Nutrition of gilts in early pregnancyand reproductive performance

Pieter LangendijkRebecca AthornTai-Yuan Chen

Emmy Bouwman

~300g /d

~500g /d

This graph is by no means a recommended feeding strategy !

Current recommendation says:

“feed gilts at a low feed level during early gestation”

Feed intake early gestation

Targets of gestation feed regime:

• Balanced achievement of pre-farrowing BW

• Sufficient body reserves

• Good birth weight

• Are there risks associated with high/low feed level?

Jindal et al., 1996

Feed level and embryo mortality

Progesterone from the ovaries is broken down in the systemic circulation by the liver

0

5

10

15

20

25

30

High Low

peri

ph

era

l p

rog

este

ron

e,

ng

/ml

High

Low

Systemic progesterone and feed levels

Studies on feeding level

1. Dyck and Strain (1983) 2. Toplis et al. (1983) 3. Pharazyn et al. (1991) 4. Jindal et al. (1996) 5,6. Jindal et al. (1997) 7. Ashworth et al. (1999) 8. Virolainen et al. (2004) 9. Virolainen et al. (2005b) 10. Quesnel et al. (2010) 11,12,13,14. Athorn et al (2011, 2012)

pregnancy rate

embryo survivalFirst 3 d!

Progesterone in the systemic circulation is broken down by the liver

0

5

10

15

20

25

30

High Low

peri

ph

era

l p

rog

este

ron

e,

ng

/ml

High

Low

Systemic and local progesterone

Progesterone in the systemic circulation is broken down by the liver

0

5

10

15

20

25

30

High Low

peri

ph

era

l p

rog

este

ron

e,

ng

/ml

High

Low

Direct transfer of progesterone from the ovaries to the uterus

Systemic and local progesterone

Local and peripheral progesterone

5.0 embryos

6.1 embryos

Cannulation of the vena cava

6 h period

A high feed level seems to increase progesterone secretion by the ovaries

Progesterone in systemic circulation

Luteal mass and progesterone

It pays to have more luteal tissue

0

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25

30

35

40

4 5 6 7 8 9

Total Luteal Weight (g)

Pro

ges

tero

ne

d5

(ng

/ml)

Effects of feed level on progesterone secretion:

Direct• increased LH• increased luteotrophic factors factors e.g. IGF-1

Indirect• Increased luteal tissue mass

R.Z. Athorn, P. Stott, E.G. Bouwman, R. Ashman, S. O’Leary, M. Nottle and P. Langendijk. Direct ovarian-uterine transfer of progesterone increases embryo survival in gilts. Reprod Fertil Dev. 2011, 23, 921–928.

Athorn, R.Z., Stott, P., Bouwman, E.G., Chen, T.Y., Kennaway, D.J. and Langendijk, P. (2012) Effect of feeding level on luteal function and progesterone concentration in the vena cava during early pregnancy in gilts. Reproduction, Fertility and Development http://dx.doi.org/10.1071/RD11295

R.Z. Athorn, P. Stott, E.G. Bouwman, and P. Langendijk. (2012) Effects of energy level and energy source on luteal function and embryo survival in gilts. Submitted to Anim Prod Sci. In Press

R.Z. Athorn, P. Stott, RS Smits, and P. Langendijk. Athorn et al Effect of feed level and energy source on pregnancy rate and embryo survival in gilts. In preparation.

R.Z. Athorn, P. Stott, RS Smits, and P. Langendijk. Athorn et al Effect of feed level and energy source on pregnancy rate and embryo survival in first litter sows. In preparation.

High (~2.8 kg)

Low (~1.4 kg)

Exp 1 (Athorn et al, 2011)

n 15 15

Total embryo survival (d0-35), %(range)

73(45-100)

65(35-93)

after implantation (d15-35), %(range)

95a

(80-100)

85b

(50-100)

Exp 2 (Athorn et al., 2012)

n 10 9

Embryo survival at d10-10.5, % 92a 77b

a,b Different superscripts within row indicate significant difference (P < 0.05)

Feed level and embryo survival

Diet LOWStarch

~1.4 kg

HIGHStarch

~2.8 kg

HIGHFat

~2.6 kg

HIGHFibre**~3.0 kg

N 31 21 23 23

Weight gain, g/d

320 ± 35a 1000 ± 55b 919 ± 53b 1055 ± 55b

Ovulation Rate 15.3 ± 0.4 14.9 ± 0.5 15.3 ± 0.5 16.3 ± 0.4

Total luteal weight, g*

6.7 ± 0.2x 7.2 ± 0.2y 7.1 ± 0.2y 6.8 ± 0.2x,y

Pregnancy rate 94% (31/33) 91% (21/23) 96% (23/24) 96% (23/24)

Total embryos* 12.2 ± 0.5 11.9 ± 0.6 11.6 ± 0.6 11.6 ± 0.7

Embryo survival*

80 ± 3% 77 ± 4% 76 ± 4% 76 ± 4%

Feed level/energy source early pregnancy

*corrected for ovulation rate, **7.2% fibre, millmix and oat hulls Athorn et al., 2012

N*BW Gain

(g/d)

Pregnancy rate

d28 (%)TB BA

Low (21 MJ DE/d)

46 421 ± 41a 83 (50/60) 12.5 ± 0.4 11.5 ± 0.4

Medium (31 MJ DE/d)

39 495 ± 45a 81 (44/54) 12.2 ± 0.4 11.3 ± 0.4

High (41 MJ DE/d)

45 912 ± 40b 91 (53/58) 11.8 ± 0.4 11.2 ± 0.4

Fibre diet (31 MJ DE/d)

42 569 ± 34a 82 (50/61) 12.3 ± 0.4 11.3 ± 0.4

Feed level/energy source early pregnancy

Rivalea, 2010

Pregnancy rate(%)

Growth rate to d25 of gestation(%)

Growth rate and pregnancy rate

P = 0.09

Treatment Control 2.5 kg

High 3.25 kg

Control 2.5 kg

High 3.25 kg

Litters at term Pregnancy at d35

n 49 47 13 15

BW gain, kg 16 ± 1.2 24 ± 1.2 14.7 ± 1.3 20 ± 1.1

Back fat gain, mm

1 ± 0.3 1.5 ± 0.3 0.8 ± 0.5 1.9 ± 0.4

FR/PR, % 89 % 75 % 87 % 95 %

LS/embryos 13.2 ± 1.2a 15.2 ± 0.5b 15.9 ± 0.9 15.7 ± 0.7

Hoving et al., 2011

Extra feed during early pregnancy (d3-25) in first litter sows

New aspect: group housing

Thesis by A.G. Kongsted (2005)

• “Sows eating less than 20 % of all observations at feeding had significant higher risk of returning to oestrus…”

• “Positive relationship between back fat gain from weaning to three weeks after mating with chance of pregnancy (P<0.05) and litter size (P=0.08).”

(Kongsted, 2005)

New aspect: group housing

Back fat gain, mm/wk

Treatment BA SB Total Born

Control (n=11) 10.6 ± 0.5a 0.3 ± 0.2 10.9 ± 0.5a

Fasted (n=11) 8.1 ± 0.8b 0.7 ± 0.4 8.8 ± 0.8b

Effects of feed incidents

1. High feed levels do not result in higher embryo

mortality

2. It is better to recommend moderate to high feed levels:

2.2-2.5 kg per day, rather than low

3. Limit feed intake in late gestation to 2.5-2.7 kg (32.5-35

MJ DE)

4. There may be a risk associated with low feed (incidents)

levels especially in group housing

Implications