2006 Abstracts - American Society of Animal Science

in the lactation cycle than cows that do not become pregnant. Thesedata warrant further investigation to select the recipient most likely toestablish a pregnancy resulting in the delivery of a healthy neonate.Key Words: Dairy cows, Milk production, Embryo transfer34 Supplementing of grazing dairy cows with fish oil and sunfloweroil enhances milk conjugated linoleic acid without affectingcows performance. L. Holmes* 1 , A. AbuGhazaleh 1 , G. Apgar 1 ,and K. Griswold 2 , 1 Southern Illinois University, Carbondale, 2 PennsylvaniaState University, Lancaster.The objective of this study was to determine the effect of adding fish oil(FO) and sunflower oil (SFO) to grazing dairy cows diet on milk conjugatedlinoleic acid (CLA) and cows performance. Fourteen Holsteincows (105 ± 19 DIM) were fed a TMR (50:50) diet for 1 wk thendivided into 2 groups (7 cows/treatment) and offered fat supplementsfor 3 wk while in pasture. Cows in group one were fed a basal diet (7.5kg DM basis) consisting of corn, soybean meal, molasses, vitamin/mineral premix plus 500 g animal fat (CONT). Cows in the secondgroup were fed the basal diet plus 100 g of FO and 400 g of SFO(FOSFO). Cows were milked twice a day and milk samples were collectedevery 3 days. Both groups grazed together on a fresh pasture forad libitum and fed treatment diets after the morning and afternoon milking.Milk production (32 .7 and 33.0 kg/d), milk fat percentages (3.8 and3.8), and milk fat yield (1.25 and 1.24 kg/d) for diet 1 and 2, respectively,were not affected (P > 0.05) by treatment diets. Compared withCONT, milk protein percentages (3.0 and 2.9) were lower (P < 0.05)with FOSFO diet, but milk protein yield (1.0 and 1.0 kg/d) was notaffected (P > 0.05) by treatment diets. The concentrations of cis-9trans- 11 CLA (0.77 and 1.41 g/100g fatty acid) and vaccenic acid (2.14and 4.76 g/100g fatty acid) in milk fat were higher (P < 0.05) for cowsfed the FOSFO over the 3 wk of fat supplementation. The concentrationof cis-9 trans- 11 CLA in milk fat reached maximum (0.84 and 1.59g/100g fatty acid for diets 1 and 2, respectively) on day 6 with bothdiets and remaining relatively constant thereafter. The concentration ofvaccenic acid in milk fat followed the same pattern of temporal changesas cis-9 trans- 11 CLA. In conclusion, supplementing grazing cows dietwith FO and SFO enhances milk cis-9 trans- 11 CLA content and thatincrease remains relatively constant after day 6.Key Words: Grazing, Fish oil, CLA35 Survey of beef consumers in the Fargo, North Dakota market:Interest in natural and source identified beef. K. A. Cook* 1,2 ,G. P. Lardy 1 , K. R. Maddock Carlin 1 , T. D. Maddock 1 , M. J. Marchello 1 ,and K. G. Odde 1 , 1 North Dakota State University, Fargo, 2 MichiganState University, East Lansing.In order to characterize beef customer preferences, buying habits andthe potential demand for a natural or source branded beef product fromNorth Dakota, a survey of 1,200 grocery customers in Fargo, ND andMoorhead, MN was conducted. The survey consisted of three parts: 1)optional demographic questions concerning age and income; 2) questionspertaining to shopping habits including grocery shopping frequency,preferences, and beef buying habits; and 3) customer interest ina beef product that was labeled either “natural” or “raised in ND.”Surveyors verbally solicited customers to complete the survey at foursupermarkets (Hornbacher’s Foods, Fargo, ND; 3 in Fargo, ND and 1 inMoorhead, MN). Frequency distributions were generated for each questionusing PROC Freq of SAS (Cary, NC). The survey found thatcustomer age and annual household income were widely dispersed. Thefemale head of the household was the primary shopper for groceries(69.1%) and 33.9 percent of the customers indicated that they shoppedfor groceries twice a week. Most customers ate beef three times a week(34.2%) and 57.2% purchased beef once a week. Additionally, 47.5% ofcustomers waited for beef to go on sale before purchase. Most customers(66.8%) used the service counter for less than 20% of their beefpurchases. A large portion (75.9%) of beef customers polled respondedthat they would be inclined to purchase a beef product labeled “raised inND” and 71.2% indicated they were willing to pay a five percent orgreater premium for a “raised in ND” beef product. Additionally, 37.8%of beef customers indicated they would be interested in purchasing a“natural” beef product and 61.9%of the customers responded that theywould be willing to pay a five percent or greater premium for a beefproduct labeled “natural.” As a result, the ND beef industry shouldconsider exploring options related to a branded beef product labeled“raised in ND” in order to capture more customers and generate morevalue for beef.Key Words: Beef, Survey, North Dakota36 The effects of myostatin on skeletal muscle re-growth followingdisuse atrophy in mice. M. Grant*, J. Koltes, and J. Reecy,Iowa State University, Ames.Myostatin is an inhibitor of muscle growth. Mutations in cattle, miceand humans create a double muscled phenotype. Muscle re-growth is animportant issue in both human and animal health. The objective of thisstudy was to evaluate the effects of myostatin on skeletal muscle regrowthfollowing disuse atrophy. Both female (n=19) and male (n=16)myostatin-null and wild-type mice were used in a hind limb suspensionexperiment. Hind limb suspension results in atrophy of weight bearingmuscles. After 10 days of hind limb suspension, skeletal muscle (gastrocnemius,extensor digitorum longus (EDL) and soleus) was collectedfrom half of the mice. The remaining mice were allowed to resumenormal ambulatory activity for 21 days after which skeletal musclesamples were collected. Muscles were flash frozen in liquid nitrogen.Body weights were collected throughout the experiment. Skeletal muscleswere analyzed for total weight, DNA, RNA and protein content. Theratios of RNA/DNA, Protein/RNA, and Protein/DNA were used asindicators of transcription, translation and hypertrophy, respectively.Results indicate that myostatin-null mice had heavier muscle and bodyweight, including a strong sex effect (P