Performance traits
As shown in table 2, the effect of different ratios of forage to concentrate was significant on all performance traits (p<0.01). Treatment containing the equal ratio of forage to concentrate caused a significant change in performance traits (p<0.01). Traits of slaughter weight (p<0.05), weight gain in fattening period (p<0.05), daily weight gain (p<0.05), feed intake (p<0.01) and feed conversion ratio (p<0.01) were increased linearly with increasing concentrate to forage ratio (table 2). This means that as the amount of concentrate in the ration increases, these traits increase with a constant linear coefficient. It should be noted that no significant nonlinear relationship was observed (p>0.05).
Table2. The effect of different forage to concentrate ratios in feed on performance traits of Zel fattening lambs
Treatment(forage to concentrate ratio)
|
Initial weight(kg)
|
Slaughter weight(kg)
|
Weight gain in fattening(kg)
|
Daily weight gain(g/d)
|
Feed consumption(g/d)
|
Feed conversion ratio1
|
80:20
|
27.8
|
50.6a
|
22.8a
|
253a
|
2109a
|
8.34a
|
70:30
|
27.6
|
52.8a
|
25.2a
|
280a
|
2196a
|
7.84a
|
60:40
|
27.9
|
54.3a
|
26.4a
|
293a
|
2201a
|
7.51a
|
50:50
|
27.7
|
58.9b
|
31.2b
|
347b
|
2280b
|
6.57b
|
P.Value2
|
0.46
|
0.01
|
0.01
|
0.01
|
0.01
|
0.01
|
SEM3
|
0.89
|
0.91
|
0.78
|
9.12
|
82.8
|
0.19
|
Linear4
|
0.89
|
0.03
|
0.03
|
0.03
|
0.00
|
0.00
|
Nonlinear
|
0.96
|
0.10
|
0.13
|
0.21
|
0.08
|
0.27
|
1- Feed conversion ratio is feed consumption divided by daily weight gain. 2- Probability value. 3- Standard error of mean. 4- P.value values of regression coefficients are presented. Common letters in each column indicate no statistically significant difference (p>0.05).
Traits related to carcass quality
Studying the effect of different ratios of forage to concentrate on carcass quality traits (table 3), it was observed that the difference between the mean weight of digestive system contents, hot and cold carcass weight, carcass percentage, and backfat thickness was significant (p<0.05).
Traits of the weight of digestive system contents (p<0.01), hot and cold carcass weight (P <0.05), carcass percentage (p<0.05), and backfat thickness (p<0.05) with increasing concentrate to forage ratio Increased linearly (Table 3). It should be noted that no significant nonlinear relationship was observed (p>0.05).
Table3. The effect of different forage to concentrate ratios in feed on the carcass quality of Zel fattening lambs
Treatment(forage to concentrate ratio)
|
Weight of digestive system contents (kg)
|
Weight of empty digestive system (kg)
|
Hot carcass weight (kg)
|
Cold carcass weight (kg)
|
Carcasses percentage (%)
|
Back fat thickness (mm)
|
Eye muscle area (cm2)
|
80:20
|
5.8a
|
4.2
|
29.8a
|
29.0a
|
57.3a
|
5.9a
|
16.9
|
70:30
|
4.1b
|
4.1
|
32.7b
|
30.9b
|
58.5ab
|
8.6b
|
17.2
|
60:40
|
4.0b
|
3.8
|
33.1b
|
31.8b
|
58.6ab
|
8.5b
|
17.0
|
50:50
|
3.8b
|
3.9
|
33.5b
|
32.0b
|
54.3b
|
8.1b
|
17.2
|
P.Value1
|
0.03
|
0.09
|
0.04
|
0.04
|
0.04
|
0.04
|
0.19
|
SEM2
|
0.30
|
0.18
|
0.69
|
0.91
|
0.83
|
0.40
|
0.33
|
Linear3
|
0.00
|
0.06
|
0.03
|
0.03
|
0.03
|
0.04
|
0.19
|
Nonlinear
|
0.06
|
0.49
|
0.19
|
0.46
|
0.03
|
0.09
|
0.27
|
1- Probability Value. 2- Standard error of mean. 3- P.value values of regression coefficients are presented. Common letters in each column indicate no statistically significant difference (p>0.05).
Traits of fat, meat and carcass bone
As can be seen in table 4, the effect of different ratios of forage to concentrate was not significant on all traits related to fat, meat, and carcass bone (p>0.05). Also, the results of regression analysis presented in table 4 show that there is no linear and non-linear relationship between changes in these traits and increasing the percentage of concentrate in the ration (p>0.05).
Table4. The effect of different ratios of forage to concentrate in feed on fat, meat and carcass bones of fattening lambs (kg)
Treatment(forage to concentrate ratio)
|
Lean meat
|
Bone
|
Subcutaneous fat
|
Intramuscular fat
|
Total carcass fat
|
The ratio of lean meat to carcass fat
|
80:20
|
7.5
|
2.1
|
1.8
|
0.8
|
2.6
|
2.9
|
70:30
|
7.9
|
2.4
|
2.0
|
1.0
|
3.0
|
2.6
|
60:40
|
8.2
|
2.6
|
2.4
|
1.0
|
3.4
|
2.4
|
50:50
|
8.5
|
2.5
|
2.6
|
1.2
|
3.8
|
2.2
|
P.Value1
|
0.07
|
0.19
|
0.27
|
0.21
|
0.10
|
0.09
|
SEM2
|
0.27
|
0.10
|
0.10
|
0.07
|
0.20
|
0.18
|
Linear3
|
0.41
|
0.76
|
0.82
|
0.90
|
0.84
|
0.23
|
Nonlinear
|
0.64
|
0.85
|
0.02
|
0.58
|
0.31
|
0.37
|
1- Probability Value. 2- Standard error of mean. 3- P.value values of regression coefficients are presented. Common letters in each column indicate no statistically significant difference (p>0.05).
Carcass components traits
Studying the effect of different ratios of forage to concentrate on the traits of carcass components (table 5), it is observed that the difference between the mean weight of traits of carcass components was not significant (p>0.05). Based on the results of Table 4, it is observed that there is no linear and non-linear relationship between changes in carcass component traits and increasing the percentage of concentrate in the ration (p>0.05).
Table 5. The effect of different ratios of forage to concentrate in feed on carcass components of fattening lambs of Zel (kg)
Treatment(forage to concentrate ratio)
|
Right side carcass
|
Neck
|
Shoulder
|
Brisket
|
Flank
|
Rack-loin
|
Legs
|
80:20
|
14.9
|
1.4
|
2.5
|
1.4
|
1.7
|
2.3
|
4.0
|
70:30
|
18.7
|
1.3
|
2.4
|
1.3
|
1.6
|
2.2
|
4.3
|
60:40
|
16.0
|
1.3
|
2.3
|
1.1
|
1.6
|
2.1
|
4.4
|
50:50
|
16.2
|
1.2
|
2.3
|
1.1
|
1.5
|
2.0
|
4.1
|
P.Value1
|
0.06
|
0.20
|
0.19
|
0.25
|
0.27
|
0.18
|
0.21
|
SEM2
|
0.82
|
0.09
|
0.10
|
0.06
|
0.11
|
0.09
|
0.08
|
Linear3
|
0.50
|
0.34
|
0.90
|
0.16
|
0.04
|
0.42
|
0.28
|
Nonlinear
|
0.31
|
0.52
|
0.83
|
0.49
|
0.36
|
0.62
|
0.67
|
1- Probability Value. 2- Standard error of mean. 3- P.value values of regression coefficients are presented. Common letters in each column indicate no statistically significant difference (p>0.05).
Traits of internal organs of the body
Based on the results of table 6, it can be seen that the effect of different ratios of forage to concentrate was not significant on the traits of internal organs of fattening lambs (p>0.05). On the other hand, there is no linear and non-linear relationship between changes in these traits and increasing the percentage of concentrate in the ration (p>0.05).
Table6. The effect of different ratios of forage to concentrate in feed on internal organs of fattening lambs Zel (kg)
Treatment(forage to concentrate ratio)
|
Feet
|
Liver
|
Lungs
|
Heart
|
Spleen
|
kidneys
|
Fat of internal organs1
|
80:20
|
1.0
|
1.0
|
0.6
|
0.2
|
0.1
|
0.2
|
1.2
|
70:30
|
1.1
|
1.0
|
0.6
|
0.2
|
0.1
|
0.2
|
1.3
|
60:40
|
1.1
|
1.1
|
0.6
|
0.2
|
0.1
|
0.2
|
1.5
|
50:50
|
1.1
|
1.1
|
0.6
|
0.2
|
0.2
|
0.1
|
1.6
|
P.Value2
|
0.41
|
0.56
|
0.68
|
0.71
|
0.31
|
0.38
|
0.21
|
SEM3
|
0.06
|
0.02
|
0.08
|
0.01
|
0.01
|
0.01
|
0.08
|
Linear4
|
0.01
|
0.02
|
0.49
|
0.09
|
0.46
|
0.08
|
0.08
|
Nonlinear
|
0.01
|
0.76
|
0.90
|
0.31
|
0.18
|
0.39
|
0.02
|
1- The total fat of the kidneys, pelvis, and internal organs of the digestive tract. 2-Probability Value. 3- Standard error of mean. 4- P.value values of regression coefficients are presented. Common letters in each column indicate no statistically significant difference (p>0.05).