Fate and Transformation of Nitrogen from ^(15)N-Labelled Rice Straw After Feeding Goat

Three goats were fed with ^15N-labelled rice straw to study the characteristics of digestion,assimilation,transformation and excretion of C and N compounds from rice straw.It was shown that the amount of ^15N transformed into the bodies of the two slaughtered goats accounted for 38.5 and 23.6% of the total amount of ^15N deposition of the experimental diet taken by each goat.The ^15N excreted through the feces and urine for the three goats accounted for 34.8,33.2 and 33.9% of the total amount of ^15N deposition in the feed of the 3 goats.The recovery of total ^15N for the two slaughtered goats were 73.3 and 57.5%,with the corresponding rates of ^15N loss 26.7 and 42.5% respectively.The digestibilities of total amino acids for Goats 1 and 3 were 68.7 and 54.0%,and the digestibilties of carbohydrates for the two goats were 74.8 and 67.7% respectively.

Effects on Growth Performance and Feed Digestibility of Hainan Black Pigs by Adding Lysine in Low Protein Diet

[Objective] The paper was to study the effects on growth performance and feed digestibility of Hainan black pigs by adding lysine in low prntein diet. [Method] A tntal of 36 Hainan black pigs with the body weight of （46.34±3.06） kg were randomly divided into three groups： con- trol group （protein level 15%, lysine level 0.83%）, experimental grnup 1 （protein level 13%, 0.83%）, and experimental group II （protein level 13%, lysine level 1.03）, each group had three replicates of four pigs. The trial lasted 35 d. [Result] The growth performance of Hainan black pig in grnup II had no significan! difference with that in contrail group （P〉0.05）. The apparent digestibility of chide protein and phosphorus of Hainan black pigs in Group II increased significantly （P〈0.05）, which were increased by 10.08% and 11.85% respectively compared to the control group; the apparent digestibility of calcium was increased, but the difference was not signifieant （P〉0.05）. [Conclusion] It will not reduce the growth performance of Hainan blaek pig when the protein level of diet is reduced by 2% and Ihe lysine level is increased to 1.03%. It is recommended that the diet can be used in the production of llainan black pig.

Characterization of dual enzyme resulted from bicistronic expression of two β-glucanases in porcine cells

Many animal feed grains contain high β-glucan in the cell wall. Pigs do not secret β-glucanase to degrade the β-glucan in their feed. The indigestible β-glucan not only blocks the release of nutrients from the grain cell wall, but also increases the digesta viscosity in the gastrointestinal tract of pigs. Therefore, dietary β-glucan significantly inhibits nutrient digestion and absorption in pigs. Transgenic expression of β-glucanase in the digestive tract of pigs may offer a solution to solve this problem. In the current study, four artificial codon-optimized β-glucanases genes was prepared and expressed in porcine cells. Only p Bg A and p Egx showed high activity in transfected pig kidney cells. To improve the p H range and p H stability of β-glucanase, the two β-glucanases, p Bg A and p Egx, were co-expressed in pig kidney cells and salivary gland cells by Linker A3 or 2A peptide. The resulting dual enzymes of p Bg A3 p Eg and p Bg2 Ap Eg showed significantly enlarged p H range and significantly increased p H stability, as compared to parental enzymes. These results provide useful data for future study on increasing the feed digestibility of pigs by transgenic expression of β-glucanase in their salivary glands.