This study was designed to examine the effects of dietary energy levels on some growth and reproductive parameters of local barred chickens in Cameroon. For this purpose, One hundred and forty four day-old barred male chicks, weighing 28.33 g in average were randomly divided into 12 groups of 12 chicks each. Three feeding programs (FP) comprising each a starter diet from day old to 12 weeks (S0: 2800 Kcal/Kg; S1: 2900 Kcal/Kg; S2: 3000 Kcal/Kg) and grower diet from 13 to 20 weeks (G0: 2900 Kcal/Kg; G1: 3000 Kcal/ Kg; G2: 3100 Kcal/Kg) were used and designated FP1, FP2 and FP3 respectively. Each of the FP was randomly allotted of 4 groups of 12 birds in a completely randomized design. Throughout experiment (1 day old to 20 weeks), body weight was recovered every 2 weeks. At 20 weeks of age, roosters were sacrificed; semen characteristic was analyzed and testes were characterized. Between 2 to 10 weeks old, body weight of cocks fed with FP3 was significantly higher (P < 0.05) as compared to others FP. Inversely, from 12 to 20 weeks, body weight of cocks receiving FP1 was significantly higher (P < 0.05) than that of cocks receiving feeding programs 2 and 3. At 20 weeks, 100% of cocks fed on FP3 produced semen versus 66.66% and 16.66% respectively for those on FP1 and FP2. Semen volume and mass motility of cocks fed on FP3 or FP1 were significantly (P < 0.05) higher than FP2. It was concluded that FP1 had more suitable dietary energy levels for growth and reproduction of local barred cocks.
Body weight of cocks receiving the lowest energy level (FP1) at 20 weeks was significantly higher than that of cocks receiving respectively the intermediate (FP2) and highest (FP3) energy level. It is well established that hypo energetic diet leads to excessive weight gain [18,30, 31]. Birds fed with low metabolizable energy diet consume more nutrients than needed, particularly protein, vitamins and minerals. They then increase their caloric intake by using part of the diet protein as source of energy without affecting the protein quantity necessary for growth [10,11,30]. Hyper energetic diet doesn’t cover quantitatively other nutritive needs such as protein, vitamins and minerals. The deficiency may negatively impact growth [18,30,31]. Body weight evolution between 2 and 10 weeks showed significantly higher values for cocks receiving feeding programs 3. This result is in agreement with the findings of Teteh et al. [
This study revealed that dietary energy level affected testicular development. In fact, testicular development was significantly higher with FP3 and FP1 compared with feeding programs 2. This may be attributed to growth dynamic within the first 10 weeks. The highest (FP3) and the lowest (FP1) dietary energy level lead to an increase of testes weight. In fact, it is well established that bird fed hypo-energetic diet uses a part of the diet protein as source of energy to compensate and then increase caloric intake [18,32], suggesting that high energy intake leads to precocious testicular development and testicular hypertrophy. The testicular development of roosters with high body weight at 8 weeks was significantly higher than that of other cocks. This result supported the findings of Brière et al. [
Semen characteristics of roosters fed with the highest dietary energy (FP3) were relatively lower when compared to those of cocks fed with the lowest dietary energy (FP1). In birds, Brière et al. [
The presented results suggested that testicular development and sexual maturity are affected by dietary energy level. This work generated first data of semen characteristic from Cameroonian local chicken. Feeding programs 1 seems to be more interesting for both growth and reproductive performances but further work is required for accurate conclusion.