Effect of Yeast Supplement on Performance of Steer Calves

The effect of Prosponse® yeast supplement fed to newly arrived steers was evaluated at the ISU Armstrong Research Farm near Lewis, Iowa. Four pens of approximately 32 head were fed similar diets with 2 pens receiving yeast supplement and 2 pens not. Calves were weighed on delivery to the feedlot and allocated on weight and sire. Calves were on test 34 days. There was no effect on daily gain or feed to gain. Dry matter intake trended higher for the yeast supplemented calves (P=.10). These data suggest that yeast supplement may improve dry matter intake in newly arrived feedlot calves.

Standardized Performance Analysis (SPA) Summary for 1999-2000 Veterinary Medicine Students

Nine Iowa State University veterinary medical students completed SPA records on herds from Iowa, North Dakota and South Dakota. The Iowa herds were included in the SPA summary for Iowa, but the six North and South Dakota herds were summarized separately. These six herds had an average herd size of 371 cows and had a financial return to capital, labor and management of $175 per cow. Total financial cost per cow averaged $286 for these herds with a range of $211 to $388. Feed utilized averaged 4,442 pounds of dry matter per cow and the average pounds of calf produced per exposed female was 506 pounds.

Nutritive Value of the Crop Residues from bt-Corn Hybrids and Their Effects on Performance of Grazing Beef Cows

One non bt-corn hybrid (Pioneer 3489) and three btcorn hyrids (Pioneer 34RO7, Novartis NX6236, and Novartis N64-Z4) were planted in replicated 7.1-acre fields. After grain harvest, fields were stocked with 3 mature cows in midgestation to be strip-grazed as four paddocks over 126 days. Six similar cows were allotted to replicated drylots. All cows were fed hay as necessary to maintain a condition score of 5 on a 9-point scale. Cows were condition-scored biweekly and weighed monthly. Forage yield and weathering losses were determined by sampling one 4-m2 location per grazed or ungrazed paddock in each field with a minimum total of 2 locations of grazed or ungrazed forage per field. To measure forage selection during grazing, samples of grazed forage were collected from the rumen of one fistulated steer that grazed for 2 hours after ruminal evacuation. Non-bt-corn hybrids had greater (P<.05) infestation of corn borers in the upper stalk, lower stalk and ear shank than bt-corn hybrids. However, there were no differences in grain yields or dropped grain between hybrids. Crop residue dry matter, organic matter and in vitro digestible dry matter yields at the initiation of grazing did not differ between corn hybrids. Dry matter, organic matter and in vitro digestible dry matter losses tended (P<.10) to be greater from the NX6236 and N64-Z4 hybrids than from the 3489 and 34RO7 hybrids and were greater (P<.05) from grazed than non-grazed areas of the fields. At the initiation of grazing, dry matter concentrations of the crop residues from the NX6236 and N64-Z4 hybrids tended to be lower than those from the 3489 and 34RO7 hybrids. Crop residues from the NX6236 and N64-74 hybrids had lower concentrations of acid detergent fiber (P<.05) and acid detergent lignin (P=.07) and higher concentrations of in vitro digestible organic matter than the 3489 and 34RO7 hybrids. Over the grazing season, corn hybrid did not affect mean rates of change in forage composition. The concentration of in vitro digestible organic matter in forage selected by steers after two weeks of grazing did not differ. However, steers grazing corn crop residues consumed forage with higher (P<.05) concentrations of neutral detergent fiber, acid detergent fiber, and acid detergent insoluble nitrogen than steers fed hay. The acid detergent fiber concentration of forage selected by steers grazing the 3489 and N64-Z4 hybrids was lower (P < .05) than concentrations from the 34RO7 and NX6236 hybrids. In order to maintain similar body condition score changes, cows grazing crop residues from the 3489, 34RO7, NX6236, and N64-Z4 hybrids required 650, 628, 625, and 541 kg hay DM/cow compared with a hay requirement of 1447 kg hay DM/cow for cows maintained in a drylot.

Effects of Bedding on Pig Performance

More pigs are being produced in bedded systems such as hoop barns due to the increase in demand for niche pork. Most of the current swine nutrition information has been generated in confinement settings without bedding. As omnivores, pigs ingest some bedding. There are questions about the effects of the ingested bedding on growth and feed utilization by the modern market pig. More knowledge in this area will allow for more accurate feed formulation in bedded systems.