Lab 2 Flashcards
what are the steps in silage making
- harvest and chop silage crop into smaller particles
- compaction - use rollers to compact material in silo (helps expel O2 and stops respiration process)
- phase 1 - increase cell respiration which makes CO2 and heat
- phase 2 - fermentation begins and acetic acid is made, pH drops from 6 to 5, temperature increases from 70 to 95F
- phase 3 - lactic acid production begins, pH drops to 4, temperature decreases to 80 to 85F
- phase 4 - lactic acid production continues, pH drops to 4, temperature maintains at 80-85F
- phases 1-4 last 21 days, which means silage is ready to use after day 21
what are the steps to hay making
- monitor the weather to find a window of 3-4 sunny days without rain in the forecast
- cutting/ moving - use mower or similar equipment to cut hay crop
- tedding - use equipment to lift and turn cut hay to promote even drying
- raking/windrowing - use appropriate machinery to rake/ windrow or gather dried hay into rows to prepare for baling, ideal moisture may not exceed 15%
- baling - baler gathers dried hay along the rows and convert this into rectangular/ round bales
- storage - baled hay is next transported to hay barn for dry storage or wrapped into plastic bad to enable storage of hay in open fields
the average yield of corn silage crop is 30 tons/acre with moisture (DM=35%). How many acres will be planted with silage corn to last 1000 dairy cows for a period of 120 days if silage comprises 40% of total mixed ration and daily feed intake per cow is 18 kg DM?
- determine cow needs: 1000 cows x 18kg DM/day x 0.4 x 120 days = 864,000 kg DM
- determine yield of silage crop: (30 tons x 2000 lb/ton x 0.35)/ 2.2 = 9,545.45 kg DM/acre
- determine acreage needed: 864,000/ 9,545.45 = 90.5 acres
although evalution of body condition can be looked at as an ongoing process, state 3 key ideal times when and why body condition scoring should be considered in a cow calf herd
- late summer - plan for management strategies eg: early weaning or supplementation for cows grazing warm season pastures or pasture quality is decreasing
- fall - plan for economical winter supplementation program to get females back to target BCS
- weaning time - cows weaning their first calves, most likely to be thin at this time
- 45 days after weaning - provides good information on how fast the cows are bouncing back after weaning
- 90 days before calving - last opportunity to get condition back on cows economically, separate thin cows from cows in good condition and feed them separately, particularly benefits young cows
- calving - indicates how well the pre calving feeding program went and the BCS score helps to plan for an appropriate weaning date
- breeding - thin cows at this time may indicate a poor match of calving season to feed resources eg: cows calving too early in the spring
- if the target bodyweight of sheep with BCS of 3.5 is 70 kg, calculate the current body weight of the sheep if their present BCS is 2.25
bodyweight change expected: 0.13 x 1.25 x 70 = 11.375 kg
current bodyweight: 70 kg - 11.375 kg = 58.625 kg
if the target body weight of a sheep with BCS of 3.5 is 70 kg, calculate the desired average daily gain (grams) if the animals would require 50 days to reach the target bodyweight (70 kg)
average daily gain expected: 11.375 kg x 1000 g = 11,375 g/50 days = 227.5 day
if the target bodyweight of sheep with BCS of 3.5 is 70 kg, use NRC guidelines to calculate the daily amount kg of supplement (ME= 3.00 Mcal/kg DM) to be fed to this sheep, the sheep is mainly fed oat hay (ME = 1.99 Mcal/kg DM)
- using NRC tables, you determine that sheep expected to gain 227.5 g/day needs 5.03 Mcal/day and consume 2.4 kg DM/day
- determine ME content of feed: 5.03 Mcal/day/ 2.4 kg/day = 2.10 Mcal/kg feed
- apply pearson square:
supplement 3.00 0.11/1.01 = 0.1089
2.10
hay 1.99 0.90/1.01 =0.8911
1.01 1.01 - total amount of supplement DM: 0.1089 x 2.4 kg/day x 50 sheep = 13.07 kg/day
