Growth Performance of Early Finishing Gilts as Affected by Different Net Energy Concentrations in Diets

Abstract

The objectives of the current experiment were to study the response of the growth performance of early finishing gilts to different net energy (NE) concentrations in diets, and to compare the NE values of diets between calculated NE values and measured NE values using French and Dutch CVB (Centraal Veevoederbureau; Central Bureau for Livestock Feeding) NE systems. In a metabolism trail, the NE concentrations in five diets used for the growth trial were determined based on digestible nutrient concentrations, digestible energy, and metabolizable energy using a replicated 5×5 Latin square design with 10 barrows (initial body weight [BW], 39.2±2.2 kg). In a growth trial, a total of 60 early finishing gilts (Landrace×Yorkshire; initial BW, 47.7±3.5 kg) were allotted to five dietary treatments of 8.0, 9.0, 10.0, 11.0, and 12.0 MJ NE/kg (calculated, as-is basis) with 12 replicate pens and one pig per pen in a 42-d feeding experiment. The NE and amino acid (AA) concentrations in all diets were calculated based on the values from NRC (2012). Ratios between standardized ileal digestible AA and NE concentrations in all diets were closely maintained. Pigs were allowed ad libitum access to feed and water. Results indicated that calculated NE concentrations in diets (i.e., five dietary treatments) were close to measured NE concentrations using French NE system in diets. The final BW was increased (linear and quadratic, p<0.05) with increasing NE concentrations in diets. Furthermore, average daily gain (ADG) was increased (linear and quadratic, p<0.01) with increasing NE concentrations in diets. There was a quadratic relationship (p<0.01) between average daily feed intake and NE concentrations in diets. Feed efficiency (G:F) was also increased (linear, p<0.01) as NE concentrations in diets were increased. The NE intake per BW gain (kcal NE/kg of BWG) was increased (linear, p<0.01) with increasing NE concentrations in diets that were predicted from both French and Dutch CVB NE systems. Linear regression indicated that predictability of daily NE intake from the BW of pigs was very low for both French (R2, 0.366) and Dutch CVB (R2, 0.374) NE systems. In conclusion, increasing NE concentrations in diets increase BW, ADG, G:F, and NE intake per BW gain of early finishing gilts. The BW of early finishing gilts is not a good sole variable for the prediction of daily NE intake.

Dietary energy level, feeder space, and group size on growth performance and carcass characteristics of growing-finishing barrows and gilts

“…Similar to our previous trials ( Smit et al, 2017 , 2018 ), changes in feedstuffs led to greater NDF and crude fiber content in low vs. high NE diets. Crude fat content was not different between low and high NE diets, which contrasts with many other studies that increased dietary NE level by adding fat to the diet ( Smith et al, 1999 ; Schinckel et al, 2012 ; Lee et al, 2015 ).…”

Effect of dietary net energy concentrations on growth performance and net energy intake of growing gilts

“…The values for NE10 of diets were greater than the values for NE7, NE8, NE9, and NE average of diets. This result agrees with the results of previous experiments [ 5 , 23 ] in which values predicted from the equation of Blok [ 3 ] appeared to be greater than those predicted from the equations of Noblet et al [ 2 ]. This discrepancy can be attributed to differences in the concept of carbohydrate utilization of pigs and in the analytical procedure of lipids [ 5 , 23 ].…”

“…This result agrees with the results of previous experiments [ 5 , 23 ] in which values predicted from the equation of Blok [ 3 ] appeared to be greater than those predicted from the equations of Noblet et al [ 2 ]. This discrepancy can be attributed to differences in the concept of carbohydrate utilization of pigs and in the analytical procedure of lipids [ 5 , 23 ]. These NE prediction equations adopt digestible nutrient concentrations of feed ingredients to estimate the NE values for diets and ingredients in a similar manner [ 5 , 24 ].…”

“…It is suggested, therefore, that both equations can reasonably be used to predict daily NE intake as a function of the BW of growing gilts. However, a similar regression analysis for finishing gilts between 40 and 80 kg was performed in our previous experiment [ 23 ], but R 2 values for the regression equations were very low (i.e., less than 0.37). Thus, we suggest that daily NE intake can be predicted solely from the BW of growing gilts, but this has little reliability for finishing gilts.…”

Determination of optimal energy system and level for growing pigs

“…This agrees with the data from Liu et al [7], who observed that growth performance improved as dietary energy concentrations increased. Several previous studies have shown similar results; increasing the energy level affects growth performance positively [22,33]. In contrast, there were no differences in growth performance among the treatments in this study.…”