Trial Site: Fairview Research Farm
Research Coordinator: Dr. Akim Omokanye
From: Peace Country Beef & Forage Association 2016 Annual Report
The Regional Silage Variety Trials (RSVTs) are an important source of information for livestock forage based production regarding the forage yield potential and quality performance of new crop varieties as they become available. The RSVTs are carried out in small plot replicated trials. PCBFA provides unbiased, comprehensive information that assists producers to make better crop choices for silage or greenfeed production. In addition to the findings presented here from our trial, the results from the RSVTs across the different trial sites in the province will also be reported in the Alberta Seed Guide (www.seed.ab.ca).
Methods
Site: The study site was at the Fairview Research Farm (NW5-82-3W6) on RR #35, MD of Fairview. The site had soybeans in 2015. Soil test at 0-6” soil depth done at Exova laboratory (Edmonton) prior to seeding showed an organic matter content of 7.3%, a pH of 5.4 (acidic) and an electrical conductivity of 0.58 dS/m. The field was cultivated before seeding.
Experimental Design: Randomized complete block design in 4 replications. Small plots measuring 11.04 m2 (118.8 ft2) were used.
Treatments (Varieties): The following 13 barley varieties consisting of eleven 2-row & two 6-row varieties were seeded:
1. Amisk- 6-row, rough awned, semi-dwarf, general purpose barley
2. CDC Austenson (Check) - 2-row, rough awned variety, high feed yield
3. CDC Coalition - 2-row, feed barley
4. CDC Maverick - a new 2-row forage variety, smooth awned for improved palatability
5. Champion - 2-row, feed barley
6. Claymore - 2-row, semi-erect, feed barley
7. CDC Cowboy - 2-row, forage variety
8. CDC Meredith - 2-row, malting barley
9. Canmore - a new 2-row general purpose barley
10. Conlon- 2-row, feed and malting barley
11. Gadsby - 2-row, rough awned, general purpose barley
12. Sundre - 6-row, feed barley for grain and forage
13. TR13740 - 2-row, feed barley
Seeding Rate: We seeded 300 plants/m2 (27.8 plants/ft2). A 6-row Fabro plot drill at 9” row spacing was used to seed. Seeding was done on May 16.
Fertility according to soil tests (actual lbs/acre): 0 N + 33 P + 47 K + 0 S (broadcast). Soil test showed adequate amounts of N & S for the crop, so N & S were not applied.
Spraying: Roundup WeatherMAX® was used as pre-emergent 7 days after seeding. In-crop spraying was done with 2, 4 - D 700 at 0.35 L/acre. Rouging (hand weeding) was done a few times.
Measurements taken at soft dough stage:
Prior to harvest, stand assessment for stand uniformity was done.
Crop height: Random plants were selected for plant height measurement at soft dough stage. Plant height was measured up to the flag leaf.
Forage yield & quality determination: At soft dough stage, plants in the 4 centre rows 10 feet long were harvested, weighed fresh, sub-sampled (about 500 grams), air dried for some days and then weighed to determine dry matter (DM) content. Forage samples were analyzed for quality using standard procedures for wet chemistry at A & L Laboratory, Toronto.
Results & Interpretation
Plant Height & Lodging
CDC Maverick significantly grew tallest (94 cm) of all varieties (Table 1). CDC Maverick was followed by CDC Cowboy (88 cm). Both CDC Maverick and CDC Cowboy grew far taller than other varieties by as much as 30 to 35 cm.
No lodging was observed with any of the varieties tested.
Forage DM yield
The forage DM was highest for TR13740 (4.4 tons/acre) and lowest for Claymore (3 tons/acre) (Figure 1). The top 3 varieties with DM yields >4.0 tons/acre were TR13740, CDC Maverick and Champion. The DM yields of TR13740, CDC Maverick and Champion as % of check (CDC Austenson) were 114, 112 and 105%, respectively.
CDC Maverick is a 2 row, smooth awned, new forage barley with CDC Cowboy parentage. In the present test, CDC Maverick had a yield advantage of 1199 lbs DM/acre over CDC Cowboy.
Forage Quality
Crude Protein (CP) - The forage CP was generally above 12% for all barley varieties tested. Only Gadsby, Amisk and CDC Coalition appeared to have higher CP than check (CDC Austenson)(Figure 2).
Overall, the varieties had forage CP content that exceeded the protein requirements of a mature beef cow, which requires 7, 9 and 11% at mid-pregnancy, late-pregnancy and during lactation. The varieties also met or exceeded the 12-13% protein needed by growing and finishing calves.
Total Digestible Nutrients (TDN) - The forage energy content (TDN) varied from 67% for CDC Austenson to 70% for Conlon and Champion (Figure 3). All varieties had adequate amounts of TDN to meet the requirements of a mature beef cow, which is 55% at second trimester, 60% at third trimester and 65% by a lactating cow. Also, the TDNs were generally well within the ranges suggested for growing and finishing calves (65-70%).
Other forms of energy - Energy is probably the most important nutritional consideration in beef cattle production. A range of 0.90-1.32 Mcal kg.-1 NEM (net energy for maintenance) has been recommended for beef cows (NRC, 2000). The NEM is an estimate of the energy value of a feed used to keep an animal in energy equilibrium, i.e. neither gaining nor losing weight.
Generally, all barley varieties screened had sufficient amounts of NEM needed for mature beef cattle during pregnancy and nursing of calves. The ability of tested barley varieties to be able to meet beef cows’ energy requirements is important to cow-calf producers in the Peace Region, particularly during winter, as this will mean a substantial savings in feed energy costs.
Minerals - The forage macro and trace minerals are shown in Table 2. The forage Ca content varied from 0.42% for CDC Cowboy to 0.60% for Amisk. Forage P, K and Mg values respectively varied from 0.17 to 0.21% P, 1.37 to 1.90% K and 0.23 to 0.31% Mg. The forage Na was highest for CDC Cowboy (0.65%) and lowest for CDC Austenson (0.46%). Forage S varied from 0.23% for Sundre to 0.29% for CDC Cowboy.
All varieties were well within the recommended Ca content for a mature beef cow, which is 0.18% Ca when pregnant or 0.42% Ca after calving.
All varieties met the P requirements of a dry gestating beef cow, but all varieties fell short of meeting the 0.26% P that is required by a lactating beef cow. The requirements of K, Mg, Na and S by a mature beef cow have been met by all barley varieties tested.
For the trace-minerals, the forage Cu, Fe, Zn and Mn contents were respectively in the ranges of 1.98 - 3.23Ug/g Cu, 99 - 154Ug/g Fe, 53 - 72 Ug/g Zn and 55 - 85 Ug/g Mn. With the exception of Cu, all the trace-minerals measured here exceeded the content needed by a mature beef cow during and after pregnancy stages. The forage Cu content of barley was far less than the 10Ug/g required by growing and finishing calves as well as mature beef cattle.
According to the Alberta Agriculture & Forestry publication “Trace Minerals for Beef Cows”, more than 90 percent of the feed produced in Alberta is low in copper. Cases of copper deficiency are common. Symptoms of deficiency include anemia, impaired reproduction in cows, bleaching of the hair coat, scours, unthriftiness, stunted growth and sudden death. A greater incidence of internal and external parasites has been not-ed in copper deficient animals. There is also an increased tendency for bones to fracture in calves and an in-creased incidence of lameness. Mineral mixes containing Ca and/or P would be good sources of supplementary trace elements if the levels of trace elements in the mix fell in the middle to upper end of the following recommended range for Cu: 2,000-3,000 mg/kg. Such minerals could be fed with red or blue salt.
Detergent Fibers (ADF & NDF) and non-fiber carbohydrates (NFC)
Both acid and neutral detergent fibers (ADF & NDF) and NFC values for barley varieties tested are shown in Table 3. The forage fiber content (measured by ADF or NDF) in particular is a strong predictor of forage quality, since it is the poorly-digested portion of the cell wall. The ADF values are important because they relate to the ability of an animal to digest the forage. As ADF increases, digestibility of forage usually de-creases. The NDF values are important in ration formulation because they reflect the amount of forage the animal can consume. As NDF percentages increase, forage DM intake will generally decrease.
Generally, NFC is more rapidly digested than fiber. It is a significant source of energy for the rumen microbes. The microbes also use NFC to make microbial protein. Conlon, Champion, TR13740 and CDC Maverick varieties in that order had the top 4 NFC values, indicating more energy and microbial protein sources in the rumen.
