en el manejo de las técnicas para manipular el reflejo de cierre del surco reticular y sus aplicaciones veterinarias tanto en la estimulación como en la inhibición, dado que la posibilidad de controlar este reflejo es de gran interés para la administración oral de diversos medicamentos en el tratamiento de ciertas enfermedades, así como para un mejor aprovechamiento de algunos tipos de alimentos.

ABSTRACT The objective of this research was to evaluate a possible corrective measure against negative metabolic states, as occurs in the advanced stage of gestation in ewes, and that sometimes produces a disease called pregnancy toxaemia. In the present research, we found that the joint administration of i.v. lysine-vasopressin (0.08 IU/kg body weight, BW) and an oral glucose solution (50 g) produces an increase in blood glucose, which persists for some time (up to 6 h); therefore, it could be used in the treatment of pregnancy toxaemia. This therapy is based on the fact that lysine-vasopressin induces gastric groove closure in adult ruminants, enabling orally administered glucose to reach the abomasum directly, from where it rapidly passes into the intestine and is immediately absorbed. We can say that the tested treatment causes a significant increase in blood glucose in ewes affected by toxaemia caused by fasting, which, although less marked than conventional therapy with intravenous drip glucose, remains longer, regularizing other parameters indicative of energy metabolism in fasting ewes.

In this work a comprehensive review of ewe pregnancy toxemia is presented. Different thematic sections were considered, for a better understanding of the predisposing factors involved, their pathophysiology, clinical signs, post mortem findings, and the diagnosis. Finally, an analysis of current therapy of the disease is presented.

En este trabajo se presenta una exhaustiva revisión de la toxemia de la gestación en la oveja. La misma ha sido dividida en diferentes secciones para lograr una mejor comprensión de los factores que predisponen a esta enfermedad, su patogenia, signos clínicos, los hallazgos postmortem y el diagnóstico. Por último se presenta un análisis de los distintos tratamientos que se utilizan en esta enfermedad.