Effect of hemoglobin and immunization status on energy metabolism of weanling pigs.

Abstract

We investigated the effect of (Hb) and immunization status on energy metabolism of newly weaned pigs. An additional focus of the study was to determine the development of circadian rhythms as evidenced by heat production patterns. Twenty-four 4-wk-old crossbred weanling barrows were placed into groups of three based on weight and litter origin, and the groups were allotted to one of four treatments. Treatments were arranged as a 2 x 2 factorial. The factors included 1) Hb status (low vs high) and 2) immunization status (antigen vs placebo). Hemoglobin status was obtained by injecting 3-d-old barrows with 100 (low) or 200 mg (high) of Fe. At 4 wk, initial blood Hb concentrations were 6.0 mM for the low group and 7.8 mM for the high group. Energy metabolism was measured using two weekly total energy and nitrogen balance collections. Energy intake and retention were higher (P < .05) in pigs with a high Hb level. Energy metabolism was not affected (P > .10) by immunization status, and heat production was not affected (P > .10) by either Hb or immunization status. Total heat production (HTOT) increased (P < .001) daily and reflected a daily increase (P < .001) in activity (HACT) and activity-free (HCOR) heat production. An increase (P < .001) in HTOT and HACT was detected for the light period compared with the dark period over the total experimental period but a decrease (P < .001) in HCOR was detected; however, HACT for the dark period was approximately half of that measured during the light period. In conclusion, Hb status affected energy metabolism; pigs having a high Hb status had a higher energy retention. Immunization status had minimal effects on energy metabolism and heat production. Additionally, the diurnal circadian rhythm seen in older pigs had not been established by 2 wk after weaning.

The Low Feed Intake in Newly-weaned Pigs: Problems and Possible Solutions

“…The weanling pigs' energy requirement for maintenance is not met until day 5 after weaning, and the pre-weaning energy intake level is not attained until the end of the 2nd week postweaning (Le Dividich and Herpin, 1994). This finding has been confirmed in several studies (van Diemen et al, 1995;Gentry et al, 1997;Moon et al, 1997;Sijben et al, 1997). The average gross energy intake during weeks 1 and 2 is only, respectively, 41% and 82% of the average during weeks 4, 5, and 6 after waning (Bruininx et al, 2001).…”

Brood size and immunity costs in zebra finchesTaeniopygia guttata

“…2c). An immunisation effect on activity can obscure metabolic effects (Gentry et al 1997). However, activity levels in the afternoon and the next morning were not affected by immunisation (Fig.…”

Parenteral iron administration in suckling piglets – a review

“…An increase in 10 g Hb/l corresponded to a daily weight gain improvement of 17.2 g. It is not clear how increased Hb levels could positively affect weight gain. According to Gentry et al (1997), pigs with a high Hb status have better energy retention. A positive effect on intestinal functions may also be involved (Larkin and Hannan 1984).…”