C. F. M. de Lange

Significance of endogenous gut nitrogen losses in the nutrition of growing pigs: A review

During the past two decades endogenous gut N losses (ENL) at the distal ileum in the growing pig have received considerable attention in swine nutrition research. Estimates of ENL are important for determining true ileal N and amino acid digestibilities and for identifying means to improve the efficiency of N and energy utilization in growing pigs. Endogenous secretions originate from various sources including saliva, pancreatic secretions, bile, sloughed off epithelial cells, serum albumin and mucin. It has been estimated that 70 to 80% of endogenous N secretions are digested and re-absorbed. Therefore, ENL represents only a fraction of total endogenous N secreted into the gut. Increased ENL are likely associated with elevated rates of gut protein synthesis. This is bound to increase maintenance energy and amino acid requirements of pigs. Traditionally, ENL were determined by feeding protein-free diets or by the regression method. Various alternative techniques (15N-isotope dilution technique, homoargini...

Impact of feeding blends of organic acids and herbal extracts on growth performance, gut microbiota and digestive function in newly weaned pigs

One hundred eighty newly weaned pigs were used to inves tigate effects of feeding organic acids and herbal extracts on growth performance, gut morphology and microbiota, and immune response in newly weaned pigs during a 4-wk period. There were five dietary treatments: control, Acid 1 (acetic, propionic, phosphoric and citric acid; 1.1% inclusion), Acid 2 (Acid 1 + 1.0% lactic acid), herbal extracts (0.75% inclusion; containing cinnamon, thyme and oregano extract), and antibiotic (110 ppm lincomycin). As compared to the control, pigs on antibiotic and Acid 2 showed higher (P < 0.05) ADG only during week 2 post-weaning, whereas pigs on herbal extract showed lower (P < 0.05) ADG only during week 3 post-weaning. Fecal coliform counts were lower (P < 0.08) in pigs on Acid 1 and 2 on day 4 post-weaning and in pigs on antibiotic and herbal extract on day 14 post-weaning. Fecal lactobacilli counts were lower (P < 0.05) in pigs on antibiotic on day 14 post-weaning. Based on PCR-DGGE, treatment influenced the compo...

Nutritional value of wheat for growing pigs: chemical composition and digestible energy content

Nutritional value of cereal grains varies greatly, and is currently estimated foremost by measuring density, whereas prediction based on chemical composition might be more useful. Thus, 16 samples of wheat were evaluated for density, chemical composition, and digestibility in growing pigs. The chemical evaluation included analyses for crude protein (CP), amino acids, neutral detergent fibre (NDF), acid detergent fibre (ADF), starch, and monomer sugars in non-starch polysaccharides (NSP). Digestible energy (DE) content was determined with growing pigs (barrows; 40.8 kg ± 5.3). Density ranged from 57.8 to 77.6 kg hL−1, CP concentration ranged from 13.0 to 18.1%, NDF concentration ranged from 12.9 to 25.0%, NSP concentration ranged from 10.5 to 16.6%, xylose concentration ranged from 4.3 to 6.5%, and DE contentranged from 3701 to 4050 kcal kg−1 Results of chemical analyses were expressed on a dry matter basis. Of the characteristics, xylose had the highest correlation with DE (r = −0.78; P < 0.001), and thus...

The gastrointestinal microbiota and its role in monogastric nutrition and health with an emphasis on pigs: Current understanding, possible modulations, and new technologies for ecological studies

The gastrointestinal microbiota is an incompletely defined, dynamic community of several hundred species of primarily anaerobic bacteria. Species composition and bacterial numbers vary depending on animal age, the gastrointestinal location and a variety of nutritional and environmental factors. The microbiota positively and negatively impacts host physiology and performance in many important ways. This review will examine the establishment and composition of the normal microbiota; its beneficial and deleterious effects on the host; and methods by which to modify the microbiota. In addition, recent advances in methodology using the techniques of molecular biology to measure and describe the microbiota are discussed. Finally, recent results using the polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) technique to examine the microbiota of pigs at different ages, different intestinal sites, and after treatment with selected feed additives will be described. Key words: Microbiota, ga...

Voluntary feed intake in growing-finishing pigs: A review of the main determining factors and potential approaches for accurate predictions

The ability of pigs to consume sufficient nutrients for optimal performance is an important consideration in commercial pork production. Nutrient intake levels are directly related to voluntary feed intake. Voluntary feed intake in pigs is influenced by several factors including environmental conditions (e.g. thermal and social conditions), animal status (e.g., age and physiological status), and feed and feeding conditions (e.g. bulkiness of the feed and feed form). Although the individual effects of many of these factors on voluntary feed intake have been investigated and quantified, little has been done to characterize their interactive effects. Under commercial conditions, voluntary feed intake is clearly influenced by multiple factors at any one time. Thus, there is a need for a means to accurately quantify voluntary feed intake in pigs as affected by the different interacting factors. Until quantitative effects of these interactions are established it is suggested that feed intake be monitored. This ...

Dietary influence on organ size and in vitro oxygen consumption by visceral organs of growing pigs

Abstract Although visceral organs represent only about 15% of the pig’s body weight, they account for about 45% of whole body oxygen consumption. The effect of diet on organ mass and in vitro oxygen consumption by some visceral organs was investigated in a study using 15 Yorkshire male castrates (18.9±1.5 kg initial body weight). Diets were based on casein-corn starch (CC), barley-canola meal (BCM) or barley-canola meal–alfalfa meal (BCM-ALF) and formulated to contain 0.088 MJ digestible energy (DE) per gram of crude protein. Pigs were fed at 2.6 times maintenance DE requirements twice daily for 3 weeks, then every 3 h for 3 days prior to tissue sampling. One h after feeding, pigs were killed and samples of the liver, jejunum, colon and caecum taken immediately. In vitro oxygen uptake was determined polarographically using an oxygen electrode. Per kg empty body weight (EBW), weight of the small intestine did not differ ( P >0.10) between treatments. Per kg EBW, weights of liver, colon and caecum were higher ( P P >0.10). However, weight-specific oxygen consumption was higher ( P P P >0.10) and lower than those in the BCM–ALF-fed-pigs. In conclusion, changes in diet composition alter energy expenditure in the liver and intestinal tissue. This appears largely mediated via effects on organ size and not via weight-specific oxygen consumption.

Application of pig growth models in commercial pork production

Pig growth models can be useful tools for identifying optimum management strategies for individual grower-finisher pig units, by integrating knowledge of nutrient utilization for growth and animal-environment interactions into one system. In addition, these models can be used to demonstrate basic principles of nutrient utilization for growth in the pig, to examine “what-if” scenarios, to aid in the development of pig breeding programs and to develop effective research programs. Models used in commercial pork production should represent the biology of growth in the pig and should be flexible, so that they can be focused easily on the needs and special conditions pertaining to particular growing–finishing pig units. For proper application of pig growth models in practice, pig units should be characterized reasonably accurately. This applies in particular to the upper limit to body protein deposition that pigs can achieve under practical conditions, feed intake at various stages of growth and the alternative...

Evaluation of chronic immune system stimulation models in growing pigs.

Two experiments (EXPs) were conducted to evaluate models of immune system stimulation (ISS) that can be used in nutrient metabolism studies in growing pigs. In EXP I, the pigs immune response to three non-pathogenic immunogens was evaluated, whereas in EXP II the pigs more general response to one of the immunogens was contrasted with observations on non-ISS pigs. In EXP I, nine growing barrows were fitted with a jugular catheter, and after recovery assigned to one of three treatments. Three immunogens were tested during a 10-day ISS period: (i) repeated injection of increasing amounts of Escherichia coli lipopolysaccharide (LPS); (ii) repeated subcutaneous injection of turpentine (TURP); and (iii) feeding grains naturally contaminated with mycotoxins (MYCO). In EXP II, 36 growing barrows were injected repeatedly with either saline (n = 12) or increasing amounts of LPS (n = 24) for 7 days (initial dose 60 μg/kg body weight). Treating pigs with TURP and LPS reduced feed intake (P < 0.02), whereas feed intake was not reduced in pigs on MYCO. Average daily gain (ADG; kg/day) of pigs on LPS (0.50) was higher than that of pigs on TURP (0.19), but lower than that of pigs on MYCO (0.61; P < 0.01). Body temperature was elevated in pigs on LPS and TURP, by 0.8°C and 0.7°C, respectively, relative to pre-ISS challenge values (39.3°C; P < 0.02), but remained unchanged in pigs on MYCO. Plasma concentrations of interleukin-1β were increased in pigs treated with LPS and TURP (56% and 55%, respectively, relative to 22.3 pg/ml for pre-ISS; P < 0.01), but not in MYCO-treated pigs. Plasma cortisol concentrations remained unchanged for pigs on MYCO and TURP, but were reduced in LPS-treated pigs (30% relative to 29.8 ng/ml for pre-ISS; P < 0.05). Red blood cell glutathione concentrations were lower in TURP-treated pigs (13% relative to 1.38 μM for pre-ISS; P < 0.05), but were unaffected in pigs on LPS and MYCO. In EXP I, TURP caused severe responses including skin ulceration and substantial reductions in feed intake and ADG, whereas MYCO did not induce effective ISS. In EXP II, ISS increased relative organ weights, eye temperature, white blood cell count and plasma acute-phase proteins (P < 0.05), confirming that repeated injection with increasing amounts of LPS induced chronic and relatively mild ISS. Repeated injection with increasing amounts of LPS is a suitable model for studying nutrient metabolism and evaluating the efficacy of nutritional intervention during chronic ISS in growing pigs.

Impact of feeding fermentable proteins and carbohydrates on growth performance, gut health and gastrointestinal function of newly weaned pigs

Feeding fermentable carbohydrates (FC) to weanling pigs may reduce the negative impact of proteolytic fermentation on gastrointestinal health and function. A total of 144 newly weaned pigs [6.23 kg body weight (BW); six pens per treatment; six pigs per pen) were used to determine the interactive effects of feeding additional fermentable protein (FP) and FC on growth performance, gastrointestinal function and intestinal health. Dietary treatments, based on a 2 × 2 factorial arrangement, were: (1) basal diet (control); (2) control + 10% poultry meal (PM) as FP source; (3) control + 5% beet pulp (BP) as FC source; and (4) control + 10% PM and 5% BP. Diets were formulated to be similar in digestible energy (DE) and digestible amino acid contents. In general, no interactive effects of FC and FP were observed (P > 0.10). During the 3-wk post-weaning period, feeding FP reduced average daily gain (ADG) (242 vs. 269 g d-1; P < 0.05), while FC increased ADG (269 vs. 243 g d-1; P < 0.05). Overall, feed intake did no...

Digestible energy contents and apparent ileal amino acid digestibilities in regular or partial mechanically dehulled canola meal samples fed to growing pigs

A study was carried out to determine the influence of partial mechanical tail-end dehulling on apparent ileal amino acid (AA) digestibilities and digestible energy content in canola meal (CM) samples for growing pigs. Twenty Landrace × Yorkshire barrows, with an initial body weight of 35 kg, were fitted with a simple T-cannula at the distal ileum. Digestibilities were determined in 12 experimental diets with observations from five pigs per diet. Five batches of regular CM were obtained from five different crushing plants in Western Canada. A fraction of these batches was partially dehulled. The regular and partially dehulled CM samples were included at 20% in a barley-based diet. One pooled high-fiber CM sample and a straight barley diet were evaluated as well. Partial dehulling increased (P < 0.05) the digestible energy (DE) content from 12.2 to 13.3 MJ kg DM−1, respectively, and the level of crude protein (CP) from 40.6 to 43.8% in regular and partially dehulled CM samples, respectively. The digestibili...