J.D. Wheat

Farrowing interval and pig performance

This report is brought to you for free and open access by New Prairie Press. It has been accepted for inclusion in Kansas Agricultural Experiment Station Research Reports by an authorized administrator of New Prairie Press. Copyright 1983 Kansas State University Agricultural Experiment Station and Cooperative Extension Service.

Birth sequence and its effects on litter size

Average farrowing interval and duration were 15.8 and 143.8 minutes for 1766 pigs born in 169 litters. Pigs born later in the litter were larger (r=.43) at birth. The correlation was -.14 between farrowing interval, average time between the birth of pigs within the litter, and litter 21-day weight. Sixteen pigs were classified as mummies and their birth sequences ranged from 1 to 15 with an average of 6.5. In 53.5 percent of the litters, the first pig born was a gilt and in 18.4 percent of the litters the first pig born was the largest in the litter. However, the first pig born was the smallest in the litter in 13.5 percent of the litters. The last pig in the litter was the smallest pig in 8.5 percent and largest in 16.3 percent of the litters. Pigs dead at birth, but not classified as mummies, ranged in birth order from 1 to 15 and had an average rank of 7.5. Among pigs dead at birth, 67 percent were boars.; Swine Day, Manhattan, KS, November 11, 1982

Farrowing duration and its effects on pig performance

Based on the first 76 farrowings recorded, average duration (the time between the birth of the first pig and of the last pig in the litter) was 129.09±7.28 minutes, and the average time interval between pigs was 15.71± 1.02 minutes. Longer farrowings were associated with longer intervals (r=.73), but farrowing duration and litter size at birth were not closely related (r=.19, P>.05). Farrowing duration was positively associated with the number of pigs born alive (r=.34, P<.0l). Farrowing interval, a better criterion of speed of farrowing than farrowing duration, was significantly associated with number of pigs alive at birth and at weaning; the correlations were, respectively, -.75 and -.78. Farrowing interval was also negatively associated with litter weight at 21 days, the correlation was -.32 (P<.05). So naturally it was negatively associated with the National Swine Improvement Federations sow-productivity index: (r=-18, P<.05). The index is 6.5 times the number of pigs born alive plus litter weight of pigs 21 days old. The number of live pigs per litter at birth averaged 9.75±.34 and at 21 days, 8.60±1.2.; Swine Day, Manhattan, KS, November 12, 1981

Stress susceptibility in pigs selected for muscling

Duroc swine selected for muscling seemingly are more susceptible to stress than are ordinary pigs. The highly significant difference in serum creatine phosphokinase (CPK) levels (an average score of 30.07) in those pigs and levels (18.88) in control-line pigs indicates that pigs selected for increased muscling are more susceptible to stress because exercise causes CPK levels to be proportionately higher in their blood serum than would be the case were the pigs not under stress.; Swine Day, Manhattan, KS, November 10, 1977

Comparison of feed consumption of pigs in two lines

This report is brought to you for free and open access by New Prairie Press. It has been accepted for inclusion in Kansas Agricultural Experiment Station Research Reports by an authorized administrator of New Prairie Press. Copyright 1976 Kansas State University Agricultural Experiment Station and Cooperative Extension Service.

Selecting for muscling in swine and resulting effects on carcass traits

This report is brought to you for free and open access by New Prairie Press. It has been accepted for inclusion in Kansas Agricultural Experiment Station Research Reports by an authorized administrator of New Prairie Press. Copyright 1975 Kansas State University Agricultural Experiment Station and Cooperative Extension Service.

Selection for muscling in swine and its effect on carcass traits

Line differences in weight, litter size at different ages, and in age, loin eye area, and backfat thickness of pigs (adjusted to 200 pounds live weight) were not significant. Sex differences in weight and backfat thickness were significant. Dam groups of progeny differed significantly (P<.0l) in-weights at birth and at 14 and 28 days old and in age, loin eye area, and backfat thickness adjusted to 220 pounds live weight. Hams produced by barrows in the select line were significantly (P<.0l) darker and firmer than those from barrows in the control line.; Swine Day, Manhattan, KS, November 14, 1974

Muscling selection in swine and its effect on carcass traits

We are attempting to develop a well-muscled line of Durocs by selecting for minimum back fat and maximum loin eye area as estimated by the Anscan and to form a control line by randomly selecting from the same base population. The lines will be compared for performance and carcass traits, including incidence of pale soft exudative carcasses. Expected and realized heritability estimates for carcass traits will be calculated.; Swine Day, Manhattan, KS, November 2, 1972