A GROUP of dairymen in New Jersey organized in 1938 the first cooperative in the United States for the artificial insemination of their cows. This method of serving females without natural mating has since become one of the most significant programs for livestock improvement in the history of American agriculture. A great deal of research has been done on all phases. A basic contribution was th...

This study recorded sexual behavior within a captive herd of 8 Asian elephants for approximately 230 hr on 50 days over a period of 10 months. The study observed a single adult and a single juvenile bull mounting cows more than 160 times. When the juvenile bull was between 4 years, 2 months and 4 years, 8 months old, he exhibited mounting behavior only on days when adult mounting occurred. Adul...

The experiment was carried out at District Artificial Insemination (AI) Center at Khulna to evaluate the conception rate of frozen semen and locally produced liquid semen. Frozen semen from five different genotypes (Local, Sahiwal×Friesian, (Local×Friesian)2×Friesian, (Local×Friesian)×(Local×Frisian×Friesian), Local×Friesian) of bulls was taken which was served by Central Cattle Breeding Statio...

In 2002 the Board of Game authorized Alaska’s first permit hunts specifically for calf moose (Alces alces). We promoted these calf hunts to help stabilize a high-density, food-stressed moose population and to compensate for declining harvests of bulls. Low harvest rates of cows (= 1% of the prehunt cow population, 1996–2001) were tightly controlled by the public. High harvest rates of bulls (21...

increased feeding frequency improve bioenergetics efficiency in lactating cows; however, there is little information about its effect on fattening animals.twelve holstein bull calves were allotted to two groups to determine the effect of feeding frequency on body weight, carcass quality and hormonal profiles. control group was fed twice a day and treated group was fed six times a day by a stand...

Ecological and life history characteristics such as population size, dispersal pattern, and mating system mediate the influence of genetic drift and gene flow on population subdivision. Bull trout (Salvelinus confluentus) and mountain whitefish (Prosopium williamsoni) differ markedly in spawning location, population size and mating system. Based on these differences, we predicted that bull trou...

Breeding objectives for beef cattle in Ireland were derived and used to define selection sub-indexes. The intention of the sub-indexes was to simplify selection decisions by commercial bull and semen buyers for situations where all of the resulting progeny are slaughtered, or when some female progeny are kept as replacement breeding cows. Separate sets of economic values for calving ease and ge...

Artificial insemination provides a method to inseminate a large number of females to a single sire that has been selected and proven to be an industry leader for economically relevant traits. Thus, genetic change in a herd can occur quickly through the use of artificial insemination. With natural service, herd bulls are also selected for economically relevant traits but are limited on the numbe...

The effect of suckling on post-partum ovarian function was monitored by weekly plasma progesterone determinations using enzyme immunoassay in 16 Small East African Zebu (Bos indicus) cows maintained with a fertile bull. Five cows continuously suckled their calves (COS), but starting 30 d after calving 6 cows remained with their calves which were prevented from suckling using nose plates (NOS) w...