Biomedical subjects

J W Keele

Publications and source records attributed to J W Keele.

57 records · Page 4Linked to original sources

PubMed1991

Effects of selection of data on estimates of breeding values by three methods for litter size, backfat, and average daily gain in swine.

Estimated breeding value was calculated based on individual phenotype (SP), an index of individual phenotype and full- and half-sib family averages (SI), or Best Linear Unbiased Prediction (BLUP). Traits considered were litter size (LS), backfat (BF), and ADG. Estimated breeding values were calculated using all data and after deletion of the poorest 5, 10, 15, or 20% of the records for BF and ADG, or 4.8, 8, 13, or 21% of the records for LS. When all data were used, expected genetic gain from BLUP was greater than for SP by 22, 7, and 31% and greater than for SI by 10, 4, and 21% for LS, BF, and ADG, respectively. Expected genetic gain was 4, 0, and 3% lower for LS, BF, and ADG, respectively, for selection on breeding values estimated by SI after the poorest 20% of the records were deleted compared with selection on estimates by SI using all the data. Genetic gain using BLUP on data with the poorest 20% of the records deleted was reduced by 5, 2, and 8% for LS, BF, and ADG, respectively, compared with genetic gain using BLUP on all the data. The advantage in genetic gain of BLUP, with 20% of the poorest records deleted, over SP was 15, 5, and 21% for LS, BF, and ADG, respectively. Although BLUP is affected to a greater degree by deletion of records than is SP or SI, selection of swine using BLUP on field data would improve response to selection over the use of SP or SI.

Adipose Tissue↗

PubMed1990

Effects of errors in pedigree on three methods of estimating breeding value for litter size, backfat and average daily gain in swine.

Estimated breeding value (EBV) was calculated based on either individual phenotype (SP), an index of individual phenotype and full- and half-sib family averages (SI) or Best Linear Unbiased Prediction (BLUP). Calculations were done with correct data or data with 5, 10, 15 or 20% of the records per generation containing pedigree errors. Traits considered were litter size (LS), backfat (BF) and average daily gain (ADG). When data were correct, BLUP resulted in an advantage in expected genetic gain over SP of 22, 7.2 or 30.8% for LS, BF and ADG, respectively, and over SI of 9.6, 3.8 or 21.4%. When sire and dam pedigrees were incorrect for 20% of the pigs each generation, genetic gain using SI was reduced by 7, 2.5 or 6.5% and genetic gain using BLUP was reduced by 9.3, 3.2 or 12.4% for LS, BF and ADG, respectively. With 20% of the pedigrees in error, the advantages in genetic gain of using BLUP over SP, the method unaffected by errors in pedigree, were 10.5, 3.8 and 14.6% for LS, BF and ADG, respectively. These results suggest that, although BLUP is affected to a greater degree by pedigree errors than SP or SI, selection of swine using BLUP still would improve response to selection over the use of SP or SI.

Adipose Tissue↗

PubMed1989

Ruminal metabolism in nonlactating cows fed whole cottonseed or extruded soybeans.

Five nonlactating Holstein cows (average weight 574 kg) with cannulas in the rumen and duodenum were fed five total mixed diets at 2.14% (DM) of BW for seven 2-wk periods to estimate the ruminal degradation of protein and fatty acids in whole cottonseed (WCS) and extruded soybeans (ESB). Lanthanum was used as an indigestible marker. Ruminal propionic acid (molar proportion) was larger and butyric acid was smaller for WCS diets than for control or ESB diets. Total VFA (mM) and acetic acid (molar proportion) were similar for all diets. Duodenal flow of nonammonia nitrogen (N) was 13% higher for ESB diets than for WCS diets, but was similar for the control and diets with WCS. The percentage of intake protein that was undegraded was 19% higher for ESB diets than for WCS diets. Ruminal and total apparent digestibilities of ADF were not reduced by the addition of oil seed. In conclusion, the protein from ESB was less degraded in the rumen of cows than protein from WCS. The addition of ESB at 12.7% (DM) or WCS at 25.3% of the diet did not reduce the apparent digestibility of fiber. The unsaturated fatty acids in WCS were not protected from ruminal biohydrogenation, presumably due to mastication of the seed coat.

Animal Feed↗