The role of dietary fibre in pig production, with a particular emphasis on reproduction

Abstract Fibres from a variety of sources are a common constituent of pig feeds. They provide a means to utilise locally-produced plant materials which are often a by-product of the food or drink industry. The value of a high fibre diet in terms of producing satiety has long been recognised. However the addition of fibre can reduce feed intake, which is clearly detrimental during stages of the production cycle when nutrient needs are high, for example in growing piglets and during lactation. More recently, fibre has been found to promote novel benefits to pig production systems, particularly given the reduction in antimicrobial use world-wide, concern for the welfare of animals fed a restricted diet and the need to ensure that such systems are more environmentally friendly. For example, inclusion of dietary fibre can alter the gut microbiota in ways that could reduce the need for antibiotics, while controlled addition of certain fibre types may reduce nitrogen losses into the environment and so reduce the environmental cost of pig production. Of particular potential value is the opportunity to use crude fibre concentrates as ‘functional’ feed additives to improve young pig growth and welfare. Perhaps the greatest opportunity for the use of high fibre diets is to improve the reproductive efficiency of pigs. Increased dietary fibre before mating improves oocyte maturation, prenatal survival and litter size; providing a consumer-acceptable means of increasing the amount of saleable meat produced per sow. The mechanisms responsible for these beneficial effects remain to be elucidated. However, changes in plasma and follicular fluid concentrations of key hormones and metabolites, as well as effects of the hypothalamic satiety centre on gonadotrophin secretion and epigenetic effects are strong candidates

Canola Proteins for Human Consumption: Extraction, Profile, and Functional Properties

Canola protein isolate has been suggested as an alternative to other proteins for human food use due to a balanced amino acid profile and potential functional properties such as emulsifying, foaming, and gelling abilities. This is, therefore, a review of the studies on the utilization of canola protein in human food, comprising the extraction processes for protein isolates and fractions, the molecular character of the extracted proteins, as well as their food functional properties. A majority of studies were based on proteins extracted from the meal using alkaline solution, presumably due to its high nitrogen yield, followed by those utilizing salt extraction combined with ultrafiltration. Characteristics of canola and its predecessor rapeseed protein fractions such as nitrogen yield, molecular weight profile, isoelectric point, solubility, and thermal properties have been reported and were found to be largely related to the extraction methods. However, very little research has been carried out on the hydrophobicity and structure profiles of the protein extracts that are highly relevant to a proper understanding of food functional properties. Alkaline extracts were generally not very suitable as functional ingredients and contradictory results about many of the measured properties of canola proteins, especially their emulsification tendencies, have also been documented. Further research into improved extraction methods is recommended, as is a more systematic approach to the measurement of desired food functional properties for valid comparison between studies

Wartosc pokarmowa nasion roslin straczkowych w zywieniu zwierzat

Omówiono najważniejsze czynniki wpływające na wartość pokarmową nasion roślin strączkowych jak skład aminokwasowy, zawartość i trawienie węglowodanów oraz związki antyodżywcze. W ostatnich latach powierzchnia uprawy roślin strączkowych pastewnych na nasiona w Polsce znacznie się obniżyła. Rośliny strączkowe są cennym źródłem białka uzupełniającego białko zbóż, jednak jego wartość dla zwierząt nieprzeżuwających jest zróżnicowana. Strawność jelitowa aminokwasów łubinów oraz białokwitnących odmian bobiku i grochu jest mniejsza, niż odmian kolorowo kwitnących. Świnie lepiej niż drób wykorzystują energię nasion strączkowych ze względu na różnice w stopniu i miejscu trawienia węglowodanów. Uważa się, że zawartość alkaloidów w nasionach uprawianych w Polsce odmian łubinu powinna zostać obniżona poprzez metody hodowlane.The main factors affecting feeding value of legume seeds such as amino-acid composition, carbohydrate content and digestion, and antinutritional substances, are discussed. During last years the area of legume crops cultivated in Poland decreased considerably. The legume seeds are a valuable source of protein complementary to cereal protein; however, their protein value for monogastric animals is variable. Ileal digestibility of amino-acids is greater in lupins and in white-flowered than in colour-flowered faba bean and pea. Due to differences in degree and site of carbohydrate digestion the pigs convert energy of legumes more efficiently than poultry. It is concluded that the content of alkaloids in seeds of Polish lupin cultivars should be reduced by proper selection