The swimming crab, Portunus trituberculatus, is widely distributed throughout the coastal waters of Asian-Pacific nations and is an important economic species in this region. The aquaculture of swimming crabs has been plagued by problems associated with low growth rates, poor flesh quality, and weak disease resistance. To overcome these problems, selective breeding programs have been suggested as a means of genetically improving these traits in stock populations.
Crossbreeding is an efficient means to increase production and quality in plants; however, hybridization is seldom reported in bamboo. We crossbred two bamboo species Phyllostachys kwangsiensis (female parent) and Phyllostachys bambusoides (male parent) for the first time, and obtained suspected bamboo hybrids. We identified two bamboo hybrids from the above parents using PCR/ISSR. We concluded that ISSR markers are useful to identify bamboo hybrids, and that breeding between bamboo species is possible and useful.
The aim of the present study was to evaluate the heterosis effects on weaning weight at 205 days (WW, n = 146,464), yearling weight at 390 days (YW, n = 69,315) and weight gain from weaning to yearling (WG, n = 59,307) in composite beef cattle. The fixed models were: RM, which included contemporary groups, class of age of dam, outcrossing percentages for direct and maternal effects, and additive direct and maternal (AM) breed effects; R, RM model, minus AM breed effects, and H, RM model, minus additive breed effects. The estimates for W205 were in general positive (P 0.01).
Lifetime dairy production, reproduction and growth traits of 75 females sired by Holstein, Jersey or Brown Swiss bulls and Holstein-Friesian x Gir dams of 1/2 to 3/4 Holstein-Friesian fractions were compared. The animals were in a single herd under the same management. Milk, fat and protein yields, concentrates fed, reproduction, and weights were recorded throughout the lifetime of the cows. The data were analyzed by least squares techniques under models including the fixed effects of breed of sire, Bos taurus fraction and year of birth.
The liveweights of 100 females sired by Holstein (H), Jersey (J) or Brown Swiss (BS) bulls out of Holstein-Friesian x Gir dams of 1/2 to 3/4 Holstein-Friesian fraction were compared. The animals were kept in a single herd under the same management. The data were analyzed separately for four age categories by least squares techniques.