Estimation of genetic trends from 1977 to 1998 of body composition and physiological state of Large White pigs at birth

Abstract

Genetic trends for body composition and blood plasma parameters of newborn piglets were estimated through the comparison of two groups of pigs (G77 and G98, respectively) produced by inseminating Large White (LW) sows with semen from LW boars born either in 1977 or in 1998. Random samples of 18 G77 and 19 G98 newborn piglets were used for whole carcass and tissue sampling. Plasma concentrations of glucose, albumin and IGF-1 were determined on 75 G77 and 90 G98 piglets from 18 litters. The G98 piglets had less carcass dry matter, protein and energy (P , 0.01) than their G77 counterparts. When expressed in g/kg birth weight, livers were lighter (P , 0.001) and contained less glycogen (P , 0.01) in G98 piglets, with no difference in the activity of the hepatic glucose-6-phosphatase between G98 and G77 piglets. Concentrations of protein, DNA, RNA in longissimus dorsi muscle were unaffected by selection. Plasma concentrations of glucose (P , 0.05) and IGF-1 (P , 0.01) were lower in G98 than in G77 piglets. On the whole, the results suggest that the improvement in lean growth rate and in sow prolificacy from 1977 to 1998 has resulted in a lower maturity of piglets at birth.

Influence of some sow characteristics on within-litter variation of piglet birth weight

“…In their study, however, the impact of selection on the other characteristics of piglets and litter at birth differed from our present findings. Despite the increase in prolificacy, they did not observe a reduction in piglet BW0 but a lower piglet maturity at birth (Canario et al, 2007). Moreover, according to Tribout et al (2003), the increase in CV BW0 over time was caused by an increase in the maximum piglet BW0 and not by a higher frequency of small piglets.…”

Body composition and blood parameters of newborn piglets from Alentejano and conventional (Large White × Landrace) genotype

“…Compared to the genetically obese Ossabaw (Stone et al, 1985) or Meishan piglets (Herpin et al, 1993), newborns from lines selected for lean tissue growth have less dry matter and protein concentrations in their body and lower liver weight. Further, 21 years of genetic selection of the French Large-White (LW) on lean growth and litter size also resulted in similar effects on the newborns (Canario et al, 2007b).…”

Estimation of genetic trends from 1977 to 2000 for stress-responsive systems in French Large White and Landrace pig populations using frozen semen

“…The expected correlation between cortisol and ECLC was confirmed in G98 pigs; however, no relationship between adrenaline and carcass composition measures was found. On the same experimental design, other studies have estimated genetic trends for traits measured at farrowing in the LW breed (Canario et al, 2007a and2007b). The results suggest that the improvement in lean growth rate and in sow prolificacy from 1977 to 1998 has resulted in a lower maturity of piglets at birth.…”

“…Moreover, this indirect selection on stress-responsive systems may be responsible for negative trends on other traits such as meat quality (Lonergan et al, 2001) or newborn survival (Canario et al, 2007a and2007b;Herpin et al, 1993). A better understanding of the molecular and physiological mechanisms involved in the relationships between endocrine systems (cortisol and catecholamines) and different production traits would help to optimize selection to improve together the level of production, carcass composition, product quality and animal welfare.…”