Ducklings were randomly allotted to one of five treatments and fed nicotinamide-unsupplemented corn-soybean basal diets containing 42.0mg/kg niacin at week 0～3 and 18.8mg/kg niacin at week 4～10 and diets supplemented with 30,60,90 or 120mg/kg nicotinamide.
1. 7 days-old yingtaogu ducklings were fed with the feedstuff that contains AFB_1(150bbp), two ducklings were dissected on every time of 12、 24、 48、 72、 96、 120、 144、 168、 192 hours and took heart、liver、 spleen、lung、kidney、brain、duodenum、 pancreas.
The results showed that:1. It was recommended for the ducklings at two weeks old to be inoculated with oil-adjuvant inactivated AIV H_5N_1, H_9N_2 or H_5N_1-H_9N_2 bivalent vaccine at the first immunity. The level of HI antibody for twice immunity at 2 and 3 weeks old respectively was higher than single immunity at 2-week-old.
day-old Tianfu meat ducklings were divided into three groups,and fed on diets as follow:con trol group(Cu12.16mg /kg),group1(Cu850mg /kg)and group2(Cu1050mg /kg)for experimen tal ob servation of copper toxicity in ducklings.
After PGCs were thawed and isolated, about 100～200 PGCs in one microliter were injected into the dorsal aorta of each stage 15 Maya duck embryo from which one microliter blood had been drawn prior to injection for the purpose of reducing recipient PGCs. The recipient embryos were incubated until hatching. Of 110 Maya duck embryos injected with chicken PGCs, 7 3%(8/110) survived to hatching.
Chicken PGCs from a line of White Leghorns were microinjected into Maya duck blastoderms at stage Ⅹ. Extragonadal development of donor PGCs in chicken duck chimeric embryos were studied by in situ hybridization with W chromosome specific DNA probes.
The variance analysis showed no significant difference between the two groups of data, which indicated that both mallard and spot-billed ducks made contributions to domestic duck evolution.
Polyacrylamide hydrogels covalently modified with duck eggwhite ovomucoid were synthesized by radical copolymerization.
The inhibitory activity of ovomucoid from duck egg white, immobilized on chitosan with the use of glutaraldehyde or carbodiimide as cross-linking agents, was studied.
Phosphorylation of the α-Subunit of Na,K-ATPase from Duck Salt Glands by cAMP-Dependent Protein Kinase Inhibits the Enzyme Activ
Proteins interacting with α1β1-type of Na,K-ATPase were revealed in pig kidney outer medulla and duck salt glands using three different methods (immunoprecipitation, protein overlay, and chemical cross-linking).
Rockweed harvest had no overall effect on the invertebrate community, but did reduce the effectiveness of ducks as predators during summer, when ducklings and associated females fed on invertebrates at the top of the rockweed canopy.
We propose that females in poor body condition start to incubate early to shorten the nest period in order to reduce their mass loss, but at the cost of reduced size and growth of the ducklings from the eggs laid after incubation start.
Females in good body condition on the other hand postpone incubation start at the cost of a longer incubation period and a higher mass loss to the benefit of synchronized hatching and a higher survival of ducklings.
We used multistate modeling to estimate relationships between probabilities of adoption by white-winged scoter (Melanitta fusca) ducklings from natal to foster females and a set of hypothesized ecological covariates.
Oxidative capacity of tissues contributing to thermogenesis in eider (Somateria mollissima) ducklings: changes associated with h