Top PDF MEAT QUALITY FROM CHAROLAIS BULLS FED DIETS WITH DIFFERENT LEVELS OF CORN SILAGE INCLUSION

A sample of 6 intensive beef farms was selected according to the feeding plan adopted during the fattening period of Charolais bulls. Two farms did not include any corn silage in the diet (CS0), while corn silage represented 22% of the dietary DM in the second group of 2 farms (CS22), and it raised up to 44% of the dietary DM in the last 2 farms (CS44). Five bulls were randomly selected from each farm to be slaughtered in the same abattoir. Bulls age was similar across treatments but the CS44 bulls had a lower carcass weight (396 kg) than the other two treatments (436 and 446 kg for CS0 and CS22, respectively). Carcass fleshiness (SEUROP) and fatness scores were not affected by the level of corn silage in the diet. Meat quality was evaluated on a joint sample of the m. Longissimus thoracis, excised from the 5 th to the 9 th rib of each right half carcass 24 h post-mortem, after an ageing period of 10 d vacuum packaged at 4°C. Meat chemical analysis showed no variations in pH, DM, intramuscular fat and protein content due to the different silage inclusion in the diet. Only the cholesterol content was progressively reduced in the meat of bulls fed increasing quantities of corn silage according to a significant negative linear trend. Meat colour, cooking losses and shear force values were not affected by the diet. Therefore, based on these findings there are no substantial arguments against the use of a large amount of corn silage in the fattening diets of Charolais bulls.

Despite the greater fat thickness on carcass of animals fed corn silage diet, this degree of finishing was not able to influence water loss during carcass cooling, inasmuch as there were no differences (P>0.05) among groups. Smaller losses were observed by Silva et al. (2008), who gave sugar cane based diets for confined bovines and found average losses of 1.91% during carcass cooling, with fat cover of 2.64 mm, whereas Fernandes et al. (2007) and Brondani et al. (2006) obtained averages of 2.11 and 2.40 mm for fat thickness on the carcass. However, those results are considered to be low for market requirement for carcass quality. According to Costa et al. (2002), fat thickness required by Brazilian meat plants is from 3 to 6 mm, because at proportions inferior to 3 mm, there is a darkening of the outer part of muscles which covers the carcass, decreasing its commercial value. Probably, in order to fit subcutaneous fat thickness required by Brazilian meat plants it is necessary to use diets with greater levels of concentrate.

ABSTRACT - The objectives of this study were to evaluate the effect of forages with different nutritional values — specifically, corn silage (CS), sugar cane (SC), and sugar cane bagasse (SB) — in diets with crude glycerin, on carcass traits, meat quality, and fatty acid profile, using young Nellore bulls finished in the feedlot. Thirty young Nellore bulls with an initial average body weight of 416.70±24.74 kg were randomly assigned to three treatments containing different sources of forage. The carcass traits and variables related to meat quality of the Nellore young bulls were not significantly influenced by different sources of forage in diets with crude glycerin. The yellow color index was significantly greater in the fat of animals fed corn silage. Heptadecenoic fatty acid was significantly lower in the meat of animals fed sugar cane bagasse. The sources of forage in diets with crude glycerin did not influence the profile of saturated, monounsaturated, or polyunsaturated fatty acids in the longissimus muscle. Overall, our results indicate that none of the treatments changed the carcass and meat quality traits of Nellore young bulls finished in the feedlot. Thus, sugar cane and sugar cane bagasse could be used in feedlot as a viable forage alternative to corn silage.

Considering the period of 28-83 days, when only the control diet did not include WGCS, it was observed that feed conversion ratio (FCR) was worse (p<0.05) for the groups that receive silage from 28 days (T2) or 42 days (T3). However, feeding birds with WGCS only during the grower (28 to 42 days) or the finisher (63 to 83 days of age) periods did not impair performance. Similar results were obtained by Sartori et al. (2002), who observed worse FCR (P<0.05) in birds fed WGCS as compared to those fed dry corn. This is in disagreement with Carrijo et al. (2000), who found better FCR for the WGCS diet as compared to the dry corn diet. Hunt et al. (1997) worked with WGCS inclusion levels of up to 40%, on dry matter basis, in broiler and turkey feeds, and found better FCR with the WGCS diets, with the best results obtained with 8 and 16% inclusion levels.

Final body weight and average daily gain were similar (P>0.05) between the bulls fed with 5 or 12% glycerin level in their diets but were higher (P<0.08) when compared to bulls that were fed no glycerin in their diets (Table 2). It has been reported that the inclusion of glycerin in Angus steer finishing diets resulted in improving the ADG by 11.4% when glycerin replaced 10% of the dry-rolled corn, but the ADG improved only 2.5% when glycerin replaced 10% of the dry-rolled corn in the diets that also contained 30% distillers’ dried grains and 15% soy hulls (Pyatt et al. 2007). Parsons et al. (2009) observed that the ADG increased by 12.6, 8.4 and 5.0% for the heifers that were fed 2, 4 and 8% glycerin, respectively, but at 12 and 16% glycerin, the ADG was reduced by 1.7 and 13.4%, respectively. However, Mach et al. (2009) did not observe glycerin level effects on ADG for Holstein bulls finished in feed-lot and fed with 4, 8 or 12% glycerin levels in their diets. These results provided evidence that glycerin could be used as an energetic ingredient that could be effectively substitute for corn in the diets of finishing bulls. The present study indicated that some potentially negative glycerin components such as salt (4.76%) and methanol (0.33%) might not exert detrimental effects on the growth of the animal when glycerin was included in the diets of bulls.

Mean percentages of the myristic (14:0) and palmitic (16:0) saturated fatty acids in steers were respectively 2.14 and 25.96%. Prado et al. (2008b) reported similar rates in crossbred bulls finished in feedlot and fed on corn silage (50%) and concentrate (50%). The two abovementioned fatty acids are hypercholesterolemic factors and cause an increase in low density lipoprotein (LDL), which provokes coronary diseases. Stearic acid (18:0) participates at an average of 18% of fatty acids in the Longissimus muscle of steers. Corn cutting height and inoculants in ensilage did not alter (P>0.05) the acid participation in steers with regard to different diets. Stearic acid is a saturated fatty acid with an 18 carbon atom chain without double links. Although saturated fat of steer beef may contribute significantly to a rise in cholesterol rates in humans (Bessa, 1999), stearic- rich fats do not have such characteristics, since they are classified as neutral fatty acids without the harmful effects to the heart as other saturated fatty ones.

The ingredients in the diets (Table 2) were weighed by hand, mixed and offered to the animals as a complete diet supplied twice a day, at 7h00 and 16h00, at an amount sufficient to supply at least 10% of the of- fered as refusals. The proportion of ingredients in diet dry matter was kept constant by weekly monitoring forages dry matter content with a Koster-type dehydration appa- ratus (Koster Crop Tester, Strongsville, OH, USA). Corn gluten meal was utilized in the sugarcane treatment to raise dietary protein to a similar content to those found in diets containing corn silage, while keeping protein quality as similar as possible, since the same amount of protein from soybean meal, and from blood and meat-and- bone meals, was maintained. The corn hybrid utilized ground in the concentrates was not identified, but as the same concentrate mix was utilized in all treatments, the effect of the texture of the corn in the concentrate was not a factor of variation in the results.

ABSTRACT. This trial aimed to evaluate the inclusion of 10% of crude glycerin associated with roughage sources on the quality of meat aged for 1, 7 or 14 days post mortem of Nellore young bulls. Thirty feedlot animals (n = 10) with initial body weight of 416.70 ± 24.74 kg and 18 months of age were assigned to three treatments: corn silage (CS), sugar cane (SC) and sugar cane bagasse (CB), using a completely randomized design. After 85 days of feeding, animals were slaughtered with 554.51 ± 38.51 kg. Samples of longissimus muscle were collected, after carcass chilling, and vacuum-packed. Diets influenced pH, meat color and subcutaneous fat (SF) (p > 0.05). Animals fed CS showed higher values of b* in SF (p < 0.05). Differences were not found in the meat fatty acid profile (p > 0.05). Aging times influenced pH and shear force of beef (p < 0.05). Beef aged for 14 days showed higher pH (5.90) and lower shear force (2.40 kgf). Diets containing 10% crude glycerin in the DM associated with CS, SC or CB had no effect on the fatty acid profile in beef. The aging process for 14 days reduces shear force, improving meat quality.

Several studies have shown that meat fatty acid profile can be significantly influenced by feedstuff used in animal diets (Pereira & Vicente, 2013). So, feeding animals with high percentages of concentrate such as feedlot diets is a possibility to modify meat fatty acid profile by decreasing biohydrogenation, which is responsible for the saturation of dietary fatty acids consumed by ruminant (Harfoot & Hazlewood, 1988). The inclusion of concentrate in the diets has high potential to manipulate the process of ruminal biohydrogenation, by inhibition of lipolysis (Doreau & Ferlay, 1994; Latham et al., 1972). Nevertheless, the unstable prices of grains have been leading researches to search for alternatives feedstuff to feed animals. Among them, crude glycerin, a byproduct from biodiesel agroindustry, has been used to replace corn in ruminant diets up to 10% of diet DM (Mach et al., 2009). Moreover, glycerin can be used as a gluconeogenic substrate to ruminants, due to the rumen wall absorption and conversion to glucose in the liver (Remond et al., 1993), or fermentation to propionate in the rumen, a gluconeogenic precursor that increases blood glucose levels after absorption in cattle (Chung et al., 2007). Thus, it was expected that a glucose supply would increase in animals fed with glycerin, which could increase lipogenesis in intramuscular fat (Smith & Crouse, 1984).

Carcass and parts traits determine the purchase decision of chicken meat consumers. Neither sunflower meal nor exogenous enzymes had any effect on carcass traits in this trial. These results are in agreement with reports from other authors, who also did not find any effects of sunflower meal or exogenous enzymes on carcass traits (Tavernari et al, 2008; Mushtaq et al., 2009). In the work of Seleh et al. (2005), the addition of cellulase to a broiler diet based on corn and soybean meal significantly reduced abdominal fat. The authors concluded that cellulase affected fat metabolism in an unknown way. However, some studies suggest that enzyme supplementation may improve carcass yield (Omojola & Adesehinwa, 2007). The use of NSPase in diets with a high sunflower meal inclusion levels Table 3 – Effects of different dietary inclusion levels of

During the finishing phase, bovines deposit large amounts of subcutaneous and visceral fats resulting in production inefficiencies affecting, in particular, meat quality. Intramuscular fat composition of ruminant meats influences the quality of the final product, which explains the importance of assessing meat fatty acid profile using different breeds and feeding strategies. On the other hand, both genetic background and finishing system may alter fat deposition, indicating their influence on adipogenic and lipogenic factors. Nevertheless, the molecular mechanisms underlying fat deposition and fatty acid composition in beef cattle are not fully understood. The present study aimed to assess the effect of breed and diet on carcass composition, the cellularity of two fat depots (subcutaneous and mesenteric adipose tissues) and their implications on the fatty acid profile and the expression levels of adipogenic and lipogenic key factors and enzymes. Forty bulls from two genetically diverse Portuguese bovine breeds, Alentejana and Barrosã, were selected. The animals were fed isoenergetic and isonitrogenous diets, which were either low or high in silage percentage, until 18 months of age. Under these experimental conditions, it was shown that the genetic background is a major determinant of carcass composition and meat quality, and that the dietary differences studied had a limited effect on carcass composition. Data revealed that the subcutaneous adipose tissue has larger adipocytes than the mesenteric adipose tissue. Overall, the results showed that the fat depots’ fatty acid composition is mostly dependent on the genetic background. Dietary silage level impacted on muscle lipid metabolism to a greater extent than on that of subcutaneous adipose tissue, as evaluated by levels of gene expression of adipogenic and lipogenic factors. Moreover, hepatic desaturation and elongation of polyunsaturated fatty acids was shown to be influenced by diet composition, possibly through the expression of genes encoding for enzymes associated with desaturation/elongation pathways. In sum, these findings highlight the importance of taking into account the genetic background while devising feeding strategies to manipulate the fatty acid composition of beef cattle tissues.

values were obtained, respectively, with the inclusion levels of 40.05, 51.95, and 49.58% FSM. Regarding color, better results were found for mortadella made with meat from animals fed 25% FSM rather than the control diet. In relation to the attributes taste and overall acceptance, animals fed diets containing 25 and 50% FSM produced mortadella with better acceptance. However, the inclusion of 75% FSM in the diet may have contributed to the presence of off- flavor in mortadella, resulting in lower acceptance. According to Howe et al. (2002), the use of fish residues in pig feed may cause negative effects on the sensory characteristics of the meat; however, in the present study, adding this ingredient did not have any effect on processed pig meat.

Plant Material. Mature leaves of Moringa oleifera (Moringa) were collected during the month of March 2015 from a crop located in the town of “La Campana”, Culiacán, Sinaloa, Mexico (25° 0’ 57’’ N, 107° 35’ 17’’W, at 120 meters above sea level). Material plant was washed with a solution of 150 ppm of sodium hypochlorite, for its later drying in an electric oven at 55-60 °C during 6 to 8 h until a constant weight to determine its moisture. Finally, it was smashed through a fine mill to obtain a homogenous particle size Moringa leaf flour. White corn (Maize) and soybean (Soya) intended for human and animal food paste was purchased in a local marketing company. Before developing the experimental diets, broken, damaged by insects, and immature grains were pulled out from the white corn, as well as of impurities. It was subsequently processed with a Thomas-Wiley mill (model 4, Thomas Scientific, Swedesboro, NJ, USA) with two mm mesh. The nutrient content and energy were analyzed according to the recommendations of The Official Methods of the Official Analytical Chemists Association (AOAC, 2000): moisture (method 934.01), fat (EE, method 920.39), protein (CP, method 960.52), dietary fiber (DF, method 985.29), crude fiber (CF, 978.10 method), ashes (method 942.05) and total carbohydrate (TC) were determined by the method of difference of [100 - (CP + EE + Moisture + ash)] in

Enzyme levels did not affect the calcium: phos- phorus ratio in bones and plasma, with mean ratios of 2:1 and 1.70:1, respectively. The bone Ca:P ratio, bones be- ing the place with the highest concentration of this min- eral, is around 2:1 (Lopes, 1998). However, the recom- mended ratio for swine diets is based on the physiology of the animal itself, and is around 1.5:1, and corresponds to values found in sow milk (Peo Jr. et al., 1991). How- ever, this experiment utilized ratios of 0.7:1.0 based on total phosphorus and 2.26:1 based on available phospho- rus. When the work is based upon available phosphorus, this ratio can range on 2:1 and 3:1 (Qian et al., 1996 and NRC, 1998). Qian et al. (1996) studied the effects of in- creasing levels of calcium and phosphorus ratio (1.2:1, 1.6:1 and 2.0:1) on weanling pigs, by using two micro- bial phytase levels (700 and 1,050 PU), and did not ob- serve effects on bone deposition; however, for DWG, DFI and FC they observed a negative linear effect, showing that phytase is more efficient when the Ca:P ratio is smaller. The total Ca:P ratio in feeds containing soybean bran can vary from 1:1 to 1.25:1 (NRC, 1998). The ratio can be less critical if excess phosphorus occurs (Prince et al., 1984, Hall et al., 1991). However, excess calcium in the diets reduces organic phosphorus bioavailability (Jongbloed et al., 1993).

Ammonium production peak was obtained 2.74 hours after giving the diet, when it was inferior to the one obtained at 3.8 hours as reported by Pina et al. (2011). Although some average values observed for ammonium production at 0 and 6 hours are low, they were superior to the ones proposed by Detmann et al. (2009), which 8 mg/100 mL of N-NH 3 would be sufficient for promoting maximal rates of microbial growth. Rumen pH was not influenced (P>0.05) by experimental diets and it presented quadratic behavior in function of collection time, with minimal value estimated at 5.99 hours after diet supply (Figure 2). The pH ranged from 6.47 to 7.00, evidencing that the inclusion of 1% of concentrate at the basis of body weight was not able to reach critical levels of pH to affect rumen fermentation. Considered as an important factor that affects rate and extension of digestion of fiber in the rumen, pH should be above 6.0 to enable greater use of forage by the ruminant (Hoover, 1986). These rumen pH values are within the ideal range for action of cellulosic bacteria in the rumen (Russel & Wilson, 1996). The influence of urea on rumen pH was reported by Carmo et al. (2001), who, in a work with sugar cane containing soybean meal, corn gluten and associations with urea as nitrogen sources, noted that the presence of urea in the diets increased rumen Figure 1 - Rumen N-NH 3 concentrations at various sample

After dressing and evisceration, the head (section in atlanto-occipital joint) and legs (section in carpal and tarsal-metatarsal joints) were removed, later recording the hot carcass weight (HCW), and the pH and the internal temperature of the carcass (0 hours post mortem), in the semimembranosus muscle were measured. The gastrointestinal tract (GIT), bladder (B) and gallbladder (GB) were emptied and washed to obtain the empty body weight (EBW), which was estimated by subtracting the weights referring to the content of the GTI, B and GB from the weight at slaughter (WS), in order to determine the biological or true yield [BY = (HCW/EBW) × 100].

Alternative protein foods, such as the fish flour has been studied with the objective to reduce the cost of the rations (Oliveira et al., 1997; Refstie et al., 1999; Booth et al., 2001; Siddhuraju and Becker, 2001, Meurer et al., 2003). However, one of the problems found for the use of this material is the lack of information of the values of digestibility of its nutrients (Mukhopadhyay and Ray, 1997). The protein sources of vegetable are cheaper than those of animal origin, but have to amino acid balance inappropriate for the application of fish (El-Dahhar and El-Shazly, 1993), besides the presence of non-starch polysaccharides that can influence in a negative way in the performance of the same (Meurer and Hayashi, 2003). However, the Nile tilapia may, from the stage of fingerling, to use of vegetable protein sources, as the single source of protein, without problems related to performance (Boscolo et al., 2001; Meurer, 2002). The dried yeast spray (LS) a material produced for the sugar alcohol, composed of cells of yeast (Saccharomyces sp.) Obtained from the fermentation broth of sugar cane in the production of alcohol (Scapinello, et al., 1996; Furuya, et al., 2000), for the process of drying spray-dryer. It has its chemical composition highly variable depending on the method of production, washing and drying (Scapinello et al., 1997; Furuya, et al., 2000). However, about 20 to 30% of total nitrogen can come from non-protein nitrogen, such as nucleic acids (Butolo, 1997), can be a source of super-estimate of the protein (Meurer et al., 2000). The dried yeast (Saccharomyces cerevisiae), in addition to a high protein level, has a high quality protein for your balance in amino acids (Ghiraldini and Rossell, 1997) even though levels of vitamins A and C are reduced, they are rich in the B complex vitamins (Butolo, 1997), stands out the levels of thiamine, reboflavine, niacin and acid pantotenic.

The mammary gland of the ruminants cannot convert C16:0 into C18:0 through elongation of the carbonated chain; however, the mammary cells present strong activity of the delta-9-desaturase enzyme that converts the stearic acid (C18:0) into oleic acid (C18:1). However, most part of the fatty acids from the de novo lipogenesis are saturated (C4:0 to C16:0), once the mammary delta-9- desaturase enzyme presents weak activity on the fatty acids with less than 18 carbon atoms (Grummer, 1991, Chilliard et al., 2001b). According to Hartman (1993), the stearic acid (C18:0) is not related to the cholesterol increase. When ingested, it is metabolized into oleic acid (C18:1). The lauric (C12:0), miristic (C14:0), palmitic (C16:0) acids and the trans fatty acids have been epidemiologically associated to the cardiovascular diseases, once they induce to increases on the blood cholesterol, the reason why researches have been aimed at the decrease on the percentile of these Oliver (1997) and Lima et al. (2000), mentioned several studies that associated the acids to cardiovascular diseases and observed, for instance, that the intervention group presenting the polyunsaturated/saturated ratio of 1:1, compared with the control group, which diet presented the polyunsaturated/saturated ratio of 0.4:1, presented very lower coronary disease incidence. The monounsaturated fatty acids (MUFAs), for example the oleic acid, do not influence the cholesterol levels; however, there are evidences that the elaidic acid (C18:1), which results from the hydrogenation process of vegetal oils, could induce to hypercholesterolemia (Lima et al., 2000).

Furthermore, other factors may contribute to increasing efficiency of lysine utilization for optimizing the production performance and meat deposition. Among them, it can be highlighted the metabolizable energy content and electrolyte balance of diets, sanitation status, temperature and environmental conditions, breed, sex and age of the birds (Campestrini et al., 2010; Meza et al., 2015). Thus, the short period of adjustment of lysine levels without maintaining the relationship with the other amino acids, combined with the maturity of the chickens that are usually slaughtered at younger ages, may also have contributed to the lack of effect on performance and carcass yield of the chickens. In this study, it was observed that only the strain, regardless of digestible lysine level adopted, contributed to influence the performance data and carcass characteristics.

complexes (Ravindran & Bryden, 1997) that may affect dietary protein digestibility. Therefore, the hydrolysis of the phosphorus-protein bond by phytase enhances amino acid digestion and absorption (Ravindran & Bryden, 1997). Camden et al. (2001) reported apparent N retention in broilers increased with the addition of phytase to diets containing reduced AvP and Ca levels. However, the findings of the present study do not agree with those studies, as dietary phytase addition did not have a positive effect on nitrogen retention. Silva et al. (2008) and Ibrahim et al. (1999) also did not obtain any improvements in N utilization in starter broilers supplemented with phytase.