Cesar Rosales Nieto - The UWA Institute of Agriculture - The ...
Cesar Rosales Nieto - The UWA Institute of Agriculture - The ...
Cesar Rosales Nieto - The UWA Institute of Agriculture - The ...
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<strong>Cesar</strong> <strong>Rosales</strong> <strong>Nieto</strong><br />
School <strong>of</strong> Animal Biology and <strong>The</strong> <strong>UWA</strong> <strong>Institute</strong> <strong>of</strong> <strong>Agriculture</strong>, Faculty <strong>of</strong> Science<br />
<strong>Cesar</strong> completed a Bachelor degree Plant and Animal<br />
Science with first class Honours at the University <strong>of</strong> San<br />
Luis Potosi in his home country <strong>of</strong> Mexico.<br />
He then worked at Mexico’s National <strong>Institute</strong> <strong>of</strong> Forest,<br />
Agricultural and Livestock Research as a researcher. In 2004<br />
he went to the United States and completed a Master degree<br />
in Animal Science, with an emphasis on the physiology <strong>of</strong><br />
reproduction, at Texas A&M University.<br />
In 2009, a scholarship from the Mexican National Council for<br />
Science and Technology enabled <strong>Cesar</strong> to come to <strong>UWA</strong> to<br />
undertake his PhD, examining the effect s <strong>of</strong> muscle and fat<br />
accumulation on the reproductive performance <strong>of</strong> female<br />
sheep.<br />
<strong>Cesar</strong> plans to submit his thesis later this year and will<br />
return to Mexico to help advance agriculture in in his home<br />
country with the knowledge gained at <strong>UWA</strong>.<br />
<strong>The</strong> University <strong>of</strong> Western Australia
THE <strong>UWA</strong> INSTITUTE OF AGRICULTURE<br />
Postgraduate Showcase 2013: Frontiers in <strong>Agriculture</strong><br />
Advancing puberty in female sheep:<br />
its all about muscle and fat<br />
<strong>Cesar</strong> <strong>Rosales</strong> <strong>Nieto</strong><br />
Graeme Martin<br />
Andrew Thompson
Acknowledgements:<br />
Team<br />
Supervisors
<strong>The</strong> Australian sheep industry<br />
Reproductive efficiency<br />
Mate ewes as lambs<br />
Economics (more lambs on the ground)<br />
Increase lambs weaned<br />
Increase in lifetime performance<br />
Increased rate <strong>of</strong> genetic gain
Puberty<br />
Internal factors<br />
External factors
Age is a secondary factor<br />
Liveweight (50 – 70%)<br />
Physiological<br />
sexual maturity has<br />
been reached<br />
Gonadotrophins<br />
LH – Luteinizing Hormone<br />
FSH – Follicle-Stimulating Hormone<br />
Ovulation<br />
Egg<br />
Ovary
Reproduction<br />
Puberty/Fertility<br />
Leptin concentration<br />
Fat<br />
(+)<br />
(-)<br />
Leptin concentration<br />
(-) (+)<br />
Fat tissue (Body Condition / Live weight)
Reproduction<br />
Follistatin<br />
Fecundity<br />
Muscle<br />
(+)<br />
(-)<br />
(-) (+)<br />
Rate <strong>of</strong> muscle accumulation
Hypothesis<br />
Higher values for growth and muscle and fat accumulation are also<br />
more able to successfully reproduce at younger ages<br />
This reproductive success is positive related to circulating<br />
concentration <strong>of</strong> follistatin and leptin<br />
Puberty<br />
‘switch’<br />
Follistatin<br />
Muscle tissue<br />
accumulation<br />
Ovulatory<br />
signal<br />
Leptin<br />
Adipose<br />
tissue<br />
Body<br />
Composition<br />
<strong>The</strong> “Adipose theory”<br />
Ovulation
Material and Methods<br />
Animals and treatments<br />
Medina (n = 136)<br />
Pingelly (n = 190)<br />
Katanning (n = 514)<br />
Sire: Wide range in genetic values (ASBV) for growth,<br />
muscle and fat<br />
Live weight was recorded (LWC)<br />
Fat and muscle scan at post-weaning<br />
Depth <strong>of</strong> Eye Muscle (EMD)<br />
Depth <strong>of</strong> Fat (FAT)<br />
Genetic value for weight (PWT)<br />
Genetic value for muscle (PEMD)<br />
Genetic value for fat (PFAT)<br />
2009 - 2011<br />
Experiment
Material and Methods<br />
Animals and treatments<br />
Puberty Period (5 to 8 months old)<br />
Vasectomized rams<br />
Harness with a crayon<br />
Fertility Period (8 to 10 months old)<br />
Entire Rams<br />
Pregnancy scan (60 days)<br />
Fertility rate
Material and Methods<br />
Data analyses<br />
• Mixed Model for age at first oestrus, puberty and fertility.<br />
• Covariates: EMD, FAT, PEMD, PFAT, PWT<br />
• Fixed Effects: BTRT (Birth type - Rear type) and Dam age<br />
• Random effect: Ewe lamb sire
Results<br />
50<br />
45<br />
40<br />
35<br />
30<br />
25<br />
20<br />
Live weight (Kg)<br />
Puberty Period<br />
Experiment<br />
Fertility Period<br />
LWC<br />
≤ 50; 35%<br />
≥ 200; 75%
Age at first oestrus (Days)<br />
240<br />
230<br />
220<br />
210<br />
200<br />
0 1 2 3 4 5 6 7 8 9<br />
PWT (Kg)
Puberty (%)<br />
100<br />
80<br />
60<br />
40<br />
0 1 2 3 4 5 6 7 8 9<br />
PWT (Kg)
Results<br />
100<br />
Puberty and muscle and fat accumulation<br />
Fat accumulation (FAT; mm)<br />
2 3 4 5 6 7<br />
Puberty (%)<br />
80<br />
60<br />
40<br />
EMD<br />
FAT<br />
15 18 21 24 27 30 33<br />
Muscle accumulation (EMD; mm)
Fertility (%)<br />
100<br />
80<br />
60<br />
40<br />
20<br />
0<br />
30 35 40 45 50 55<br />
Live weight at start <strong>of</strong> Mating (Kg)
100<br />
Fat accumulation (FAT; mm)<br />
2 3 4 5 6 7<br />
Fertility (%)<br />
80<br />
60<br />
40<br />
20<br />
0<br />
EMD<br />
FAT<br />
15 18 21 24 27 30 33<br />
Muscle accumulation (EMD; mm)
Results<br />
Fertility and hormonal control<br />
Leptin (ng/mL)<br />
0.8 1.2 1.6 2 2.4 2.8 3.2<br />
100<br />
Fertility (%)<br />
80<br />
60<br />
40<br />
Follistatin<br />
Leptin<br />
20<br />
1 3 5 7 9<br />
Follistatin (ng/mL)
Total follistatin (ng/mL)<br />
5<br />
Leptin (ng/mL)<br />
2.2<br />
4<br />
1.8<br />
3<br />
1.4<br />
2<br />
15 20 25 30 35<br />
Muscle accumulation (mm)<br />
1<br />
Follistatin<br />
Leptin
Conclusion<br />
Puberty<br />
‘switch’<br />
X<br />
Follistatin<br />
Muscle tissue<br />
Intramuscular<br />
fat<br />
Ovulatory<br />
signal<br />
Leptin<br />
Live weight<br />
Adipose<br />
tissue<br />
Body<br />
Composition<br />
Growth<br />
Ovulation
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