Effects of feeding a no-roughage diet to feedlot cattle compared to traditional corn-soybean meal-hay diet [abstract]

Abstract only availableThe present experiment utilized a group of 16 Angus-based steers. The steers in group two (control group) were fed a traditional corn-soybean meal diet with free choice fescue hay available. Calves on group one (test group) were fed a no-roughage diet (blood meal and fish meal, as a primary protein source.) The experiment was conducted in two 3.5 acre lots with ad libitum access to a self-feeder within each pen. Calves were divided into two groups using randomized separation. Calves were weighed at the onset of the project (day 0), again at day 72, and then a final weight was taken on all calves prior to slaughter in one of the three selling groups (165, 216, and 264 days). Self-feeders were filled only when they were empty and feed troughs were cleaned out every 3 to 4 days or as fines were built up in the bunks. Calves were sent to slaughter at National Beef in Dodge City, Kansas. The average market price for the calves in the test group was $148.21 versus the control group which was$140.63. The final difference in total revenue between the two groups equaled $1485.56. Feeding no-roughage diets is a new concept that has been shown to improve feed efficiency in research studies. This experiment was the first on-farm study that has been conducted. Feeding the no-roughage diet improved carcass quality grade which is why the carcass value was approximately$8 greater for this group. In addition the no-roughage group had heavier carcass weights which resulted in this treatment having approximately $1500 more value than the traditionally fed calves. There no-roughage diet cost was a$119.17 more difference in the total feed costs than the traditional diet of the feed bill. The net advantage to nutritionally improving the diet was approximately $1300 total, or$162.50 per calf.CAFNR On Campus Research Internshi

Coupling ammonia-N production with ammonia-N uptake in the rumen

Abstract only availableMicrobial efficiency is defined as a measure of microbial yield in the rumen per unit of organic matter fermented. Because the ruminant is dependant on microbial mass for its supply of amino acids, the nutritional goal is to maximize microbial efficiency. However, an excessive supply of nutrients to rumen microbes can result in waste. Excessive waste can have negative economic and environmental consequences. A study was conducted to determine if prediction of ammonia-N release could be optimized with bacterial ammonia uptake in the rumen. The hypothesis of this research was that a diet could be formulated such that ammonia-N release would match the ammonia uptake by rumen microflora. To test this hypothesis, a continuous culture system of twenty fermentors placed in a 39ºC water bath was used. Dietary treatments were basal, 0.33X, 0.66X, X, and 1.33X. The optimal diet (diet X) was formulated using substrates with complementary degradation rates in order to maintain an optimal ammonia level of 2 mM (Satter & Slyter, 1973). Following an acclimation period of 4 days, samples were collected for 3 days. Collected samples were analyzed for organic matter digestibility (OMD), concentration of volatile fatty acids (VFA), pH, and microbial efficiency. Microbial efficiency was maximized for diet X. As the degradable protein level increased in the diet, VFA increased and pH decreased. The degradable protein level did not influence OMD. Conclusions from this data were that increasing degradable protein increased fermentative activity but not microbial yield. We further deduced that previous research conducted in our laboratory was valid in concluding that ammonia-N requirements could be modeled. This will enhance diet formulation for ruminants.F.B. Miller Animal Sciences Summer Undergraduate Research Progra

The measurement of residual feed intake to determine feed efficiency of pregnant Hereford heifers

Abstract only availableThe large potential improvement in profitability is what makes feed efficiency such a studied and concerned topic in the beef industry today. Currently, no herd exists in the United States that has been selected solely for the purpose of measuring and improving feed efficiency. The objective of this study was to rank forty-two pregnant Hereford heifers based on their feed efficiencies, so that they may be mated to bulls of known efficiency. The long term goal of this project is to create both efficient and inefficient herds for future feed efficiency research. These heifers were acquired from various beef producers across the state to ensure genetic variation within the herd. The heifers were fed an alfalfa/grass hay to which they had ad libitum access. Their diet was 86% dry matter and contained 58% neutral detergent fiber, 38% acid detergent fiber, and 14% crude protein on a dry matter basis. The individual intake of each heifer was recorded by the GrowSafe® feed intake system. Expected feed intake was calculated as a regression of actual intake on average daily gain and metabolic mid-weight. Expected feed intake was subtracted from actual feed intake to calculate the residual feed intake value of each individual heifer. Residual feed intake was then used as a measure of feed efficiency. The average body weight at the start of the study was 488 kg. Heifers consumed on average 17.77 ± 5.24 kg/d, and the herd gained at a rate of 0.77 ± 0.32 kg/d. The most efficient heifer consumed 9.78 kg/d less than was expected, while the most inefficient heifer consumed 11.54 kg/d more than was expected. Calculating residual feed intake as a means of determining feed efficiency will enable us to establish both efficient and inefficient herds for further research.F.B. Miller Undergraduate Research Program in Animal Science

Nutritional Skewing of Conceptus Sex in Sheep: Effects of a Maternal Diet Enriched in Rumen-Protected Polyunsaturated Fatty acids (PUFA)

doi:10.1186/1477-7827-6-21Evolutionary theory suggests that in polygynous mammalian species females in better body condition should produce more sons than daughters. Few controlled studies have however tested this hypothesis and controversy exists as to whether body condition score or maternal diet is in fact the determining factor of offspring sex. Here, we examined whether maternal diet, specifically increased n-6 polyunsaturated fatty acid(PUFA) intake, of ewes with a constant body condition score around the time of conception influenced sex ratio.The research was supported by USDA/CSREES/NRI Grant 2001-35203- 10693 (to RMR) and a Life Sciences Molecular Biology Fellowship, University of Missouri (partial salary support for MPG)

Modifications in Soybean Seed Composition to Enhance Animal Feed Use and Value : Moving From a Dietary Ingredient to a Functional Dietary Component

Animal feed is the primary user of the nonoil component of soybeans. Breeding and gene modification strategies have been successfully employed to alter the seed composition of soybeans in a manner that enhances their use in animal feeds. Examples include altering amino acid profiles, fatty acid composition, oligosaccharide removal, and most notably phytic acid reduction. Such enhancements are required if soybeans are to maintain their use level in animal feeding applications. As advancements in genetic modification continue, an even greater level of animal feed applications will ensue through development of soybeans that have antimicrobial, health, and biogeni properties. Thus, soybeans in the future may not be produced as much for use as a protein feedstuff or as a source of oil, but rather for their ability to promote beneficial physiological properties or to enhance food safety.Includes bibliographical reference

Management considerations in beef heifer development (1997)

Because decisions about selecting and managing replacement beef heifers can affect the future productivity of an entire cowherd, programs to develop breeding heifers have focused on the physiological processes that influence puberty. The timing of puberty critical to whether a heifer remains in the herd and whether lifetime productivity is optimized.New December 1997 -- Extension website