feeding young ruminants Flashcards
the rumen structure and pH of a young calf is different to an adult how
- no absorptive ability due to lack of developed papillae
- pH is relatively lower
what is needed to hep the rumen develop
- innoculation and establishment of the anaerobic ruminal microbial ecosystem
- initiation of starter feed consumption
- fermentation processes and absorption mechanisms
low rumen pH results from
- undesired shift in the microflora
- inefficient digestion
- decrease in rumen motility
- increase in keratinisation
- weaning = common time for low rumen pH because volume of starter intake increases significantly
how does the calf’s rumen develope the microbiome
- when born, GIT is sterile
- gains bacteria from environment and colostrum/milk
- rumen microflora of a pre-ruminant is different from that of a mature ruminant
- starch concentrated increase the gram negative bacteria which produce butyrate and propionate (great source of energy for growth of rumen wall
- fibre increases gram positive bacteria which produce acetate
what are the pros and cons to feeding liquid whole milk to calves
pros:
- increased fat content
- lower labour
cons:
- can fluctuate in solids %
- MAP transmission
- cost
what are the pros and cons of feedinf milk replacer to calves
pros:
- consistent solids %
- cost
- heat treated (lowers total bacteria count)
cons:
- lower fat content
- higher lactose content
- labour intensive
compare skimmed milk replacer, whey replacer and plant based replacer. which one is best choice to feed a calf and why
skimmed MR is best - plant based proteins are designed for the rumen, not the abomassum so hard to digest. whey doesnt form a goot abomassal clot
how often do calves need to be fed
legally if under 1 month must be fed at least twice a day
- ideally ad lib/robotic
how much do calves need to be fed
- varies with desired daily live weight gain, age, environmental conditions
- rough rule of thumb: 900 g per day
what are the aims of feeding solids to young ruminants
- stimulate microbial population
- increase capacity
- stimulate rumen papillae formation
- provision of energy
- development of rumination
- impact on behaviout
what is the aim of feeding concentrates to young ruminants
- provide VFAs
- feeds microbial population
- develops rumen epithelium (papillae)
- provision of energy
at what age can you begin introducing concentrates to young ruminants
can be offered from day 3 of age after milk (less is more)
at what age should young ruminants begin consuming concentrates as part of their standard diet
2 weeks
at what age are concentrates considered an energy source for calves
3 weeks
at what age should the rumen be functioning well
10-12 weeks
what are the aims of feeding forage to young ruminants
- development of ruminal muscular layers
- mitigate low rumen pH
- establishment of microflora prior to weanin
what age should young ruminants be fed forage
- introduced from 3 days old
- should be availible by 2 weeks of age
how should forage be presented to calves and why does forage quality matter at this stage in development
- short chop length (3-4cm) prevents sorting and increases intake
- ideally forage should have LOW palatability at this age because we dont want them to overfill on forage (want to develope papillae by feeding concentrates to make VFAs)
- dont offer silage to calves below 6 months as their rumens cant digest this properly
what pre-requisite are we looking for at weaning in ruminants
a developed rumen which can efficienctly digest solid feed
- increased rumen capacity
- developed papillae for efficient abosorption
- correct rumen pH
- balanced and functioning microbiome
how do we know when to wean a beef calf
- usually separated from dam at 6-8 months
- by 6.5 months 75% of diet should already be solids
when should you introduce creep feed to calves and what should feed be composed of
- introduce 6-10 weeks before weaning to reduce stress, minimise drop in performance and reduce risk of pneumonia
- composition: 14-16% crude protein, 12.5 MJ ME/kg DM
- ad lip or no more than 1-1.5 kg/head
how do we know when to wean dairy calves
- some farms will have a set “age” they wean
- calf should have doubled its BW since birth
- minimum 6 weeks of age, common 8 weeks
how should dairy calves be weaned
step down weaning programs
- starts 10-14 days prior to weaning
- involves 25-50 % reduction in milk feeding during the first few days
- 2nd reduction is usually repeated 5-7 days prior to weaning
- increase solid feed consumption during weaning process
- avoid abrupt (cold turkey milk feeding) with dairy calves
dairy calves from 0-8 weeks should be fed:
- whole milk/milk replacer (6L BID)
- Ad lib concentrate and forage
dairy calves from 8-10 weeks should be fed:
- eating > 1-2kg concentrate
- gradual decrease of milk
- increased amount of concentrate
- ad lib forage
dairy calves older than 10 weeks should be fed:
- concentrate
- forage
- moving to higher % of a hougher energy dense forage
outline the diet changes of lambs from birth to weaning to growing
