Reduction in the protein level and addition of oil in diets for finishing pugs under different temperatures

Abstract

-The objective of this study was to evaluate the effect of reducing the crude protein (CP) with the use of amino acids in diets with the same amount of calories anddifferent levels of soybean oil (SO) for finishing pigs kept in two different ambient temperatures. A total of 120 barrows (initial weight of 68.0±1.9 kg) were utilized for the experiment. The design was of randomized blocks in a 2 × 3 × 2 factorial arrangement (two levels of CP, 16.2 and 13.7%; three levels of SO, 1.5; 3.0 and 4.5%; and two ambient temperatures, 19 and 31 °C), totaling twelve treatments with five replicates for thirty days. The heat reduced feed intake (FI) of the animals, regardless of the levels of CP and SO used, and reduced weight gain (WG) in diets with reduced CP and SO or higher SO. The increased level of CP and SO improved feed conversion (FC) when the animals were kept in thermoneutral environment and given a diet with higher protein content. The reduction in CP increased FI only in the thermoneutral environment. In the heat, WG increased in diets with higher levels of SO, without influencing FC. The manipulation of diet and temperature did not affect most carcass traits. The SO reduced backfat thickness (BT) only in diets with high CP and animals kept in thermoneutral environment. The reduction of CP increased the BT only in diets with high content of SO, both in hot and thermoneutral environments. Heat reduces FI and the inclusion of SO does not improve performance or carcass characteristics in these conditions. The reduction in CP improves WG only in diets with high oil content; however, it increases BT. In thermoneutral environment, increasing the SO is beneficial for performance and carcass characteristics, except when diets with reduced CP are used. The reduction in CP improves performance only in diets with low oil content.

Sequential feeding with high-fat/low-crude protein diets for two lines of growing-finishing pigs under daily cyclic high ambient temperature conditions1

“…Because feed intake at high ambient temperatures is limited by the capacity of the animal to dissipate heat, the greater feed intake of HF/LP pigs might be explained by the lower thermic effect of the diet. These results are consistent with previous literature (Spencer et al, 2005;Rodrigues et al, 2012) that similarly reported a greater performance of heat-stressed finishing pigs fed high-fat/low-CP diets.…”

Redução da proteína bruta em rações sobre os balanços metabólicos de suínos mantidos em diferentes condições térmicas

“…As rações experimentais (Tabela 1) foram formuladas para atender as recomendações nutricionais propostas por Rostagno et al (2005), com exceção da proteína bruta (PB), que foi reduzida de acordo com os tratamentos (20,5; 19,4; 18,3 e 17,2%) e realizada a devida suplementação com aminoácidos sintéticos. Para tanto, foram realizadas as análises de PB, do milho e farelo de soja, no Laboratório de Nutrição Animal da UNIOESTE.…”

Evaluating equations estimating change in swine feed intake during heat and cold stress1

“…The biological influence of heat stress is impacted by duration of exposure to extreme temperatures (Renaudeau et al, 2007), night cooling (Xin and DeShazer, 1991;Patience et al, 2005), relative humidity (Huynh et al, 2005), diet composition (Jørgensen et al, 1996;Kerr et al, 2003), and genetics (Brown-Brandl et al, 2001;Sutherland et al, 2006), among others. In particular, ME content (Baldwin and Sainz, 1995;Rodrigues et al, 2012), protein and AA balance (Kerr et al, 2003;Spencer et al, 2005;Wolp et al, 2012), dietary additives (Zier-Rush et al, 2014) ,and mineral concentrations (Haydon et al, 1990;Kim et al, 2009) all affect responses to heat stress. To understand the relationships among variables, a mixed-effect linear model of absolute intake was also derived from the data set.…”