Adjustment in the diet amino acids concentration according to the circadian rhythm of growing-finishing pigs

Author(s)

Alini Mari Veira

• Document type: Doctoral Thesis
• Press: Jaboticabal. 2021-07-12.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Ciências Agrárias e Veterinárias. Jaboticabal
• Defense date: 2021-05-07
• Advisor: Luciano Hauschild; Paulo Henrique Reis Furtado Campos; Luan Sousa dos Santos

Abstract

In swine nutrition, feeds are formulated according to the growth stage of the animals and, predominantly, a single diet is provided for a long period within a phase feeding system. In this system, when the objective is to optimize the performance of a group of animals, nutrients are normally supplied in excess mainly at the end of each phase. Thus, due to the high cost of feeds, combined with the excretion of polluting elements, nutritional strategies must be proposed and evaluated. Within this context, programs that allow to provide a diet that meets the daily requirement of animals have shown to be promising since they allow to reduce costs and excretion of polluting elements. In this context of precision nutrition, it is important to highlight that the efficiency of nutrient use may vary throughout the day, according to the variations in the metabolic state (catabolism and anabolism) of the animals determined by the circadian cycle. Therefore, adjusting the nutritional concentration of the diet to fluctuations in the metabolic status of pigs throughout the day may be a promising strategy to improve to improve the rational use of nutrients and consequently reduce costs and environmental impact. Thus, with this thesis aimed to evaluate the effects of adjusting the concentration of nutrients in the diet according to the circadian rhythm of the metabolic state of pigs on metabolism and growth performance. For this, two experimental tests were performed: (i) metabolism and (ii) performance and body composition. In the metabolism assay, the objective was to evaluate nitrogen balance and nutrient metabolism of pigs fed diets with different amino acid concentrations in the morning and afternoon meals, respectively. A total of 24 male pigs (initial body weight 35 ± 3.32 kg) were housed in metabolic cages and submitted to three feeding programs (8 animals per treatment). A daily feeding program (DP), which a diet with 100% of amino acid (AA) requirements was provided in morning and afternoon meals; and two sequential feeding programs (SEQ): sequential feeding program with 40% reduction and increase in AA concentration (SEQLH) in the morning and afternoon, respectively; and sequential feeding program with 40% increase and decrease in AA concentration in the morning and afternoon (SEQHL), respectively. The metabolic experiment lasted 21 days, consisting of 7 days of adaptation and 14 days of experiment. The nitrogen (N) balance was performed using the total collection method. Blood collections were performed on days 7 and 14 with two collections each day: the first after fasting (preprandial) and the second 2.5 hours after the first meal of the day (postprandial). Nutrient metabolism was measured by analyzing the serum or plasma concentrations of lactate, glucose, triglycerides, total protein, albumin and urea present in the blood. The animals from SEQHL showed a tendency for lower daily weight gain (11%, P = 0.06), and had a worse feed efficiency (10%, P = 0.02) compared to the DP and SEQLH. However, SEQLH and DP animals showed similar performance (P < 0.05). Urinary N excretion was higher (17%, P = 0.03) and N retention (%) tended to be lower for SEQHL animals compared to SEQLH animals (7%, P = 0.08). However, animals from DP and SEQLH showed similar N balance (P < 0.05). Plasma concentrations of preprandial glucose were higher for SEQHL animals compared to DP and SEQLH animals (5%, P = 0.04). On day 7, serum concentrations of total protein and preprandial albumin were higher for SEQLH animals compared to DP and SEQHL animals (43 and 38%; P < 0.01). The animals from SEQHL had higher serum concentration of postprandial urea than those from DP and SEQLH (28%; P < 0.01). Therefore, in this first study it was concluded that the provision of diets with low and high levels of AA in the morning and afternoon meals, respectively, can improve the protein metabolism of growing pigs. In the second study the objective was to evaluate the performance, body composition and nutrient balance of pigs fed diets with different levels of decrease and increase in AA concentration in the first and last 12 hours of the day, respectively. A total of 68 barrows (initial body weight 25 ± 2.67 kg) were distributed in a randomized block design (body weight) in four treatments (17 animals per treatment): daily feeding program (SD), where a diet containing 100% of the AA concentration was provided 24 hours a day; and three sequential feeding programs (SEQ), with different levels of variation in the concentration of AA, in which the pigs received a diet with a reduction (-20, -30, -40%) in the concentration of AA from 0000 to 1159 h ( period 1; P1) and increase (+20, +30, +40%) from 1200 to 2359 h (period 2; P2), respectively. The experiment lasted 82 days (25 to 100 kg), divided into three experimental phases. Statistical analyzes consisted of evaluating the comparison between feeding programs (DP vs SEQ), and linear and quadratic responses according to the increase in the concentration of AA levels in the diet. During phase 1, average daily feed intake, daily lysine intake, body weight and body protein tended (P < 0.09) to increase quadratically with increasing variation in dietary AA levels, while body lipid increased (P < 0.03) quadratically with increasing variation in dietary AA levels. During phase 2, feed efficiency increased (P = 0.01) linearly with increasing variation in dietary AA levels, while weight gain and protein gain tended (P = 0.09) to increase linearly with increasing variation in dietary AA levels. During phase 3, the animals in the SEQ, when compared to the DP group, showed similar performance and body composition (P > 0.05), however a tendency for a higher N excretion was observed (12%; P = 0.05). Therefore, the results of the present study indicate that adjusting dietary AA concentrations according to the circadian rhythm (catabolism and anabolic state) improves protein deposition for pigis from 25-50 kg. In addition, this adjustment tends to increase daily weight gain, body weight and body protein for pigs from 50-70 kg. These better responses were observed in a 40% decrease and increase in the first and last twelve hours of the day, respectively, in the diet amino acid levels recommendation. (AU)

• FAPESP's process: 17/18734-1 - Sequential feeding plan with variation in the amino acid level at every 12 hours for growing pigs
• Grantee: Alini Mari Veira
• Support Opportunities: Scholarships in Brazil - Doctorate