Efficiency of energy and protein deposition in swine measured by dual energy X-ray absorptiometry (DXA)

Abstract

A series of studies were conducted using dual energy X-ray absorptiometry (DXA) to measure energy and protein deposition in pigs. In an initial validation study DXA was compared directly with slaughter analysis as a method for measuring energy deposition in pigs. During growth from 30 to 60 kg the mean value for carcass energy deposition measured by DXA was 251 MJ compared to 249 MJ by chemical analysis (R 2 =0.94). Subsequently it was shown that both compensatory growth and the addition of ractopamine to the diet resulted in an improvement in efficiency of protein deposition (PE), however, ractopamine also resulted in a reduction in the efficiency of energy deposition (k g ). Another study was conducted to compare the efficiency of utilization of dietary energy and protein by control and IGF-I transgenic pigs in response to dietary conjugated linoleic acid (CLA). Addition of CLA to the diet resulted in a reduction in k g , though there was no difference in k g based on genotype or sex. The PE was higher (P<0.05) in the IGF-I transgenic pigs. DXA was also used to assess energy deposition in pigs that were either homozygous stress non-sensitive (NN), heterozygous (Nn) or homozygous stress sensitive (nn). During growth from 30 to 60 kg or 60 to 90 kg there were no differences in the efficiency of either energy or protein deposition. In conclusion, DXA can be used to replace the comparative slaughter technique for measuring energy and protein deposition in pigs, thus this approach is useful for identifying differences in energy and protein deposition in pigs of different genotypes or when subjected to various dietary treatments.

Relationships among dual-energy X-ray absorptiometry, bioelectrical impedance and ultrasound measurements of body composition of swine

“…The DXA technique has been used to measure the body composition of live pigs (MITCHELL & SCHOLZ 1997, 2008, MITCHELL et al 2002, SCHOLZ & FÖRSTER 2006, BEE et al 2007) and pig carcasses (MITCHELL et al 1998). The total body DXA scan provides measurements of total body fat, lean, bone mineral and bone mineral density.…”

Efecto de la alimentación en la fase de lactancia sobre la eficiencia de utilización del alimento en el período posdestete y su relación con la microbiota del tracto digestivo, el estatus oxidativo e inmunológico en el ganado ovino = Effects of early feed restriction during the post-weaning period on feed efficiency, gastrointestinal microbiota, anti-oxidant status and immunity parameters of lambs

“…Los autores del estudio asociaron esta mayor eficiencia alimentaria con un incremento en la capacidad de gluconeogénesis hepática y concluyeron que podía representar un riesgo para el desarrollo de obesidad . No obstante, es conveniente señalar que a esa edad las ovejas ya habían dejado de crecer y solamente podían acumular grasa, mientras que, en animales en crecimiento, la ganancia de peso basada en el depósito de grasa es menos eficiente que la obtenida con el depósito de proteína (Mitchell and Scholz, 2008).…”