Life Sciences Commons^™

Genetic Parameter Estimates For Reproductive Traits Of Male And Female Littermate Swine, R. O. Bates, D. S. Buchanan, R. K. Johnson, R. P. Wetteman, R. W. Fent, L. K. Hutchens

Department of Animal Science: Faculty Publications

Reproductive traits of purebred and crossbred pigs produced in a four-breed diallel mating system using the Duroc, Landrace, Spotted and Yorkshire breeds were collected for five consecutive farrowing seasons (two farrowing seasons/year) beginning in fall 1976. Paternal half-sib heritabilities and genetic correlations for testicular traits (120 boars from 36 sires), serum testosterone (TE) and luteinizing hormone (LH) concentrations before and after treatment with gonadotropin releasing hormone (GnRH; 131 boars from 37 sires) and breeding performance traits (151 boars from 38 sires) were estimated. Heritability estimates were generally small to moderate except for sperm/gram testis (SGT), LH concentrations before (LH0) and …

Effects Of Adding Fat To The Sow Lactation Diet On Lactation And Rebreeding Performance, G. C. Shurson, M. G. Hogberg, N. Defever, S. V. Radecki, E. R. Miller, Win Butler

Department of Animal Science: Faculty Publications

One-hundred-three multiparous sows were randomly assigned to one of two lactation diets containing either no supplemental animal fat (C) or 10% added fat (F) during two seasons, summer (S) and winter (W), in a 2 X 2 factorial arrangement of treatments. Sows were placed on their respective dietary treatments 1 wk prior to farrowing and were fed these diets ad libitum throughout the 28-d lactation period. Weekly feed intake and total feed intake were not affected by diet or season, while weekly metabolizable energy (ME) intake tended to be higher during wk 1 and 3, and was higher (P<.04) during wk 2 for sows fed diet F. Sow weight loss from farrowing to 21 d of lactation and to weaning (28 d) were unaffected by diet or season. Average pig birth weight was .15 kg higher (P<.O1) for pigs born during S compared with those born in W. Sows receiving diet F had heavier litters at 21 d (P<.01) and heavier average pig 21-d weights (P<.O1). This was primarily due to the 13.1% increase (P<.04) in estimated milk yield and the higher fat concentration (P<.O01) of milk consumed by the pigs nursing sows fed diet F. Interval between weaning and re-breeding was shortened by 5.9 d (P<.01) for sows during W than during S, and tended to be lower for sows fed diet F (7.3 d) compared with that of sows fed diet C (9.7 d). Farrowing percentage was unaffected by diet but tended to be increased during W (78.9%) compared with S (65.1%). No differences between mason or diet were noted on number of pigs born or number of pigs born alive in the subsequent parity. No diet • season interactions were observed, except for crude protein concentration of sow's milk, which was higher in milk from sows fed diet C during season W (P<.04).

G86-820 How To Maximize Income By Managing Days Dry, Jeffrey F. Keown

University of Nebraska-Lincoln Extension: Historical Materials

This guide discusses the benefits of maintaining the optimum calving interval and offers suggestions for accomplishing this reproductive management technique.

Most dairy producers are aware that an optimum calving interval is 365 days. This is a normal lactation length of 305 days with a dry period of 60 days. This interval is often looked at as a goal to strive toward rather than a goal that must be reached to maximize income from the sale of milk.

G86-822 How To Estimate A Dairy Herd's Reproductive Losses, Jeffrey F. Keown

University of Nebraska-Lincoln Extension: Historical Materials

Remedies for herd losses caused by calving interval, dry periods, A.I. performance, and age at first freshening.

One of the major areas of lost income to the dairy producer is in the reproductive performance of the dairy herd. These losses are often overlooked because they are indirect costs. If producers could be given a monthly bill indicating the amount of money that improper reproductive management has cost them, then drastic changes would occur.

The majority of reproductive losses occur in the following areas:

1. Calving interval too long or too short.

2. Dry period too long or too short.

3. …