Comparison of the effects of several feed restriction periods to control ascites on performance, carcass characteristics and hematological indices of broiler chickens

Abstract

This experiment was conducted to evaluate the effect of some feed restriction regimes on the performance, carcass characteristics and hematological values of broiler chickens. A number of 480 one-day-old Cobb broilers were distributed into 24 floor pens and reared for 42 days. A basal diet was formulated according to the NRC (1994) recommendations for starter (1-11 d), grower (12-28 d) and finisher (29-42 d) periods. The restricted birds were fed 8 h per day from 7 to 21 (R7-21d), 14 to 28 d (R14-28d) or from 21 to 35d (R21-35d), while the control birds were fed ad libitum. Birds and feed were weekly weighed, and dead birds were submitted to necropsy to determine the cause of death. At the end of experiment, blood samples were taken from 3 birds per pen, birds were weighed, and organ weights were recorded. All birds in the feed restriction treatments had lower body weight gain and feed intake than those fed ad libitum. Feed conversion ratio (FCR) was better in birds under R7-21d as compared to the control group (p<0.05). R7-21d and R14-28d birds presented lower general mortality and death due to ascites as compared to ad libitum-fed broilers. The birds under R21-35d and R14-28d treatments had lower breast weight and abdominal fat weight as compared to control birds, respectively (p<0.05). A similar trend was observed for the percentage of the mentioned cuts. The right/total ventricular weight ratio (RV/TV) was significantly lower both in R7-21d and R14-28d treatments as compared to the control group. Blood constituents, such as glucose, cholesterol, and lactate dehydrogenase were also significantly altered by feeding regimes (p<0.05). The results of present study showed that R7-21d reduced ascites incidence, but had no significant effect on growth performance

Thyroid Hormone and Blood Metabolites Concentrations of Broiler Chickens Subjected to Feeding Time Restriction

“…These findings indicate that plasma albumin concentrations of the feed restricted broiler were normalized and remain as the value of ad libitum broilers during realimentation period. Result of the present study was in agreement with the results of El-Fiky et al (2008) and Boostani et al (2010) who also show that plasma albumin concentrations were not affected by feed availability for 4 h/d (2.03 vs 2.14 g/dl) at 49 d of age, and feed availability for 8 h/d (1.74 vs 1.78 g/dl) at 42 d of age.…”

“…This finding indicate that feeding time restriction had lower intensity of feed restriction, so that there was not any change reserve protein during feed restriction. The other repots, the feed restriction through feed availability for 8 h/d during 7-21 d of age (Boostani et al, 2010), and skip-a-day for 6 d during 8-18 d (Bratte, 2011) were not influence plasma protein concentrations at age of 42 d (3.76 vs 3.89 g/dl) and 56 d (5.60 vs 6.40 g/dl).…”

“…The other research, Jang et al (2009) reported that the quantitative and qualitative feed restrictions during 7 d from 8-14 d decreased plasma protein and albumin concentrations of broiler chickens. However, Boostani et al (2010) reported that feed availability for 8 h/d from 7-21 d did not influence plasma proteins and albumin concentrations of broiler chickens.…”

“…A number of variations of feed restriction including limiting the time of daily access to feed (Khetani et al, 2009;Onbasilar et al, 2009;Mohebodini et al, 2009), removal of feed for up to 8 h a d or skip-a-day feeding, allowing birds to feed only once/h and feeding once every other day (Demir et al, 2004;Khajali et al, 2007;El-Fiky et al, 2008;Benyi et al, 2009Benyi et al, , 2010Boostani et al, 2010;Saffar & Khajali, 2010), have been evaluated but results have been conflicting (Navidshad et al, 2006;Cornejo et al, 2007;Khetani et al, 2009;Ghazanfari et al, 2010). However, Mohebodini et al (2009) on the respective research indicated that although intermittent feeding through free access to feed during four periods of 2 h (06:00-08:00, 12:00-14:00, 18:00-20:00, and 24:00-02:00) from 7-21 d of age had lower on body weight gain than control (436.3 vs 495.3 g), but had no effect on weight gain during realimentation period from 22-42 d of age.…”

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“…Thus, birds which had achieved the body weight in a short period of time will have the feed efficiency improved due to a decreasing in their maintenance requirements (Leeson & Summers, 2005). For this reason, currently has aroused interest in the use of programs of food restriction to modify the pattern of growth, and reduce its maintenance requirement, seeking compensatory growth (Boostani, Ashayerizadeh, Mahmoodian, Fard & Kamalzadeh, 2010;Butzen Ribeiro, Vieira, Kessler, Dadalt & Della, 2013;Trocino, Piccirillo, Birolo, Radaelli, Bertotto, Filiou, Petracci & Xiccato, 2015). Compensatory growth refers to the abnormal rapid growth observed in animals of the same age and in the same lineage that previously had restricted feeding (Butzen et al, 2013).…”