Ruminal parameters, rumen development, nutrient digestibilities, and N utilization were estimated in Holstein calves fed starch from different sources. Ground corn, ground barley, ground wheat, and crimped oats were used to formulate 4 isostarch (25% of starter dry matter) pelleted diets. These diets were randomly allocated to calves (16 calves per treatment, 8 female and 8 male) and fed ad libitum along with mixed grass hay throughout the experiment. Ruminal contents and blood were sampled at d 35, 50, and 70 of age to estimate ruminal parameters and plasma beta-hydroxybutyrate, respectively. At d 70, twenty-four male calves (6/treatment) were randomly selected, euthanized, and forestomach weight, papillae length (PL), papillae width (PW), rumen wall thickness (RWT), and papillae concentration were measured. At d 63, twenty-four female calves (6/treatment) were randomly selected and moved to metabolism stalls to estimate total tract apparent nutrient digestibilities and N utilization. Female calves were given 2 wk for adaptation to experimental facilities and then total collections of feces and urine were made from d 77 to 84 of age. Ruminal pH at d 35 of age was higher in calves fed corn and oat diets than in those fed barley and wheat diets. Ruminal pH at d 50 and 70 of age was the lowest in calves on barley diets followed by those on oat and wheat diets and then by those on the corn diet. Ruminal total volatile fatty acid concentrations at d 35 of age were greatest in calves fed corn or wheat diets followed by those fed barley and oat diets. Calves on corn and wheat diets maintained greater ruminal volatile fatty acids concentrations at d 50 and 70 of age. Ruminal ammonia, acetate, propionate, butyrate, and blood beta-hydroxybutyrate concentrations were also greater in calves on the corn and wheat diets. Full and empty weights of forestomach, PL, PW, RWT, and papillae concentrations were greater in calves on corn and wheat diets. Daily average intake of nutrients (dry matter, crude protein, neutral detergent fiber, starch, Ca, and P) was greater in calves fed corn and wheat diets than in those fed barley and oat diets. Starch source did not influence the total tract apparent digestibilities of nutrients in calves. Daily N retention (g/d) was greatest on the corn diet followed by the wheat diet and then the barley and oat diets. In conclusion, calves on a corn diet have greater ruminal capacity to accommodate feed bulk. More physically and metabolically functional rumens in calves on corn and wheat diets probably resulted in greater feed consumption and N retention.

portion of the resistance in the field is the result of physiological resistance or escape mechanisms. These Little is known about the inheritance of partial resistance in soyescape mechanisms could include flowering date, lodgbean [Glycine max (L.) Merr.] to sclerotinia stem rot, caused by the fungal pathogen Sclerotinia sclerotiorum (Lib.) de Bary. This ing, canopy architecture, and maturity, which have all information would be useful to soybean breeders who are developing been shown to be significantly associated with disease cultivars with resistance to sclerotinia stem rot. Our objectives were severity (Boland and Hall, 1987; Nelson et al., 1991; to study the inheritance of partial resistance to sclerotinia stem rot Kim et al., 1999). and to present the initial results from mapping quantitative trait loci Our objectives were to study the inheritance of partial (QTL) that confer this resistance. The research was conducted by resistance to sclerotinia stem rot and to present the testing 152 F 3 -derived lines from a cross between a partially resistant initial results from mapping QTL that control this recultivar, Novartis Seeds S19-90 (formerly Northrup King), and a sussistance. ceptible cultivar, Williams 82, for resistance to sclerotinia stem rot and agronomic traits at two Michigan locations in each of 2 yr. These MATERIALS AND METHODS lines were also evaluated for 123 genetic markers to map resistance genes. The resistance of the lines, measured with a disease severity Genetic Material index (DSI), was normally distributed across environments. Significant (P Ͻ 0.05) genotypic variation, genotype ϫ location, andOne hundred fifty-two F 3 -derived lines were developed by single seed descent from a cross between Novartis Seeds S19genotype ϫ year interactions were observed for DSI. The broad-sense heritability estimate for DSI across both locations and years was 0.59.90, which has a high level of partial resistance to sclerotinia stem rot, and Williams 82, which is highly susceptible to the More severe disease was significantly correlated with greater lodging, later date of maturity, later R1 date, and greater plant height. Three

Holstein calves were fed pelleted iso-starch (25% of starter dry matter) diets containing barley (n = 16), corn (n = 16), oat (n = 16), and wheat (n = 16) starch for 12 wk of age. Feed consumption, nutrient intake, body weight (BW) gain, skeletal growth, and selected blood metabolites in calves during preweaning (d 1 to 49) and postweaning (d 50 to 84) periods were measured. Average daily starter consumption during pre-weaning and postweaning periods was the greatest in calves fed corn died followed by those fed a wheat diet and then in those fed barley and oat diets. During the preweaning period, the calves provided corn and wheat diets consumed greater amount of mixed grass hay than those fed barley and oat diets. During the postweaning period, mixed grass hay intake was the greatest in calves provided corn diet followed by those fed a wheat diet and then in those fed barley and oat diets. Nutrients (dry matter, crude protein, starch, and neutral detergent fiber) intake followed the solid feed consumption pattern in calves. Body weight and body measurements (body length, body barrel, heart girth, wither height, and hip height) at birth and at weaning (d 49) in calves fed different starch sources were similar. Body weight and body measurements at postweaning (d 84) were the greatest in calves fed a corn diet followed by those fed a wheat diet and then in those fed barley and oat diets. Overall average BW gain and total dry matter intake were the greatest in calves fed a corn diet than in those fed wheat, barley, and oat diets. Feed efficiency was greater in calves fed corn and wheat diets than in those fed barley and oat diets. Blood glucose, blood urea N, triglycerides, cholesterol, and creatinine were reduced with the advancing age of calves. Lesser blood glucose and greater blood urea N concentrations at wk 8, 10, and 12 of age were noticed in calves fed corn diet than in those fed barley, oat, and wheat diets. Occurrence of diarrhea was more frequent in calves fed oat diet than in those provided barley, corn, and wheat diets. Starch sources did not influence respiratory score, rectal temperature, and general appearance score. In conclusion, the calves on corn diet consumed more solid feed and gained greater BW than those fed barley, oat, and wheat diets.

Simple sequence repeat markers developed from maize se-cytological mapping in rye (Secale cereale L.). p. 121-122 In P.E. McGuire and C.O. Qualset (ed.) Progress in genome mapping of quences found in the GENBANK database: Map construction.

Sclerotinia stem rot, caused by the fungal pathogen Sclerotinia sclerotiorum (Lib.) de Bary, has increased in importance for soybean [Glycine max (L.) Merr.] in recent years. The objectives of this research were to evaluate soybean genotypes for resistance to Sclerotinia stem rot over several field locations and compare these disease ratings with seed yields, other agronomic traits, and parentage. Eighteen soybean genotypes were evaluated for resistance to Sclerotinia stem rot and agronomic traits in six Michigan environments over 3 yr. The average disease severity index (DSI) of the 18 genotypes at a single environment ranged from 2.1 to 49.9. Mean DSI values over locations differed (P < 0.05) among the genotypes. The genotypes ‘NKS19‐ 90’, ‘Asgrow A2506’, ‘Colfax’, and ‘Corsoy 79’ had the greatest resistance to Sclerotinia stem rot. The DSI ratings of the 18 genotypes were significantly correlated between environments for only five of 15 pairs of environments. Over the six environments, a greater DSI of genotypes was significantly correlated with reduced seed yield and more plant lodging. Disease severity index was not significantly correlated with plant height at maturity, date of flowering, or date of maturity over the environments. Genotypes with parentage tracing to ‘Williams’ or ‘Asgrow A3127’ had a greater average DSI than genotypes with no parentage tracing to these cultivars. This suggests that the use of these cultivars as parents may have caused greater disease susceptibility in contemporary cultivars.