Colostrum yield and litter performance in multiparous sows subjected to farrowing induction

The consumption of colostrum at a low level can compromise the survival and growth of piglets. Therefore, this study aimed to evaluate the effect of farrowing induction on colostrum yield, IgG concentration and the survival and performance of piglets until the weaning. Sows of parity 3 to 7 were assigned into two groups: Control (n = 48), sows with spontaneous farrowing; and induction (n = 48), sows induced to farrow on day 114 of gestation with a PGF₂ analogue. Colostrum and blood samples were collected from the sows, at farrowing and 24 hr later. Blood samples from the piglets were collected at 24 hr after birth. The performance of the piglets was evaluated in a subsample of 28 litters from each group. All piglets were weighed at 7, 14 and 20 days of age. The farrowing length, the number of piglets born alive, stillborn piglets, weight at birth, litter weight at birth and colostrum yield were not significantly affected (p > .05) by farrowing induction. There was no difference between the groups (p > .05) in the percentage of sows with obstetric interventions. Serum IgG concentration, in both sows and piglets, and colostrum IgG concentration were similar between the groups (p > .05). Furthermore, survival rate, piglet weight and litter weight at 7, 14 and 20 days of age were also similar between the groups (p > .05). Therefore, it can be concluded that the farrowing induction performed on day 114 of gestation does not affect the colostrum yield, the IgG concentration in colostrum and serum of piglets, and the litter performance until the weaning.     

Expression of Interleukin (IL)‐1β and IL‐1 Receptors Genes in the Hypothalamus of Anoestrous Ewes after Lipopolysaccharide Treatment

This study was designed to determine the effect of intravenous lipopolysaccharide (LPS) administration on the secretion of interleukin (IL)‐1β and IL‐1 receptors (IL‐1Rs) gene expression in the hypothalamus of anoestrous ewes. Gene expression of IL‐1β and its receptors was assayed by the real‐time polymerase chain reaction. The expression of IL‐1β in the hypothalamus was detected using Western blot. Our results showed that IL‐1β mRNA is transcribed in the ovine hypothalamus. Lipopolysaccharide increased (p ≤ 0.01) the IL‐1β gene expression in the pre‐optic area 2.4‐fold, the anterior hypothalamus (AHA) 3.4‐fold, the medial basal hypothalamus 3.7‐fold and the medial eminence 3.9‐fold. The pro‐form and mature form of IL‐1β protein were found in the hypothalamus after endotoxin injection. In general, the endotoxin also increased more than two times (p ≤ 0.01) the expression of IL‐1 receptor type I (IL‐1R1) and type II (IL‐1R2) genes in the hypothalamus, except the AHA, where the number of IL‐1R2 mRNA was extremely low and not sufficient to the quantitative analysis. These results demonstrate that the peripheral immune/inflammatory challenge increases the IL‐1β expression in the hypothalamus. This endogenous IL‐1β seems to be involved in the modulation of processes which are regulated at the hypothalamic level. One of these processes could be a reproduction.     

Quantifying interactions between compound properties and macropore flow effects on pesticide leaching

The objective of this study was to investigate the interactions between compound properties and macropore flow effects on pesticide leaching. To this end, the dual‐porosity MACRO model was used to simulate leaching of 60 hypothetical compounds with widely differing sorption and degradation characteristics using a pre‐calibrated scenario from Lanna, south‐west Sweden, representing a structured clay soil. The model predicts that, in the worst case, macropore flow increases leaching by more than four orders of magnitude for moderately to strongly sorbed compounds with relatively short half‐lives. However, it was also notable that leaching of some very mobile compounds is actually reduced by macropore flow. For pesticides leaching between 0.0001 and 10% of the applied dose (without macropore flow), the impact of pesticide properties on leaching is markedly reduced. This suggests that reductions in applied dose become a relatively more attractive and effective means of decreasing leaching from structured soils. © 2000 Society of Chemical Industry     

Endotoxin-induced platelet aggregation in heparinised equine whole blood in vitro

Endotoxaemia is a leading cause of death among horses. Thrombocytopenia is a common finding in clinical and experimentally-induced cases of endotoxaemia and can lead to coagulopathies, including disseminated intravascular coagulopathy which is usually fatal. In this study it was shown that endotoxin (3 ng ml⁻¹ to 25 μg ml⁻¹) can aggregate equine platelets in heparinised whole blood in vitro. The endotoxin-induced aggregation (EIA) was shown to be dependent on the presence of leucocytes in the blood and did not occur when detoxified endotoxin was used, suggesting that lipid A was necessary for the response. Aspirin (1 mmol litre⁻¹) had no effect on EIA whereas apyrase (40 μg ml⁻¹) completely abolished it and CV3988 (3 to 30 μmol litre⁻¹) (a competitive antagonist of platelet-activating factor) inhibited the response in a concentration-dependent manner. It is concluded that endotoxin activates equine platelets at low concentrations through an indirect mechanism that involves calcium, leucocytes, adenine nucleotides and platelet-activating factor.     

Effect of high PaCO2 and time on cerebrospinal fluid and intraocular pressure in halothane-anesthetized horses

The effects of different arterial carbon dioxide tensions (PaCO2) on cerebrospinal fluid pressure (CSFP) and intraocular pressure (IOP) were studied in 6 male halothane-anesthetized horses positioned in left lateral recumbency. Steady-state anesthetic conditions (1.06% end-tidal halothane concentration) commenced 60 minutes following anesthetic induction with only halothane in oxygen. During atracurium neuromuscular blockade, horses were ventilated, and respiratory rate and peak inspiratory airway pressure were maintained within narrow limits. The CSFP and IOP were measured at 3 different levels of PaCO2 (approx 40, 60, and 80 mm of Hg). The PaCO2 sequence in each horse was determined from a type of switchback design with the initial PaCO2 (period 1), established 30 minutes after the commencement of steady-state anesthesia, being repeated in the middle (period 3) and again at the end (period 5) of the experiment. Measurements taken from the middle 3 periods (2, 3, and 4) would form a Latin square design replicated twice. The interval between each period was approximately 45 minutes. Data from periods 2, 3, and 4 indicated that CSFP (P less than 0.05) and mean systemic arterial pressure increased significantly (P less than 0.05) with high PaCO2. Mean central venous pressure, heart rate, and IOP did not change significantly during these same conditions. Measurements taken during periods 1, 3, and 5 were compared to assess the time-related responses to anesthesia and showed a significant increase in CSFP, a significant decrease in mean central venous pressure, and a small (but not statistically significant) increase in mean systemic arterial pressure.     

Embryo Production in Superovulated Goats Treated with Insulin Before or After Mating or By Continuous Propylene Glycol Supplementation

Seventeen adult and cyclic Moxoto goats were synchronized using 60 mg MPA vaginal sponge for 11 days and 50 μg cloprostenol, 48 h before sponge removal, and superovulated with 120 mg pFSH i.m. in decreasing doses at 12 h intervals for three consecutive days. In seven goats, 0.2 IU/kg BW/day of long acting insulin was subcutaneously injected at same time as pFSH, and in the other five goats, the same dose of insulin was injected for three consecutive days starting 24 h after mating. Finally, five goats were supplemented with an oral dose of 80 ml/goat/day of propylene glycol continuously during the experiment. The animals were flushed at 7 days after mating and the embryos were classified based on International Embryo Transfer Society criteria. Blood samples were collected every 3 days for insulin assay. Administration of insulin raised the insulin levels of the goats (p < 0.05), whereas in the group treated with propylene glycol, insulin rate was different only between FSH treatment and after mating (p < 0.05). Similar rates of recovery for total (80.05 ± 9.78%) or transferable structures (61.03 ± 15.13%) were obtained. Treatment was not influenced (p > 0.05) by responsiveness to superovulation, which averaged 64%. By contrast, insulin treatments were shown to increase the number of embryos considered excellent with respect to goats supplemented with propylene glycol (p < 0.05). When insulin was given before mating, a strong relationship (r = 0. 90) (p < 0.05) between number of transferable embryo and ovulations was observed in the animals. In conclusion, superovulated goats treated with low doses of exogenous insulin resulted in an enhancement in embryo quality, which was related to changes in circulating insulin concentrations.