Table 2.
Chemical composition (g/kg DM), IVOMD (g/kg), and ME (MJ/kg DM) of trees species (n = 4) and herbaceous browsed by goats in Southern Mediterranean forest rangeland of Northern Morocco during two contrasting years.
| Item | 2016 (Dry Year) | 2017 (Wet Year) | SEM | p-Value (2016–2017) | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Spring | Summer | Autumn | SEM | p-Value | Spring | Summer | Autumn | SEM | p-Value | S | Y | Y × S | ||
| Olea europaea | ||||||||||||||
| DM | 461 a | 437 b | 426 b | 5.57 | 0.003 | 444 a | 423 b | 414 b | 4.76 | 0.002 | 3.95 | <0.001 | <0.001 | 0.801 |
| OM | 954 a | 912 b | 907 b | 8.1 | 0.004 | 970 a | 920 b | 918 b | 8.67 | 0.001 | 5.94 | <0.001 | 0.017 | 0.753 |
| CP | 76.3 | 79.3 | 82 | 2.86 | 0.773 | 66.7 b | 94.0 a | 89.3 a | 4.92 | 0.019 | 2.81 | 0.024 | 0.359 | 0.101 |
| CT | 4.20 a | 2.17 b | 3.20 ab | 0.32 | 0.004 | 3.87 a | 1.77 b | 2.63 ab | 0.327 | 0.002 | 0.228 | <0.001 | 0.051 | 0.888 |
| EE | 94.0 b | 123 a | 79.6 c | 6.39 | <0.001 | 99.0 b | 131 a | 85.0 c | 7.02 | <0.001 | 4.67 | <0.001 | 0.005 | 0.722 |
| NDF | 415 b | 449 a | 442 a | 5.72 | 0.005 | 404 b | 459 a | 450 a | 8.8 | <0.001 | 5.1 | <0.001 | 0.512 | 0.065 |
| ADF | 314 a | 258 b | 265 b | 9.74 | 0.008 | 302 | 279 | 276 | 5.29 | 0.067 | 5.44 | <0.001 | 0.306 | 0.14 |
| ADL | 159 | 151 | 161 | 2.51 | 0.282 | 147 b | 164 a | 174 a | 4.41 | 0.008 | 2.53 | 0.011 | 0.178 | 0.012 |
| IVOMD | 499 | 517 | 517 | 4.28 | 0.105 | 505 b | 528 a | 530 a | 4.84 | 0.043 | 3.35 | 0.005 | 0.062 | 0.886 |
| ME | 6.85 c | 8.12 a | 7.59 b | 0.193 | <0.001 | 6.96 b | 7.97 a | 7.75 a | 0.161 | <0.001 | 0.122 | <0.001 | 0.649 | 0.305 |
| Quercus canariensis | ||||||||||||||
| DM | 564 c | 690 a | 634 b | 18.3 | <0.001 | 548 c | 678 a | 620 b | 18.8 | <.0001 | 12.8 | <0.001 | 0.001 | 0.859 |
| OM | 939 | 961 | 963 | 4.91 | 0.054 | 950 | 967 | 974 | 4.38 | 0.054 | 3.41 | 0.003 | 0.058 | 0.871 |
| CP | 104 a | 63.7 c | 72.3 b | 6.23 | <0.001 | 90.7 a | 77.3 b | 79.0 b | 2.22 | 0.001 | 3.22 | <0.001 | 0.095 | <0.001 |
| CT | 20 | 26.7 | 17.3 | 2.15 | 0.194 | 14 | 16.3 | 12.7 | 1.09 | 0.438 | 1.45 | 0.081 | 0.008 | 0.554 |
| EE | 18.2 b | 24.6 a | 24.0 a | 1.18 | 0.015 | 21.7 | 27.3 | 28 | 1.3 | 0.075 | 0.947 | 0.002 | 0.014 | 0.897 |
| NDF | 488 c | 550 a | 525 b | 9.25 | <0.001 | 480 c | 560 a | 535 b | 11.9 | <0.001 | 7.33 | <0.001 | 0.157 | 0.036 |
| ADF | 322 c | 372 b | 394 a | 10.7 | <0.001 | 317 c | 382 b | 404 a | 13 | <0.001 | 8.19 | <0.001 | 0.01 | 0.003 |
| ADL | 114 c | 157 b | 176 a | 9.44 | <0.001 | 103 c | 168 b | 189 a | 13.1 | <0.001 | 7.85 | <0.001 | 0.255 | 0.025 |
| IVOMD | 602 a | 406 c | 446 b | 30 | <0.001 | 607 a | 414 c | 454 b | 29.3 | <0.001 | 20.4 | <0.001 | 0.007 | 0.694 |
| ME | 8.69 a | 6.00 b | 6.30 b | 0.427 | <0.001 | 8.82 a | 5.81 c | 6.42 b | 0.462 | <0.001 | 0.305 | <0.001 | 0.775 | 0.159 |
| Quercus ilex | ||||||||||||||
| DM | 571 b | 612 a | 601 a | 6.25 | <0.001 | 551 b | 596 a | 588 a | 7.14 | <0.001 | 5.02 | <0.001 | <0.001 | 0.509 |
| OM | 943 | 953 | 957 | 3.34 | 0.251 | 955 | 960 | 968 | 3.36 | 0.322 | 2.59 | 0.086 | 0.048 | 0.926 |
| CP | 114 a | 70.3 b | 71.3 b | 7.6 | 0.001 | 99.7 a | 83.0 ab | 78.0 b | 4.03 | 0.039 | 4.18 | <0.001 | 0.687 | 0.029 |
| CT | 26.3 b | 60.0 a | 55.0 a | 5.31 | <0.001 | 22.7 b | 48.3 a | 45.7 a | 4.17 | <0.001 | 3.42 | <0.001 | <0.001 | 0.097 |
| EE | 17.7 | 19.1 | 19 | 0.83 | 0.803 | 19.6 | 22.6 | 23.6 | 1.1 | 0.35 | 0.786 | 0.302 | 0.034 | 0.736 |
| NDF | 568 a | 534 b | 506 b | 9.82 | 0.004 | 553 a | 539 ab | 512 b | 7.58 | 0.045 | 6.02 | <0.001 | 0.889 | 0.399 |
| ADF | 352 | 322 | 333 | 5.77 | 0.071 | 342 | 334 | 345 | 3.91 | 0.559 | 3.44 | 0.063 | 0.416 | 0.256 |
| ADL | 170 | 163 | 171 | 3.18 | 0.582 | 162 b | 175 ab | 192 a | 5.16 | 0.024 | 3.13 | 0.039 | 0.083 | 0.071 |
| IVOMD | 508 a | 410 c | 459 b | 14.4 | <0.001 | 513 a | 424 c | 468 b | 13.1 | <0.001 | 9.49 | <0.001 | 0.049 | 0.673 |
| ME | 7.16 a | 5.99 c | 6.59 b | 0.172 | <0.001 | 7.38 a | 5.87 c | 6.70 b | 0.223 | <0.001 | 0.137 | <0.001 | 0.317 | 0.146 |
| Quercus suber | ||||||||||||||
| DM | 587 b | 650 a | 604 b | 9.7 | <0.001 | 573 b | 639 a | 589 b | 10.2 | <0.001 | 7.03 | <0.001 | 0.004 | 0.932 |
| OM | 968 a | 957 ab | 947 b | 3.8 | 0.04 | 978 | 969 | 963 | 3.5 | 0.212 | 2.94 | 0.01 | 0.009 | 0.829 |
| CP | 85 | 78.3 | 88.3 | 2.36 | 0.229 | 75.3 | 91 | 95 | 3.83 | 0.057 | 2.22 | 0.056 | 0.374 | 0.056 |
| CT | 119 | 132 | 124 | 2.93 | 0.196 | 110 | 118 | 116 | 2.7 | 0.48 | 2.29 | 0.11 | 0.02 | 0.796 |
| EE | 25 | 26 | 27.3 | 1.12 | 0.752 | 28.6 | 29.3 | 30.3 | 1.09 | 0.86 | 0.861 | 0.653 | 0.081 | 0.988 |
| NDF | 579 a | 502 b | 485 b | 14.7 | <0.001 | 565 a | 511 b | 490 b | 11.5 | 0.004 | 9.07 | <0.001 | 0.982 | 0.164 |
| ADF | 377 a | 348 b | 311 c | 10.1 | 0.001 | 367 a | 367 a | 321 b | 8.22 | 0.003 | 6.36 | <0.001 | 0.223 | 0.097 |
| ADL | 168 a | 134 b | 133 b | 6.12 | 0.002 | 161 | 146 | 149 | 2.98 | 0.069 | 3.41 | <0.001 | 0.061 | 0.036 |
| IVOMD | 543 a | 406 c | 506 b | 20.4 | <0.001 | 550 a | 421 c | 513 b | 19.2 | <0.001 | 13.6 | <0.001 | 0.003 | 0.412 |
| ME | 8.05 a | 6.00 c | 7.34 b | 0.296 | <0.001 | 8.19 a | 5.84 c | 7.51 b | 0.353 | <0.001 | 0.223 | <0.001 | 0.605 | 0.085 |
| Herbaceous | ||||||||||||||
| DM | 463 c | 631 a | 516 b | 25 | <0.001 | 446 c | 616 a | 495 b | 25.6 | <0.001 | 17.5 | <0.001 | 0.019 | 0.923 |
| OM | 916 a | 870 b | 855 b | 9.8 | 0.002 | 931 a | 883 b | 872 b | 9.5 | 0.001 | 6.87 | <0.001 | 0.013 | 0.958 |
| CP | 156 a | 78.3 b | 65.7 b | 14.2 | <0.001 | 142 a | 91.0 b | 76.7 b | 10.1 | <0.001 | 8.45 | <0.001 | 0.291 | 0.006 |
| CT | 2.42 b | 4.17 a | 2.97 b | 0.323 | 0.048 | 2.2 | 3.53 | 2.43 | 0.287 | 0.116 | 0.217 | 0.006 | 0.176 | 0.865 |
| EE | 19.9 | 22 | 23.3 | 0.823 | 0.262 | 22.6 | 26.3 | 26.3 | 1.12 | 0.349 | 0.789 | 0.11 | 0.027 | 0.872 |
| NDF | 517 | 568 | 497 | 15.4 | 0.147 | 508 | 580 | 507 | 16.2 | 0.087 | 10.8 | 0.014 | 0.827 | 0.865 |
| ADF | 339 b | 363 a | 269 c | 14.7 | 0.001 | 326 b | 379 a | 283 c | 14.6 | 0.001 | 10.1 | <0.001 | 0.426 | 0.216 |
| ADL | 71.4 | 75.7 | 64.3 | 2.76 | 0.265 | 67.0 b | 89.0 a | 79.0 ab | 3.95 | 0.043 | 2.53 | 0.031 | 0.056 | 0.106 |
| IVOMD | 804 a | 651 c | 705 b | 22.7 | <0.001 | 807 a | 658 c | 719 b | 22 | <0.001 | 15.3 | <0.001 | 0.223 | 0.771 |
| ME | 12.0 a | 9.25 c | 10.7 b | 0.405 | <0.001 | 12.1 a | 9.57 c | 10.8 b | 0.364 | <0.001 | 0.265 | <0.001 | 0.097 | 0.334 |
DM, dry matter, OM, organic matter; CP, crude protein; CT, condensed tannins; EE, ether extract; NDF, neutral detergent fiber; ADF, acid detergent fiber; ADL, lignin; IVOMD, in vitro organic matter digestibility; ME, metabolizable energy; S, season; Y, year; SEM, standard error of the means. Within a row, values with different letters are significantly different (p < 0.05).