Reproduction performances and conditions of group-housed non ...

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- Paper IV - 4. Discussion The average litter size was high compared to earlier studies, whereas the percentage of sows re-mated corresponded to several previous on-farm studies (Gjein & Larssen, 1995; Olsson & Svendsen, 1997; Hansen & Kongsted, 2002). The high litter sizes of the sows involved in this study, support that group housing of non-lactating sows does not necessarily lead to poor reproduction performance. The chance of pregnancy (P=0.02) and number of born piglets per litter (P=0.08) decreased with decreased back fat gain from weaning to three weeks after mating. Furthermore, sows eating less than 20% of the observations at feeding were in markedly higher risk of returning to oestrus compared to sows eating more frequently (P
- Paper IV - cial effect on high ranked sows (equal to the sows receiving fewest aggressions) more than a suppressing effect in sows of low rank in respect to weaning to oestrus interval. A negative effect of a poor body condition at weaning on weaning to oestrus interval is well documented in experimental studies (reviews by Dourmad et al., 1994; Whittemore, 1996). In this study, however, this effect was seen only in first parity sows. This indicates that first parity sows are more sensitive to a low back fat at weaning compared to older sows as also proposed by Whittemore & Morgan (1990). These results show that if it is difficult to avoid poor body condition at weaning, special attention should be given in the post weaning period to young sows. The negative effect of a low back fat depth at weaning might be caused by reduced LH level (Aherne & Kirkwood, 1985). Since boar stimuli after weaning may stimulate LH secretion in sows with metabolic constraints (Langendijk, 2001), careful boar stimulation could perhaps counterbalance the negative effect of poor body condition at weaning. In agreement with a previously experimental study (Young et al., 1990), a relation between back fat depth and culling was found, in that sows with a very low back fat depth at weaning (less than 10 mm) were more likely to be culled later in the non-lactating period compared to sows with 10 mm or more back fat (P
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Reproduction performances and condi
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Contents Summary………………
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Paper II - Summary - A review of 15
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- Sammendrag - SAMMENDRAG Antallet
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- Sammendrag - søgt. Positive korr
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- Background and aim - systems and
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- Outline of this thesis - OUTLINE
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- How does group housing vary in pr
Page 23 and 24:
- How does group housing vary in pr
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- Paper I - Effect of energy intake
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- Paper I - 1. Introduction The num
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- Paper I - Therefore, the aim of t
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Refer ence Table 1. Effect of energ
Page 34 and 35:
- Paper I - Therefore, low energy s
Page 36 and 37:
Table 2. Effect of energy intake in
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- Paper I - However, this does not
Page 40 and 41:
Table 3. Effect of energy intake in
Page 42 and 43: - Paper I - Feeding sows 16, 27 or
Page 44 and 45: - Paper I - gonadotrophins (LH, FSH
Page 46 and 47: - Paper I - the first four weeks af
Page 48 and 49: - Paper I - Cosgrove, J.R., Foxcrof
Page 50 and 51: - Paper I - Matschke, G.H., 1964. T
Page 52: - Paper I - Tribble, L.F., Orr, D.E
Page 55 and 56: - Paper III - Indicators of feed in
Page 57 and 58: - Paper III - 1. Introduction The n
Page 59 and 60: Table 1. Applied feeding and housin
Page 61 and 62: - Paper III - performed. The sow ha
Page 63 and 64: - Paper III - proximately three wee
Page 65 and 66: - Paper III - Table 3. Overall mean
Page 67 and 68: Table 5. Correlations between all c
Page 69 and 70: Back fat W, mm Back fat gain, AM-F,
Page 71 and 72: - Paper III - from three weeks afte
Page 73 and 74: - Paper III - Number of skin lesion
Page 75 and 76: - Paper III - In herds practising g
Page 77 and 78: - Paper III - Previous work have fo
Page 79 and 80: References - Paper III - Andersen,
Page 81 and 82: - Paper III - Kongsted, A.G. 2004a.
Page 83 and 84: - Paper IV - Relation between repro
Page 85 and 86: - Paper IV - 1. Introduction Group
Page 87 and 88: - Paper IV - ing compared to number
Page 89 and 90: - Paper IV - mixed model using the
Page 91: Table 2. Estimates and standard err
Page 95 and 96: References - Paper IV - Aherne, F.X
Page 97 and 98: - Paper IV - Olsson, A.-C., Svendse
Page 99 and 100: - General discussion - GENERAL DISC
Page 101 and 102: - General discussion - However, an
Page 103 and 104: References - General discussion - A
Page 105 and 106: - Conclusions - 6. CONCLUSIONS Two
Page 107 and 108: - Appendix 1 - APPENDIX 1 LITTER SI
Page 109 and 110: - Appendix 1 - they are mature i.e.
Page 111 and 112: - Appendix 1 - Soon after ovulation
Page 113 and 114: - Appendix 1 - Crombie, P.L., 1970.
Page 115: - Appendix 1 - Scott, M.A., 2000. A
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