Predicting Effective Caloric Value of Nonnutritive Factors: I. Pellet Quality and II. Prediction of Consequential Formulation Dead Zones

Abstract

Two experiments were conducted with male broilers to 1) establish a methodology for predicting effective caloric value (ECV), defined as dietary caloric density (CD) necessary for broilers to achieve specific BW and feed conversion ratio (FCR) combinations under standardized conditions and 2) quantify the ECV attributable to pellet quality (PQ), defined as the pellet to pellet fines ratio in the feeder. In experiment 1, chicks were reared to 56 d on diets varying in CD. Dietary caloric densities examined ranged from 2,650 to 3,250 kcal of MEn/kg. Pen BW, feed intake, and FCR were measured at 21, 42, and 56 d. On 42 and 56 d, carcass traits were measured. Increasing CD significantly enhanced BW, energy consumption, and FCR. Feed intake remained similar across the upper 3 CD treatments to 42 d. By d 56, feed consumption tended to decline as CD increased. Increasing CD beyond 3,066 kcal of MEn/kg diet did not increase lean tissue accretion, while fat deposition rose disproportionately. Experiment 1 results enabled development of equations whereby CD, hence ECV, might be predicted using BW and FCR. In experiment 2, 38-d-old broilers were used to evaluate PQ effects on growth, feed intake, FCR, and behavior in a 7-d FCR assay. The BW gain and FCR were significantly enhanced by pelleting and were positively correlated with PQ. Feed intake was not affected by PQ. The experiment 1 model was validated for experiment 2, as it closely estimated the CD for diets of similar PQ used in experiment 1. Results suggest pelleting contributes 187 kcal/kg of diet at 100% PQ and that the ECV declines curvilinearly as PQ falls. Birds were observed eating less and resting more as PQ increased, suggesting that ECV of pelleting is mediated by energy expenditure for activity. These studies provide a method for estimating ECV of nonnutritive factors that impact BW, FCR, or both. Further, the application reveals potential for creation of formulation "dead zones" whereby dietary changes to enhance CD may be offset due to reduced ECV.

Desempenho, eficiência de utilização dos nutrientes e estrutura do trato digestório de pintos de corte alimentados na fase pré-inicial com rações de diferentes formas físicas

“…Segundo Nir et al (1994) e Jensen (2001), a peletização reduz o gasto de energia das aves para mantença, aumentando a energia líquida de produção, portanto, há mais energia disponível para o ganho. A peletização favorece a eficiência de retenção da energia metabolizável aparente, o que justifica a melhor conversão alimentar das aves alimentadas com rações peletizadas ou trituradas (McKinney & Teeter, 2004;Lemme et al, 2006).…”

“…Esse melhor desempenho tem sido associado ao aumento da digestibilidade dos nutrientes da ração (Moram, 1987;Zelenka, 2003) e ao aumento da densidade da ração, o que permite maior ingestão de nutrientes e, conseqüente-mente, maior taxa de crescimento (Toledo et al, 2001;Engberg et al, 2002;McKinney & Teeter, 2004).…”

“…De acordo com Nir et al (1994), a peletização reduz o gasto de energia das aves para o consumo proporcionando redução na energia de mantença e aumentando a energia líquida de produção, o que favorece a energia disponível para o ganho. McKinney & Teeter (2004) observaram que, além de favorecer o consumo de ração, a peletização aumenta a eficiência de retenção da energia metabolizável aparente. Krabbe (2000) observou que a granulometria da ração pré-inicial influenciou os valores de energia metabolizável determinados e a retenção de nitrogênio e da MS na primeira semana.…”

Effect of phytase with or without multienzyme supplementation on performance and nutrient digestibility of young broiler chicks fed mash or crumble diets

“…These results are similar to those reported by Nir et al (1995), Engberg et al (2002), Svihus et al (2004) and Cutlip et al (2008). These improvements have been variously attributed to increased nutritional density, increased nutrient intake, changes in the physical form of the feed, reduced feed wastage, decreased energy expenditure while eating (McKinney and Teeter, 2004;Skinner-Noble et al, 2005;Amerah et al, 2007;Cerrate et al, 2009;Yang et al, 2010), increased starch digestibility (Parsons et al, 2006), and improved apparent metabolisable energy (AME) and nutrient retention (Svihus et al, 2004;Adeyemi et al, 2008) mechanical action resulted in a rupture of the cell walls and thus made encapsulated nutrients of the feedstuff more accessible to digestive enzymes (Vande and Schrijver, 1988;Cutlip et al, 2008). Phytase and multienzymes plus phytase supplementation increased BW (3.3 and 4.6%) and BWG (3.7 and 4.9%), improved FCR (4.8 and 6.6%), and decreased feed intake by 1.6 and 2.2%, respectively, of the improvement in FCR as compared with those chicks fed a diet without enzyme supplementation.…”

“…Furthermore, growth performance of broilers fed a crumble or pellet diet was better than those fed on mash feed (Jahan et al, 2006;Cutlip et al, 2008). Pelleting or crumbling improved nutrient digestibility, decreased feeding time, and was easier to eat (McKinney and Teeter, 2004;Skinner-Noble et al, 2005;Amerah et al, 2007;Cerrate et al, 2009;Yang et al, 2010;Attia et al, 2012). Jafarnejad et al (2010) reported that body weight (BW) and FCR were significantly improved in broilers fed crumble-pellet diets compared with those fed mash diets.…”