A team of researchers from South Dakota State University examined the use of microbially enhanced, or fungi-treated soy protein (MSP) in place of soybean meal in pelleted starter feeds for calves.
The group published their work in the Journal of Dairy Science.
“The objectives of this research were to conduct a feeding study to determine the effects of MSP in dairy calf starter pellets on growth performance, which was evaluated based on feed intake, BW [bodyweight], body frame size, blood metabolic profile, fecal consistency scores, and apparent total-tract nutrient digestion,” they said. “As part of this, we also wanted to determine if the increased calf starter pellet CP [crude protein] from the MSP benefited the calves.”
During the 12-week study, researchers found that calves getting a pelleted MSP starter with an enhanced milk replacer (MR) maintained growth using less starter than those getting a soybean-meal-based (SBM) pellets.
“Calves fed MSP in starter pellets with conventional MR had comparable growth performance to calves fed pellets with SBM and MR formulated for accelerated growth, especially in the preweaning period,” said the researchers. “Calves fed MSP with MR formulated for accelerated growth had similar growth performance with less starter pellet intake compared with calves fed SBMA [soybean meal accelerated].”
Why enhanced soy protein?
Early growth in dairy calves includes development of immunological and digestive systems, that can alter animal performance, said the researchers. High protein milk replacer and starter feeds were created to support that growth.
Most of the proteins in these products are milk-based, which increases the cost of the feeding programs, they said. But, they have been found to improve performance better than plant-based proteins.
Dry feed intake in this period also is needed to help develop a functioning rumen, as early consumption improves ruminal butyrate, they said. It also has been shown to reduce weaning stress by increasing reticulorumen development and helping calves move from liquid to dry feed.
A new process uses fungi to aerobically process soybean meal (SBM) and boost the protein content and digestibility while reducing the anti-nutritional compounds, said the researchers. The microbially enhanced soy protein (MSP) has performed similar to fishmeal in aquaculture studies, but has not been fed to calves.
There is a potential that fungal cell walls and beta-glucans found in the MSP may generate prebiotic attributes, they said. “Because of its unique nutritional properties, MSP may be a beneficial feed for dairy calves with developing digestive systems,” they added.
However, past research using fermented SBM in dairy calf diets has been inconclusive, with some research finding improving immune responses and others not having that reaction, said the researchers. MSP is similar to fermented SBM as it is generated using an aerobic incubation, but it has more protein and fewer anti-nutritional elements.
The group hypothesized that as MSP has more protein of better quality than SBM, it could be used in a starter pellet with a conventional milk replacer to generate similar results to a pellet made from soybean meal and an improved MR.
“We also hypothesized that feeding MSP in pellets with MR formulated for accelerated growth may have additive benefits,” they said.
In the experiment, 36 calves were given one of three diets ad libitum, said the researchers. “The three [feeds] were (1) MSP pellets with MR formulated for accelerated growth (MSPA), (2) SBM pellets with MR formulated for accelerated growth (SBMA), and (3) MSP pellets with conventional MR (MSPC),” they added.
Feed intake were noted daily, and body weights, frame size and blood samples were collected twice every two weeks, they said. Fecal samples were taken five times for a three-day period during the last week of the study to check for apparent total tract digestibility.
Calves getting the SBMA diet had the largest intake and, those receiving the MSPC diet had the smallest intake, said the researchers. Plasma urea nitrogen was largest for calves getting the MSPA diet and smallest for the MSPC calves, while serum glucose levels were similar for all groups.
“Overall, mean BW were greater for calves on the MSPA treatment compared with calves fed MSPC with SBMA in the middle and similar to both,” they said. Hip height and heart girth was largest for MSPA calves, and those getting both MSPA and SBMA were the longest, they added.
IGF-1 levels were highest for calves getting SBMA, they said. And, those getting MSPC had the largest amount of triglycerides.
“Findings partially agreed with our hypothesis and demonstrated that feeding MSP as major ingredient in starter pellets has potential to maintain calf performance with less DMI [dry matter intake],” said the researchers.
There was a similar average daily gain for the diets, but a feed-to-week interaction resulted in calves getting the MSPC diet being lighter than those in other groups, they said. The gain-to-feed ratio was similar for the feeds but again a week to diet relationship was noted.
“Treatments had similar total-tract dry matter digestibility, but calves fed MSPC had greater crude protein digestibility than SBMA, with MSPA similar to both,” they said.
Source: Journal of Dairy Science
Title: Growth performance of calves fed microbially enhanced soy protein in pelleted starters
Authors: N. Senevirathne, J. Anderson, W. Gibbons, J. Clapper