Publications by authors named "P van der Aar"

Three different regression approaches were applied to determine the optimal digestible (d.) and analyzed Val:Lys ratios for broiler performance and carcass yield. One-day-old male Cobb 500 broilers (n = 960) were assigned to 1 of 8 diets, with 6 pens/diet and 20 birds/pen, for 42 days.

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The addition of methionine in the poultry feed industry is still facing the relative efficacy dilemma between DL-methionine (DLM) and hydroxy-methionine (HMTBA). The aim of this study was to compare the effect of dietary DLM and HMTBA on broiler performance at different levels of total sulfur amino acids (TSAA). The treatments consisted of a basal diet without methionine addition, and 4 increasing methionine doses for both sources resulting in TSAA/Lysine ratios from 0.

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The aim of this study was to assess the effect of standardized ileal digestible (SID) Lys levels of the diet on the growth performance, carcass characteristics, and meat quality of entire males (EM), surgical castrates (SC), and males vaccinated with a gonadotropin-releasing hormone (GnRH) vaccine (GV). In total, 252 crossbred pigs were fed 6 different experimental diets consisting of 3 sexes (EM, SC, and GV pigs) and 2 dietary SID Lys levels (2008 CVB standard SID Lys recommendation [Std] or 15% extra SID Lys [+15]) according to a 3-phase feeding scheme (d 0 to 35, 35 to 70, and 70 to 105 of experiment) with 6 pens per treatment and 6 pigs per pen. To determine if dietary SID Lys could be reduced for GV males after the second vaccination, an additional dietary treatment was included (GV+15-Std).

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To examine the effect of inclusion insoluble nonstarch polysaccharides (iNSP) in weaned diets on postweaning piglet performance, intestinal activity, and microbial composition 2 experiments were designed. In Exp. 1, 180 piglets were weaned at 28 d of age and divided over 3 treatments: positive control (PC; highly digestible protein), negative control (NC; standard cereal-based diet), and an experimental diet {iNSP; standard + 15% iNSP [wheat straw and oat (Avena sativa) hull]}.

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The effect of low-density diets on bird performance, egg composition, and embryonic development was studied with 2,100 female and 210 male Cobb broiler breeders from 25 to 60 wk of age. The experiment included 5 treatments. These included a control group with a normal density diet (ND, 2,800 kcal of AME/kg).

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