THE FLORIDA CATTLEMAN AND LIVESTOCK JOURNAL
Performance of Beef Calves Provided Molasses-based Creep Supplements
Dr. John Arthington
Creep feeding is a management tool used to provide supplemental nutrients to pre-weaned calves. The word “creep” refers to the process by which the calf is allowed to creep into (or access) a space that is designed to exclude the cow. There are multiple designs of systems that will achieve this goal ranging from complex to very simple. In general, fencing structures or electrified wire that is positioned 36 to 42 inches above the ground are adequate to allow calf access but exclude cow access. The rationale for creep feeding is centered on the concept that the cow’s milk will only provide about half of the nutrition required by a 4 month-old calf. Without supplemental feed, the calf must obtain the remainder of its nutrition from forage. Often the forage base may be of limited quality for the calf to fulfill this deficit. This is further confounded by an inability to consume large amounts of forage due to an underdeveloped rumen. If milk and forage together cannot supply the calf with adequate nutrition, then sub-optimal body weight gain can be expected.
There are three types or categories of creep feeding. Two types involve the provision of feed or feed byproducts, within a cow-exclusion area, that are offered either 1) free-choice (unlimited creep), or 2) limited (limited-intake creep). The third type involves the management of a high-quality pasture forage that is only allowed to be grazed by pre-weaned calves (i.e. creep grazing).
Decisions regarding creep feeding beef calves must weigh the cost of implementing this management tool against the value of unrealized body weight due to inadequate nutrition. Most studies involving unlimited creep feeding have found that the value of this “added” gain, due to creep feeding, is poorly efficient, meaning that the pounds of creep feed needed to produce 1 lb of added gain is typically more costly than the value of that added gain. During the early weeks of creep feeding it is not uncommon for this ratio to be as great at 12 to 15:1. As days of creep feeding advance, this conversion ratio typically improves, thus producers can realize the greatest economic benefits of creep feeding when the management system can be applied to the herd for over 90 days. Despite the number of days creep feeding is offered, the economics of the practice continue to be debatable. Calves will experience some level of daily gain, despite the provision of creep feed, so it is important that beef producers understand the calculation used to estimate “added” gain. Added gain is the difference between the daily gain of calves consuming creep feed vs. those not consuming creep feed. This added or additional gain is attributed to the creep feed consumed and is often times of less value than the cost of feed required to produce it. In general, unlimited creep feeding becomes more economical as feed prices decrease and calf prices increase.
The economic considerations described above are attributable to unlimited creep feeding situations. Another option for consideration is limited creep feeding, which is designed to provide a small amount of supplemental nutrition targeted to fill gaps in protein and/or energy deficiency and compliment the value of the milk and forage consumed by the calf. In Florida, Dr. Bill Kunkle previously investigated the effects of providing cottonseed meal to pre-weaned calves. Intake was limited by the inclusion of salt which was gradually increased in the formula (up to 8%) to limit intake to approximately 0.50 to 0.75 lb/d. A summary of 6 experiments revealed that calves experienced 0.30 lb/d of added gain while consuming an average of 0.65 lb of cottonseed meal daily. Each pound of added gain required 2.2 lb of cottonseed meal. Although these experiments revealed significant variation among studies, they collectively suggest that pre-weaned beef calves can experience efficient, cost-effective added gains when provided limit-fed creep supplements.
In Florida, as well as much of the Gulf coast region, the use of molasses-based liquid feeds for the supplementation of beef cows is common. These supplements can be fortified to increase the protein, energy, and/or vitamin and mineral profile of the product. Some of ingredients commonly added to molasses supplements include urea, vegetable meals (i.e. cottonseed meal), byproducts (dried distillers grains), fats and oil, and minerals and vitamins. Molasses-based supplements are also readily consumed by pre-weaned calves and have an added benefit of self-limiting intake.
The objective of these studies was to examine the influence of free-choice, molasses-based creep supplements on the efficiency and cost-effectiveness of added gain in pre-weaned beef calves.
Two experiments were conducted at the Range Cattle Research and Education Center in Ona. Each experiment was repeated among consecutive years resulting in 4 years of data. The experiments were conducted using fall-calving (October – December) beef herds and were initiated in April of each year and concluded at weaning (122, 117, 104, and 102 days, respectively). Liquid creep supplements were based on a sugarcane molasses carrier with ingredients added as described below. Supplements were offered to calves in cow-exclusion areas within open 90-gallon tubs.
The first experiment utilized Braford cow/calf pairs grazing established summer bahiagrass pastures. Treatments were applied to eight pastures containing approximately 17 cow/calf pairs per pasture. Treatments consisted of 1) no creep, 2) molasses + urea creep, and 3) molasses + urea + Alimet® creep. Alimet® (Novus International, St. Louis, MO), a commercial source of rumen bypass sulfur-containing amino acids (TSAA), was blended into the molasses + urea formulation (0.63%as-fed basis) and provided 0.22% TSAA.
The second experiment utilized Brangus-crossbred cow/calf pairs grazing established bahiagrass pastures. Treatments were applied to 12 pastures containing 4 and 3 cow/calf pairs in years 1 and 2, respectively. Treatments consisted of 1) no creep, 2) molasses + urea creep, and 3) molasses + cottonseed meal creep.
There was significant annual variation in the consumption of liquid creep supplement in the first experiment with almost twice as much supplement consumed in year 2 vs. year 1 (0.50 vs. 0.19 lb/d, respectively). Further, in year 2, calves provided creep supplements with Alimet® consumed almost 1/3 less than calves provided supplements without Alimet®. This difference is likely due to an offensive odor which is characteristic of this ingredient. There effects of treatment on supplement intake in the second experiment, with calves consuming an average of 1.03 lb of supplement daily.
In the first experiment, creep supplementation resulted in 0.14 lb/d of added gain compared to calves receiving no creep supplement. The ADG of calves consuming supplements containing Alimet® was 5.1% less than calves consuming supplements without Alimet® (Table 1). This response is likely the result of reduced supplement intake vs. a direct effect on calf growth. Although supplement intake was greater in the second vs. first experiment, there was no effect on calf ADG (Table 1). Overall, calf ADG was less in both years of the second experiment compared to the first.
There was no impact of creep supplement on change in cow body weight or body condition score over the supplementation period; however, cows in the second experiment had less body weight and body condition at both the start and end of the supplementation period compared to cows in the first experiment.
These results support the earlier findings by Dr. Bill Kunkle and his research involving limit-creep supplements based on cottonseed meal and salt mixtures. Calf performance responses, as measured by the added gain realized by creep supplementation, are highly variable and cannot always be described by amounts of creep feed consumed. This variability has large and direct impacts on the cost effectiveness of the management system. In our studies, using liquid molasses-based creep supplements, we realized a 4-year average cost of gain of $0.53 / lb of added gain – not including the costs associated with feeding equipment and labor. Although this value may appear cost-effective, in 2 of the 4 study years the cost of added gain exceeded the per lb value of the calves we sold.
|Table 1. Effects of liquid molasses-based creep-feed formulations on performance of beef calves over approximately 100 days prior to weaning (Experiment 1 and 2).|
|Item||No Creep||Molasses + Urea||Molasses + Urea + Alimet||Stnd. Error||Ingredient Comparison 1||Creep vs. No Creep|
|- - - - - - - - lb - - - - - - - -|
|Experiment 1 2|
|No Creep||Molasses + Urea||Molasses + Cottonseed Meal|
Experiment 2 3
|1 Ingredient comparison = Alimet® vs. No Alimet® (Exp. 1) and Urea vs. Cottonseed Meal (Exp. 2).|
|2 Pooled results of a total of 265 calves (2 years; 8 pastures/year; n = 3 pastures each for creep supplements and 2 pastures for no creep control).|
|3 Pooled results of a total of 84 calves (2 years; 12 pastures/year; n = 4 pastures/treatment).|