Life Sciences Commons^™

Ten Generations Of Selection For Predicted Weight Of Testes In Swine: Direct Response And Correlated Response In Body Weight, Backfat, Age At Puberty, And Ovulation Rate, Rodger K. Johnson, Gregg R. Eckardt, Thomas A. Rathje, Denise K. Drudik

Department of Animal Science: Faculty Publications

Selection for predicted weight of testes at 150 d of age (PWT) was practiced for 10 generations to determine the effect on reproductive and growth traits in swine. Mass selection among boars (line TS) or random selection (line C) was practiced beginning with the F3 generation of a Large White x Landrace composite population. Population size in each line was 40 to 45 litters by 15 sires per generation. Responses were estimated by regressions on cumulative selection differentials for PWT and on generation number and by mixed-model derivative-free REML procedures. The realized heritability of PWT was .35 ± .02 and …

Effect Of Weaning Date On Performance Of Beef Cows, R. J. Pruitt, P. A. Momont

South Dakota Beef Report, 1994

Records from 92 mature crossbred cows calving in March and April were used to determine the effect of weaning calves 40 days earlier than the traditional weaning time on cow weight change, body condition, and reproductive performance. When calves were weaned early (September 14 versus October 231, their dams gained more weight from September 14 to early December and had higher body condition scores in December than the dams of later weaned calves. The two nutritional treaments imposed after calving were important in explaining the effects of earlier weaning on cow reproductive performance. For cows that were fed grass hay …

Terrapene Carolina Carolina, Joseph C. Mitchell, Rafael O. De Sá

Biology Faculty Publications

TERRAPENE CAROLINA CAROLINA (Eastern Box Turtle). REPRODUCTION. Female Terrapene carolina containing oviductal eggs have been recorded in Virginia from 26 May to 25 July (Mitchell, in press. The Reptiles of Virginia. Smithsonian Inst. Press, Washington, D.C.). Other reports of reproduction in Terrapene (see list in Ernst and McBreen 1991. Cat. Amer. Amphib. Rept. 512.1-512.13) indicate that nesting occurs in late spring and early summer throughout its range.

Out-Of-Season Births Of Elk Calves In Wyoming, Bruce L. Smith

United States Fish and Wildlife: Staff Publications

ive out-of-season births of Rocky Mountain elk were documented over a 24-month period at the National Elk Refuge, Wyoming. One of four November neonates was radio-instrumented and subsequently died seven days later due to hypothermia. An April-born calf was killed by a coyote. Supplemental winter feeding of elk at the Refuge may increase the frequency of asynchronous reproduction.

Ec94-271 Understanding Mare Reproduction, Kathleen P. Anderson

University of Nebraska-Lincoln Extension: Historical Materials

Many producers who raise horses find breeding mares rewarding, yet frustrating. Mares and stallions are traditionally placed in the breeding herd due to successful performance records, with littie considerations for their reproductive capacibilities. Basic understanding of the mare's reproductive physiology can improve reproductive efficiency and foaling rates. A mare manager's goal should be to get the maximum number of mares pregnant, in the shortest amount of time, and to deliver a live, healthy foal each year.

G94-1197 The Genetics And Management Of Sound Feet And Legs, Jeffrey F. Keown

University of Nebraska-Lincoln Extension: Historical Materials

Sound management of feet and legs in dairy animals affects performance. This guide offers suggestions for good management practices.

Two major parameters affect the selection process for any trait: the heritability of the trait as well as the variation associated with the trait.