Hot Stuff, Summer 1996
The following "Hot Stuff" articles appeared in the Summer 1996 issue of New Mexico Resources:
Homing in on the Range
Animal science graduate students Lisa Appeddu and Jason Sawyer both live dual lives.
Tuesdays through Thursdays, they live like most students on campus-going to classes, meeting with professors, and studying. But from Friday until Monday night each week, they live and work 180 miles away at NMSU's Corona Range and Livestock Research Center-corralling, feeding, and studying cattle.
"We have to be very gentle with the cattle, so they'll let us do everything we have to for the research," explains Appeddu, who is working on her doctorate. "We have to be their friends."
Appeddu and Sawyer are studying under the direction of Mark Petersen, a professor with NMSU's animal and range sciences department.
"My project is to evaluate the diet quality of the forage and how it changes throughout the year," says Sawyer, who is starting a master's degree program. He's hoping to identify potential nutritional limitations in the diet to see what supplements may be necessary.
In another project, the researchers are trying to find a protein supplement that will improve reproductive efficiency in range beef cows. But to accomplish that they must follow some strange and time-consuming ranching practices.
"So we can feel confident about making recommendations to ranchers in the state, we often do things ranchers wouldn't do," Petersen says.
That includes spending as much as six hours corralling the cattle and individually feeding them exact amounts -- instead of just pouring the feed on the ground.
"We do our own work, gathering the cattle," Appeddu says. "It's really good practical experience."
In the end, the researchers hope following strict feeding practices and repeating experiments will result in solid information for New Mexico's ranchers.
"When we look at the current situation of low cattle prices, high feed prices, and a lack of forage on the range due to low rainfall, a low-cost, effective supplement is very important," Petersen says.
In one study, they found that 80 percent of the two-year-old cows fed a combination of cottonseed meal, blood meal, and feather meal conceived in the first 21 days of the fall breeding season. That was about a 20-percent improvement over other supplements tested.
"The idea is the sooner the cows get pregnant, the larger their calves will be next year, and the sooner those calves will reproduce," Petersen explains.
Bringing up Beetles
Three years ago, Stephanie Liesner didn't even know what a lady beetle larva looked like. Today, the College of Agriculture, Consumer and Environmental Sciences junior knows more about the bug's life cycle than she ever imagined.
Liesner is responsible for keeping a lady beetle colony, which was imported from China, thriving in order to support biological control research at the College.
Biological control is managing undesirable plants, insects, and animals by using beneficial insects, predators, or diseases.
Joe Ellington, a professor in NMSU's entomology, plant pathology, and weed science department, is studying how well the lady beetle, commonly called lady bug, controls pecan aphids. In past years, aphids have been a difficult problem in some locations, although they've been less of a problem recently, he says. On some occasions, the aphids can be expensive and difficult to manage.
"The rearing and release of lady beetles is an attempt to reduce the pecan aphid problem to a level requiring less management and insecticide use," Ellington says.
During most of the year, Liesner maintains the colony at about 2,000 lady bugs. As summer approaches, she works to increase the numbers so researchers can release as many as 500,000 bugs in Mesilla Valley pecan orchards.
Keeping the lady bugs alive keeps Liesner and Jessica Vigil, a student assistant, busy. The colony's environment must be carefully controlled for temperature, humidity, and amount of daylight in plastic boxes bought at local discount stores, modified so air can circulate. The adult lady bugs are fed grain moth eggs every other day.
When male and female lady bugs pair up, Liesner isolates the couples in their own "honeymoon suites." Liesner and Vigil must be ready to snatch larvae that hatch from the bugs' tiny eggs or they will be dinner for the couple. The students use small paint brushes to pick up and move the bugs around.
"When I'm trying to increase the colony and save as many larvae as possible, I may sit at a table for six hours or more a day and separate out the larvae and put them in petri dishes," Liesner says. "It's very tedious, but I've learned more in this job than in any class I've taken."
Formulating a Thesis
When a local raspberry grower's jam faded from red to pink, graduate student Cecelia Garcia-Whitehead started looking for a more attractive fruit spread formula.
"Who's going to buy pink raspberry jam?" Garcia-Whitehead asks. "Maybe a pink ice cream, but not a pink jam. It's just not a salable item."
So Garcia-Whitehead went to work to develop a better, value-added raspberry spread under the direction of Lisa McKee, an assistant professor with NMSU's home economics department.
"We ended up canning more than 600 half-pint jars of five different kinds of raspberry spread," Garcia-Whitehead says. "We started at 7a.m. on a Tuesday and finished at 11 that night. We took breaks to eat and just to sit down and rest for a while, but we got it all canned in one day."
The formulas they're testing include one made with Nutrasweet, another with sugar, and the rest with red raspberry, grape, or apple juice concentrates. "We chose these sweeteners over high fructose corn syrup or corn syrup so the product can be labeled as all natural," she explains.
Then the researchers collected initial chemical, color, and taste test data on the spreads. "I've peeked at some of the comments written for the taste test," Garcia-Whitehead says. "And I think that most of them were acceptable products. We got lots of comments that this would be great on ice cream, or on yogurt, or short-bread, so maybe this product can be used for more than just a fruit spread."
But Garcia-Whitehead will have to wait to make final formula recommendations -- Ņand to finish her master's degree thesis -- until she checks the color of her raspberry spreads again at three and six months.