Efficiency of fat deposition from nonstarch polysaccharides, starch and unsaturated fat in pig

The aim was to evaluate under protein-limiting conditions the effect of different supplemental energy sources: fermentable NSP (fNSP), digestible starch (dStarch) and digestible unsaturated fat (dUFA), on marginal efficiency of fat deposition and distribution. A further aim was to determine whether the extra fat deposition from different energy sources, and its distribution in the body, depends on feeding level. A total of fifty-eight individually housed pigs (48 (sd 4) kg) were used in a 3 x 2 factorial design study, with three energy sources (0.2 MJ digestible energy (DE)/kg0.75 per d of fNSP, dStarch and dUFA added to a control diet) at two feeding levels. Ten pigs were slaughtered at 48 (sd 4) kg body weight and treatment pigs at 106 (sd 3) kg body weight. Bodies were dissected and the chemical composition of each body fraction was determined. The effect of energy sources on fat and protein deposition was expressed relative to the control treatments within both energy intake levels based on a total of thirty-two observations in six treatments, and these marginal differences were subsequently treated as dependent variables. Results showed that preferential deposition of the supplemental energy intake in various fat depots did not depend on the energy source, and the extra fat deposition was similar at each feeding level. The marginal energetic transformation (energy retention; ER) of fNSP, dStarch and dUFA for fat retention (ERfat:DE) was 44, 52 and 49 % (P>0.05), respectively. Feeding level affected fat distribution, but source of energy did not change the relative partitioning of fat deposition. The present results do not support values of energetic efficiencies currently used in net energy-based system

THE EFFECT OF HIGH DIETARY FERMENTABLE CARBOHYDRATE CONTENT ON THE FATTENING PERFORMANCE AND CHEMICAL BODY COMPOSITION OF FATTENING PIGS

The aim of the present study was to evaluate the effect of dietary fermentable carbohydrates (FC = faecal digestible organic matter - faecal digestible crude protein- faecal digestible crude fat - starch - sugars) on the body composition and meat quality of pigs. A total of seventy two Stamboek hybrid pigs were housed in groups of six per pen (two pens with gilts and two with barrows per treatment). Three diets were formulated with a low, medium and high FC content (63, 148, 233 g/kg in the grower diets (45-75 kg) and 67, 152, 237 g/kg in the finisher diets (75-110 kg)). Feed and water were offered ad libitum. At slaughter (110 kg LW) lean meat percentage, meat quality and chemical body composition were determined. Our data indicated, that carcass grading was improved by dietary FC. Diet with the high level of fermentable carbohydrates decreased fatness of the carcass and the organ fraction. It can be concluded that the fattening performance (FI, ADG, FCR) was not affected adversely by the high FC intake, but carcass quality in pigs could be improved. Feedstuffs high in fermentable carbohydrates can be valuable ingredients for pig diets, once their energy content has been properly estimated

Modelling of nutrient partitioning in growing pigs to predict their anatomical body composition. 2. Model evaluation

The objective of the present paper was to evaluate a dynamic mechanistic model for growing and fattening pigs presented in a companion paper. The model predicted the rate of protein and fat deposition (chemical composition), rate of tissue deposition (anatomical composition) and performance of pigs depending on nutrient intake. In the model evaluation, the predicted response of the pig to changes in model parameters and to changes in nutrient intakes is presented. As a result of the sensitivity analysis, changes in the maintenance energy requirements and the fractional degradation rate of muscle protein had the greatest impact on tissue deposition rates. The model was also highly sensitive to changes in the maximum velocity and steepness parameter of the lysine utilisation for muscle protein synthesis. The model was further tested by independent published results. The model successfully predicted the response of pigs to a wide range of variation in nutrient composition. Consequently, the model can be applied to develop feeding strategies to optimise pig production. It also enables prediction of the slaughter performance and the meat quality

IMPACT OF PHYTASE SUPPLEMENTATION ON THE CALCIUM AND PHOSPHOROUS RETENTION IN HIGH PRODUCING LAYERS

The calcium and phosphorous retention of layers was evaluated at different production levels (45 - 75 - 95 % of final production peak) with Hy-Line Brown hybrid layers during the first twelve weeks of the laying cycle. 32 layers evenly distributed over 4 treatments (Trts). The Ca content of the diets was identical across all Trts (32,5 g/kg), while P contents and phytase activities differed. In the first Trt the P content of the diet was 2.5 g/kg non-phytate P, without any phytase added. In the second Trt the P content of the diet was reduced by 40 % compared to Trt 1 (1.5 g/kg non-phytate P) without phytase supplementation. In the third and fourth Trts the P content of the diets was the same as in 2 (1.5 g/kg non-phytate P) but the diets were supplemented with phytase (3-phytase produced by trichoderma reesei) at a rate of 250 PPU/kg (Trt 3) and 500 PPU/kg (Trt 4), respectively. According to the results the different P content of the diets affected (P≤0.05) the rate of Ca retention at all trial phases. In the case of reduced P level diets the different phytase inclusion rates did not influence the amount of Ca retained by the birds (P≥0.05). Within the same Trt Ca retention increased (P≤0.05) with increased production intensity. At reduced P content phytase improved (P≤0.05) the P retention of the layers at all trial phases. There was no difference between both phytase application rates. As a result of phytase supplementation P retention reached the P retention of positive control birds (Trt 1) in all trial phases

Modelling of nutrient partitioning in growing pigs to predict their anatomical body composition. 1. Model description

A dynamic mechanistic model was developed for growing and fattening pigs. The aim of the model was to predict growth rate and the chemical and anatomical body compositions from the digestible nutrient intake of gilts (20-105 kg live weight). The model represents the partitioning of digestible nutrients from intake through intermediary metabolism to body protein and body fat. State variables of the model were lysine, acetyl-CoA equivalents, glucose, volatile fatty acids and fatty acids as metabolite pools, and protein in muscle, hide-backfat, bone and viscera and body fat as body constituent pools. It was assumed that fluxes of metabolites follow saturation kinetics depending on metabolite concentrations. In the model, protein deposition rate depended on the availability of lysine and of acetyl-CoA. The anatomical body composition in terms of muscle, organs, hide-backfat and bone was predicted from the chemical body composition and accretion using allometric relationships. Partitioning of protein, fat, water and ash in muscle, organs, hide-backfat and bone fractions were driven by the rates of muscle protein and body fat deposition. Model parameters were adjusted to obtain a good fit of the experimental data from literature. Differential equations were solved numerically for a given set of initial conditions and parameter values. In the present paper, the model is presented, including its parameterisation. The evaluation of the model is described in a companion paper

Ileal digestibility of amino acids in pig feeds and its use in diet formulations

The effects of four protein sources (soybean meal, sunflower meal, pea and fish meal as the main protein source) were investigated on fattening performance, carcass and meat quality traits and body composition of pigs. Eight animals per treatment received the diets from 30 to 105 kg live weight at a level of 3.0 times maintenance requirement of energy. Diets were formulated on the basis of ileal digestible protein and amino acid content of feedstuffs. Protein sources resulted similar fattening performance from 30-105 kg body weight. From 30 to 60 kg soybean treatment had lowest performance. The protein source treatments did not alter the body composition, lean meat percentage, liver weight and meat quality (intramuscular fat content, pH 45 min and 24 hours after slaughter, drip loss, meat lightness and hue measured 24 hours and 4 days after slaughter). It can be concluded that protein sources can be replaced without affecting overall fattening performance, carcass and meat quality and body composition if diet formulation is based on the ileal digestible amino acid contents of feedstuffs. However the lower performance of the soybean treatment in the first phase may indicate that ileal digestible Lys content of heat treated protein sources may not characterise the feedstuffs well enough. It may be that young pigs are more sensitive to unavailable lysine by the way