Nutritional intervention during gestation alters growth, body composition and gene expression patterns in skeletal muscle of pig offspring

Abstract

Variations in maternal nutrition during gestation can influence foetal growth, foetal development and permanently 'programme' offspring for postnatal life. The objective of this study was to analyse the effect of increased maternal nutrition during different gestation time windows on offspring growth, carcass quality, meat quality and gene expression in skeletal muscle. A total of 64 sows were assigned to the following feeding treatments: a standard control diet at a feed allocation of 2.3 kg/day throughout gestation, increased feed allowance of 4.6 kg/day from 25 to 50 days of gestation (dg), from 50 to 80 dg and from 25 to 80 dg. At weaning, Light, Medium and Heavy pigs of the same gender, within litter, were selected based on birth weight, individually penned and monitored until slaughter at 130 days post weaning. Carcass and meat quality traits of the semimembranosus (SM) muscle were recorded post mortem. A cross section of the semitendinosus (ST) muscle encompassing the deep and superficial regions were harvested from pigs (n 5 18 per treatment) for RNA extraction and quantification of gene expression by real-time PCR. The results showed that doubling the feed intake from 25 to 50 dg reduced offspring growth, carcass weight, intramuscular fat content and increased drip loss of the SM muscle. Interestingly, protein phosphatase 3 catalytic subunit -a-isoform, which codes for the transcription factor calcineurin, was upregulated in the ST muscle of offspring whose mothers received increased feed allowance from 25 to 50 dg. This may provide an explanation for the previous observed increases in Type IIa muscle fibres of these offspring. Increasing the maternal feed intake from 50 to 80 dg negatively impacted pig growth and carcass weight, but produced leaner male pigs. Extending the increased maternal feed intake from 25 to 80 dg had no effect on offspring over the standard control gestation diet. Although intra-litter variation in pig weight is a problem for pig producers, increased maternal feeding offered no improvement throughout life to the lighter birth weight littermates in our study. Indeed, increased maternal nutrition at the three-gestation time windows selected provided no major benefits to the offspring.

Mitochondrial biogenesis is decreased in skeletal muscle of pig fetuses exposed to maternal high-energy diets

“…Decreases in mtDNA copy number have been reported in kidney and liver of offspring of rat dams fed a high-fat diet during gestation (Taylor et al, 2005;Burgueño et al, 2013). In addition, it has been reported that increased maternal nutrition in pigs and rats did not provide advantageous effects on offspring muscle growth and mtDNA copy number (McNamara et al, 2011;Latouche et al, 2014).…”

Maternal backfat depth in gestating sows has a greater influence on offspring growth and carcass lean yield than maternal feed allocation during gestation

“…Altering feeding levels at different time points during the gestation period of the sow can influence piglet growth rates (Bee, 2004;McNamara et al, 2011) and subsequent sow reproduction (Lawlor and Lynch, 2007), both of which are key factors for efficient and profitable pig production. As a commercial pig spends nearly half its life in utero, optimum nutrition and environmental conditions during this time are essential to maximise pig productivity.…”

Delayed muscle development in small pig fetuses around birth cannot be rectified by maternal early feed restriction and subsequent overfeeding during gestation

“…Increasing feed and energy intake of sows (over the recommended levels) during specific periods of gestation had either no effects on total fiber number and the ratio of secondary to primary fibers (Markham et al, 2009) or even this decreased muscle weight in the progeny (Nissen et al, 2003;Cerisuelo et al, 2009). In offspring from sows overfed during the 50 to 80 days of gestation and fed back to a standard level during the last third of gestation, no difference for MYOG, a regulatory gene involved in myogenesis, was shown but a higher expression level of IGF1 acting on postnatal growth was demonstrated in treated pigs at market weight (McNamara et al, 2011). A reverse strategy may be to induce catch-up growth mechanisms during the last trimester of gestation after an initial period of restricted maternal feeding.…”