Spineless cactus shows strength as feed supplement

A team of researchers in Brazil evaluated the use of the plant both with and without urea as a supplement for cattle raised on forage. The group was examining nutrient intake, partial and total digestibility and ruminal kinetics in steer getting the non-conventional diet supplement.

“This study aimed to evaluate the effect of using spineless cactus enriched with urea to replace a traditional multiple supplements on ruminal digestibility of dry matter and other dietary constituents using samples obtained from the omasum, and also to assess the nutrient intake, total and intestinal digestibility, and ruminal kinetics,”​ said the researchers.

The group found the combination of 2% urea and spineless cactus improved ruminal digestibility of dry matter (DM), neutral detergent fiber (NDF) and crude protein (CP), said the researchers.

“Spineless cactus enriched with up to 2% urea efficiently replaces traditional multiple supplements, since intake and nutrient digestibility, intake rates, and passage and digestion rates of the diets were similar to those observed when using the traditional supplement,” ​they said.

Cactus and urea​

In some areas animal production systems use pasture as an economical source of nutrients, said the researchers. But during dry seasons forage scarcity can result in weight loss or delay the development of cattle.

Supplements are used to maintain needed growth, they said. But the additives have to be formulated to improve intake and digestion of forage.

“In efficient production systems, supplementation is adopted as a technological practice to complement the pasture, aiming at an output compatible with the genetic potential of animals, since concentrated supplements such as corn and soybean meal have high prices on the market, compromising the economic efficiency of the system,”​ noted the authors. “The supplementation of beef cattle allows correcting nutrient deficiencies, improving forage utilization and animal performance, increasing economic return (Kunkle et al., 2000), and possibly shortening reproductive, growth, and fattening cycles.”​

Spineless cactus can be an important feed stuff for cattle with low crude protein, and fiber amounts and higher energy levels, said the researchers. When combined with urea, it may offer a lower cost feed supplement than other vegetable proteins.

Previous research with the alternative supplement has demonstrated similar average daily gain in dairy cattle when the combination replaced corn in the diet, they said.

“We hypothesized that spineless cactus enriched with urea, in the form of a multiple supplement, could replace traditional supplements composed of corn, wheat bran, and soybean meal for cattle,”​ wrote the team.

The study ​

During the experiment, five cross-bred steers with cannulas were given a series of diets, said the researchers. The diets included a control involving a traditional multiple supplement and a diet including spineless cactus and four differing levels of urea – 0%, 1%, 2% and 3%.

The basal diet was a Tifton-85 hay, which had a high neutral detergent fiber level and offered low amounts of crude protein, they said.

“The trial lasted 80 days, with five consecutive 16-day periods, and was divided into a 7-day adaptation (Storry and Sutton, 1969 and Menezes et al., 2011) and 9-day sampling,”​ they said.

During the trials, researchers collected samples of omasal digesta and fecal matter and indigestible neutral detergent fiber (iNDF) was estimated, they said. Rumen contents were collected on days 14 and 16 to establish rate of digestion and ruminal pool.

“Samples of feeds, orts, feces, ruminal content, and omasal digesta were analyzed for dry matter (DM; method 934.01), organic matter (OM; method 930.05), crude protein (CP; method 968.06), and ether extract (EE; method 920.39),”​ they said. And, ingestion rates (ki), passage (kp), degregdation of NDF (kd) and NDFi (kpi) were established, added the researchers.  

Results​

The inclusion of the urea linearly improved the crude protein intake of the cattle, said the researchers. There was a quadratic effect in response to intake of dry matter, organic matter (OM) non-fiber carbohydrates (NFC), NDF and OM.

However, the intake level for many nutrients was lower for cattle getting the spineless cactus without urea, they said.

“There was an improvement in ruminal digestibility of DM, NDF, and CP when spineless cactus was enriched with urea,”​ they said. And, there was an improved rate of intake (ki) when urea was added to the cactus supplement.

For the spineless cactus enriched with 3% urea diet, the rumen digestibility of CP was higher than the control diet, they said. And, the passage rate was similar to the control diet.

But there were no changes to the ruminal pool of dry matter, NDF and iNDF when urea was added to the feed, said the researchers.

Source: Livestock Science​

Title: Intake, total and partial digestibility of nutrients, and ruminal kinetics in crossbreed steers fed with multiple supplements containing spineless cactus enriched with urea​

DOI: doi:10.1016/j.livsci.2016.04.008​

Authors: C.T.F. Costa, M.A. Ferreira, J.M.S. Campos, A. Guim, J.L. Silva, M.C.B. Siqueira, L.J.A. Barros, T.D.Q. Siqueira