Maximizing Reproductive
Performance in
Beef Cows
Spring 2004 Cow Calf Programs
Mauston-March 6
Plover-March 13
Montello-March 20
Keith VanderVelde
Livestock Agent
Marquette Co. UWEX
Reproductive Performance
Cows Job Description is ??
Reproductive Performance
Cows Job Description
1. Produce & Wean Live calf each 365 Year
Requires regular breeding
2. Make a positive return to labor & management
Dependent on Feed Cost
Calf Prices
Reproductive Performance
It all starts with the heifers
1. Reach Puberty at 10 months of age
1. Varies by breed-Jersey to Brahman
2. Use 65% of mature weight as guide when to breed
3. Breed heifer to calve 30 days in advance of cows
1. Allows heifers more time post partum
2. Requires additional feed and labor
Reproductive Performance
It all starts with the heifers
1. At calving
1. Assist after 30 minutes of hard labor
2. Feed heifers to weigh 85% of mature size
3. Have heifers on gaining weight 30 prior to calving
thru rebreeding
4. Body condition scores should be 5 or 6
Reproductive Performance
Cows need regular reproduction
1. Cows must rebreed 85 days after calving to
stay on 365 day calving interval
2. Cows need to be gaining weight from calving to
rebreeding
1. Calves will compete for energy
2. Energy and protein needs increase by 50% after
calving
Reproductive Performance
How to manage cows to insure regular reproduction
1. Feed cows to gain from mid-gestation to 90 days after
calving
2. Body Condition Cows in the fall and spring
3. Consider calf removal as a management tool
4. Provide adequate high protein, high energy feed for
period from calving to rebreeding
1. Consider hold back the best feed for this period
2. Supplement with grain and Soybean Meal
Maximizing Reproductive Performance
• Vaccination Programs
–
–
–
–
BVD and IBR
Leptospirosis
Campylobacteriosis(Vibro)
Trichomoniasis(Trich)
Maximizing Reproductive Performance
• Vaccination Programs
– Yearly vaccinations recommended for open
herd with animals coming into herd
– Or Vaccinate in response to disease outbreak is
best suited to closed herds
Maximizing Reproductive Performance
• Vaccination Programs
– Recommended
• BVD
• IBR
• PI3
• Bovine Respiratory Syncitial Virus(BRSV)
• Clostridial strains
• Haemophilus somnus
• Pasteurella haemolytica
• Lepto
Maximizing Reproductive Performance
• Conduct annual Pregnancy Checks
– Can be done 45 days after bulls are removed
– Or should be done 4 months after bulls are
introduced to cows for rebreeding
– Open cows should be culled or moved to a
alternate calving program—Fall Calving
– BULL Management
• Fertility Check bulls 60 days before
breeding season
Maximizing Reproductive Performance
• Leaving the Bull Out Too Long
– Length of Breeding Season Matters
– Oklahoma, Texas, New Mexico Study, Glenn Selk, OSU
Extension Animal Reproduction Specialist
– 394 Ranch Records
– Positive Relationship between number of days of breeding
season on cost per hundred weight of calf weaned
– For each additional day of breeding season the cost per cwt
increased by 4.7 cents and pounds of calf weaned per cow
decreased by 0.158 pound
Maximizing Reproductive Performance
• Leaving the Bull Out Too Long Conclusions:
– 365 day breeding season results in additional cost of
$13.63 per hundred weight of weaned calf as opposed
to the 75 day breeding season.
– 365 day breeding season results in 46 fewer pounds
sold per cow per year when compared to 75 day
breeding season
– On a 50 cow operation the impact is:
• Two thousand ninety one (2291) less lbs sold
• An increased cost of $68.15 per head for 500 lb calf
• $3408 increased cost assuming 100% conception rate
Body Condition Scoring
• The main factors determining the pounds-of-calfweaned in a beef herd are growth rate of the
calf, the proportion of cows pregnant and the
calving patterns of the cow herd.
• Producers working with beef cows should:
1) Know how to estimate body condition
2) Understand the influence body condition has on production.
3) Know how and when to change body condition.
4) Be able to calculate the costs and returns for changing
body condition.
Practical Importance of
Body Conditioning Scoring
• Body condition scoring is a subjective measure of
the amount of fat in an animal’s body.
• Body condition influences production in a beef cow
herd in three ways:
1) Growth rate of a calf suckling a thin cow is decreased.
2) Pregnancy rate in thin cows is lowered.
3) Thin cows become pregnant later in the breeding season
and thus calve later in the following year.
Determination of
Body Condition
• Two methods currently used to determine body
condition are:
1)Measurement of covering over the ribs, shoulder and back.
2) Measurement of covering over the short rib and tailhead.
• Both methods appear to be accurate, and the
system used is largely a matter of preference.
• The Nebraska System scores cows from 1 (thin)
through 9 (fat) and the Scottish System from 1
(thin)to 5 (fat).
1……………………………emaciated
2……………………………very thin
3……………………………thin
4……………………………borderline
5……………………………moderate
6……………………………good
7……………………………fleshy
8……………………………fat
9……………………………extremely fat
Pregnancy Rate and Post-Partum Estrus
• Studies have shown a decrease in pregnancy rates in thin cows
• Cows that were grazed on similar pastures during a 120-day
breeding season varied in pregnancy rate from 23% for body
condition score ‘2’ to a 95% pregnancy rate for body condition
score ‘7’
• Other studies have shown similar results with the difference
ranging from 10% to 20% less in pregnancy rates for cows with
body condition score of ‘4’ or less.
• The reason the pregnancy rate is lowered is cows that are in thin
condition have a delay in the onset of estrus.
Body condition and pregnancy rate in a
group of cows in Florida
BODY CONDITION NEAR CALVING
No. Of
Cows
Pregnant
2
3
4
5&6
7
very thin
thin
borderline
moderate
good
115
545
564
344
234
After
5
Breeding
60 days (%)
15
19
40
56
120
days (%)
51
73
86
95
23
Missouri Trial Young Beef Cows
Condition score
at calving
3
4
5
5.5
-1
189
161
133
118
Condition score change after calving to day 90
-0.5
0
0.5
1
1.5
2
173 160 150 143 139 139
145 131 121
115 111 111
116
103
93
86
83
82
102
89
79
72
69
66
Proportion of cows showing estrus at
different times after calving
Body Condition
2-3
Thin
4-6
Moderate
7-8
Good
No. of Cows
272
364
50
Days post-calving
30
40
50
60
70
80
90
3a
19
34
46
55
62
66
7
21
45
61
79
88
92
13
31
42
91
96
98
100
a
% of cows showing estrus by this time.
Condition at calving
determines rebreeding rate
Post-Calving Nutrition
• It is desirable to maintain cows at a BCS of 5 or
more through breeding. Cows less than 5 need to
be fed to improve their condition, which is
expensive to accomplish while nursing a calf.
• Research shows that moderate condition cows
losing weight after calving tended to show estrus
sooner after calving than cows gaining weight.
Post-Calving Nutrition
• These differences continued until 80 postcalving.
• This information indicated that body
condition at calving has more influence on
the onset of estrus than feed level postcalving.
Growth Rate of the
Suckling Calf and Milk
Production of the Cow
• Milk consumption and calf growth rates were
lower in thin conditioned heifers than those
that were in moderate condition.
• The energy level received post-calving had
little influence on milk production or calf
growth in heifers.
Growth Rate for the
Suckling Calf and Milk
Production of the Cow
• This data indicates that cows that calve thin
will have lower milk production and,
consequently, slower calf growth than those
calving in moderate or good condition.
Improving Production by
Changing Body Condition
Improvement in body condition will improve the
pounds-of-calf-weaned in three ways:
1) Calves suckling a cow in moderate or good condition grow
faster than calves suckling a thin cow.
2) More cows in moderate or good body condition will be
pregnant at the end of the breeding season.
3) More cows in moderate or good body condition will calve early
next year.
Weight Changes Needed to Change BCS
CHANGE
TO
FROM
2
T
Increase in weight needed O
(lbs.)
T ADG Needed to make
FAT & CALF &
A Change (lbs.)
a
MUSCLE MEMBRANES L 70days
100days 150 days 200 days
5
Dry Preg. Cow 241
Wet Cow
5
Dry Preg. Cow
Wet Cow
5
Dry Preg. Cow
Wet Cow
5
Dry Preg. Cow
Wet Cow
3
4
5
a
100
341 4.9
3.3
2.2
1.8
241
0
241 3.3
2.4
1.6
1.1
161
161
100
0
261 3.8
161 2.2
2.6
1.6
1.8
1.1
1.3
.9
80
80
100
0
180 2.6
80 1.1
1.8
08
1.1
05
.9
04
0
0
100
0
100 1.3
0
0
.8
0
.6
0
.4
0
Last 100 days of pregnancy.
What is “GOOD” Body
Condition?
Body Condition 3
Body Condition 6
Body Condition Scoring Tips
Have a neighbor score your cows
Accept his scores
We often see our own cows too often
If in doubt about condition put in chute
and feel animal over the ribs.
Feed to improve to desired condition
If cows are too fat 7+ do not put on diet
until rebreeding has occurred