Jørgen Svendsen

Intestinal Transmission of Macromolecules (BSA and FITC-Dextran) in the Neonatal Pig: Enhancing Effect of Colostrum, Proteins and Proteinase Inhibitors

The effects of colostrum and constituents/factors in colostrum which may influence intestinal macromolecular transmission in the newborn preclosure pig were investigated. Unsuckled piglets were given, by use of a stomach tube, bovine serum albumin (BSA) and fluorescein-isothiocyanate (FITC)-labelled dextran 70,000 (FITC-D) as markers together with colostrum or the factors under study. The serum levels of BSA and FITC-D 4 h after feeding were then determined as a measure of the transfer. It was found that the two colostrums tested, bovine and especially porcine, markedly enhanced the transmission of both BSA and FITC-D. Furthermore, increasing amounts of the model proteins, BSA and bovine IgG (50-200 mg/ml), significantly increased the transfer of FITC-D, whereas unlabelled dextran 70,000 given in similar amounts did not. Proteinase inhibitors obtained from sow colostrum or soy bean also enhanced the transmission of both BSA and FITC-D while the inactive inhibitors, given as trypsin-inhibitor complexes, had no effect. On the other hand, addition of a proteinase, porcine trypsin, significantly decreased the transmission of FITC-D. These findings indicate that the intestinal transmission of macromolecules in the preclosure piglet is governed by the amount of protein available in the intestine. Therefore, feeding colostrum with a high protein content and proteinase inhibitors is likely to favour efficient intestinal transmission, although other colostrum factors may also be of importance.

Development of exocrine pancreas function in chronically cannulated pigs during 1-13 weeks of postnatal life

The development of exocrine pancreas function was studied in Swedish Landrace pigs surgically fitted with a chronic pancreatic duct catheter and a duodenal re-entrant cannula. The juice secretion and output of total protein and trypsin activity were followed before (basal secretion) and after feeding (postprandial secretion) during the first 1–13 weeks of life. The results showed that throughout the suckling period, up to 4–5 weeks of age, the basal pancreas function remained low and the secretory response to feeding, i.e., nursing sow milk, was also low. After weaning, the pancreatic juice secretion as well as the output of protein and trypsin activity markedly increased with respect to both basal and postprandial levels. Furthermore, the enzyme composition of the pancreatic juice changed qualitatively during this period. During the first 2 weeks of life, the intravenous administration of cholecystokinin (CCK) and secretin did not stimulate exocrine function, but a significant effect was achieved from 3–4 weeks of age. These results showed that there was both an increase in exocrine pancreas function and a qualitative change in the hydrolytic enzyme pattern during porcine postnatal ontogeny, apparently correlated with the changes in diet around weaning. An increase in the response of the pancreas to hormonal stimulation was also observed during the suckling period.

Levels of immunoreactive insulin, neurotensin, and bombesin in porcine colostrum and milk.

High concentrations of insulin (411 ± 214 μU/ml), neurotensin-like (265 ± 72 pg/ml), and bombesin-like immunoreactivities (1995 ± 288 pg/ml) were detected in porcine colostrum using radioimmunoassay, as compared to the levels found in sow blood serum at farrowing (5 μU/ml, <12 pg/ml, and 17 pg/ml, respectively). After 72 h of lactation, the levels of insulin and neurotensin-like immunoreactivities had decreased to 28 ± 17 μU/ml and 89 ± 23 pg/ml, respectively, while the bombesin-like activity remained constant. Characterization with reversed-phase high performance liquid chromatography showed that the insulin immunoreactivity eluted at the same position as the insulin standard, while the elution patterns of the neurotensin-like and bombesin-like immunoreactivities (eluted in three separate peaks) did not correspond to that of their respective standards. The biological function of the peptide hormones in colostrum/milk may be as triggers of the developmental changes taking place in the nursing neonate, especially in the gastrointestinal tract.

Induction of Exocrine Pancreas Maturation at Weaning in Young Developing Pigs

The influence of weaning, at either 4 or 6 weeks of age, on the maturation of the exocrine pancreas was studied in naturally reared Swedish Landrace pigs that had no access to solid food. The pigs were surgically fitted with chronic catheters at 3 weeks of age, permitting periodic sampling of pancreatic juice and blood in conscious animals ≤4 weeks after weaning. During the suckling period, pancreatic fluid and enzyme secretion remained low, both before (preprandial) and after (postprandial) milk ingestion. After weaning at 4 or 6 weeks of age, juice secretion, output of total protein, and levels of different hydrolases (amylase, trypsin, lipase, and carboxylester lipase) and the cofactor colipase all increased markedly postprandially. Moreover, after weaning, the plasma insulin level increased postprandially. This did not happen before weaning, although blood glucose levels always rose after feeding. The data showed a relationship between the time of weaning and the induction of exocrine pancreatic maturation in pigs. This finding implies that postnatal development of pancreatic function is triggered by the dietary change from sow milk to dry solid food. In contrast, the age of the pig appears to be of minor importance, since weaning at either 4 or 6 weeks of age gave a similar result.

Insulin involvement in intestinal macromolecular transmission and closure in neonatal pigs.

Summary: The involvement of insulin in the intestinal transmission of macromolecules to blood and the cessation of this transport (intestinal closure) was studied in neonatal pigs by measuring the serum levels of the markers bovine serum albumin and fluorescein isothiocyanate labelled dextran 70,000 (FITC‐D) at 4 h after gavage feeding. In naturally suckled pigs, intestinal closure at 18 h was shown to be associated with an increase in serum immunoreactive insulin (IRI) levels. Similarly, intestinal closure obtained at ?? lactose/kg, was accompanied by an increase in serum IRI levels. Neither high serum IRI levels nor closure were observed in fasted pigs or in pigs gavage fed a total of 12 g lactose/kg. The effect of exogenous insulin on intestinal macromolecular transmission was studied by injecting 5 IU insulin/kg subcutaneously at 3 and 6 h, respectively, in newborn pigs gavage fed 10 ml sow colostrum/kg at 3 h intervals. This resulted in a reduction in the transmission of the markers when tested at 12 h, in comparison to littermates receiving the same amount of colostrum and littermates suckling the sow. It appears as if insulin, reflected as high serum levels over an extended period of time, is involved in the regulation of macromolecular trans?? ?? ulated that insulin may be involved in these processes by initiating the synthesis of membrane structural proteins in the enterocytes.

Development and regulation of porcine pancreatic function

SummaryA surgical and experimental procedure was developed to enable the collection of pure and inactivated pancreatic juice during the growth of the pig. Studies have shown that, during the suckling period, both the basal and the secretory responses to suckling are low, if present at all. After weaning, basal levels of the total exocrine secretion, total protein, amylase, and trypsin, respectively, increase slightly, while the postprandial levels of total protein, amylase, trypsin, lipase, colipase, and carboxylester lipase, respectively, increase markedly. The pancreatic juice enzyme composition changes qualitatively and the antibacterial activity of the pancreatic juice also significantly increases. Piglet age appeared to be of minor importance, since weaning at either 4 or 6 wk of age gave the same results. Secretin and CCK administered together in supraphysiological doses only significantly affect exocrine function from 3–4 wk of age. However, CCK may also affect the exocrine pancreas indirectly via reflexes initiated intraduodenally. Milk consumption in the suckling pig leads to a postprandial increase in glucose levels but not insulin. Milk, appears to be able to regulate the exocrine pancreas to produce only the amount and type of enzymes required for digestion. Thus, milk components or digestive products may affect pancreas function regulation. Studies show that enterostatin, the procolipase activation peptide, may inhibit pancreatic secretion mediated indirectly through the GI tract. Pancreastatin, an endocrine peptide, inhibits both insulin secretion and protein and trypsin secretion to pancreatic juice. In hypoinsulinemic (alloxan + streptozotocin diabetes) pigs (15–20 kg), no postprandial pancreatic juice response is seen, although CCK 33 + secretin can stimulate pancreatic secretion. Hypoinsulinemic pigs have a reduced capacity for glucose tissue utilization, suggesting that tissue metabolism and exocrine pancreas secretion are related.

Intensive (commercial) systems for breeding sows and piglets to weaning

Abstract This chapter describes and discusses some of the present day housing systems in the breeding section, dry sow unit and farrowing and lactation units in commercial pig production. These are ‘intensive systems’, wherein an attempt is made to have an efficient use of the available resources in the northern temperate zone. The recent and the future developments are briefly considered. The biological requirements of the animals at the different production stages and the problems encountered are also explained, especially with respect to welfare and commercial requirements. In addition the role of the stockperson for the success of these systems is noted.

Effects of a Strategic Feed Restriction on Pig Performance and Health during the Post-weaning Period

Abstract Digestive and metabolic changes in pigs during the post-weaning period were studied to elucidate the effects of feeding strategies on pig performance and health. Sixteen creep fed litters were divided at weaning (5 weeks of ages); half the litter was fed ad lib (FF), while the other half was fed restricted (RF) from day 3 to day 8 after weaning (restrictive period: 50% reduction on day 3, another 50% reduction on day 4, minimum ration 100 g pig−1 day−1, the same amount on days 5 and 6, double the amount on days 7 and 8, and then ad lib). Food intake (per pen), weight and diarrhoea (individually) were registered daily for 14 days post weaning. Studies of faecal haemolytic E. coli (days 4, 5, 6, 8 and 14), blood plama levels of total cortisol and immunoreactive cationic trypsin (IRCT) (days 2, 6, 9 and 14) and body temperature (days 1, 2, 3, 5, 6 and 8) were done on two pigs per pen. During the restrictive period the RF pigs had significantly lower diarrhoea score, fewer number of antibiotic treatm...

Effect of Feeding Environment on Performance, Injuries and Behaviour in Growing-finishing Pigs: Group-Based Studies

Ten batches of pigs (608 pigs) were used in this investigation (live weight interval 20-120 kg). Four different feeding systems were tested: one dry feeder, four dry feeders, trough feeding or one wet/dry feeder per pen of 16 pigs, respectively. The one dry feeder treatment led to an increase in skin injuries, a more spread feed intake pattern, an increased variation in carcass meat percentage and an increased variation in daily weight gain (DWG) when the pigs were restrictively fed, compared with observations for the pigs in the four dry feeders treatment. The effect of a reduced number of feeding places was most pronounced when the pigs were fed restrictively. Besides the possible negative financial effects for pig producers, these findings indicated that competition for feed impaired the well-being of the pigs. Pigs fed in a trough had a lower DWG and higher feed conversion ratio than did those fed using four dry feeders, probably due to feed spillage and the different feed intake pattern. Giving pigs the possibility of adding water to the feed increased the daily feed intake when feeding ad libitum, resulting in a higher DWG. It also reduced the negative effects of competition on performance, but not the negative effects on skin injuries.

Protease Inhibitor Levels in Porcine Mammary Secretions

The total trypsin inhibiting capacity (TIC), and the content of the individual protease inhibitors, both the specific colostrum protease inhibitor (SCTI) and the serum-type inhibitors, i.e., alpha 2-macroglobulin f and s, inter-alpha-trypsin inhibitor, alpha 2-antitrypsin and alpha 1-protease inhibitor, were quantified in porcine mammary secretions throughout lactation using immunoprecipitation methods. In addition, albumin, of serum origin, and beta-lactoglobulin, a milk-specific protein, were quantified and used as references. In presuckled colostrum, high levels of TIC, SCTI, albumin and beta-lactoglobulin were found, while the serum-type inhibitors appeared in amounts related to their molecular weights ranging from 3-6% of the adult serum levels for the macroglobulins to 42% for alpha 1-protease inhibitor. These parameters all decreased during lactation. The levels of TIC and SCTI especially decreased during the first days of lactation, and SCTI disappeared from milk after 5-7 days. Mature milk showed low TIC levels, about 0.1 IU/ml, which originated from the low amounts of the serum-type inhibitors (1-4% of the adult serum level). The levels of both alpha 2-macroglobulin f and s decreased less than albumin did in sow milk, while the other inhibitors decreased more or on the same order as albumin. A considerable variation in the amounts of the protease inhibitors between individuals and also between different teat secretions of the same sow, especially in colostrum, was evident. The possible physiological functions of the protease inhibitors in the mammary gland of the sow and in the gastrointestinal tract of her nursing offspring are discussed.