No abstract

The chemical composition of silage from whole crop barley {Hordeum vulgare L.) harvested at head emergence, milk or dough stage of maturity was estimated and palatability and digestibility trials on sheep were conducted. Crude protein and ADF content in DM decreased with advancing maturity from about 104 to 84 and 350 to 306 g/kg, whereas DM, ADL and N-free extractives increased at the same time from 222 to 317; 27 to 39.6, and 439 to 522 g/kg, respectively. Palatability and voluntary intake of silage produced from barley harvested at milk and dough stages of maturity were higher. The proportion of lactic acid to total acids was similar in all silages (0.85), the percent of NH 3-N in total N decreased with advancing maturity from 13.3 to 10.0. Voluntary silage DM intake increased with maturity of barley, but digestibility of crude fibre, NDF, ADF, ether extract and N-free extractives decreased.

Ninety Isa Brown laying hens aged 28 weeks, kept in individual cages, were randomly divided into 6 groups of 15 birds each. Six isoproteinous diets differing in crude fat content and fatty acid (FA) composition were prepared. The source of added fat was linseeds (50 g/kg diet), regular cultivars (Omega and Opal) with a high content of α-linolenic acid (HA), or a modified cultivar (Linola) with low α-linolenic acid-and high linoleic acid (LA) contents, soyabean oil, or LA linseed oil (20 g/kg diet). The control diet, with no fat supplement, contained 19 g, while the experimental diets, 38 g of crude fat per kg. The diets were fed for a 12-week and eggs were collected for chemical analysis at weekly intervals. The dietary fat level had no effect on the fat level in egg yolks. Eggs from hens fed diets with HA linseeds contained 3 times more α-linolenic acid, 2.5 times more EPA (C 20:5n-3 ) and DHA (C 22:6n-3 ) and 27% less arachidonic acid (C 20:4n-6 ) than control eggs (P<0.01). Those from hens fed with LA linseed, LA oil or soyabean oil, had similar levels of linoleic acid, EPA and DHA as control eggs and 14% more arachidonic acid. The ratio of n-6/n-3 PUFA was 3:1 in eggs from hens provided with HA linseed, while in the other groups it ranged from 9:1 to 14:1. In contrast to regular linseed, the use of linseed low in α-linolenic acid and rich in linoleic acid in hen diets is not beneficial for the functional value of eggs.

The chemical composition, fatty acid profile, content of amino acids, minerals, and gross energy of seeds of some commercial linseed oily cultivars: brown-seed (Flanders, Opal and brown-seed mixture) and yellow-seed (Hungarian Gold, Linola™947, Linola™989, Hungarian ecotype) were determined. The nutritive value of seeds for ruminants was also assessed according to the Polish IZ-INRA (1997) standards. Lysine was the main limiting AA for all cultivars. There were significant differences between cultivars in the contents of unsaturated fatty acids, C 182 , C lg . 3 . In the Linola™947 and Linola™989 cultivars, the level of linolenic acid (C, 83 ) was very low (about 2%), but the level of linoleic acid (C 2 ) was over 72% of total acids. There were differences between cultivars in PDIN and PDIE.

The objective of the study was to determine the nutritive value of grain of different maize cultivars for broiler chickens. The study involved 45 Ross 308 broilers (9 groups with 5 chickens per group) aged 42 to 49 days. Chickens were fed the grain of maize cultivars Pioneer PR39H84, Smok, Arobase, Moncada, Pioneer PR39G12, Eurostar, Opoka, Boruta, and Nysa ad libitum. The cultivars of maize differed in basic chemical composition, contents of amino acid and fibre fractions, as well as fatty acid profiles. Variations in chemical composition among different maize cultivars had an effect on the extent of basic nutrient digestion and on the energy value of grain in broiler chickens. For practical utilization of maize in broiler feed mixtures it will be important to determine the content of insoluble fibre, as it is negatively correlated with nutrient digestibility and the AME N value of grain (r=-0.69; P<0.05).