NITRATES IN CORN SILAGE
Excessive nitrates in corn silage can cause death to cows very quickly. Drought corn can have higher than normal nitrate concentrations when fed as forage. Fields having manure and additional nitrogen have the greatest risk for high nitrate levels. Droughts following good spring growth such as this year produces the greatest risk of high nitrate levels. Rainfall late into a drought and close to harvest will cause a spike in nitrate levels. Cloudy weather increases the nitrate levels. Deficiencies in potassium which was evident this season along with phosphorus and manganese can cause an elevated level of nitrates. Nitrates accumulate in the oldest parts of the plant.
Ways to reduce nitrates in corn silage include allow complete fermentation process as this can reduce nitrate levels 30 to 50%; avoid harvesting where excess nitrogen from manure and commercial nitrogen was applied; minimize nutrient deficiencies; harvest on bright sunny days; do not harvest until at least three days following a soaking rain following a period of dry weather; cut corn higher than six inches as the lower part of the stalk has the highest nitrate concentration; and dilute high nitrate corn silage with feed grains or hay. Be sure to collect and submit a sample of the silage after the ensiling process and before feeding at a minimum and also consider collecting a sample at harvest time to have some indication of any elevated levels.
Pigweeds can also have high nitrate levels during droughts. Scout fields for the presence of waterhemp before silage harvest to know if there is an increased risk of nitrates due to this pigweed species.
MANAGING STAPHYLOCOCCUS AUREUS IN
BULK TANK MILK FROM OHIO DAIRY HERDS
The dairy industry has changed considerably over time due to selection of cows for milk yield and in housing and management of cows. Since 1970 milk production per cow in the United States has nearly doubled and herd size has increased from 19 to 120 cows. Published data available from Ohio herds regarding management practices or prevalence of contagious mastitis organisms may no longer be current.
A study which included a survey was conducted to estimate prevalence of Staphylococcus aureus in Ohio dairy bulk tank milk samples, assess herd characteristics and management practices associated with presence of Staphylococcus aureus in bulk tank milk, and describe topics of importance for Ohio dairy producers.
Staphylococcus aureus was found in 69 to 72% of bulk tank milk samples. The higher the somatic cell count (>150,000 cells/ml) the greater the likelihood Staphylococcus aureus was present. Post-milking teat dip (97%) was the most commonly used milking procedure according to the survey. Only 49% of farmers practiced pre-milking stripping, pre- and post-milking teat dipping, and used a single towel. The sequential practices of pre-milking stripping, pre- and post-milking teat dipping and use of a single towel reduced the presence of Staphylococcus aureus in bulk tank milk greater than doing any of these procedures singularly. Herds where owners were involved in milking had lower detection of Staphylococcus aureus compared to farms where only hired hands performed milking. Farmers practicing quarantine, which were few (20% of respondents), had substantiallly less Staphylococcus aureus (46% without) compared to those not practicing quarantine. Staphylococcus aureus was less frequent in bulk tank milk with sand bedding compared to not having sand bedding.
The authors concluded that findings indicate that frequent training of employees and review of the milking procedures and their implementation may be needed to maintain good udder health.
eCALVING APP FOR TOUCHSCREEN ANDROID
MOBILE DEVICES IS AVAILABLE
Keeping timely, accurate, and reliable calving records is important to a comprehensive calving management program. Trouble-shooting calving-related losses is difficult without meaningful records making it difficult to implement effective corrective measures.
Dr. Gustavo M. Schuenemann with The Ohio State University developed eCalving, a touchscreen Android application (app), for dairy producers and personnel to easily record and manage calving-related records in real-time. The eCalving app is currently available at http://ecalving.com within OSU Veterinary Extension web site. The app is free of charge and user-friendly. Personnel will need to know what to look for and why it is important regarding calving and colostrum management for the app to work effectively. Training for calving personnel to increase technical knowledge/skills and build teamwork is available from Dr. Schuenemann upon request. The app will help keep more accurate and complete records of calving-related events associated wtih stillbirth and calf development. Some novel components of the app include a rolling list of active cows with an alarm to monitor calving progress and time in labor and a rolling list of active calves within 24 hours after birth.
The app was field tested. Greater than 90% of the participants said the app was easy to use and would keep using it. The field testing showed decision-makers can monitor calving events and losses while acounting for effect of management. The e-Calving app can be utilized as an integral part of a proactive calving management program.
GENOMIC TESTING OF DAIRY CATTLE
Genomic testing of dairy cattle became available in 2009 after the sequencing of the bovine (cattle) genome. Genomic testing involves the use of single nucleotide polymorphism markers from tissue samples from a calf or cow. The benefit of genomic testing is to determine whether a young animal received a better than average or poorer than average sample of genes from its parents. This genetic information allows the grower to measure the animal’s future performance rather than waiting until the animal starts producing milk to measure the animal’s performance. Before genomic testing the industry waited two years to measure the performance of a heifer and waited five years for a bull.
There are many uses of genomic testing. One is selling the animal. Do you sell the animal for the beef market because it will not produce well or sell a bull calf for the semen market instead of for the beef market? Another is breeding decisions. Do you breed a heifer with conventional breeding or obtain sexed embryos from a superior female to implant in other females or breed an inferior heifer with beef semen to produce a crossbred beef animal or breed with a genetically different bull to reduce inbreeding? Parent identification is another use. Another good use is testing of heifers prior to purchasing. Eliminating undesirable or lethal genes from breeds is another use. Testing allows growers to do progeny validation instead of progeny testing.
After six years of using genetic testing, most experts agree this is improving the dairy industry and is a profitable practice for dairy producers to adopt. Genomic selection offers an opportunity to select superior replacements, but MANAGEMENT early in the life of a calf determines the true lifetime performance regardless of genetic merit.
DAIRY INDUSTRY BRIEFS (DIBS)
Plummeting prices in the dairy industry are creating critical cash-flow and long-term survivability issues on Ohio's 3,328 dairy farms. Cost-cutting decisions must be made with full awareness of both short and long-term production and economic consequences.
OSU Extension's Dairy Working Group, a collaboration of OSU Extension and OARDC faculty is identifying and addressing critical issues in five areas:
- Nutrition and feed costs
- Reproduction and health
- Calf and heifer management
- Business issues
- People and stress management
New DIBS (Dairy Industry BriefS) have been posted atand will continue to be posted regularly. Please check this web site for up-to-date news and information.