resources allocation in reproductive rabbit does · resource allocation in reproductive rabbit...

Resource allocation in reproductive rabbit does: genetic strategies for a suitable performance

J.J. Pascual, C. Cervera, M. Baselga Giornate di Coniglicoltura ASIC Forlì (Italy), 10-11 April 2013

Resources allocation in reproductive rabbit does: genetic strategies for a suitable

performancePascual J.J., Cervera C., Baselga M.Institute for Animal Science and Technology



Rabbit health“main handicap of the current rabbit farming”

New challenge(as ERE)

Young rabbitsgut health

weaning dietsadditives...

Rabbit female ??current breeding systems

nutrient partitioningimpact on health

“Global health and welfare of the farm”

Litter effect on digestive troubles

0

20

40

60

80

100

0 20 40 60 80 100

Acc

umm

ulat

ive

mo

rtal

ity in

fatt

enin

g (%

)

Acummulative females (%)

22% of females responsible for 50% of the mortality

Quevedo et al., 2003



1996-1997 2011--2012

7

9

10

11

8

199 -199 -

7

9

10

11

8

Genetic selection programmes

Changes in nutrient partitioning ? lifespan and farm health compromised ?

NBA

NBA

NW

NW

“Selection for litter size”

female

requirements

“Selection for growth rate”

New reproductive management



Nutrient partitioningAvailable resources

Growth Gestation Milking Health

Food Body reserves

“Changes in the proportions

addressed to each of them

with the physiological state

and age”

Relative priorities of the female change (GARUNS: Martin and Sauvant, 2010) “Resources

allocation and

body condition

seems to be

genetically

driven”



Independence resources-mobilisationPrimiparous low body size limited intake

Litter size standardised

150

200

250

300

350

400

3200 3500 3800 4100 4400

Inta

ke f

irst

lact

atio

n (g

DM

/d)

Body weight of primiparous does (g)

Punctualnegativebalances

malfunctioning

of animal

=

natural adaptation

ensure evolutionary

successPost‐natal investment

No. pregnancies

Rabbits:Success ofselection forlitter size

“How rearing, feeding and selection is

affecting nutrient partitioning, and so

reproduction and lifespan?”



Input

Body condition Reproduction

Survival

Next offspring

Current offspring

5

5,5

6

6,5

7

-32 -24 -16 -8 0 8 16 24

days respect to partum

Perire

nal f

at thi

ckne

ss (

mm

)

“Enough evidence of a genetic component driving body fatness”

Body condition evolution:

Maximum aprox. 10 d before kindling

Minimum around kindling

Recovery after parturitionResults in vivo (PFT, TOBEC and BIAS)

“This course

of the body

reserves is

slightly

different from

other species”

Body condition and reproduction



Evolutionary success of rabbits, “the number”:

Fertile acceptance at postpartum

Early lactation recovery: feed slope > milk slope

Relevance of body condition around kindling:

Quevedo et al., 2006b:Pre-partum losses

Post-partum recovery

Post-partum fertility

r = + 0.29 ***

Females that were not effectively AI at 11 d

PFT losses in late pregnancy,

PFT at partum and recovery in early lactation

Savietto, 2012

Feed intake

Milk yield

Perirenal fat thickness (mm)

Effectively mated

No effectively mated




5

5,5

6

6,5

7

-32 -24 -16 -8 0 8 16 24

days respect to partum

Perire

nal f

at th

ickn

ess

(mm

)

TOBEC BIAS PFTNegative balance during lactation??

Primiparous, sometimes !!

Multiparous, no relevant !!

Lactation-gestation concurrence:

- lower milk and recovery

- but less recovery time

Main risk of imbalance in late pregnancy!!

weaning to kindling

Relative risk of culling

7.16a

2.44b

lactation empty

1.00b

Theilgaard et al. (2006)

130 farms

303,250 females

“To take care with programmes which would

not allow an adequate recovery before partum”




“How is genetic selection affecting resources allocation?”

Genetic selection in livestock: Productive level

Negative associated effects: + fertility

+ incidence of metabolic diseases

+ viability of the offspring

30870 kg in 365 d (85 kg/d)Rabbit does: + 125% replacement

+ health problems (mainly digestive)

Selection for growth rate (GR)

GR: Feed intake and FCR

Tendency to excessive fatness

Lifespan (Theilgaard et al., 2006)

Fertility and litter size (Castellini et al., 2006)

Abnormal spermatozoa (Du Plessis et al., 2010)

More research is needed

Genetic selection and resource allocation

1

Selectionlitter size

2 3 4Lactation week

Selectiongrowth

rate



♀ line V x ♂ line A15th gener. 16th gener.

♀ H1

♀ line V x ♂ line A26th gener. 31st gener.

♀ H2

Quevedo et al., 2006

Mant

Growth

Rep

Growth

Rep

MantRep+

Rep

Crec

MantMant

Crec

Rep

Mant

Growth

Rep

Survival??

0-21 d

117b

21-28 d

112112

DM

inta

ke

113a

Lactation day0 7 14 21 28

H2

H1

Dai

lym

ilkyi

eld

(g)

H1

PFT at 10th day (mm)

9.13a

9.25b

H2

“Selection for litter size at weaning has increased female capacity to obtain resources”

Selection for litter sizeAntagonism reproduction - survival



No-restricted environment: 11.6 MJ DE/kg DM

DE intake Milk yield

Litter size Litter survival

partum0,0

0,2

0,4

0,6

0,8

1,0

Rel

ativ

ere

prod

uctiv

epr

iorit

y

Friggens, 2003

In no-restricted conditions selection for litter size:

+ pre-partum effort (litter size)+ post-partum milk (litter survival)

Selection for litter size at weaning:Changes in nutrient partitioning addressed to ensure

its evolutionary success

“n”

Litter growth

a

b

0,80

0,90

1,00

1,10

1,20

1,30

1,40

1,50

1,60

0 7 14 21 28 35 42 49 56 63 70 77

b

a

70

95

120

145

170

195

220

245

270

-7 0 7 14 21 28 35 42 49 56 63 70 77

a

ab

b

400

900

1400

1900

2400

2900

3400

3900

4400

-7 0 7 14 21 28 35 42 49 56 63 70

Selection for litter size



DE intake change Milk yield change Body energy change

When resources are limited selection for litter size:

+ Intake + Body energy+ Milk yield + Litter size

Priority for Priority forcurrent litter next litter

8.5a

10.1b

Selection for litter size seems to increase the environmental sensitivity of the animals

.

Perhaps no a weakness !!

Strategy to ensure its evolutionary success ??

In a restricted environment: 9.1 MJ DE/kg DM

**

*

*

*

*

*

-0,40

-0,30

-0,20

-0,10

0,00

0,10

0,20

0,30

0 7 14 21 28 35 42 49 56 63 70 77

**

*

*

* * *-50

-40

-30

-20

-10

0

10

20

0 7 14 21 28 35 42 49 56 63 70

*

*

*

*

***

-5,00

-4,00

-3,00

-2,00

-1,00

0,00

1,00

-7 0 7 14 21 28 35 42 49 56 63 70 77 84 91

Selection for litter size



♀ line VSelected for litter size at weaning during

31 generations

♀ line LPFounded using animals with at least 25

parities and 8.5 kits weaned

Theilgaard et al., 2007

vs.

Selection for reproductive longevity:

No relevant reduction of reproduction

Delay of senescence??

Greater soma: higher plasticity under high productive conditions.

Use of body reserves to maintain reproduction under challenge conditions?

8

8,5

9

9,5

10

10,5

11

11,5

0 1 2 3 4 5 6 7 8

LP

V

No. born alive Body weight (kg)

Selection for longevity



DE intake Milk yield Body energy

When the resources are limited, foundation for reproductive longevity:

First lactation:+ Quick adaptation to DE level+ Lower reduction: Milk yield

Body energyBorn alive at 2nd partum

+0.26

0.72

Effect of restriction in No. born alive

0.53

2.55*

2nd partum 3rd partum

Second lactation:+ Both lines adapted to DE level+ Clear symptoms of exhaustion in V36

Body energy Born alive at 3rd partum

In a restricted environment: 9.1 MJ DE/kg DM

*

*

*

*

**

-0,40

-0,30

-0,20

-0,10

0,00

0,10

0,20

0,30

0 7 14 21 28 35 42 49 56 63 70 77

*

*

* **

*

* * *-50

-40

-30

-20

-10

0

10

20

-7 0 7 14 21 28 35 42 49 56 63 70

**

-3,50

-3,00

-2,50

-2,00

-1,50

-1,00

-0,50

0,00

0,50

1,00

-7 0 7 14 21 28 35 42 49 56 63 70 77 84 91

Selection for longevity



Intake Reserves

Total born Born alive

“Robust females: less sensible to environment”

“Stable production in long term without boast”

1,15

1,20

1,25

1,30

1,35

N R

28,5

29,0

29,5

30,0

30,5

31,0

N R

9,0

9,5

10,0

10,5

11,0

11,5

N R

8,2

8,7

9,2

9,7

10,2

N R

Robust femaleUnder

challenge conditions

More resources

Maintains body

reserves

Guaranty for

reproduc‐tion

Maintains litter size

Reduced risk of culling

Higher longevity

Robustness



LP V16 V36

Total lymphocytes (106/L) 2816b 2969b 2467a

B Lymphocytes (106/L) 131ab 167b 107ab

CD25+ (106/L) 52b 40b 31b

Normal conditions (14-20ºC) (Ferrian et al., 2012a)

Heat stress conditions (25-36ºC)

1500

2000

2500

3000

3500

4 dpp 10 dpp partum 2

Total lymphocytes

Immunological challenge with LPS (Ferrian et al., 2012b)

Cumulative mortality rate

C-reactive protein

Haptoglobin

Could be improved the general health

conditions of the farm using animals with a higher robutsness?

Robustness – Immune response



LSB Rob GR

Daily weight gain (g/d) 35,4a 35,5a 45,8b

Mortality (%) 19,0b 9,5a 16,5b

Morbidity (%) 6,6b 3,9b 9,9b

Genetic selection- Growing period (Arnau et al., 2013)

Mortality %

Robustness – Immune response

14,6

27,6

3,6

20,5

8,5

36,5

0,00

10,00

20,00

30,00

40,00

Medicated feed No medicated feed

LSB Rob GR

Lymphocytes counts at weaning (García-Quirós et al., 2013)

GR

LSB

Further efforts about the possible effect of

genetic type on young rabbits health is

needed !!Rob



Conclusions1. Resources allocation (partitioning of available resources into vital functions)

are genetically driven, and they are mainly addressed to allow expression of

the traits selected in rabbit females.

2. When environment ensure enough resources, selection can improve

economic traits without penalties.

3. But when it becomes limiting, preferential allocation of resources in ‘selected’

traits (growth, reproduction…), can reduce the ability of animals to respond

to other demands (such as coping with disease, stress…).

4. Main works show that genetic selection in rabbit by litter size at weaning has

increased prolificacy but also the ability to obtain resources, without

compromising the survival of rabbit females when resources are ensured.

5. However, farms are frequently subjected to punctual challenges (feed quality,

heat stress, pathogens…). Under these conditions, particular nutrient

partitioning of females characterised by a higher robustness could be

recommended to maintain an adequate productive level in long-term.



Grazie [email protected]



HealthWelfareLifespanFemale survival

Short-term productionFeed intakeMilk yield

Reproductive efficacyFertility

Prolificacy

Bodyconditionof rabbitfemale

Bodyconditionof rabbitfemale

HealthWelfare

Litter development

Suitable feeding and breeding programmes

resources allocation in reproductive rabbit does · resource allocation in reproductive rabbit...

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