Beef Suckler Cow Management

What are the key reproductive targets for beef cow herds?

365 d calving interval

<5% cows culled as barren

0.95 calves/cow/year (95% of bred cows will wean a calf)

Compact calving within 80% calved in six to eight weeks

Replacement rates 16-18%

Heifers calving at 24 months old and early calving season

Why does a tight calving period matter in beef production?

Earlier the calf is born, the more kg of beef to sell

Older calves spread disease to younger calves

Bullying if different sizes of calves

Management procedures need to be more specific/tailored

Lack of consistency amongst batch when selling calves

Pubery at different times → teenage pregnancy

If heifer calves staying as replacements, earlier parturition measn more likely to be of size/maturity for mating at 14 months.

The most important reproductive parameters which determine the reproductive efficiency in beef herds are what?

Onset of puberty in heifers, interval from calving to return to heat in postpartum cows, heat detection efficiency where AI is used, and breeding success (conception + pregnancy rates)

What are the underlying issues that may arise as a result of aiming for reproductive efficiency in beef herds?

Heifer management, resumption of ovulation and estrous cyclicity postpartum, AI management and cost, bull fertility, pregnancy losses

What is the typical goal of beef suckler herds for their heifers in regards to breeding and parturition ages?

Aim to calve at 2 years old, which means breeding at 14 months old

Practically/biologically, what must/should occur before breeding a heifer?

2 cycles to establish her as pubertal AND 65% of mature weight at time of breeding

What is the KPI target in regards to ovulation and estrous cyclicity of beef cows in our beef farming systems?

<5% barren rate and 65% pregannt after first 3 weeks of breeding

What factors can delay resumption of cyclicity in our beef cows?

BCS loss should be less than 0.5 (on 5 point scale)

Maternal bond

(BCS 1.75 shows significant delays in post partum ovualtion time)

Beef cows with a __ due to low BCS at calving will also have reduced conception opportunities in the breeding season

Prolonged PPI

When in the breeding season do we see the highest percentage of anestrous cows?

Beginning of mating season

List three situations where an otherwise healthy cow/heifer may be anestrous at the beginning of the breeding season.

Late calving cows, cow had calved at low BCS, heifers not reaching puberty yet (12-13 mo of age when breeding season starts for example)

Give some reasons why we may see barren rates in our cows. (4)

Expecting cows to get pregnant when nutritional demands from milk production are high

PP diseases cause anestrous and decreased conception rates

Few farms have regular fertility visits to identify subclinical issues

Feed may not be enough volume/high enough quality

Bull vs AI… What are some advantages of using a bull?

Hassel free

Bull vs AI… What are some disadvantages of using a bull?

Dangerous, rearing and purchasing costs, biosecurity risks when buying in, questionable fertility (bull dependent)

Bull vs AI… What are some advantages of using AI?

Improved genetic merit, allows variability in bulls, can maintain a closed herd

Bull vs AI… What are some disadvantages of using AI?

Need training, conception rates (50%) lower than natural service of fertile bull, need to estrus detect or synchro, repeat synchro is logistically difficult, additional handling, cost of straws themselves

Bull vs AI… What is the cost per cow per year of using a bull for breeding?

36.40 GBP

Bull vs AI… What is the cost per cow per year of using AI for breeding?

23.85 GBP

Bull vs AI… What is the cost per cow per year of using AI for breeding if synchronizastion is needed?

45.38 GBP minimum

In regards to abortion rate, what is the KPI in beef herds?

<2%

What are infectious causes of abortion in beef herds?

Bacillus lichenformis, listeria, BVD, neospora, salmonella, leptospirosis, Q fever, E coli, IBR

What are non-infectious causes of abortion in cows?

Moving, stress, drugs, changing groups (bullying)

What is the KPI target for perinatal mortality?

<2%

What is perinatal mortality defined as?

Calves that are born dead or dead within 48 hours

What is the target calf mortality rate?

0%

What is calf mortality defined as?

Calf death between 2 days of age - weaning

What is the goal DLWG of beef calves?

1.2-1.8 kg

What are the top two reasons calves die outside of the perinatal mortality time frame?

Dystocia and failure of passive transfer

What are two of the most clinically significatn reasons for perinatal mortality in beef calves?

Anoxia developing during parturition and infections

What infectious diseases most commonly impact a calves DLWG?

Scour, pneumonia, clostridial diseases

What is the target involuntary cull rate in beef farms?

<1%

What is the target deaths rate in beef farms?

0%

What is considered the “overriding target” of beef production systems?

95% of cows put to bull rear a calf to weaning