Rodolfo Cardoso, Texas A&M University Aug. 29, 2018
ARSBC 2018, Ruidoso, N.M. 1
Nutritional Programming of Puberty in Bos indicus-influenced Heifers
Rodolfo C. Cardoso, D.V.M., Ph.D.Assistant Professor
Department of Animal Science
ARSBC Symposium, Ruidoso, NM - 2018
PRESENTATION OUTLINE
• Importance of timing puberty in replacement heifers
• B. taurus vs. B. indicus (Brahman)-influenced
• Nutritional programming of puberty -- Hormones and Neuroendocrine Mechanisms-- Timing (Stair-Step Approach)-- Dietary Energy Source-- Interaction of pre-and postnatal nutrition on pubertal programming
• 4 million replacement beef heifers enter the U.S. cow herd annually
• Lifetime productivity is heavily-dependent upon heifer’s ability to reach early sexual maturation (GOAL: 1st calf as 2-year-olds)
• Conceiving during the first 21 days of the breeding season as a yearling increases the probability of continued early calving and long-term retention in the herd
• Multiple estrous cycles before targeted first breeding positively influences fertility
• Cows must wean 3 to 5 calves to pay for the cost of their own development; thus longevity is extremely important
IMPORTANCE OF THE TIMING OFPUBERTAL ONSET IN HEIFERS
MATURATION OF THE REPRODUCTIVE NEUROENDOCRINE AXIS
SECRETION OF GONADOTROPINS
OVARIAN STIMULATION(Follicular Development/Estrous Behavior)
UTERINE DEVELOPMENT AND OVULATION(Tract Score)
SEQUENCE OF EVENTS LEADING TO PUBERTY
ABILITY TO BECOME PREGNANT
• Genetics (Breed Type/Mature Body Weight)
• Pre- and Post-Weaning Nutrition
• Critical Body Weight/Adiposity/Nutritional imprinting
MAIN FACTORS AFFECTING SEXUAL MATURATION IN
THE HEIFER
GENETICS
Rodolfo Cardoso, Texas A&M University Aug. 29, 2018
ARSBC 2018, Ruidoso, N.M. 2
NUTRITIONAL PROGRAMMING OFPUBERTY IN HEIFERS
Nutritional Programming
Jersey-Brown-Swiss-Angus-Hereford-Simmental-Limousine-Charolais-Brahman
8 10 12 14 16 18 20
B
Wean or Purchase
60-75 dayBreeding Season
Pubertal Onset
0 9 12 14 16 Age (mo)Feb Nov. April
Pubertal Onset
600 lb 0.4 lb ADG 660 lb (55% MBW) 600 lb 1.2 lb ADG 780 lb (65% MBW)
Birth
600 lb Nutritionally-Programmed 780 lb (65% MBW)
Pubertal Onset
1200-LB MATURE COWS
600
650
700
750
800
Nov De c Ja n F eb Ma r Apr
BW
(lb)
WeaningBreeding Season
Nutritional Programming of Puberty in Beef Heifers
• The goal of nutritional programming is to create a metabolic imprint during the early juvenile period at the hypothalamic level that results in an accelerated timing of puberty
BW
, kg
Lep
tin,
ng/
ml
-17 to
-16
-13 to
-12
-9 to
-8
-5 to
–4
-1 to
0
275
300
325
350
375
Pooled SEM:12.1
3
4
5
6
Pooled SEM:0.4
Weeks relative to puberty Garcia at al., 2002
Leptin and Puberty in Heifers
• Appetite and satiety
• Neurite outgrowth
• GnRH secretion
• Permissive facilitator of puberty
1 00
1 20
1 40
1 60
1 80
2 00
2 20
2 40
2 60
1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4
Body
Wei
ght (
kg)
Week of Experiment
HF-LG HC-HG
Body Weight and Average Daily Gain
** P < 0.0001
Allen et al., J. Anim. Sci. 2012
0
0.1
0.2
0.3
0.4
Prop
iona
te:A
ceta
te
HF-LG HC-HG
**
Circulating Insulin, IGF-1 and Leptin
0
0 .2
0 .4
0 .6
0 .8
1
1 .2
1 .4
Insu
lin (n
g/m
l)
HF-LG HC-HG0
2 0
4 0
6 0
8 0
1 00
1 20
1 40
IGF-
1 (n
g/m
l)
HF-LG HC-HG
**
0
0 .5
1
1 .5
2
2 .5
3
3 .5
4
4 .5
Lept
in (n
g/m
l)
HF-LG HC-HG
***
*** P = 0.001** P < 0.002* P < 0.05
*
Allen et al., J. Anim. Sci. 2012
Rodolfo Cardoso, Texas A&M University Aug. 29, 2018
ARSBC 2018, Ruidoso, N.M. 3
100
200
300
400
Age (mo)4 146 10 128
Period IVNutritional Programming
Period I Period II Period IIIPubertal Onset
BW (K
g)
Pube
rty
(%)
100
50
0
HG
L
G
Puberty attainment
HG: ADG = 1 Kg/dayLG: ADG = 0.5 Kg/day
• When does the metabolic programming for early puberty occur?
• Can we nutritionally alter the timing of puberty while optimizing other aspects of growth and development?
0
2
4
6
8
10
12
14
16
0 4 8 12 16 20 24 28 32 36
Lept
in (n
g/m
l)
Time (Wk)
LGH GSS-1SS-2
100
150
200
250
300
350
400
450
4 6.5 9 11. 5 14
BW, k
g
Age, mo
LGH GSS-1SS-2
Nutritional Model Circulating Leptin
Arrows: Diet transition
Stair-Step Nutritional Regimen
Arrows: Diet transition
Cardoso et al., 2014, J. Anim. Sci.
a
c cb
0
10
20
30
40
50
60
70
80
90
100
16 20 24 28 32 36 40
Heife
rs p
uber
tal (
%)
Time (Wk)
LCHCSS-1SS-2
Stair-Step Nutritional Regimen Programs the Onset of Puberty in Beef Heifers
Cardoso et al., 2014, J. Anim. Sci.
8 mo 9 mo 10 mo 11 mo 12 mo 13 moAge
Optimal TimingLG
HG
SS1 results in ~ 7% overall savings in feed costs during the development period.
Nutritional Programming of Puberty in Beef Heifers
• Dietary Energy Source
0
0. 25
0. 5
0. 75
1
Aver
age
Dai
ly G
ain
(kg/
d)
a a
b
b
HF-LG HC-LG HF-HG HC-HG
100
120
140
160
180
200
220
240
16 18 20 22 24 26 28 30
Bod
y w
eigh
t (kg
)
Mean age (wk)
LG HG
***
***
****
*P < 0.02 **P < 0.004; ***P < 0.0007; ****P < 0.0001 a,b P < 0.004
Allen et al., J. Anim. Sci. 2018
BODY WEIGHTS AND ADG OF HEIFERS FED AT A LOW OR HIGH RATE OF GAIN
USING TWO DIETARY ENERGY SOURCES
Switch to PubertyCommon Diet
ng/m
l
2.0 lb/day ADG 1.3 lb/day ADG
Allen et al., J. Anim. Sci. 2018
Rodolfo Cardoso, Texas A&M University Aug. 29, 2018
ARSBC 2018, Ruidoso, N.M. 4
Nutritional Programming of Puberty in Beef Heifers
• Interaction of pre-and postnatal nutrition on pubertal programming
ROLE OF MATERNAL NUTRITIONAL STATUS?
7.5 - 8
5 - 5.5
3
BW (l
b)Bo
dy C
ondi
tion
Scor
e
Weeks
*
Low Gain and High Gain Heifers
RESULTS TO DATE
• Changes in circulating concentrations of leptin (dams)
• An increase in the number of GnRH neurons in close apposition to NPY neurons due to low maternal BCS
• A reduction in expression of genes involved in leptin transport across the blood-brain barrier
¤ Hormonal and neuroendocrine alterations suggest that low maternal BCS may result in delayed puberty in the heifer offspring (to be confirmed)
¤ These neuroendocrine alterations can have long-term negative effects on reproduction (to be confirmed)
• Nutritional acceleration of puberty is associated with key alterations in the neuroendocrine system of heifers
• Neural plasticity associated with the juvenile period (4 to 8 mo of age), provides for opportunities to nutritionally-modulate age at puberty
• Managerial approaches that use a stair-step feeding regimen can exploit important efficiencies for growth, mammary development and timing of puberty
• Prenatal perturbations in metabolic/nutritional status are likely to delay puberty in heifers and have long-term detrimental effects on reproduction
SUMMARY AND CONCLUSIONS
Rodolfo Cardoso, Texas A&M University Aug. 29, 2018
ARSBC 2018, Ruidoso, N.M. 5
SUMMARY AND CONCLUSIONS
“Puberty occurs when heifers reach about 65% of their mature weight”
however…WHO? (Genetics)• Bos taurus vs. Bos indicus-influenced
WHEN? (Timing of BW gain)• Early development vs. late development
HOW? (Dietary Energy Source)• High-Concentrate vs. High-Forage
WHAT? (Prenatal Environment – Fetal Programming)• Adequate vs. Inadequate Maternal Nutrition
AcknowledgementsTexas A&M University• Dr. Gary Williams• Dr. Marcel Amstalden (1970-2014)• Dr. Tom Welsh• Dr. Carey Satterfield• Dr. Luis Tedeschi• Meaghan O’Neil• Sarah West• Emma Britain Caraway • Youwen Zhang• Carolyn Spencer• Dorota Zieba• Michelle Garcia• Marlon Maciel
University of Nevada – Reno• Dr. Bruna Alves
North Dakota State University• Dr. Chung Park
Funding