Sequential feeding system with nutritional adjustments for pigs growing and finishing phases of two genetic lines submitted to cyclical heat stress

Author(s)

Alícia Zem Fraga

• Document type: Master's Dissertation
• Press: Jaboticabal. 2018-04-25.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Ciências Agrárias e Veterinárias. Jaboticabal
• Defense date: 2018-02-23
• Advisor: Luciano Hauschild; Paulo Henrique Reis Furtado Campos

Abstract

This study aimed at evaluating the sequential feeding system as a tool to attenuate the effects of cyclic heat stress in two genetics of growing-finishing pigs. Eighty 22kg (± 2.5) BW barrows were assigned in a completely randomized experimental design, in factorial scheme 3x2 (3 feeding programs and 2 genetic lines; 3FP and 2GL) being the animal the experimental unit. The FP were: Control (CON), high-fat/low-crude protein (HF/LP) and Sequential Feeding [SEQ, from 1800 to 1000 h control diet (Time-Period 1, TP1) and from 1000 to 1800 h HF/LP diet (TP2)]. The temperature was 22.3 ± 0.4ºC for TP1 and 30.2 ± 0.5ºC for TP2. The experimental period lasted 84 days subdivided into three phases, growing 1 (0 to 20d), growing 2 (21 to 48d), and finishing phase (49 to 83d). Feed intake was recorded using Automated Feeder System. Pigs were weighed at beginning and end of each experimental phase and on days 0, 35 and 75 were measured the body composition. There was interaction between GL and time-period (TP) for average feed intake (AFI) per hour (P < 0.05). At 22ºC the AFI did not differ between lines (P > 0.05), but at 30ºC the line B pigs had higher values than line A (P < 0.05). There was interaction (P < 0.05) between FP and GL for energy cost of lean gain. From 35 to 75d, SEQ had similar energy cost of lean gain for line A compared to CON (P > 0.05). However, for both lines, SEQ had higher the energy cost of lean than CON (P < 0.05). In growing 1 e 2 there was not difference (P > 0.05) between HF/LP and CON for ADFI and ADG. But in finishing phase, higher results for these variables and energy cost for gain were observed for HF/LP (P < 0.05). In growing 2, SEQ had higher ADG (P = 0.04) and similar energy cost of gain (P = 0.24) compared to CON program. In finishing phase, the SEQ allowed reducing NE intake (P < 0.01) and had a similar ADG (P > 0.05) than HF/LP. In addition, SEQ had similar energy cost of gain compared to CON (P > 0.05) in this phase. Fat mass and fat mass gain were similar between SEQ and HF/LP (P > 0.05), but both higher than CON (P < 0.05). In conclusion, the supply of different diets adjusted to the variation of the temperature over the day is an efficient approach to attenuate the heat stress effect, but with subsequent fatter carcasses. In addition, regarding energy efficiency for lean deposition the sequential feeding is an efficient program to be applied for the genetic line less tolerant to heat stress. (AU)

• FAPESP's process: 16/08682-1 - Sequential feeding system with nutritional adjustments for pigs in growing and finishing phases of two genetic lineages exposed to condition of cyclical heat stress
• Grantee: Alícia Zem Fraga
• Support Opportunities: Scholarships in Brazil - Master