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Biomedical subjects

D E Franke

Publications and source records attributed to D E Franke.

25 records · Page 2Linked to original sources
PubMed1985

Sheath area in Brahman and grade Brahman calves and its association with preweaning growth traits.

Data from 439 Brahman (B) and grade Brahman (GB; 7/8 Brahman or more) calves born from 1970 through 1975 at the USDA Subtropical Agricultural Research Station were used to estimate least-squares means, heritabilities and genetic correlations for sheath area and preweaning growth traits. Grade Brahman calves weighed more (P less than .01) at birth and gained more (P less than .01) preweaning than B calves, although sheath areas were not different. Males exceeded (P less than .01) heifers in all preweaning growth traits and had larger (P less than .01) sheath areas. Heritabilities were: sheath area, .45 +/- .13; birth weight, .25 +/- .13; average daily gain, .38 +/- .15 and weaning weight, .35 +/- .15. Genetic correlations between sheath area and birth weight, average daily gain and weaning weight were .23 +/- .35, .58 +/- .25 and .52 +/- .27. These results suggest selection could be effective in reducing sheath area in B and B-derivative breeds, but would be antagonistic to preweaning growth traits. Because of relatively low phenotypic correlations between sheath area and preweaning growth rate (.27) and weaning weight (.29), continued emphasis on increasing growth rate or weaning weight could generally be maintained with careful attention to avoiding large sheath areas through independent culling level or index selection procedures.

Abdomen↗
PubMed1985

Additive and heterosis effects on preweaning traits, maternal ability and reproduction from crossing of the Angus and brown Swiss breeds in Florida.

Angus (A), Brown Swiss (S) and A X S reciprocal F1 (AS) dams were mated to A, S and AS (also reciprocal F1) sires resulting in nine breed groups of progeny with varying proportions of Angus and Brown Swiss breeding. Breed group of dam and of sire significantly influenced birth weight, preweaning daily gain, weaning weight, 205-d weight, condition score and frame size. The means for birth weight and weaning weight were 33 and 213 kg, respectively. Brown Swiss bulls sired calves with the heaviest birth and weaning weights. Calves produced by S dams likewise were heavier at birth and weaning. Pregnancy rates were influenced significantly by year, age and breed of dam and averaged 79, 95 and 92% for S, AS and A cows, respectively. Survival rate averaged 97% and was not influenced significantly by any of the effects examined. Because survival rates were similar for all breed groups, the results for weaning rate paralleled those for pregnancy rate. Genetic influences on preweaning growth traits and survival rate were partitioned into additive breed differences (B) and heterosis (H) effects for direct (d) and maternal (m) components. Pregnancy and weaning rates were examined using similar analyses except that genotype of service sire of dam replaced that of the offspring for the direct additive breed and direct heterosis components. The Bd values indicated that the Angus breed was inferior (P less than .01) to the Brown Swiss breed for all preweaning growth traits except for condition score, in which the Angus breed surpassed (P less than .01) the Brown Swiss. The Bm values also showed an advantage for the Brown Swiss breed for all preweaning growth traits. The additive maternal effect (the genotype of the females exposed), Bm, was important for pregnancy rate and weaning rate (P less than .001 and P less than .05) but not for survival rate (P greater than .10). The direct additive breed effect was not important for any reproductive trait. Direct heterosis did not affect any of the preweaning or reproduction traits; however, maternal heterosis (Hm) significantly affected all traits except birth weight, frame score and survival rate. The Hm estimates were 12.0 and 8.4 kg for weaning weight and 205-d weight, respectively. The Hm estimates for pregnancy rate, survival rate and weaning rate were 10, 2 and 13%, respectively.

Animals↗
PubMed1980

Breed and heterosis effects of American Zebu cattle.

The Brahman (American Zebu) has been evaluated in numerous crossbreeding studies throughout the Southern United States. Brahman females producing straightbred calves have usually been found to have a lower calving percentage, calf survival rate and weaning rate than other contemporary straightbreds, although they have been reported to be superior or competitive in some studies. Birth weights of Brahman calves have been larger than those of Angus, smaller than Charolais and comparable to those of Herefords. Brahman steers generally have had lower postweaning daily gains, lower carcass grades, less backfat and higher Warner-Bratzler shear values than other contemporary straightbreds. Heterosis estimates for reproduction have been small and variable in producing F1 calves, but larger and positive for reproductive traits of F1 cows. Birth and weaning weight heterosis estimates averaged 3.3 and 21.7 kg for F1 calves and 1.9 and 31.1 kg for calves of F1 cows. Small and variable heterosis estimates have been found for all carcass traits.

Animals↗
PubMed1979

Protein requirement of hamsters fed a natural diet.

The dietary protein requirement for growing hamsters was studied in two 5-week feeding trials using 52 weanling hamsters in the first trial and 37 in the second. Diets prepared primarily from natural ingredients supplied protein from four sources and contained 13.7, 16.7 and 19.7% protein in the first trial and 10.6, 13.7 and 16.7% protein in the second. Mean daily body weight gains of 2.04, 2.04 and 1.99 g/day, respectively, in the first experiment were not significantly different. In the second trial, daily gains of 1.55, 1.79 and 1.93 g/day were significantly improved when the dietary protein was increased from 10.6 to 13.7 and 16.7%. The maintenance requirement for protein by the adult hamster was evaluated in two nitrogen balance studies using four adult males fed a diet with 7.8% protein and seven fed 5.6%. The mature males remained in positive nitrogen balance and gained a slight amount of weight with both levels of protein.

Animals↗