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Forage Systems for Developing Beef Heifers
This study, conducted at the Forage Systems Research Center (FSRC) at Linneus, MO, compared development of Polled Hereford heifers in two forage systems alfalfa-bromegrass (AB) with no grain concentrate supplementation vs. tall fescue (TF) (low endophyte) with grain supplementation.
For heifers to calve at 22-24 months, they reach puberty at 12 to 14 months of age. The onset of puberty is dependent on three interrelated factors age, weight, and breed. Age at puberty is significantly affected by live weight gain from weaning to puberty. Occurrence of puberty is very dependent on body weight (BW) and condition. While a heifer needs to be a certain age at puberty, she must also achieve a necessary target weight. Heifers typically reach puberty at about 65% of their projected mature weight. Feeding management strategy should be to have replacement heifers reach this target weight before the beginning of breeding season.
Nutrition plays a key role in a heifer's ability to reach a target weight and onset of puberty. Energy and protein intake affect weight and overall body condition of the heifer. If a heifer is in poor condition, she will not begin to cycle. Nutritional status of heifers after weaning has a greater impact on reproduction performance than does pre-weaning gain. Forage quality has a direct influence on the nutrient intake of heifers. Heifers fed high quality alfalfa hay (51% Digestible Dry Matter (DDM)), for winter feed reached puberty younger and had a first service conception rate 16% higher than heifers receiving low quality hay.
For two-year-old heifers, lowest conception rates occur with low energy intake both pre- and post calving. Feeding high energy levels post calving after the heifer has received low pre-calving energy levels does not fully correct the low conception rate.
Materials and Methods
Sixty Polled Hereford replacement heifers were selected from the FSRC herd and assigned to treatments in early December. Heifers remained on the trial until their first calf was weaned. Heifers were fed free choice of either alfalfa-bromegrass hay or tall fescue hay and a grain supplement. In the spring, heifers were grazed on replicated pastures of either alfalfa-bromegrass or low endophyte Ky31 tall fescue. Each pasture was grazed by 12 to 15 yearling heifers and 8 two-year-old heifers with calves for each of 4 years. Seasonal stocking rate was about 2 acres per animal unit.
Heifers were fed to reach a 650 lb. target BW at breeding time (13-15 mo.). The grain supplement (15% Crude Protein (CP)) fed with the TF winter phase treatment contained 87.5% corn and 12.5% soybean oil meal. Mineral and salt was provided free choice. Total grain fed (5 lb./day) each year averaged 765 lb./head for yearlings and 680 lb./head for two-year-olds. In 1988, grain was fed to AB heifers due to extremely low hay quality.
Yearlings and two-year-olds were co-grazed during summer and separated in winter. Heifers remained outside the entire year, and turned to pasture April 25, 2 weeks before breeding season began. Heifers were exposed to bulls for 60 days.
Rotational grazing was utilized; tall fescue pastures were in three paddocks with one used for hay and AB was in six paddocks with two cut for hay. Rotation among paddocks was based on forage availability. The intention is to begin grazing at 2000 lb./acre of forage available and leave 1000 lb./acre as residual. Pastures had been limed and fertilized to soil test previous to the beginning of the trial. Fescue pastures were fertilized with 100 lb. N/acre annually in split application. The TF paddocks used for hay received 60 lb. N in March and 40 lb. in August. Phosphorus and potassium was applied on a replacement basis.
Results and Discussion
The AB hay was higher in CP and TDN and lower in fiber than the TF (Table 1). Body weight, gain, and conception rate for yearlings is shown in Table 2. The target weight of 650 lbs. BW at breeding was achieved for both treatments. Average weights for each year ranged from 601 to 724 lbs. and tended to be greater for TF than for AB, probably due to the grain supplement fed with TF in winter phase. Conception rates ranged from 55 to 96% among years and treatments. There was a strong tendency for conception to be higher for heifers that reached the target BW at breeding than heifers that did not. Body weights of 700 lb. or greater were achieved during three years (one year for AB and two years for TF) and the conception rate for those years was 90% or above. This result leads to speculation that the target weight was set too low for optimum conception rate in these yearling Herefords.
Body weight at breeding, change in BW pre-calving (February), post calving (May), and conception for two-year-old heifers is shown in Table 3. Gains across years on summer pasture were equal for both treatments (Table 3) but were more consistent for AB than TF.
The average BW ranged from 807 to 937 lbs. for May (breeding time) across years and treatments. Conception rates ranged from 31 to 89%. There appeared to be a strong relationship between heavier BW in May and higher conception rates. Heifers consistently lost weight (Table 3) pre-calving and gained weight post calving but relationships between weight gain or loss and conception did not seem to exist. Apparently, weight changes were not large enough in this trial to affect conception. These findings again emphasize the importance of high quality forage for the two-year-old cow, which is growing as well as lactating. Target weight for two-year-old Hereford heifers at the start of the second breeding season in this trial appeared to be near 875 lbs.
Practical Conclusions and Implications
British breed beef heifers need to gain 1.1 lb. or more per day from weaning to first breeding in order to have a good chance to conceive and remain in the herd. Results from this and previously reported research indicate that a forage system with little or no grain supplementation can be adequate to develop heifers and obtain conception rates of 90%. However, the probability of conception rates of less than 90% is great due to the difficulty in maintaining consistently high forage quality for the growing heifer. The most critical period is from weaning to first breeding season.
Heifers in 450 to 600 lb. weight ranges can process only about 1.5% BW of neutral detergent fiber (NDF) as compared to about 2.0% for mature cattle. For this reason, forage quality must be excellent if the objective is to develop replacement heifers on forage alone. Recently weaned heifers need to top graze a 30-40% vegetative legume-grass mixture or be fed very high quality legume grass hay.
Heifers should be weighed periodically and if they are not on schedule to meet their target weight, use of concentrate supplementation or other growth aids (deworming etc.) may be cost effective.
Author: James Rogers, Livestock Specialist From: Fred Martz, Research Professor, Ron Morrow, Professor, and Tammy Helvey-Cundiff, Graduate Assistant, FSRC
Month in Ag Connection] [Ag Connection - Other Issues Online]
Lease or Not to Lease Farm Equipment
Leasing equipment may be a way of
reducing the cost of your machinery. Not all leases are the same, so carefully examine the
terms of any lease agreement. Lease arrangements change frequently, so if you considered
leasing in the past, you may want to take a look at it again.
Leasing allows you to control machinery assets without ownership. Plan to negotiate your lease.
UMC Guide 429, Leasing Farm Machinery, lists the following items as possibilities for negotiation:
Other items to consider:
To evaluate leasing versus purchasing, Ray Massey, commercial agriculture crops economist, has developed a spreadsheet called Equipment Lease Analyzer to evaluate the economic differences between leasing and purchasing equipment. It is available for download from the Ag Electronic Bulletin Board at: http://agebb.missouri.edu/download/equipment.zip
UMC Guide 429, Leasing Farm Machinery, gives some basics on leasing that you should examine. This guide is available from your local University of Missouri Extension Center or on the World Wide Web at: http://muextension.missouri.edu/xplor/agguides/agecon/g00429.htm
For more information, or assistance in web access, contact your local extension center.
Month in Ag Connection] [Ag Connection - Other Issues Online]
Pesticide Application Using Electrostatic Spray ProcessElectrostatic sprayers were developed and tested in the 1970s as a result of the Middle East oil embargo. These sprayers give pesticide spray droplets a negative electric charge, causing the spray to be physically attracted to the plant's slightly positive electric charge. The attraction between spray and plant is forty times stronger than the force of gravity on the spray droplets, resulting in a higher percentage of the pesticide contacting the plant and a reduction of off-target movement of the pesticide.
Since the pesticide spray droplets all have the same electrical charge, they are repelled from each other. This results in equally spaced droplets, which creates a more uniform spray application. With this increase in coverage and more uniform spray pattern, the total amount of pesticide being sprayed could possibly be reduced and still achieve the desired level of pest control.
When the oil embargo ended, the use of electrostatic pesticide sprayers in row crop agriculture also ended, as it became more economically feasible to apply field pesticides by traditional methods. This technology has been adopted and further developed by other agriculture and non-agriculture related industries. Until recently, agricultural use of electrostatic spray processes had been by greenhouse horticulture companies with insecticides. The spray process allowed companies to use less insecticide while achieving superior insect control. But, can electrostatic spray process also be used with herbicides to achieve weed control while using less herbicide in crop fields?
The Tweedie Commercial Agriculture area south of Carrollton on Highway 65 was used to test the effectiveness of the electrostatic spray process for weed control in soybeans. Post herbicide application was made using a Melroe Spra-Coupe ESP (Electrostatic Spray Process) field pesticide sprayer. Five different herbicide formulas were used at three different rates. Grass control herbicides and all surfactants were applied at labeled rates. For each plot, half of the plot was treated with the ESP system turned on and the other half of the plot was treated with the ESP system turned off. Plots were set at 60 feet wide and were the length of the field. All treatments were duplicated.
The soybean crop was planted on May 18, 1998 and received a single post emergence herbicide application on June 17, 1998. No pre-plant herbicides were applied. Herbicides used included: 1 quart Roundup, 1 pint Basagran + 1 pint Blazer, 2 pints Blazer / Status, 8 ounces Cobra, and 8 ounces Resource + 4 ounces Cobra. Herbicides were applied at rates of 1.5, 1.0, and 0.5 times the labeled application rate.
Resulting control and crop damage varied for all treatments for ESP and non-ESP applications. After averaging the percentage of weed reduction for each plot and its duplicate, a T test was used to determine if there was an overall difference between ESP and non-ESP for all 15 treatments, and no statistical difference could be determined. Again using a T test, treatments were tested for statistical differences between the ESP and non-ESP plots grouping by rate of application, and no statistical difference could be determined.
Although no statistical difference could be shown between the ESP system and conventional herbicide application system, the data shows that for all 15 treatments, the percentage of control for the ESP plots ranges from 71.5 to 100 while the non-ESP plots range from 55 to 100 percent control. This could be an indication that the use of electrostatic spraying provides a more consistent level of weed control. Understand that these results are from one-year at one-location. More results will be needed under varying climatic and weed spectrum conditions to really evaluate ESP sprayers.
Author: Darin Starr, Ag Engineering, Ron Alexander, Agronomy, Parman Green, Farm Business Management and Dale Watson, Livestock Specialist, Missouri Soybean Merchandising Council Cooperating
in Ag Connection] [Ag Connection - Other Issues Online]LLC "Have It Your Way"
If you have any interest in changing your business organizational structure, recent tax law changes warrant your giving limited liability companies (LLCs) another look. A 1997 IRS ruling makes it possible to "check the box" as to whether your LLC will be taxed as a partnership or a corporation. Interests in an LLC are defined as members; whereas interests in partnerships and corporations are known as partners and shareholders, respectively.
LLCs are state statute defined entities. Missouri does not limit the number of members in an LLC. In fact, Missouri allows one (1) member LLCs. If you organize as a one member LLC, the federal government does not require the LLC to file a separate income tax return. The member simply reports the LLC's taxable income and expenses on their 1040 Schedule C or Schedule F. While LLCs are relatively easy to establish, professional legal and tax advice is strongly recommended before "diving in."
Ag Connection - April 1999