Purdue News
Purdue News
One way to keep costs down is to lower the cost of feed, says Purdue University animal scientist Layi Adeola. Sorghum is one lower-cost, yet nutritious, alternative to corn that producers in southern and central parts of the United States sometimes feed hogs, but there's a problem. Hogs, other livestock and even people have trouble gaining weight on sorghum because of its high tannin content.
"With a high-tannin diet, there can be as much as a 20 percent to 50 percent decrease in weight gain," Adeola says.
Adeola investigated the problem and found that tannins attach themselves to certain digestive enzymes on the membrane in the small intestine. Unfettered, the enzymes snag passing proteins and carbohydrates, break them down into amino acids and sugars, and make them available to go into the animal's bloodstream. When bound to tannins, however, the enzymes are unable to catch and break down passing food molecules. Potential nutrition passes through instead of being absorbed.
Adeola would like to foil the tannins.
"Right now any remedy is still speculative," he says. "But when we understand the whole picture, we may be able to look for agents that could reverse or decouple the binding between tannins and enzymes." And that could help plant breeders create a sorghum variety that's a more nutritious, less costly livestock feed.
Another way to keep production costs low is to use antibiotics only when they're really needed, says Purdue animal scientist Mark Diekman.
Many hog producers use antibiotics routinely to help keep hogs healthy. In many situations, routine use of antibiotics is warranted. However, hogs raised in all-in/all-out (AI/AO) management systems live in such a disease-free environment that antibiotics could be a waste of money for the producer, Diekman says.
Diekman and animal sciences graduate student Amy Ice raised 200 barrows in AI/AO and 200 barrows in continuous management systems. Half of each group received antibiotic treatment, the other half did not. At the end of six months, hogs in the AI/AO group had fewer lung lesions and produced more lean meat than did the hogs in the continuous management system. However, the AI/AO group that was given antibiotics did no better than the untreated AI/AO group.
Diekman stresses that the results are preliminary, but they suggest that for hogs raised in AI/AO management systems, routine use of antibiotics could be a waste of money.
Money is also on the minds of consumers looking for meat in the grocery, but it isn't their only concern. Today consumers are looking for leaner cuts, says Purdue animal scientist Allan Schinckel. It's a healthy move, but Schinckel is concerned that as consumers push hog producers to raise leaner and leaner pork, meat quality might suffer.
"The swine industry does not have a serious problem, yet," Schinckel says. "However, if payment and selection for extreme leanness continues, the percent of intramuscular fat will decline to the point that the pork will become much drier and tougher, especially when overcooked."
As he has searched for ways keep lean pork tender and juicy, Schinckel has studied fat deposition in average-lean and very lean pigs. He fed low-fat diets to half of the pigs from each group, high-fat diets to the other half. The average-lean pigs on high-fat diets deposited more fat in their muscles, and the meat from them was more marbled. Very lean pigs, on the other hand, did not deposit more intramuscular fat. In fact, the fat deposits were nearly identical for very lean hogs no matter how much fat they were fed.
From this, Schinckel concluded that average-lean and very lean genetic lines of hogs deposit fat differently in their muscle tissue. This difference likely is partially responsible for differences in pork quality.
Sources: Layi Adeola, (765) 494-4848; e-mail, ladeola@ansc.purdue.edu
Mark Diekman (765) 494-4829; e-mail, mdiekman@ansc.purdue.edu
Allan Schinckel, (765) 494-4836; e-mail, allan_schinkel@acn.purdue.edu
Writer: Rebecca J. Goetz, (765) 494-0461; e-mail, rjg@aes.purdue.edu
Purdue News Service: (765) 494-2096; e-mail, purduenews@purdue.edu
