Midterm 2: Beef 1 Flashcards
________ x ________ = nutrient intakes in absolute amounts per day to satisy requirements
nutrient concentrations in feedstuff (%DM, g/kg of DM) x dry matter intake (kg/day)
what are the 3 big priority of nutrients for beef cattle IN ORDER of biggest priority to least priority?
- 1st priority: maintenance of pregancy (both mother and fetus)
- 2nd priority: production (growth and milk)
- 3rd priority: reproduction (breeding or rebreeding)
what are the 3 major components of beef cattle production?
- cow calf
- stocker/backgrounding
- finishing
the goal of a cow calf production is
to produce one live calf per cow per year
cow calf operations utilize what kind of diet?
- high fiber diets
average cow is what weight at weaning?
520kg
what is the diet like in a cow calf production?
minaly forages like pasture, hay, crop residues, supplemental energy, protein, mineral and vitamins as needed
why are most calves born feb to april?
minimize heat stress that could happen from July to September, and to provide high quality and quantity of forages to support the momma cows in lactation
when are beef calves usually weaned? what is average weaning weight? when are most calves sold after weaning?
5 to 9 months
240kg
usually sold in 60 days following weaning
in beef cows, immunoglobulin absorption ceases after how long after birth? when is maximum colostrum ingestion?
24 hours
max colostrum ingestion in the first 3 hours of life for the calf
what are the 3 main effects when there is failure of passive transfer in beef calves?
- increased risk of getting sick in the first month by 6 times
- increased risk of dying before weaning by 5 times
- decreased weaning weight by about 15kg
if a beef calf is not suckling what should you do?
feed colostrium or colostrum replacer, ideally 10% of their body weight in the first 6 hours after birth
what is “creep feeding” in beef calves? what are the objectives of using creep feeding?
giving supplemental feed to calves before they are weaned, and the concentrate is formulated specific for the calves, basically the calf has access to a bunker to make adjustment of weaning easier (adult cows do not have access to it)
objectives:
- ease stress of weaning
- reduce burden on thin or young growing cows
- increase in average daily gain in the calves
- use supplemental feed when pasture availability or quality is low
- supplement the calves of heifers (first time moms) which have lower milk production
- to increase stocking rates
creep fed beef calves will: (4 things)
- be heavier at weaning than non creep fed calves
- consume grains in drylot background programs more readily
- regain losses from weaning and shipping faster
- often exhibit a lower incidence of post weaning morbidity and mortality
creep feeding rations for feeding calves are usually what % crude protein?
14 to 18%
what are some benefits of early weaning?
- eliminate the cows nutrient requirements for lactation
- improve cow body condition score
- dry matter intake decreases by about 25%
- decreased trampling losses (removal of calves)
- improves in 30% forage availability for the cow
- early weaned cows are highly efficient at converting feed to live weight
when is early weaning of calves recommended? when is the earliest they can be weaned, and when are they usually weaned?
- recommended when cows body condition score or forage supply is low
- calves can be weaned after 2 months or as soon as the rumen is functional, but usually done with calves around 4 months
what does “preconditioning” calves mean?
this is when they are vaccinated 2x, dewormed, castrated, dehorned, and trained to eat from a bunk and drink from a trough
after weaning, heifers and bull calves are moved to what type of diet? This diet is fed to acheive what goal?
high forage diet, fed to acheive puberty and optimize reproductive efficiency
when do young heifers and bulls reach their mature weight?
4 to 5 years of age
heifers that conceive earlier in the first breeding season….
have a greater probability of weaning more and heavier calves during their lifetime
selection for earlier puberty will do what 2 things:
- decrease feed costs for maintenance
- increased reproduction performance
breeding season for heifers should start when? and why?
30 days earlier than the cows because:
- they require a longer period of time to return to normal cycling after calving
- to give them extra time to regain body condition score and grow before the second breeding season
what are the major cause of variation in age at puberty?
pre and post wenaing nutrition (aka, the nutrition of the young cow before and after weaning will have a huge effect on how soon they reach puberty)
in what way does post weaning nutrition affect pregnancy rates?
the higher the average daily gain, the higher the pregnancy rates, and the younger the age at puberty
heifers have a mature body weight of _____. usually weight at weaning is ______ at 205 days
600kg
230kg
what is the amount of post weaning growth to acheive puberty at 13 months?
they need to gain 130 kg in 185 days which is 0.70kg per day
heifers should be kept at what body condition score?
5 to 7
what are the consequences of over conditioning heifers?
- increasing feeding cost
- increase incidence of silent heat
- decrease conception rate
- decrease embryonic and neonatal survival
- increasing calving difficulty
- decrease mammary development and milk production
what are the vitamins of particular concern in beef cattle?
A,D, and E
high quality forages are rich in what vitamins? what happens when these forages are stored?
A and E
they are lost during storage
how do beef cows get vitamin D?
can be made by the animals exposued to light (may become a concern during winter and indoor animals)
what kind of diet do heifers usually get after breeding? how about the last third of gestation?
usually a high forage diet
the last third of gestation will require concentrate supplementation to sustain the rapid fetal growth
in each third of gestation what is the feed for a heifer?
1st: grass pasture
2nd: hay or swath grazing
3rd: hay + concentrate to sustain rapid fetal growth
poor heifer cocneption rates are realted to ______, so you should check 4 things if your heifers arent conceiving?
nutrition
- age and weight (breeds differ)
- body condition score
- if vitamin/minerals are being supplemented
- for inappropriate use of implants (implants interfere with breeding and result in poor reproductive performance)
in order to produce one calf per year, a cow should be pregnant no longer than how many days after partuition (previous calving)?
80 days
post partum anestrus is affected by:
- parity
- season
- calf presence and suckling
- breed
- dystocia
- nutritional status
what is ideal body condition for beef cows? in a cow with ideal body condition, should you see an outline of the spine? how many rib outlines should you see?
3 or 3.5 on a 5 scale, and 5 to 6 on a 9 scale
no spine outline, 1-2 ribs
the principal cause of poor reproduction performance OR extended post partum anestrus is
undernutrition (feed shortage or poor quality feed)
________ are important to maximize reproduction performance
adequate nutrition pre and post partum
true or false: cows calving in good body condition (above 5) have a higher postpartum interval
FALSE! they have a LOWER post partum interval (time from calving to the subsequent conception)
thin cows benefit from what kind of diet after partuition?
higher energy diets (flushing)
true or false: a cows requirement greatly increases in the last third of pregnancy
true! requirements may be higher than what is supplied by forage diets, large increase in energy, protein, Ca, and P
true or false: birth weights for calves is reduced only if a cow is underweight
false! bith weights will be reduced if cows are overtly fat OR thin
when do lactating cows have peak milk production?
around 8 weeks postpartum (5 to 14kg per day)
______ is the period of greatest nutritional demand
post partum
true or false: cows with higher milk production have higher energy requirements
true
inadequate nutrient intake during post partum/lactation leads to what 3 things?
- delayed rebreeding
- failure to conceive
- weight loss
what is the relationship between BSC at breeding and calving interval?
very thin cows have a longer calving interval and fat cows have a shorter calving interval, but the ideal body condition is 5, because it lines up with calving interval of around 365 days, which is 1 year, which is what we want
describe the schematic of the different programs/locations a beef cow goes through from birth to death
late winter/spring calving–>summer grazing then to either a) stocker programs b) feedlot finishing c) winter feeding. From stocker programs, to feedlot finishing, from feedlot finishing to slaughter
cow calf systems use what kind of land?
lands that are not suitable for row-crop production (grain)
why is it important to match the breed/size to the available resources?
different breeds and sizes of cows require different amounts and qualities of feed, so if you don’t match the resources with the cows you will lose money (for example, using big cows and not feeding them enough leading to low slaughter weights, or using small cows and feeding them too much and losing money on too much feed)
what are the main reasons why cows in a cow-calf system are culled and replaced with replacement heifers?
usually reproductive failure, older cows, lack of productivity, cows that produce light weight calves at weaning, temperment, udder problems, etc
cows ______ is an economically important trait in beef cow herds
longevity
true or false: the cut off for failure of passive transfer of passive immunity is higher for beef than it is in dairy
true, for beef it shouldnt be lower than IgG 24g/L, and in dairy it’s 10g/L
true or false: supplementing with vitamin. Dcan be expensive so it’s best if cows get vitamin D naturally rather than a supplement
FALSE! usually the vitamins A,D and E can all be supplemented together and it’s VERY affordable and the benefits will always outwiegh the costs
what is the best way to make sure there are no mineral deficiencies or toxicities in the feed?
analyse the feed samples, remember the soil content will affect the content of the forage, which will affect how much minerals you need to supplement
is having a free choice mineral supplement a good idea?
yes, but you need to make sure the animals are actually eating it
why do pregnant heifers in the last 3rd gestation have such a high energy requirement?
because not only are they growing a fetus and the fetus is growing, she is also still growing! cows do not fully mature for a few years, so during her first pregancy, she still needs to grow!
true or false: overnutrition is more common than undernutrition
false, undernutrition is more common
why is it hard to tell which cows have a higher energy requirement during lactation?
it’s hard to tell how much milk each is producing, we don’t milk them, but the ones that produce more milk do have a higher requirement
if you don’t feed cows enough during lactation (if you don’t adjust the nutrient requirements for lactation), what 3 things can happen?
- delayed rebreeding
- failure to conceive
- weight loss
when cows are lactating and/or pregnant, it roughly should coincide with what season? During this time, what is the majority of the feed? How are minerals and salts given during this time?
summer pasture
majority of feed is good quality pasture, usually don’t need to supplement unless there’s a drought or bad crop year, etc. Mineral and salts given free choice
gestation after weaning usually coincides with what time of year? what is the ultimate objective during this time?
winter feeding period (assuming calving was in the spring)
objective: maintain cow health and optimal BCS at the lowest possible daily feed cost, feeding them in the cheapest ways possible
during gestation after weaning for cows (not heifers), how much weight should cows in good condition gain?
60-80kg, equivalent to calf and uterus growth, but the actual moma cow isn’t growing anymore so it’s not as much as a pregant heifer
what is the logic behind placing cows in different feeding groups?
so you can give them different feeds that meet their group requirements, for example mature cows in good condition can be kept on just a maintenance ration (except for last 3rd of gestation), heifers and 1st and 2nd calf cows can be kept together because they have a higher requirement (still growing), thin and old cows can be kept together which are fed similar to heifers. thin, old, and heifers can be kept together if 3 groups is not possible
what is swath grazing? how does it work?
an option for winter feeding, used to extend the grazing season, to reduce feed, labor and manure handling costs.
annual cereals are seeded in may/june and are swathed from august to september when the crop reaches the soft to late dough stage and before killing frosts
why do you need to restrict access to swath grazing fields?
the cows can trample swaths over a large area and waste a bunch of it
what are crop residues and what do they contain?
residues are the leaves and stems left over after harvesting grains like wheat, barley, rice straw, and corn stover. they are high in fiber and lignin, and low crude protein content, low digestibility, low energy. Animals should be supplemented with protein to maximize rumen fermentation (since microbes need protein to break down fiber)
true or false: you should not feed straw to lactating cows and heifers
true
max daily dry matter intake of straw for non lactating cows is what percent of body weight?
1.5%
how much extra should you feed cows when it gets below -20 degrees?
1kg/head/day for every 10 degree drop below -20
with legume or grass hay what should your Ca:P ratio be? how about with straw, greenfeed, or cereal silage?
1:1
2:1
post calving, how should minerals and salt be given?
requirements go up 25-40%, and it should be mixed in with the grain to ensure adequate intake
true or false: snow is a good option to provide cows with water in the winter
false! they can eat it and it can help, but they need actual water
how much water should a non lactating vs a lactating cow drink?
non lactating: 3 parts water for 1 part dry matter
lactating: additional 0.8 L for each kg of milk produced
how should water intake change with an increase in temperature?
water intake and requirements will be increased
