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

Abstract

This study was conducted to evaluate the effects of sequential feeding technique in two genetic lines (GL; Line A [cross having a greater proportion of Pietrain] and Line B [cross having a lower proportion of Pietrain]) of growing-finishing pigs reared under daily cyclic high ambient temperature conditions. Seventyeight castrated male pigs (22 ± 2.5 kg BW) were housed in a single group and were allocated to one of the three feeding programs: control (CON, 24 h control diet), high-fat/low-crude protein (HF/LP, 24 h high-fat/low-crude protein diet), and sequential feeding (SEQ, control diet from 1800 to 1000 h and HF/LP diet from 1001 to 1759 h). Cyclic high ambient temperature was induced by exposing the pigs to 22ºC ambient temperature from 1800 to 1000 h (time-period 22ºC, TP22) and to 30ºC from 1001 to 1759 h (TP30). The experimental period lasted 84 days and was divided into 3 growth phases, growing 1 (from day 0 to 20), growing 2 (from day 21 to 48) and finishing (from day 49 to 83). Feed intake was recorded in real time using an automatic feeder system. Pigs were weighed at the beginning and end of each experimental phase. Animal body composition was measured through dual-energy X-ray absorptiometry on days 0, 35, and 70. The ambient temperature averaged 22.3 ± 0.4ºC during TP22 and 30.2 ± 0.5ºC during TP30, characterizing the condition of daily ambient temperature variation that which pigs are usually exposed in tropical climate areas. During growing phase 1, the feeding programs had negligible effects on pig performance (P > 0.05), whereas during growing phase 2, ADG was greater in SEQ than in CON pigs (7%; P = 0.04). During the finishing phase, HF/LP pigs had greater ADFI (+ 10%) and ADG (+ 8%) than CON pigs. Lean mass and gain did not differ among feeding programs (P > 0.05). Overall, fat mass and gain were similar between SEQ and HF/LP pigs (P > 0.05), and both were greater than those of CON pigs (P < 0.05). On the basis of pig performance per phase, the supply of high-fat/low-crude protein diets (SEQ and HF/LP feeding) improved the performance of pigs under daily cyclic high ambient temperature. However, the use of these techniques resulted in fatter carcasses and in higher energy cost of gain. Finally, pigs with greater proportion of Pietrain genes had decreased growth performance in our experimental conditions.

Genetic selection modulates feeding behavior of group-housed pigs exposed to daily cyclic high ambient temperatures

“…Equipment such as electronic feeders provides a promising approach to evaluate pigs feeding behavior responses since it allows recording automatically information on feed intake of individual pigs in a group-housed condition [ 7 ]. In a previous study, we have demonstrated that pigs selected for improved lean tissue accretion (i.e., with a greater proportion of Pietrain genes) had lower growth performance when housed under daily cyclic high ambient temperature conditions [ 8 ]. We hypothesized that in such conditions, pigs prioritize feed intake in the coolest hours of the day and that their feeding behavior is modulated by genotype.…”

Effects of Ambient Temperature on the Performance and Thermoregulatory Responses of Commercial and Crossbred (Brazilian Piau Purebred Sires × Commercial Dams) Growing-Finishing Pigs

“…The loin eye area was significantly decreased in response to high ambient temperature in commercial pigs, whereas it was not affected by ambient temperature in Piau crossbred pigs. Because protein deposition is directly associated with metabolic heat production [ 25 , 26 ], its reduction at high ambient temperatures may be interpreted as a strategy of commercial pigs to attenuate negative effects of heat stress. Because this response was not observed in Piau crossbred pigs, increased thermotolerance of this genotype could be suggested.…”

“…The fact that lipid deposition was not affected by ambient temperature could be associated with the increased energetic cost of protein compared to adipose tissue deposition. For instance, although 2 ATP are necessary to deposit lipid, a peptide bond synthesis from amino acids needs at least 5 ATP [ 26 , 27 ]. This suggested that commercial pigs prioritized inhibiting proteogenesis over lipogenesis at high ambient temperatures to thermoregulate.…”

“…This suggested that commercial pigs prioritized inhibiting proteogenesis over lipogenesis at high ambient temperatures to thermoregulate. Similarly, Fraga et al [ 26 ] reported that pigs with a greater proportion of Piétrain genes had an increased susceptibility to heat stress due to their presumed increased metabolic heat production associated with a greater growth rate and lean tissue deposition.…”

Occurrence of heat waves and the prediction of feed intake of sows raised in a tropical environment

“…Lower feed intake in sows under high ambient temperature can be minimized by combining crude protein reduction with essential amino acid supplementation and energy addition (Renaudeau and Noblet, 2001;Renaudeau et al, 2012). Diets with low crude protein and high energy in the hottest hours of the day, and control diet in the coolest hours of the day under high daily cyclic ambient temperatures have been studied (Fraga et al, 2019).…”