ACCOUNTING FOR MANAGEMENT IN COST OF LIVESTOCK DISEASE STUDIES

Assessing the impacts of livestock disease on productivity is enhanced when the management abilities of producers are taken into consideration. One method of doing this is to develop a management index of several production/marketing practices using correspondence analysis which can combine several practices into a few variables. Also, through correspondence analysis herds can be divided into better managed and more poorly managed herds to test the association of management on herd health, productivity, and profitability.Farm Management,

DIGITAL DERMATITIS ON U.S. DAIRY OPERATIONS

The NAHMS Dairy '96 Study was designed to provide both participants and the industry with information on the nation's dairy animal population for education and research. The USDA's National Agricultural Statistics Service (NASS) collaborated with NAHMS to select a statistically valid sample yielding 2,542 producers. Included in the study were 20 states that represented 83.1 percent of the U.S. milk cows as of January 1, 1996. Data on digital dermatitis were collected during the second phase as Federal or state Veterinary Medical Officers (VMO's) or Animal Health Technicians (AHT's) contacted producers from February 20 through May 24, 1996 to complete a questionnaire. Contact for this paper: Steven OttNAHMS, dairy, cattle, footwarts, heelwarts, lameness, hoof, digital dermatitis, Livestock Production/Industries,

IMPORTANCE OF INCOME IN COW-CALF MANAGEMENT AND PRODUCTIVITY

The USDA's National Animal Health Monitoring System (NAHMS) collected data on management practices and cow-calf herds as a source of family income from a representative sample of cow-calf producers from 23 of the leading cow-calf states. Overall, 2,713 producers with one or more beef cows participated in the NAHMS Beef '97 Study, representing 85.7 percent of the beef cows and 77.6 percent of the beef cow operations in the United States as of January 1997. Producers whose cow-calf herds were the primary source of family income were more productive than those whose herds were a supplemental source of income. Cow-calf herds were the primary source of income for 14 percent of the producers and provided supplemental income for 69 percent of the producers. While average herd size was larger for primary income herds, nearly half of the herds with 100 or more cows were non-primary income herds. Producers whose herds were a primary source of income were more likely to dehorn cattle, castrate bull calves, and practice artificial insemination and semen testing than producers whose herds were not a primary source of income. Primary income producers were also more likely to vaccinate preweaned calves. Due to greater weaning rates and a higher weaning percentage, primary income producers produced more pounds of weaned calf per exposed cow than did non-primary income producers (440 vs. 400 pounds). Contact for this paper: Stephen OttNAHMS, beef, cattle, cow-calf, epidemiology, economics, marketing, management, production, income, dehorning, castration, vaccinations, breeding, calving, semen testing, Livestock Production/Industries,

MARKETING PRACTICES IN BEEF COW-CALF OPERATIONS

The National Animal Health Monitoring System (NAHMS) Beef '97 Study collected data on the marketing practices of 2,713 beef cow-calf producers representing 85.7% of all beef cows as of January 1, 1997, in 23 leading cow-calf states. Of the operations included in the study, 67.4% sold steer calves, and 52.1% sold heifer calves for slaughter in the year preceding the study. By number of operations, auction was the most common method of selling steers (84.9% of operations) and private treaty was the second most popular marketing method (10.4% of operations). By number of steers sold, private treaty was the most common marketing method. For operations selling either steer or heifer calves, smaller operations were more likely to use auctions as a marketing method, and larger operations were more likely to use strategies such as video, forward contracts, or sale on a carcass basis. As marketing calves on a single day makes profitability dependent on daily market fluctuations, producers may want to consider diversifying marketing strategies to decrease the effects of market volatility. Larger operations were more likely to make use of forward pricing methods: while forward pricing was used by only 1.5% of operations in 1996, 13.4% of operations with 300 or more beef cows utilized this method of marketing. Larger operations were more likely to sell calves in the preceding year than smaller operations; smaller operations with outside income may be able to defer sales for another year during poor markets. Contact for this paper: Stephen OttNAHMS, beef, cattle, cow-calf, epidemiology, economics, marketing, management, weaning, auctions, income, forward pricing, futures contracts, Livestock Production/Industries,

DAIRY HERD MANAGEMENT PRACTICES FOCUSING ON PREWEANED HEIFERS

The National Dairy Heifer Evaluation Project ( NDHEP ) was conducted by the National Animal Health Monitoring System (NAHMS ) from April 1991 through July 1992 with the assistance of 1,811 producers from 28 states. Producers included in the study each had herds of 30 or more milk cows, representing 78 percent of the milk cows in the U.S. The average total of cattle and calves on each operation was 169.4. The main breed on 94.9% of operations was Holstein. Slightly over 46 percent of operations stated reproductive problems as the cause of low milk production of cows culled from the herd. Newborn calves were separated from their mothers before nursing on 28.0 percent of operations and less than 12 hours after birth on 39.6 percent of operations. On 64.0 percent of operations, calves received their first feeding of colostrum via hand feeding from a bucket or bottle. Of operations using hand feeding, 94.6% fed first milk from the mother (as opposed to other colostrum or substitute) to calves. Calves received, on average, between two and four quarts of colostrum during the first 24 hours. A variety of liquid feeds were used after colostrum was fed; the two most widely utilized were milk replacer ( 59.0 percent of operations ) and milk from cows recently calved ( 51.9 percent of operations ). Calves were weaned from liquid ration at an average age of 7.9 weeks. The average age of heifers at first calving was 25.9 months. The most common illness among dairy heifer calves was scours (53.8 percent of operations ), with respiratory problems as the second most common illness (12.1 percent of operations ). Scours was estimated to cause 52.2 percent of deaths ( 4.4 percent of calves born ) among dairy heifer calves from birth to weaning; respiratory problems were estimated to cause 34.8 percent of deaths ( 0.8 percent of heifer inventory ) among heifers from weaning age to first calving. Contact for this paper: Stephen OttNAHMS, dairy, cattle, monitoring, epidemiology, preweaning, heifer, production, morbidity, mortality, death loss, illness, colostrum, calving, dehorning, vaccination, scours, antibiotics, feed, milk replacer, Livestock Production/Industries,

ECONOMIC OPPORTUNITIES FOR DAIRY COW CULLING MANAGEMENT OPTIONS

Due to a lack of national information about cull dairy cows, the USDA's National Animal Health Monitoring System (NAHMS) Dairy '96 Study investigated culling management practices. Operations included in the study represented 83.1 percent of U.S. milk cows. Most dairy cows were culled for reasons associated with their inability to profitably produce high-quality milk and calves; reasons for culling were not usually related to ill health or systemic disease. Results showed that almost all cull dairy cows in the US are intended for beef slaughter, as only about 4.4 percent were sent to other dairy operations. Nearly 77 percent of cows intended for beef slaughter were sent to markets, auctions, and sale barns, while 22 percent were sent straight to slaughter facilities. However, high levels of transportation of cull dairy cows can result in stresses, bruising, and disease exposure. producers of larger herds, classified as having 200 or more cows, tended to cull a larger percentage of cows for low production that was unrelated to disease than did producers of smaller herds, classified as having fewer than 100 cows: cows having low production consisted of 28.1 percent of cull cows from larger herds versus 19.2 percent of cull cows from smaller herds. Use of specific milk production levels to determine timing of culling in combination with monitoring of cow health in order to market cows earlier can prevent losses due to condemnations at slaughter, which can cost the producer $12 for every nonfed bovine marketed. Contact for this paper: Steven OttNAHMS, dairy, cattle, monitoring, epidemiology, production, economics, culling, transportation, milk, marketing, disease, slaughter condemnation, Livestock Production/Industries,

Supernova Fallback onto Magnetars and Propeller-powered Supernovae

We explore fallback accretion onto newly born magnetars during the supernova of massive stars. Strong magnetic fields (~10^(15) G) and short spin periods (~1-10 ms) have an important influence on how the magnetar interacts with the infalling material. At long spin periods, weak magnetic fields, and high accretion rates, sufficient material is accreted to form a black hole, as is commonly found for massive progenitor stars. When B ≾ 5 × 10^(14) G, accretion causes the magnetar to spin sufficiently rapidly to deform triaxially and produces gravitational waves, but only for ≈50-200 s until it collapses to a black hole. Conversely, at short spin periods, strong magnetic fields, and low accretion rates, the magnetar is in the "propeller regime" and avoids becoming a black hole by expelling incoming material. This process spins down the magnetar, so that gravitational waves are only expected if the initial protoneutron star is spinning rapidly. Even when the magnetar survives, it accretes at least ≈0.3 M_☉, so we expect magnetars born within these types of environments to be more massive than the 1.4 M_☉ typically associated with neutron stars. The propeller mechanism converts the ~10^(52)erg of spin energy in the magnetar into the kinetic energy of an outflow, which shock heats the outgoing supernova ejecta during the first ~10-30 s. For a small ~5 M_☉ hydrogen-poor envelope, this energy creates a brighter, faster evolving supernova with high ejecta velocities ~(1-3) × 10^4 km s^(–1) and may appear as a broad-lined Type Ib/c supernova. For a large ≳ 10 M_☉ hydrogen-rich envelope, the result is a bright Type IIP supernova with a plateau luminosity of ≳ 10^(43)erg s^(–1) lasting for a timescale of ~60-80 days

Stellar and nuclear-physics constraints on two r-process components in the early Galaxy

Proceedings of "Nuclei in the Cosmos 2000", Aarhus, DanmarkComment: 3 pages, 2 figures; to be publ. in Nucl. Phys.