The effects of diets with reduced crude protein and digestible energy content on the performance of growing and finishing pigs and the characteristics of slurry produced

1999 ◽  
Vol 1999 ◽  
pp. 24-24
Author(s):  
P A Lee ◽  
A Armsby

Formulating diets to match more closely the requirements of the pig for amino acids results in diets which are lower in crude protein (CP) than conventional commercial diets. The lower intake of nitrogen (N) which is concomitant with these diets results on lower N excretion. The excretion of excess N requires energy and previous nutrient balance work undertaken at Terrington (Lee and Kay, 1998) indicated that the ‘energy sparing’ effect of the reduced crude protein diets can be utilised by reducing the digestible energy (DE) content of reduced CP diets whilst at the same time maintaining the level of N retention. The objective of this work was to determine the performance carcass characteristics and slurry characteristics of growing/finishing pigs given reduced CP/DE diets.

1998 ◽  
Vol 1998 ◽  
pp. 33-33
Author(s):  
P.A. Lee ◽  
R.M. Kay

Manipulation of dietary nitrogen content can reduce nitrogen excretion (NE) by the pig by 40 per cent (Kay and Lee, 1995), which has major implications for pollution legislation. Past work (Kay and Lee, 1996) has shown that whilst reduced crude protein (CP) diets reduce NE whilst maintaining nitrogen retention (NR), there is also an increase in backfat depth at slaughter. This suggests an ‘energy sparing’ effect from the lower levels of excess amino acids which might be exploited to lower the cost of the reduced CP diets. The objective of this experiment was to determine the NR and NE of growing and finishing pigs offered diets with reduced CP and Digestible Energy (DE) contents compared with commercial diets or diets with reduced CP content only.


1998 ◽  
Vol 1998 ◽  
pp. 33-33 ◽  
Author(s):  
P.A. Lee ◽  
R.M. Kay

Manipulation of dietary nitrogen content can reduce nitrogen excretion (NE) by the pig by 40 per cent (Kay and Lee, 1995), which has major implications for pollution legislation. Past work (Kay and Lee, 1996) has shown that whilst reduced crude protein (CP) diets reduce NE whilst maintaining nitrogen retention (NR), there is also an increase in backfat depth at slaughter. This suggests an ‘energy sparing’ effect from the lower levels of excess amino acids which might be exploited to lower the cost of the reduced CP diets. The objective of this experiment was to determine the NR and NE of growing and finishing pigs offered diets with reduced CP and Digestible Energy (DE) contents compared with commercial diets or diets with reduced CP content only.


1977 ◽  
Vol 57 (1) ◽  
pp. 111-120 ◽  
Author(s):  
A. G. CASTELL

Low erucic acid cultivars of Brassica campestris L. (Span and Torch) and B. napus L. (Midas and Tower) were used to examine the effects of cultivar on the performance of 132 crossbred pigs fed, from 23 kg to 89 kg liveweight, diets containing ground rapeseed. The oil percentages and levels of total glucosinolates (mg/g oil-free meal) were, respectively, 39.1 and 8.2 (Span), 40.2 and 7.8 (Torch), 44.7 and 12.0 (Midas), 43.2 and 3.4 (Tower). Growth rates on 17% crude protein diets containing 10% rapeseed in experiment 1 ranged from 637 g/day (Midas) to 797 g/day (Tower), a significant (P < 0.05) difference, although feed:gain ratios and carcass measurements did not differ significantly between the four dietary groups. Results from experiment 2, in which B. campestris cultivars were used as 0 and 10% of pelleted diets fed for two 45-min periods daily, indicated that rapeseed depressed daily feed intake and gain significantly (P < 0.01) but did not adversely affect carcass measurements. Increasing the dietary level of B. napus cultivars, from 0 to 15% in experiment 3, depressed daily feed intake and gain of pigs fed Midas (P < 0.05) or Tower (NS) diets. Feed:gain ratios and carcass data were similar to those of the control pigs. Although Midas-fed pigs exhibited poorer (P < 0.01) live performance, their carcasses had less backfat (P < 0.01) with higher Carcass Value Indices (P < 0.01) and Record of Performance Scores (P < 0.05) than those fed tower diets. Results from the three experiments suggested that inclusion of rapeseed influenced the performance of growing–finishing pigs by an effect upon both the energy content and glucosinolate level of the diet consumed.


2019 ◽  
Vol 97 (Supplement_2) ◽  
pp. 204-204
Author(s):  
Q, Huang ◽  
D Pangeni ◽  
Hayford Manu ◽  
L Hanson ◽  
S K Baidoo

Abstract Aim was to determine standardized ileal digestible Val to Lys ratios for growing - finishing pigs fed low CP diets on performance, BUN and carcass characteristics. SID Val to Lys ratios for BW 42.5 to 70.3 kg, 70.3 to 98.1 kg and 98.1 to 128.7 kg pigs. Pigs (n = 400, 10 pens / treatment, 8 pigs / pen) blocked by BW and randomly assigned to 1 of 5 treatments. Diets were SID Val to Lys of 0.55, 0.60, 0.65, 0.70 and 0.75. Data analyzed as a RCBD with PROC MIXED procedure of SAS with pen (experimental unit), treatment (fixed effect), and BW block (random effect). In phase 1, linear and quadratic increase of ADG (Linear, P = 0.03; Quadratic, P = 0.04), BUN decreased (Linear, P = 0.01; Quadratic, P = 0.04). SID Val:Lys for ADG, linear broken-line and quadratic model were 0.64 and 0.66, respectively. BUN for SID Val:Lys were 0.63 (P = 0.01) and 0.70 (P = 0.04). In phase 2, ADG increased (Linear, P = 0.04; Quadratic, P = 0.01) and G:F increased (Linear, P = 0.02; Quadratic, P = 0.04). a linear (P = 0.04) and quadratic (P = 0.01) increase in ADG. SID Val:Lys ADG were 0.66 and 0.70. with the increase of SID Val:Lys ratios. SID Val:Lys for G:F were 0.70 and 0.75, respectively. In phase 3, the SID Val:Lys to maximize ADG were 0.67 (Linear, P = 0.04) and 0.72 (Quadratic, P < 0.01). as the SID Val:Lys increased. Supplementation of low CP diets with high levels of SID Val:Lys increase decreased (Linear, P = 0.02) fat depth, at 0.65. but no effect on other carcass characteristics. In conclusion, SID Val:Lys requirement for ADG in three phases were 0.64, 0.66, 0.67, and 0.66, 0.70, 0.72, using a linear broken-line and quadratic model respectively. BUN and fat thickness appears to be minimized at Val:Lys ratio of 0.65 and a potential to increase lean percentage.


2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 16-17
Author(s):  
John K Htoo

Abstract For more than two decades, numerous studies have been conducted evaluating the effects of lowering CP level in pig diets. It is now accepted that lowering dietary CP level and adding crystalline amino acids (CAA) improves N utilization and consequently reduces N excretion. Increased availability of CAA such as Lys, Thr, Met, Trp, Val (Ile, Arg and His) allows nutritionists to further reduce dietary CP level while meeting pigs’ AA requirements more closely. However, pig performance was sometimes compromised when the dietary CP level was reduced more than 4 percentage units and adding high inclusion levels of CAA. An increase in backfat thickness was also sometimes reported when feeding finishing pigs with low CP diets. The potential reasons for such inconsistent results are due to the deficiency of the next limiting AA (typically Val and Ile), inaccurate feed mixing and insufficient amount of non-essential AA (NEAA) in the low CP diets. Formulating low CP diets on similar energy content as for the high CP diets on ME basis sometimes led to a greater backfat thickness in finishing pigs which was mainly due to increased energy utilization of pigs fed low CP diets coupled with the excess energy being stored as carcass fat. Based on the results of these experiments, optimal growth performance, carcass quality and N retention of pigs can be maintained when low CP diets are balanced for adequate levels of both essential AA and NEAA on the standardized ileal digestible basis combined with formulating on NE basis. Research suggests that keeping a maximum total Lys:CP ratio of 7.4% could overcome deficiency of NEAA in the low CP diets. Based on published N-balance studies, 1 percent unit dietary CP reduction results on average 9% reduction in N excretion in pigs which is an effective approach to become more sustainable pork production.


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