The present study was conducted to investigate theeffectsofdifferentsizesofinsolublegritongrowthperformanceandcarcasstraitsinbroilerchickens. A total of 200 broilers (Ross 308), 10 days old, were randomly allotted to five experimental equal groups with four replicates of 10 chickens (five male and five female) and fed with basal diet + ground wheat (without grit); basal diet + whole wheat (without grit) and basal diet contain 1.5% gritof diet with sizesof 2, 3 and 4 mm. Growthperformance (evaluated through weight gain, feed intake and feed conversion ratio) was determined on day 24 and 42. Also, carcasstraits (relative weights ofcarcass, breast, thigh, liver, heart, gizzard and intestine) and intestine length were assessed on day 42. Weight gains and feed conversion ratio were significantly improved in broilers added with grit 2 mm compared to the control group (p<0.05), whereas; carcasstraits were not significantly altered. These data suggest that grit with size of 2 mm improve growthperformanceinbroilerchickens.
The ascites syndrome (ascites) is the primary cause of death for rapidly growing broiler strains, resulting in economic loss (Hassanzadeh et al., 2009). Ascites is a condition in which the body cavity accumulates serous fluid, leading to carcass condemnation or death (Julian, 1993). The causes ofthe syndrome are multifactorial and mainly induced by exogenous and/or endogenous factors. An imbalance between oxygen supply andthe oxygen required to sustain rapid growth rates and high food efficiencies is believed to be the primary cause of ascites inbroilerchickens (Decuypere et al., 2000 & 2005; Julian, 2005). The housing environment, including factors such as temperature (cold or fluctuating temperatures) and air quality (dust concentration, carbon dioxide levels, and oxygen levels), is known to influence the incidence of ascites inbroilerchickens. The incidence of ascites greatly increases at altitudes greater than 1300 meters above sea level, presumably because ofthe low oxygen partial pressure (Hernandez, 1987). Physiologically, low
Inthe present experiment, significantly (p≤0.05) better FCR was observed in pedigree birds (2.38±0.01) compared with mass-selected birds (2.39±0.01) and random-bred controls (2.45±0.01). Birds from 10-week-oldparents showed better FCR (2.39±0.01) compared with those from 12 (2.40±0.01) and 14-week-old (2.43±0.01) parents. Inthe present experiment, CBF had no effect on FCR; however, FCR was significantly affected (p≤0.05) by the interactions between CBF and selection strategies and age groups. The interaction of selection strategies with parental age groups significantly influenced (p≤0.05) cumulative FCR. However, no significant effect of selection methods, CBF or parental age groups on mortality % was observed inthe current experiment. Inthe present experiment, pedigree birds presented significantly better FCR compared with mass-selected and random- bred control birds, which may be due to the lower maintenance requirements and lower fat deposition of pedigree-base selected birds. Usually, there is a favorable correlation between feed conversion ratio andgrowth because of enhanced pulsative growth hormone release and ultimately live weight gain. The selection for better feed conversion inbroilerchickens resulted in direct selection for carcass leanness. Similarly, in another study (Marks, 1980), better FCR was observed in Japanese quails selected for high body weight for 42 generations compared with random- bred controls. Birds from 10-week-old parents showed better FCR compared with the progenies of 12- and 14-w-oldparents, possibly because younger birds have better feed conversion ratio than older ones. However, Sohail et al. (2013) did not report any significant effect of age onthe FCR of Peshawari Aseel chickens.
Dietary linseed oil inclusion levels had a quadratic influence (p<0.05) on feed conversion ratio (Table 2) in both studied periods, as shown by the equations FCR = 1.9342 - 0.032015X + 0.0020349X2, R2 = 0.92 and FCR = 2.1884 - 0.03445X + 0.00203547X2, R2 = 0.90, up to the levels of 7.87 and 8.46% for the periods of 21-42 and 21-56 days of age, respectively. This behavior may be related to the linear increase in feed intake without the corresponding increase in weight gain. These results are consistent with those of Murakami et al. (2009), who included increasing linseed oil levels inbroiler diets during the period of 1-43 days of age and observed a linear improvement in feed conversion ratio, demonstrating the beneficial effectsof this oil source onbroilerperformance. However, in a subsequent study, Murakami et al (2010) found that feed conversion ratio worsened when linseed oil was fed during the starter phase (1-21 days) and no effect thereafter (22-49 days).
Proximate composition, pH and bulk density ofthe two types of banana meal are given in Table 2. The proximate composition ofthe two types of banana meal was not significantly different. The proximate components ofthe banana meals were similar to those values reported by Adeniji et al. (2007). The CP contents of banana meals were lower than that ofthe commonly used cereals and their by- products in poultry feeds (NRC 1994). Furthermore, the protein profile of banana was found to be deficient in lysine, methionine and tryptophane (Emaga et al., 2011). Therefore, the protein value of banana meal is assumed to be low.
ofbroilerchickens raised under different temperatures that received feed with or without yeast extract and prebiotic inthe pre-initial phase. One thousand four hundred and forty one-day old male chicks were used, raised indifferent climate chambers. Feed with or without the addition of yeast extract and prebiotic was offered only inthe pre-initial phase (1 to 7 days). From the eighth day on, every chick received the same feed, readjusted according to usual recommendations. A randomized complete experimental design was used in a 3 × 2 × 2 factorial arrangement, consisting of three environmental temperatures (hot, comfort and cold) and two levels of yeast extract (with or without) and prebiotic (with or without). Theperformanceofthe birds was evaluated considering weight gain, feed intake, food conversion and viability at 42 days of age. Carcass yield and intestinal morphometry were also evaluated. Environmental heat impaired performanceandcarcass yield. Prebiotic inclusion inthe pre-initial feed increased weight gain and enhanced food conversion of birds raised under hot conditions. The inclusion of products inthe feed ofbroilerchickens raised in hot and cold environments has beneficial effectson chicken intestinal villi.
This study evaluated theeffectsof dietary non-phytate phosphorus (NPP) and 1α-hydroxycholecalciferol (1α-OH-D 3 ) onthegrowthperformance, bone mineralization, andcarcasstraitsof 1- to 21-day-old broilerchickens. Onthe day of hatch, 600 male Ross 308 chicks were weighed and randomly assigned to 12 treatments, with five cages of 10 birds each. A 6 × 2 factorial arrangement was applied, consisting of 0.20%, 0.25%, 0.30%, 0.35%, 0.40%, or 0.45% NPP and 0 or 5 μg/kg of 1α-OH-D 3 . The basal diet contained 0.52% calcium (Ca) and was not supplemented with vitamin D 3 . Dietary NPP levels significantly affected growthperformanceand tibia mineralization (except width) of broilers; by contrast, meat yield and organ relative weight were not influenced by NPP. The inclusion of 1α-OH-D 3 improved growthperformance, tibia mineralization, andcarcassand breast yield, whereas it decreased the relative weights ofthe liver, heart, and kidney. A significant interaction between NPP and 1α-OH-D 3 was observed for body weight gain (BWG), feed efficiency (FE), mortality, serum Ca and P levels, tibia breaking- strength, ash weight, and Ca content, as well as breast yield and heart relative weight. These results suggest that broilers fed with 5 μg of 1α-OH-D 3 per kg of diet obtain optimal growthperformanceand tibia mineralization when dietary NPP level was 0.30% andthe analyzed Ca to NPP ratio was 1.97.
Lysine needs of starting chicks (up to Day 21) have been studied extensively (Schwartz et al., 1958; Hewitt & Lewis, 1972; McNaughton et al., 1977; Han & Baker, 1991; Han & Baker, 1993). Different recommended levels of dietary lysine have been determined across laboratories because numerous variations have existed among experiments (e.g., genetic strain, environmental temperature, feed ingredients, protein source and quality, and sex (Han & Baker, 1991; Han & Baker, 1993). It has been shown that current NRC (1994) recommendations for lysine up to d 21 are too low for todays commercial broiler (Han & Baker, 1991; Vasquez & Pesti, 1997; Kidd & Fancher, 2001). Furthermore, recent studies have shown an increase inperformance when dietary lysine during the starter phase is higher than recommended levels (Kidd et al., 1998; Kidd & Fancher, 2001). Such effects were observed for the Ross x Ross 508 male (Kidd & Fancher, 2001) andthe Avian 34 x Avian male (Kidd et al., 1998). Carcasstraitsinthe former studies were also improved by early dietary lysine. It was concluded that optimum performance was obtained when birds were fed high dietary lysine levels not only during the starter period, but when
al., 2004). Similarly, Gowda and Sastry (2000) confirmed a significant improvement of SMS on body weight gain and attributed its effects to antioxidant activity inthe protein synthesis stimulation by the bird’s enzymatic system. The higher weight gain was reported by Chakarverty and Parsad (1991), in SMS supplemented group. Kalorey et al. (2005) reported the protective role of SMS against aflatoxicosis onthe weight of bursa of fabricius. As evident from some researches, aflatoxins reduced lymphoid organs weight (thymus, bursa and spleen) in aflatoxicosis (Tedesco et al., 2004). Silybum marianum was more efficient to protect the spleen against adverse effectsof aflatoxin as compared with the synthetic toxin binders (Kalorey et al., 2005).
No signif icant int eract ion w as observed bet w een genetic group and dietary metabolizable energy level f or w eight gain (Table 2); t heref ore, only t he main treatment effects w ill be discussed. AgRoss 308 group w eight gain w as 46% higher than PCLC. Analyzing perf ormance dif f erences bet w een t ypical 1957 and 1991 broilers, Havenst ein et al. (1994a) report ed a w eight gain improvement of more than 300% during this period. The authors also found the diet based on 1991 recommendat ions improved non-select ed line w eight gain in 26% at 43 days. As PCLC line represents a more modern broiler than 1957 one, these significant dif f erences w ere expect ed. A comparison bet w een diets reveals progressive rise in w eight gain according t o elevat ion in energy consum pt ion. Leeson et al. (1996) also observed im provem ent in w eight gain according to rise in energy consumption; how ever, as broilers are capable of controling feed intake according t o energy requirement s, t he same result s w ere not described w hen diets w ith different energy levels w ere applied in an ad libitum feed program.
Bir d h u sba n dr y: A straight run flock of one-day-old determination ofcarcasstraits. Thechickens were Cobb-400 broilerchickens (N=1600) with an average mechanically stunned followed by exsanguination. body weight of 43.5 (±1.19) g were assigned to four The carcasses were defeathered and eviscerated. The dietary treatments for 35 days. Each treatment group dressed carcass weight was determined after complete had four replicates with 100 birds in each replicate. The removal of organs and gastro intestinal (GI) tract. replicates were housed in pens (3.2m x 3.2m) on litter Internal organs (heart, liver and spleen) and gizzard composed of saw dust and wood shavings. All birds were severed out and washed with phosphate buffered were vaccinated against Newcastle disease (on days 5 saline to remove blood and tissue debris. Giblet weight and 20) and Infectious bursal disease (on day 13). Bird was expressed as the combined weight of heart, liver management was according to the recommendations ofand gizzard. Liver and spleen were also weighed Cobb Management Guide . The chicks received the separately. The entire GI tract was removed, soaked in phosphate buffered saline to remove the blood and designated treatment diets within 12 h of their hatching.
ABSTRACT – The aim of this study was to evaluate theeffectsof bulls’ temperament kept at three different space allowances (6, 12, and 24 m 2 /animal) ongrowthperformance, carcasstraits, meat quality traitsand animal welfare. The specific objectives were: 1) to evaluate theeffectsof space allowance on bulls’ temperament; 2) to evaluate theeffectsof temperament ongrowthperformance, carcassand meat quality traitsof beef cattle kept indifferent space allowance; 3) to evaluate theeffectsof temperament on adrenal gland morphometric and its relationship to space allowance; 4) to determine the relationship between adrenal gland morphometric and bruise severity onthecarcass, at different space allowance. The study was conducted using 1,350 bulls (450 Nellore and 900 cross-bred Angus or Caracu x Nellore) raised on pasture and finished in a commercial feedlot. Temperament was assessed by the flight speed (FS) test on day 0 (FS 0 ), 35 (FS 35 ) and 87 (or last day;
D 3 ). Results showed that the Ca to NPP ratio, vitamin D source, and their interaction affected body weight gain (BWG), feed intake (FI), feed efﬁciency (FE), andcarcassand breast yields, as well as tibia weight and length and ash weight inbroilerchickens from 1 to 42 d of age. Broilers fed 1α-OH-D 3 had higher BWG and FI as well as tibia breaking strength, weight, length, diameter, and ash weight than birds fed 25-OH-D 3 at 42 d of age. The Ca to NPP ratio had a quadratic effect on BWG, FI, mortality, as well as tibia breaking strength, weight, length, ash weight, and ash and P contents in 42-d-old broilers. Broilerchickens at 42 d of age obtain optimal growthperformanceand bone mineralization at the Ca to NPP ratio of 2.32 when 1α-OH-D 3 or 25-OH-D 3 are used as the vitamin D source.
Theeffectsof cashew nut shell liquid (CNSL) ongrowthperformance, carcass yield, relative weight of internal organs and microbiology of digestive tract ofbroilerchickens were investigated. Five hundred and forty male broiler chicks at one day of age were arranged in a completely randomized design with six treatments and six repetitions with 15 broiler chicks each. The treatments were: control (T1 – without growth promoter virginiamycin and CNSL); inclusion levels of 0.10mL (T2), 0.20mL (T3), 0.30mL (T4) and 0.40mL (T5) of CNSL/kg of feed; and commercial promoter virginiamycin (T6). At 21 and 40 days of age, body weight, feed intake, feed conversion and viability of birds were similar in all treatments. Carcass yield was higher inthe treatment with thegrowth promoter when compared to the control treatment. There was a linear increase incarcass yield when the level of CNSL was increased inthe diet. The relative weight ofthe intestine was lower inthe treatment containing virginiamycin when compared to the treatment without the inclusion of additives. The relative weight ofthe intestines decreased when the levels of inclusion of CNSL were increased. There was a gradual reduction of Escherichia coli concentration reaching the lowest number onthe CNSL level of 0.30mL/kg. It was concluded that CNSL showed similar performanceand slaughter yield as thegrowth promoter and reduced the concentration of Escherichia coli inthe intestinal contents.
This study evaluated the effect ofdifferent probiotics and prebiotics ontheperformanceof broilers. One-day-old male broiler chicks from the Cobb strain (n=1,260) were randomly distributed in a 3 x 3 factorial arrangement, considering 3 probiotics and 3 prebiotics sources. Nine treatments with 4 repetitions and 35 birds per parcel were used. The results showed that there was no influence of treatment on feed intake at thedifferent rearing phases. Better weight gain (p<0.05) was seen when diet was supplemented with the phosphorylated mannanoligosaccharide-based prebiotic (MOS) compared to diets without prebiotics. Feed conversion of birds fed diets with probiotics and prebiotics was better than feed conversion of birds not receiving such additives. Such better results were seen inthe initial period (1 to 21 days), but not inthe following period (1 to 35 days) or inthe total period (1 to 42 days). Better rearing viability was seen when MOS was used together with organic acidifier when compared to the diets without prebiotic. Viability was worst when no prebiotics or probiotics were used. It was concluded that beneficial effects were seen inperformanceof birds at 21 days when thegrowth promoters were used, but not at 42 days of age. Nevertheless, there was better growth viability at 42 days of age when growth promoters were added.
Harsh environmental conditions result in important economic losses for the poultry industry in tropical countries. Heat exposure impairs broilers performance, especially during growing and finishing periods, as their ability to dissipate heat decreases according to body growth. The primary consequence of heat exposure is reduction in feed intake (Geraert et al., 1996a), a physiological response in order to decrease metabolic heat production and to maintain body homeostasis (Koh & Macleod, 1999). However, heat exposure also impairs survival rate (Deaton et al., 1986), weight gain, and feed conversion ratio ofbroiler flocks (Geraert et al., 1993, Faria Filho, 2006), which have a direct impact onthe profitability of this activity. Moreover, lower breast yield and higher fat deposition were described in broilers exposed to heat (Ain Baziz et al., 1996; Geraert et al., 1996a), which are undesirable, considering the economic value of breast meat and that excessive amount of fat inbroiler carcasses is not well accepted by customers.
et al. 2006, Wang and Gu 2010). Mountzouris et al. (2010) pointed out that no consistent conclusions can be drawn regarding the effect of increasing probiotic administration level ongrowthperformance due to the contradictory results found inthe literature and suggested the occurrence of an optimal strain-dependent concentration of each ofthe probiotics tested. Onthe other hand, it has been suggested that efﬁ cacy for most probiotics in animals could be achieved with a daily intake of 1 x 10 7 to 1 x 10 9 microorganisms (Mountzouris et al. 2010, Shim et al. 2010). Inthe present work, according to the manufacturer´s speciﬁ cations, the calculated average daily intake of microorganisms was 1 x 10 6 and 2 to 4 x 10 7 inthe P1 treatment andthe P2, P3 and P4 treatments, respectively, which could explain why the P1 treatment did not improve theperformancetraits compared with the control treatment. Onthe other hand, most ofthe above-mentioned works andthe present one were carried out with chickens raised in cages or do not specify the rearing system. The rearing system (ﬂ oor vs. cage) may affect the observed productive results (Santos et al. 2008). Furthermore, theeffectsofbroiler feed supplementation with alternatives to growth-promoting antimicrobials, such as probiotics, may depend onthe rearing system due to differences inthe hygienic conditions (Pirgozliev et al. 2014). Thus, rearing conditions should be taken into account for a more complete interpretation ofthe experimental data from research on probiotic supplementation effects.
Gut microflora has significant effectson host nutrition, health, andgrowthperformance by interacting with nutrient utilization andthe development of gut system ofthe host. This interaction is very complex and, depending onthe composition and activity ofthe gut microflora, it can have either positive or negative effectsonthe health andgrowthof birds (Yang et al., 2009). Chicks grown in a pathogen-free environment grow 15% faster than those grown under conventional conditions, where they are exposed to bacteria and viruses. The focus of alternative strategies has been to prevent proliferation of pathogenic bacteria and modulation of indigenous bacteria, so that the health, immune status andperformance are improved (Yang et al., 2009). The pharmacological action of active plant substances or herbal extracts in humans is well known, but in animal nutrition the number of precise experiments is relatively low (Mohamed et al., 2011). Basil known as sweet and garden basil, a member ofthe Lamiaceae family, is commonly cultivated throughout Mediterranean region (Abbas, 2010). The leaves and flowering tops of sweet basil are used as carminative, galactogogue, stomachic and antispasmodic medicinal plant inthe folk medicine (Sajjadi, 2006). However, recently the potential uses of O. basilicum essential oils, particularly as antimicrobial and antioxidant agents, have also been investigated. The chemical composition of basil oil has been the subject of considerable studies. There is extensive diversity inthe constituents ofthe basil oils and several chemotypes have been established from various phytochemical investigations. However, methyl chavicol, linalool, methyl cinnamate, methyleugenol, eugenol and geraniol are reported as major components ofthe oils ofdifferent chemotypes of O. basilicum. (Sajjadi, 2006). We have no information about the relationship between in vitro antimicrobial potential and efficiency of essential oils inbroilerchickens. Perhaps essential oils, which inhibit pathogenic and nonpathogenic bacteria, are more efficient inbroilerchickens. The objective ofthe present study was to evaluate the antimicrobial activities of basil essential oil against pathogenic and non-pathogenic bacteria and their effectsonbroilerchickens.
Zilpaterol supplementation improved weight gain (p=0.0003) and feed conversion ratio (p=0.005) in all treatments compared with the control group, but it did not affect feed intake on days 34-40 (p=0.09). However, on days 41-47 days, zilpaterol did not significantly affect growthperformance. There are some reports about differenteffectsof β-agonists onthegrowthperformanceof animals. Ansari-Pirsaraei et al. (2007) demonstrated that terbutaline did not affect daily weight gain, but reduced feed conversion ratio (FCR) of male broilers when5 and 10 mg/kg were fed, respectively. Onthe other hand, in some studies, ZH supplementation increased average daily gain and gain efficiency in feedlot lambs (Estrada-Angulo et al., 2008), steers (Avendano-Reyes et al., 2006) and cattle (Vasconcelos et al., 2008). However, Felix et al. (2005) did not observe any effect of ZH supplementation on
The use of Syn in poultry production encourages a healthy gut via certain possible mechanisms, such as enhancing the immune system (Hamasalim, 2016), lowering pH, and increasing protective gut mucus (Nikpiran et al., 2014), creating an antimicrobial effect (Likotraﬁti et al., 2016), increasing the digestibility of nutrients (Awad et al., 2008), and enhancing nutrition performance (Elfaki and Mukhtar, 2015; Pelícia et al., 2004). In previous studies conducted on poultry, it was reported that the use of Syn enhances growthperformance (Vahdatpour et al., 2011; Min et al., 2016) andcarcass yield (Pelícia et al., 2004). Sahin et al. (2008) reported that the addition of Syn to broiler rations did not have any effect on total serum protein, albumin, and total cholesterol levels.