First parity productivity of selected commercial sows
This study analysed first parity productivity records over a determined time period of three years from two selected commercial pig production units on the Highveld, and determined whether seasonal differences in productivity occur in relation to seasonal temperature fluctuations, and whether ther...
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University of Pretoria
2013
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| Online Access: | http://hdl.handle.net/2263/31215 Lucht, HL 2010, First parity productivity of selected commercial sows, MSc (Agric) Dissertation, University of Pretoria, Pretoria, viewed yymmdd <http://hdl.handle.net/2263/31215> http://upetd.up.ac.za/thesis/available/etd-08292011-164914/ |
| Summary: | This study analysed first parity productivity records over a determined time period of three years from
two selected commercial pig production units on the Highveld, and determined whether seasonal
differences in productivity occur in relation to seasonal temperature fluctuations, and whether there is
a difference in seasonal productivity between farms. The total pool of records used in various models
corresponded to first parity breeding records from two farms for 2600 sows born between 1 March
2004 and 28 February 2007. Parameters of performance taken from the records included 1) Date of
birth (DoB), 2) Year of Birth (YoB) of gilt, 3) Season of Birth (SB) of gilt, 4) Age at first service
(AFS), 5) Season of First Service (SS), 6) Year of First Service (YoS), 7) Number of Services (NoS),
8) Farrowing date (FD), 9) Year of Farrowing (YoF), 10) Season of Farrowing (SF), 11) Total number
of piglets born (TB), 12) Number of piglets born alive (BA), 13) Number of stillborn piglets (BD),
14) Number of mummified piglets (GA), 15) Weaning date (WD), 16) Backfat thickness (BF) of the
gilts at farrowing (BFF), 17) BF at weaning (BFW) and 18) Weaning to service interval (WSI). The
gilts from both farms were of the same synthetic genetic line and originated from one of three Farms
of Birth (FoB). Daily maximum and minimum outdoor temperature data for the period between 1
January 2005 and 31 December 2007 were obtained from the South African Weather Service for the
areas in which the production farms are situated. There were seasonal differences in productivity
between years, within years and between farms but were not necessarily directly linked to the
seasonal temperature fluctuations in all cases. The FoB influenced AFS significantly (P<0.0001).
For farms pooled there was no seasonal difference in AFS between gilts born in summer and gilts
born in autumn, winter and spring. However, gilts born in autumn were younger at AFS than gilts
born in winter (P < 0.0001) and spring (P=0.0008), but differences in AFS of gilts born in winter and
spring were not significant. There was no difference in TB or BA from sows receiving either one or
two services before successful conception. There was no seasonal difference of TB or BA between
gilts first served in summer, autumn, winter or spring. There were, however, fewer TB from gilts served during 2006 than from gilts served during either 2005 (P=0.0007) or 2007 (P=0.0002) but
differences in TB from gilts served during 2005 and 2007 were NS. There was no difference in BA
between years. For farms pooled, there was no seasonal difference in WSI between gilts farrowed in
summer, autumn, winter or spring. There was a tendency for the sows to return to service during the
summer months more than in any other season. There was a seasonal difference in number of piglets
born per litter between farms between years. === Dissertation (MSc (Agric))--University of Pretoria, 2010. === Animal and Wildlife Sciences === MSc (Agric) === Unrestricted |
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