Responses of Pigs of Different Genotypes to a Variation in the Dietary Indispensable Amino Acid Content in Terms of Their Growth and Carcass and Meat Quality Traits.

Schiavon Schiavon,Gallo Gallo,Carcò Carcò,Sturaro Sturaro,Bona Bona

doi:10.3390/ani9080508

Schiavon Schiavon, Gallo Gallo + Show 3 more

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https://doi.org/10.3390/ani9080508

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Abstract

Simple SummaryThe aim of the experiment was to study the response of pigs of different genotypes to a variation in their dietary amino acid allowance. Ninety-six crossbred barrows of two lean paternal genetic lines (Hypor Maxter and PIC 337) were housed in eight pens from body weight 60 to 145 kg and fed quasi ad libitum on feeds with either high or low ileal digestible indispensable amino acid contents. The high and low amino acid feeds were formulated to have the same standardized ileal digestible (SID) lysine, methionine, tryptophan and threonine contents per unit of crude protein, but provided 9.4 to 8.0 (assumed to be non-limiting) or 8.5 to 6.5 (close to National Research Council recommendations) g/kg of SID lysine, respectively. The low amino acid feed reduced the estimated N excretion compared with the high, without affecting growth, carcass yield, carcass anatomical composition and meat quality traits. Genetic line had trivial effects and the amino acid level × genotype interaction was never significant. We concluded that the two pig genotypes did not differ sufficiently in growth potential and leanness to respond differently.We studied the response of pigs from two crossbred genetic lines (GL) in the 60 to 145 kg body weight interval to a variation in the indispensable amino acid (AA) content of their feed. Ninety-six barrows of two paternal GLs (Hypor Maxter and PIC 337) were housed in eight pens and fed quasi ad libitum on feeds differing in their standardized ileal digestible (SID) indispensable AA contents. Pigs in four pens received feeds containing 9.4 to 8.0 g/kg of SID Lys (HAA), considered non-limiting, while the others received feeds containing 8.5 to 6.5 g/kg of SID Lys (LAA). The two feeds had identical indispensable lysine, methionine, tryptophan and threonine contents per unit of crude protein (CP). Feed intake, growth, carcass weight, and the weights of the lean and fat cuts were recorded, and samples of longissimus lumborum were analyzed. Data were analyzed using a two-way factorial mixed model. The LAA feed lowered the estimated N excretion (p < 0.001) compared with HAA, without affecting growth, carcass or meat quality traits. Genetic line had trivial effects and the AA level × genotype interaction was never significant. The two pig genotypes did not differ sufficiently in growth potential and leanness to respond differently.

Highlights

Pigs of different genotypes may differ in their potential for lean growth, which affects their protein and amino acid (AA) requirements [1]
Each pen was equipped with a single-space electronic feeder (Compident Pig–MLP, Schauer Agrotronic, Prambachkirchen, Austria) programmed to supply the pigs with the planned daily amount of feed and to record the amount of feed eaten by individual pigs, in accordance with Schiavon et al (2018) [9]
There was good correspondence between the body lipid mass estimated from body weight (BW) and BF depth measured by ultrasound and the weights of the lard and bacon, the main fat components of the carcasses

Summary

Introduction

Pigs of different genotypes may differ in their potential for lean growth, which affects their protein and amino acid (AA) requirements [1]. Pigs selected for lean growth are expected to have greater protein requirements and to utilize AA more efficiently for protein retention and growth [4]. He et al (2016) [5] showed that low-protein diets positively affect ileal amino acid digestibility and the gene expression of digestive enzymes in growing and finishing pigs. When nutrient supplies are limiting, their partition among body constituents and functions tends to be similar regardless of genotype [6,7]. When pigs of different genetic backgrounds are fed non-limiting diets, the differences between genotypes may be more apparent, a pattern that would be evidenced by a feed × genotype interaction

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