Effect of dietary protein level on carcass traits and meat properties of Cinta Senese pigs

Abstract

The aim of this study was to test the effect of various dietary protein contents (CP) on the carcass traits and the meat quality of Cinta Senese pigs. A total of 60 Cinta Senese pigs were equally distributed in four dietary groups that were balanced for sex (barrows and gilts) and live weight. The animals in the groups were fed one of four diets (80CP, 100CP, 130CP and 160CP) containing different CP contents (80, 100, 130 and 160 g/kg, respectively). The diets were administered to the pigs during the entire growing-fattening period in a controlled dose of 90 g/kg W 0.75 , to a maximum of 2.5 kg/day per animal. The duration of the trial was~250 days, ending when the animals reached the target slaughter weight of 145 kg. The 80CP diet produced fatter carcasses than did the other diets; no differences in carcass composition were found among the animals fed the other three diets (total lean cuts: 57.4%, 61.4%, 60.8% and 61.3% for 80CP, 100CP, 130CP and 160CP diet, respectively). The sample joint composition confirmed the highest fatness and the lowest meatiness of pigs fed 80CP. This same pattern was evident for the composition of the muscle ( Longissimus lumborum) containing the largest amount of i.m. fat, and the lowest protein content in the 80CP group. Moreover, the 80CP diet resulted in the lightest and yellowest meat with the highest cooking loss. A principal component analysis of the physical and chemical traits of the meat revealed three first factors that explained 56% of the total variance. Among them, only the intersection of Factor1, which combined mainly lower pH at 24 h postmortem and higher drip loss, cooking loss, lightness and yellowness, with Factor2, which associated higher toughness, higher protein and lower fat content, graphically appeared to discriminate the 80CP diet from the other ones. In conclusion, a diet with 80 g/kg of CP content was inadequate for this local breed, while, in consideration of the cost of protein feed and the need to reduce N pollution, the 100CP diet would be an optimal compromise for the growth-fattening of Cinta Senese pigs.

Effects of Protein Restriction on Performances and Meat Quality of Cinta Senese Pig Reared in an Organic System

“…Despite the different dietary regimen, no modifications in weight gain, average daily gain (ADG), and backfat thickness were observed at the end of the growing phase. During the following finishing phase any parameters reached the statistical significance The observed values for ADG and backfat thickness are in line with those reposted on previous studies on Cinta Senese [19,21]. However, results on the growing phase are in contrast with those reported by several authors who, in lean genotypes, spotted a clear negative effect of protein restriction on growth performances [6,22,23,24,25].…”

Effects of Different Protein Levels on the Nitrogen Balance, Performance and Slaughtering Traits of Cinta Senese Growing Pigs

“…Currently, this knowledge is available only for Iberian pigs whose protein and energy requirements, as well as their optimal ratio, have been studied for each rearing phase [5,6,25,26]. Previous studies on Cinta Senese evaluated the whole growing-fattening period [8,9,27]. These studies highlighted the lower protein requirements of Cinta Senese compared to that of lean genotypes, whose recommended protein intake for growing pigs is 16% CP [15].…”

“…In a meta-analysis study, the same authors also observed that the carcass components of obese genotypes follow a different pattern of relative growth in comparison with the lean genotypes [7]. In the Cinta Senese breed, two studies were carried out, testing four diets with increasing CP contents (8%, 10%, 13% and 16%) in animals from 50 to 145 kg [8,9]. Considering both the growth performance and slaughtering traits of the whole post-weaning-fattening period, the authors stated that a content of 10% CP in the diet was adequate to fulfill Cinta Senese protein requirements.…”

Protein Restriction with Amino Acid-Balanced Diets Shrinks Circulating Pool Size of Amino Acid by Decreasing Expression of Specific Transporters in the Small Intestine

“…It is widely accepted that, as long as AA are balanced with supplementation of crystalline AA, the nutritive value of protein-restricted diet is similar to the conventional diet in terms of growth performance and body composition in pigs [12, 30, 31]. However, when the dietary CP content was reduced by 8 percentage units, the performance of growing pigs was reduced as a result of inadequate supply of nitrogen for the synthesis of dispensable AA [30].…”