Abstract :
The objective of this study was to determine the effect of forage:concentrate ratio on growth performance, nutrient digestibility
and carcass characteristics of growing Baladi (black) kids. Thirty-two male kids (initial body weight =15.3±1.3 kg) were assigned
randomly to four dietary treatments (8 kids/treatment) in a completely randomized design. Experimental diets were: (1) high
forage (HF); (2) medium high forage (MHF); (3) medium low forage (MLF); (4) low forage (LF), and contained 60:40, 45:55,
30:70 and 15:85 forage:concentrate ratios, respectively. Metabolizable energy contents were 2.39, 2.56, 2.73, and 2.90 Mcal kg−1
for the HF, MHF, MLF, and LF diets, respectively. Diets were isonitrogenous (16% CP) and were fed twice daily for 68 days. Dry
matter intake for kids fed the MLF diet was greater (P < 0.05) compared with kids fed the HF, MHF and LF diets. Metabolizable
energy intake was higher (P < 0.05) for kids fed the MHF, MLF and LF diets (average = 1.73 Mcal day−1, S.E. = 0.1) compared
with kids fed the HF diet (1.40 Mcal day−1). Average daily gain (ADG) for kids fed the LF diet (179 g day−1) was greater (P
< 0.05) compared with kids fed the HF diet (78 g day−1). Kids fed the MHF and MLF diets had intermediate ADG (average
116 g day−1). Dry matter, OM and CP digestibilities increased (P < 0.05) with increasing the concentrate portion of the diets.
The NDF and ADF digestibilities decreased (P < 0.05) with the increasing levels of concentrates in the experimental diets. Kids
fed the HF and MHF diets had the greatest NDF and ADF digestibility (average = 60.1 and 53.8 %, respectively). Hot and cold
carcass weights were greater (P < 0.05) for kids fed the LF diet compared with kids fed the HF diet. Kids fed the MHF and
MLF diets had intermediate hot and cold carcass weights. Kids fed the LF diet had higher (P < 0.05) liver weights compared
with kids fed the MLF diet. On the other hand kids fed the MLF diet had greater (P < 0.05) liver weights (498 g) compared with
kids fed the HF diet (387 g). Kidney, spleen, heart and skin weights were not affected by the dietary treatment. Ruminal pH for
kids fed the HF diet (6.92) was greatest (P < 0.05) and declined linearly for the MLF and LF diets to 6.09. This study indicates
that increasing the concentrate portion of fattening diets increases ADG, improves feed efficiency and carcass characteristics of
growing Baladi kids. Higher concentrate diets reduced production costs compared to higher forage diets as well.
© 2004 Elsevier B.V. All rights reserved
