Diet density during the first week of life: Effects on energy and nitrogen balance characteristics of broiler chickens

Abstract

This study aimed to determine effects of diet density on growth performance, energy balance, and nitrogen (N) balance characteristics of broiler chickens during the first wk of life. Effects of diet density were studied using a dose-response design consisting of 5 dietary fat levels (3.5, 7.0, 10.5, 14.0, and 17.5%). The relative difference in dietary energy level was used to increase amino acid levels, mineral levels, and the premix inclusion level at the same ratio. Chickens were housed in open-circuit climate respiration chambers from d 0 to 7 after hatch. Body weight was measured on d 0 and 7, whereas feed intake was determined daily. For calculation of energy balances, O2 and CO2 exchange were measured continuously and all excreta from d 0 to 7 was collected and analyzed at d 7. Average daily gain (ADG) and average daily feed intake (ADFI) decreased linearly (P = 0.047 and P < 0.001, respectively), whereas gain to feed ratio increased (P < 0.001) with increasing diet density. Gross energy (GE) intake and metabolizable energy (ME) intake were not affected by diet density, but the ratio between ME and GE intake decreased linearly with increasing diet density (P = 0.006). Fat, N, and GE efficiencies (expressed as gain per unit of nutrient intake), heat production, and respiratory exchange ratio (CO2 to O2 ratio) decreased linearly (P < 0.001) as diet density increased. Energy retention, N intake, and N retention were not affected by diet density. We conclude that a higher diet density in the first wk of life of broiler chickens did not affect protein and fat retention, whereas the ME to GE ratio decreased linearly with increased diet density. This suggests that diet density appears to affect digestibility rather than utilization of nutrients.

Effects of Bile Acids and Lipase Supplementation in Low-Energy Diets on Growth Performance, Fat Digestibility and Meat Quality in Broiler Chickens

“…However, LE diet intake was more as compared to HE diet which is similar with the findings of Harrington et al (2015) and Hosseini et al (2018) who reported that increased dietary energy could reduce the feed intake of broilers. Similarly, Lamot et al (2017) reported that increasing -b Means within a row with different superscripts are significantly different (p<0.05). § SEM: Standard error of mean.…”

Apparent metabolizable energy of cereal grains for broiler chickens is influenced by age

“…Second, the FI during the first week post-hatch is low as the hatchling adapts to the move from yolk nutrition to oral nutrition. It has been accepted that the dietary energy has a regulatory role on FI and birds alter their feed consumption primarily to meet their energy requirements ( Leeson et al, 1993 ; Lamot et al, 2017 ). Zelenka (1997) speculated that the decrease in AMEn with advancing age could be due to increased feed consumption.…”

Nitrogen maintenance requirements and potential for nitrogen retention of pullets in growth phase

“…Considering the NMR results obtained in each period, an average value of 327 mg/BW kg 0.67 /day was calculated for pullets in growing phase. Silva et al (2013) and Bonato (2013) According to Lamot et al (2017), diets with different nitrogen and energy balance provide synthesis of body protein; that is, there is a minimum retention of nitrogen even though there is an energy cost. When considering that the animal does not ingest nitrogen, it is assumed that a part of the body protein is degraded to make up the pool of free amino acids and part of the mobilized amino acids is re-synthesized to meet the metabolic priorities.…”