Feeding Of Dairy Calves (A14), Feeding Of Dairy Heifers (A15) Flashcards
When dairy calves separated from their mothers?
First days of life!
≠weaning
Birth weight of calves? When is weaning happening?
40-45 kg
Male calves are sold at approx 10 days old
Weaning (end of milk replacer feeding) happens at age 50-90 days (depending on technology) with weight of 80-100 kg
Colostrum feeding of calves
- placenta of ruminants doesn’t let immunoglobulins cross, therefore colostrum feeding is essential !
- mainly IgG
- protein content is much higher combating to milk (~14%)
- in the first 2 hours 3-4 litres must be consumed by newborn
- colostrum is collected from cows right after giving birth and Ig content is measured individually and mixture is made from collected colostrum
- high quality colostrum has ≥50 mg IgG/ml
- in next 12 hours + 2 litres
- temperature of colostrum is important (38-39Cº), if tº is lower then reticular groove doesnt open
- if milk is acidified heat treatment is not that important because low pH opens reticular groove
- in the first 2 days ~ 10 litres of colostrum should be given
- then Ig can’t be absorbed and Ig content of colostrum drops
- colostrum given till 10 days of age and in total 35 litres are fed to calf
Milk replacer in dairy calf feeding
- from first week of age but nowadays from 2nd day of age!
- high quality milk replacers are made of skim milk and/or whey
- in skim milk fat is removed and to reach sufficient energy it should be supplemented with plant oils and fat soluble vitamins
- in first weeks milk replacer is given 2x/day (3-3,5 l/ day) from 4th week: 8l, last days: 1-1,5l
- usually ratio is 1:9 (milk replacer:water) but now its labelled
- too concentrated milk replacement may lead to diarrhea
- CP: ~ 24%
- EE: ~ 20%
Drinking water in feeding of dairy calves
Free choice water is needed!! (10-15 litres/ day)
Hydration and rumen development!!!!
Solid feed in calves nutrition
- from 7-10th days of life
- calf starter diet: pellets, CP: ~ 18% —> VFAs, important for rumen papillae development: ad libitum (free access)
- hays: fiber content is needed for development of rumen muscular mass. Hays can be fed alone
Nowadays hays are involved calf starter diet and then calf starter diet has remarkably higher CF content
High quality hay: high in CP and low in CF
Development of stomach chambers in calves
- at first abomasum is the largest chamber: 2x of prestomach
- at age of 2 months prestomach becomes larger
- at the age of 4 months proportion of chambers is typical for adult cattle
Weaning of calves
- 1 day old calves are separated from their mothers
- weaning = end of milk replacement feeding
- key point of weaning is not age, not weight but DM intake capacity of the calf !!
- to be weaned at least 1,5 kg of DM daily (2/3 concentrates, 1/3 from hay)
- usually between 50-90 days and weight between 80-100kg
Post-weaning period
- calves are housed in small groups (~30 animals)
- lasts until age 5-6 months (180-200 kg BW)
- ## calf starter diet is changed to calf grower diet (CP: 16-17%) and TMR is introduced
Goals of feeding of dairy heifers
- high-level milk production
- can be kept in breeding for long period
Isometric and allometric growth (dairy heifers)
- isometric: proportional growth of organs to body weight aging: sex organs
- allometric growth: rate of organ development to weight gain is non-linear: mammary glands (udder)
In case of mammary glands development, it is isometric until 3 months of age and after that it has allometric growth till 2-3 ovulation and then its isometric again until 1st calving
Therefore imbalanced feeding (mainly not sufficient energy supply) in allometric growth period —> adverse effect on development of udder
Puberty of heifers
- puberty = 1st fertile ovulation
- significantly correlating to body condition (body fat content)
- optimum body condition score 3-3,5 BCS
- endocrinological background (adipose tissue, leptin, GnRH, FSH, LH, follicular maturity) is proper
- if body condition below optimum -> abnormal endocrinological background -> abnormal fertility
Raising of heifers. Moderate raising
- body weight for 1st insemination: ~ 350 kg
- moderate feeding level + 15% of intensity (“physiological” intensity of feeding)
- daily bw gain is 800-850 g
- optimum fertility
- can be inseminated at age of 13-15 months, bw minimum 350kg
- calving: ~24 months, bw: ~550 kg
Raising of heifers. Intensive raiding
- DWG: 1000-1200 g
- insemination: 12-13 months of age
- advantage: profitability up (increased milk production, decreased generational interval)
- disadvantage: shorter life span, probability of dystocia increases
Heifer feeding. Phases
- Till 1 year of age
- 12-22 months (till 8th moth of pregnancy)
- 22 months - calving (last 2 months of pregnancy)
