The study aimed to assess the growth performance and meat quality of ducks when fed diets either with or without beet pulp silage (BPS). A total of 180 Cherry Valley male ducks were reared for 49 days across two feeding periods (days 1–28 and 29–49) and were divided into three groups, each having six replicates. Group 100CD received a commercial diet (CD) ad libitum. Group 70CD:30BPS was given a mixture of CD and BPS in a 70:30 ratio, also ad libitum. Group rCD:alBPS followed a free-choice feeding approach, with a restricted CD (30% lower than the standard dose) and ad libitum access to BPS (double feeders). Slaughter yield and meat quality (pH, color, drip loss, water-holding capacity, texture, and chemical composition were analyzed (12 birds per group). Group 100CD exhibited the highest body weight up to day 28, while rCD:alBPS had the lowest. During the first 28 days, rCD:alBPS showed a lower growth rate and weight gain, but from day 29 onwards, their growth rate surpassed that of the other two groups. Group 70CD:30BPS had the highest starter feed intake, while both 100CD and 70CD:30BPS showed the highest grower feed intake. Interestingly, rCD:alBPS demonstrated the lowest feed conversion rate since day 29 and throughout the entire rearing period, indicating efficient feed utilization. Additionally, the European Broiler Index was higher in the rCD:alBPS group, further supporting the benefits of this particular feeding regimen. As for carcass characteristics, rCD:alBPS showed higher relative weight of skin with subcutaneous and abdominal fat. Conversely, these ducks had lower weights for both gizzard and wings. The pectoral muscles from 100CD had higher protein, salt, and fat content but lower water content compared to the other groups. The water-holding capacity in leg muscles was lower in 100CD than in 70CD:30BPS and rCD:alBPS. Protein content in 100CD and rCD:alBPS was higher than in 70CD:30BPS. Collagen content was highest in 100CD, salt in 70CD:30BPS, fat in both 100CD and 70CD:30BPS, and water in rCD:alBPS. Overall, a free-choice feeding approach with a restricted diet and ad libitum access to BPS positively impacted feed conversion. The use of a limited diet led to better feed utilization. Moreover, the lack of negative effects on body weight gain and carcass characteristics suggests that ducks efficiently utilize nutrients from both feed and silage. This feeding method, which incorporates roughage, can be recommended for rearing ducks.
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