The effect of feeding ractopamine (Paylean) on muscle quality and sensory characteristics in three diverse genetic lines of swine1,2

Abstract

The present experiment utilized Berkshire (n = 76), Duroc (n = 81), and high-lean commercial crossbred (n = 75) barrows and gilts with an initial BW of approximately 85.1 kg. Pigs were fed a standard commercial diet (17.6% CP, 1.02% lysine) supplemented with ractopamine hydrochloride at a level of 0 or 10 ppm for 28 d. The experiment was conducted in a randomized complete block design, with animals blocked within genetic line according to litter, gender, and weight, for a total of four blocks per genetic line for each treatment. Pigs were harvested at a commercial abattoir and chilled for 24 h at 1 to 4 degrees C. At 24 h postmortem, wetness and firmness scores and ultimate muscle pH were measured in the center of the longissimus muscle (LM) at the 10th to 11th rib interface. Visual and instrumental color and marbling score were measured at 48 h postmortem on a fresh cut LM surface. Percentage of chemically extracted intramuscular fat (IMF) was measured, and a trained sensory panel evaluated cooked LM chops for juiciness, tenderness, and chewiness. Cooking loss (%) and instrumental measurement of tenderness also were measured on cooked LM chops. Ractopamine treatment increased ADG (P < 0.01) and LM area (P < 0.05), but had no effect (P > 0.05) on LM quality, sensory attributes, or instrumental measures of palatability. Berkshire LM received higher tenderness and juiciness (P < 0.05) scores and had lower cooking losses (P < 0.05) and instrumental tenderness (P < 0.05) than LM from the Duroc and high-lean lines. Loins from barrows were firmer (P < 0.05), had lower drip loss percentages (P < 0.05), and received greater tenderness scores (P < 0.05) than the LM from gilts. Genetic line x treatment and gender x treatment interactions were detected for IMF. The LM of Berkshire pigs fed ractopamine had lower (P < 0.05) IMF than Berkshires fed the control diet, with no interaction in the other lines. Purebred barrows (Berkshire and Duroc) had greater (P < 0.001 and P < 0.05, respectively) IMF than their respective purebred gilts, with no gender difference in IMF in the high-lean line. Results from the present study indicate that feeding ractopamine does not affect most muscle quality and palatability characteristics. However, the genetic line x treatment interaction for loin IMF suggests that feeding ractopamine might reduce IMF within the loin muscle of genetic lines that have a propensity to produce greater levels of IMF.

Influence of rearing system, diet and gender on performance, carcass traits and meat quality of Polish Landrace pigs

“…However, barrows had more (P , 0.05) intramuscular fat than gilts, which is in line with the higher carcass fat content observed for castrates, and greater (P , 0.05) dry matter, a finding in accord with the literature (Stoller et al, 2003;Ferná ndez-Dueñ as et al, 2008). These findings are not surprising because castration favours intramuscular fattening of meat (Barton-Gade, 1987).…”

“…Even though initial pH was not significantly affected by gender, ultimate (48 h) pH of barrows was lower (P , 0.05) Stoller et al (2003) reported similar Warner-Bratzler shear force values for the longissimus muscle between barrows and gilts. In addition, these authors observed that the percentage of intramuscular lipid was less in the longissimus muscle from the gilts than barrows (2.27% v. 2.70%, respectively), which concurs with the results of the present study (Table 5).…”

Alimentação de suínos em terminação com dietas contendo ractopamina e extratos cítricos: desempenho e características de carcaça

“…Porém, outro estudo observou que a densidade energética não altera o consumo em animais suplementados com ractopamina (APPLE et al, 2004). Apesar de haver algumas discordâncias com relação ao efeito da suplementação de ractopamina sobre o consumo alimentar, de modo geral, maiores ganhos de peso foram observados (STOLLER et al, 2003). No presente estudo, porém, o ganho de peso não foi afetado pela ractopamina.…”

Características químicas y sensoriales de la carne de cerdo, en función del consumo de dietas con ractopamina y diferentes concentraciones de lisina

“…This agrees with studies in which IMF increased in pigs fed RAC (10 ppm) and had CP (16 %) levels higher than those used here (16,35) . However, in other studies no changes in pork chemical composition were observed in pigs fed diets higher RAC and CP levels: 20 ppm RAC, 17 % CP (36) ; 10 ppm RAC, 16 % CP (37) ; 10 ppm RAC, 17 % CP (38) .…”

“…A certain amount of IMF is considered essential for cooking and maintaining good meat quality (45) . Fat RAC y 16 % de PC) (37) ; (dieta con 10 ppm RAC y 17 % de PC) (38) .…”