Final report for LS14-266
The Gulf Coast region has abundant forage resources during most of the year. All around the US, there is a trend showing that consumer demand for grass-fed beef is increasing. Adding to this trend, consumers are more inclined to support locally-produced products, favoring localized economies. Forage-finished beef can be beneficial in the human diet and promotes environmentally sound practices, improving soil nutrient cycling, conserving soil and water, and minimizing the dependence on non-renewable resources.
Of major interest in the grass-fed beef industry is the study of any possible breed type effect on these systems. Breed types can provide alternatives for small and very small beef and dairy producers. Gillespie et al. (unpublished data) conducted a survey of approximately 1,000 forage-fed beef producers nationwide. Seventy-five percent of respondents with a farm of 40 acres or less reported using British breeds. This number increases to 92% when farms are between 40 and 80 acres.
In Louisiana and the SE region of the US, Holstein steers may provide an additional source of income for struggling dairy producers. Demand for these steers for forage-fed programs may help increase the prices producers receive for them. The use of “rare” or “heritage” beef breed types such as those derived from the Criollo cattle (Pineywoods, Florida Cracker, Longhorn, etc.) can also be an excellent genetic resource for small producers. These breeds are of small frame with concomitant low forage demand, hardy, and very well adapted to the heat and environment of the Southeast region. There is very little information on the performance and carcass characteristics of these breeds or comparisons of them with conventional beef and dairy breeds under similar management conditions. A British breed that is considered by producers (and that will be evaluated on one of the collaborator farms) as the typical for forage fed systems is Dexter. It is a small frame animal with mature weights around 1000 lb. Unfortunately, there is a time period (45-60 days) between weaning (usually mid-October) and the time cool-season annuals are ready for grazing that negatively affects animal performance. This 'fall forage gap' or 'transition period' is normally filled using warm-season grass hay only or balage or hay plus supplement with concomitant increased costs of production. Conventionally planted pastures are usually ready earlier than no-tilled but effects on soil characteristics are different. Alternative forages such as brassicas are available and may provide abundant forage mass and quality during this time.
With the help of producers who will provide information (animal performance, cover crops production) and host pasture-walks, we hypothesize that planting brassicas with a mix of small grains and clovers will improve animal performance during the 'transition period' and hence the sustainability and profitability of beef stocker and forage-fed finishing operations. Our objective is to evaluate the impact of two forage systems that differ in the intensity of resources used and breed types on productivity, carcass and soil characteristics, and economics.
1) Evaluate the interaction between forage systems and traditional (Angus) and non-traditional (Holstein and Pineywoods) breed types. This evaluation will be conducted by measuring the productivity and economic sustainability of producing beef on 100% forage diets and on the impact of tillage and forage systems on soil physic-chemical properties.
2) Measure the impact of breed type (Pineywoods, Braford, and Dexter) and the use of cover crops (brassicas, clovers, small grains and native grasses) under different management practices (rotationally grazed, stockpiled forages) at the farm level.
3) On-farm research and outreach program will be run jointly enhancing technology transfer through theory and on-hand work. Pasture walks will be organized annually on each of these farms and at the Iberia Research Station (IRS). Information will also be disseminated via peer-reviewed journals, extension publications, magazines and other venues. A workshop in Year 3 will compile all information dealing with animal productivity, effect of forage system on soil characteristics and economic analyses
Objective 1. In October of years 1 and 2, 60 (20/breed type) fall-weaned steers (Angus, Holstein, and Pineywoods) were randomly allotted to 4 groups 5 steers each within breed, and 2 groups of each grazed each of the forage systems. This allotment of steers allowed us to determine appropriate area for grazing on each breed types which differ in body weight (Holstein > Angus > Pineywoods). Based on our previously SARE-funded project the stocking rate used was 1.5 steers/ha.
Forage systems (treatments) were: 1) Conventional and no-till planted annual ryegrass for winter grazing (75% of the area) and bermudagrass for summer grazing (25% of the area) plus bermudagrass hay for transition periods; and 2) Conventional and no-till planted multispecies cover crops for the fall transition period and winter grazing (25% of the area), followed by ryegrass+white clover for winter grazing (50% of the area), then alfalfa/peanut hay until alyceclover + pearl millet + cowpeas mixed pastures (25% of the area) for summer grazing.
For 2 consecutive years, pastures in systems (treatments) 1 and 2 were planted in mid-September and fertilized at that time with 50 units of N per hectare. In treatment 1, 75% of the area of the system was planted with annual ryegrass (Lolium multiflorum), half as no-till and the other half on a conventionally prepared seedbed. In treatment 2, similar soil management practices (no-till vs. conventional tillage) were used for planting the multispecies cover crop ('cocktail') composed of: pearl millet (Pennisetum glaucum), forage soybean, cowpeas (Vigna unguiculata), annual ryegrass, rye, oats (Avena sativa), purple turnips (B. rapa L. var. rapa (L.) Thell), kale (Brassica napus), radish (Raphanus sativus), and clover. The winter pastures, white clover + annual ryegrass, were no-tilled as previously described for annual ryegrass in treatment 1. Treatment 1 used bermudagrass hay for the fall and spring (if needed) transition period(s) produced from hay meadows (cv. 'Jiggs') available at the Iberia Research Station. Treatment 2 will use alfalfa or peanut hay for the spring transition period that was purchased as needed. In treatment 1, a 1-ha pasture of Tifton-85 bermudagrass (Cynodon dactylon) was available for each replicate (4 ha total). Summer pastures, alyceclover + pearl millet + cowpeas, for summer grazing in treatment 2 were no-till planted in late May of years 1 and 2 in 25% of the area of the system.
Calves born at the LSU AgCenter stations (Angus, Holstein) were identified, weighed, tagged, and castrated at birth. Health protocols were followed in each station. Pineywoods cattle were purchased from commercial farms. Cattle followed the same health protocol as other steers.
Steers in treatments #1 and #2 were rotationally stocked based on forage mass and grazing pressure (kg BW/ha)
Cost estimates were made on the basis of quantities of inputs used in each of the experimental groups and input prices as provided in the LSU Agricultural Center's annual cost and returns estimates for Louisiana beef and forage production.
Soil samples under imposed different forage system treatments with both conventional and no-till practices were collected yearly and analyzed using established methods for monitoring plant nutrient availability and changes in soil properties. In addition, multi-nutrient tests for soil available N, P, K, Ca, Mg as well as short term CO2 respiration tests for carbon availability were determined. Aggregate stability, an important parameter soil physical property, were determined using the wet-sieving procedure. In addition, organic carbon associated with different aggregate fractions were determined to assess the forage system impact on organic carbon accumulations. Nitrogen use efficiency was evaluated by the recovery efficiency procedure based on the increase in crop uptake of the N and other nutrients in above-ground parts of the plant in response to fertilizer nutrient applied.
Objective 2. Four farms were selected for collaboration. Two of these farms used diverse cover crop pasture during the transition period for recently weaned calves. Only one farm planted mixed pastures as cover crops both years; however, in both years the stand was lost due to deer infestation. The second farm planted cover crops only one year and could not be grazed due to excessive rainfall and flooding of all the pasture. The other two farms allowed gathering information regarding performance and carcass data of forage-fed beef cattle.
Objective 3. Pasture walks at farms and the Iberia Research Station; field day at IRS.
No differences in animal performance were observed between Systems 1 and 2 hence data were summarized based on breed types (Table 1). Angus and Holstein steers had greater ADG than Pineywoods, while Angus performed better than Holstein steers during summer months. Pineywoods had lower ADG probably due to the fact that as a breed type it has not been selected for growth. As a heritage breed it is extremely important for maintaining diversity and as such it should be considered. Even though it was not evaluated, many producers raising them would say that Pineywoods are extremely adapted to our weather conditions (temperature and humidity) as well as resistant to internal and external parasites.
|Table 1||Average daily gains, lb|
|Day 0 to first harvest||2.80||2.78||1.79|
|To second harvest||1.30||0.98||0.80|
One issue certainly in their advantage is that they need a smaller area due to their body size. On average the BW of Pineywoods throughout the different grazing periods was 55-60% of that of Angus and Holstein. Related to this difference it is also their daily dry matter intake (DMI) which is much smaller than the other 2 breeds. Estimations conducted on this regard during the month of March of each year, showed that the daily DMI on cool season pastures was 2.75%, 2.89% and 2.60% of their BW for Angus, Holstein, and Pineywoods, respectively. Based on the average BW of the steers at this moment, these represent 22.5, 27.1, and 13.0 lb DM per animal per day, respectively. Important to observe is the fact that summer ADG are really small compared to winter gains. Determinations of temperature humidity index during the summer months indicate that steers were in moderate to severe heat stress during most of the day. It has been proven that this factor may decrease DMI 30-40% which in turns may reduce ADG.
Tables 2 shows the carcass characteristics of these steers at the first harvest date (out of coll season pastures; late April-early May of each year). As expected due to their breed production objectives, Angus steers had greater marbling, fat thickness and ribeye area than steers from the other breed types, which were similar and much leaner.
|TABLE 2||LATE SPRING HARVEST|
|12th rib fat thickness, in||0.21||0.08||0.06|
|Ribeye area, sq in||10.2||8.8||8.5|
|*300-390 = Slight|
Table 3 presents data of the second harvest which as conducted in September of each year. Data show a similar trend than for the first harvest with greater values for Angus for marbling, fat thickness, and ribeye area.
|TABLE 3||EARLY FALL HARVEST|
|12th rib fat thickness, in||0.34||0.04||0.1|
|Ribeye area, sq in||10.6||8||9.8|
|*300-390 = Slight; 400-490 = Small; 500-590 = Modest|
The economic analysis of steer breed type differences in returns, expenses, and returns above expenses per cwt determined that Angus and Holstein steers were not different between them at returns above expenses of $173/cwt and $178/cwt respectively; however, when considering grazed area and including hay production of non-grazed areas there were no differences between the 3 breed types.
Routine soil nutrients including K, Ca, Mg, Zn and soil pH changed little over the timeframe of this project, whereas P and S showed large variability, which were likely due to the specific sampling points influenced by grazing. Long-term bermudagrass field showed generally greater soil C than annual ryegrass field. No till ryegrass+clover (measured at the end of 3 years project) tend to increase fractions of > 2mm and 0.25-2 mm aggregates compared to ryegrass alone. In addition, ryegrass+clover tend to increase C content associated with all aggregate fractions as well as C associated with silt and clay fractions. Long-term bermudagrass fields also tend to have greater large aggregate fractions (> 2mm and 0.25-5 mm) as well as aggregate C contents than pastures planted with annual ryegrass. Soils under the “cocktail” pasture appeared to have similar C content in large aggregate fractions as compared to summer pasture field of bermudagrass.
Analysis of soil microbial community using phospholipids fatty acid (PLFA) method showed that No-till Ryegrass+Clover and “cocktail” treatments increased overall microbial biomass as well as fungi populations. The ryegrass+clover treatment also significantly increased the ratio of Gram-positive to Gram-negative bacteria. In addition, the no-till ryegrass+clover treatment showed greater stress level to Gram-negative bacteria than the rest treatments based on the cyclopropyl monounsaturated ratio (CMR) of (Cyc17:0+Cyc19:0)/(16:1w7c+18:1w7c). These results along with those of aggregate fractions and organic C under different pasture crop systems suggest that the inclusion of legume such as clover significantly enhance soil health. For uptake of nutrients, however, the conventional tilled ryegrass tends to have greater nitrogen use efficiency followed by bermudagrass, then no-till ryegrass and ryegrass+clover pastures.
Farms dealing with grass-fed beef production are identified as Farms 1 and 2. Farm 1 produces Pineywoods cattle, harvest them in an abattoir close to the farm and commercialized the product in farm markets. Fourteen steers were tagged when they were received (5 of them castrated) and weighed. Depending on weather and producer's availability, steers were weighed at least 4 times per year until harvested. Carcass data were collected. Pastures were annual ryegrass (on average) from January to April while a bahiagrass/bemudagrass was available from June to September/October. Hay from these summer pastures were fed during the transition periods. On average, steers weighed 315 lb at the time of purchased with an estimated age of 12-15 months of age. On average, steers were harvested approximately 418 days after with an average weight of 644 lb (ADG=0.79 lb). At the abattoir and after restriction of water and feed, BW was on average 619, hot carcass weight was 309 lb, REA was 8 sqin, fat thickness 0.15 in, select and KPH 1.5%. Farm 2 produces crossbred steers with influence of Dexter, Shorthorn, and Red Poll breeds. Average body weight at harvest was 1218 lb. Average carcass characteristics were: 631 lb of HCW, high select-low choice, REA of 10.1 sqin, and 0.22 in of fat thickness.
A pasture walk was held in the second year in one of the farms with cover crops (12 attendees). This pasture walk was used to visit the farm, look at the cover crop stand and planned for grazing. However a week later excessive rainfall caused flooding of most of the farm including the area of the cover crop. The other two with grass-fed beef cattle were held in the first year in March (13 and 21 attendees respectively). Pastures and cattle were observed. Emphasis was placed on the discussion of the type of animal that is needed for grass-fed beef production (size, breed type) and pasture management including stocking rates, grazing pressure, use of electric fences, watering systems, etc. The Iberia Research Station hosted 2 pasture walks (16 and 29 attendees, respectively) in second year (August and October) where animal performance and forage data production were presented, carcass data from the first year, economics, and marketing strategies. Data (first 2 years) and the experiment itself were presented during the station's annual field day (March 2016, 201, and 2018) with 129, 98, and 113 attendees, respectively.
Educational & Outreach Activities
Turnage, Z. J. 2018. Analyses of alternative forage-based pasture systems for maximizing profitability in grass-fed beef production. LSU; 54 pages.
This program development generated outputs such as advisory team meetings, peer-reviewed scientific articles (preparation) and conference proceedings and abstracts, trained agents and graduate students, and other outreach end points. The most important outcomes generated by this project for advisory community and producers include: Understanding of federal program support for small and very small forage-fed beef producers; effects of grazing on cover crops, effect of these cover crops and other swards on soil properties and nutrient use efficiency; differences among breed types based on their genetic selection/potential and adaptation to small farms; systems and breed types effects on economics and profitability; pasture management and response of different forage alternatives (grasses, legumes, brassicas) to grazing pressure; effect of temperature and humidity on animal grazing behavior and how this relates to performance. Most importantly, producers and extension personnel got an excellent look at what can be done through intensification of beef production as well as the type of product that can be obtained with different breed type and age at harvest.
Working with producers that are conscious of their work and progressive enough to apply new management practices and with a true interest in the development of the grass-fed beef industry have been a privilege. They have promoted the pasture walks and open the doors of their farms to other farmers, agents, and research community. They were the enablers of the network that was created due to these activities and were interested and supportive of the project throughout its lifetime. They have learned to manage cover crops for different objectives (support soil health, grazing, or erosion control) and recognize the potential of heritage breeds for grass fed beef production.