Dimitri Moreira de Freitas

Respostas de frangos de corte a aumentos graduais na relação entre treonina e lisina

An experiment was carried out with the objective of evaluating the effects of graded increases in the ratios between digestible threonine (Thr) and lysine (Lys) in the diet on broilers from 15 to 37 days old. The increases on Thr levels were obtained with higher amounts of soybean meal (SBM) or L-threonine (L-Thr) in the diets. One thousand and two hundred Ross x Ross 308 male chicks were placed in a factorial arrangement with the three ratios between Thr and Lys (63.5, 66.0 and 68.5%) and the two sources of Thr previously cited. Each of the six treatments had eight replicates of twenty five birds. The diets were formulated to attain minimum requirement levels of other nutrients and energy. There were no effects of the Thr level on live performance responses, water intake, litter dry matter, foot pad dermatitis, carcass and processing yields. In addition, there were no effects of the source of Thr on body weight, feed intake, litter dry matter, foot pad dermatitis, carcass, breast tenders, thighs and drumsticks yields. However, feed conversion was better (P=0.009) and water intake was higher (P=0.011) when the increase on Thr was originated by SBM, whereas breast meat yield was higher (P=0.035) with diets supplemented with L-Thr. An interaction between level and source of Thr was identified for weight gain and feed conversion demonstrating improvement when birds were fed 68.5% Thr to Lys ratio I

Responses of fast and slow growth broilers fed all vegetable diets with variable ideal protein profiles

One thousand eight hundred and ninety male broilers of two strain crosses (fast and slow initial growth) were fed different ideal protein profiles in four-phase feed programs: 1 to 7, 8 to 21, 22 to 34 and 35 to 40 days of age. All vegetable, corn-soybean meal feeds were formulated to maintain the Met+Cys:Lys and Thr:Lys relationships at 75 and 65%, respectively, on true digestible basis. Three ideal protein profiles were used: low, medium and high. From 1 to 21 days of age, half of the birds fed low and high diets were changed to high and low diets, respectively. Birds on the medium diet were kept on the same diet until the end of the study. A 3 × 2 (ideal protein profile x strain cross) factorial design was used for the period from 1 to 21 days and a 5 × 2 design thereafter. Carcass and commercial cuts were performed at 34 and 40 days of age to determine corresponding live weight and carcass yields. In general, the fast strain growth was superior in comparison to the low one when live performance and carcass and commercial cuts were evaluated. Live performance was positively affected by the increases in the dietary protein profiles; however, processing yield parameters could not be related with the dietary parameters. The low diets, which have similar protein contents to those used in some integrations, were shown to produce poor responses and, therefore are not recommended for broilers from 1 to 40 days of age. Alternating low and high ideal protein profiles at 21 days could result in similar feed conversions, and therefore, can lead to production cost reduction.

Studies with sanguinarine like alkaloids as feed additive in broiler diets

This research included two studies evaluating the live performance of broilers fed Sangrovit ® (minimum of 1.5% sanguinarine, a quaternary benzo[c]phenanthridine alkaloid extracted from Macleaya cordata). Both studies were conducted using Ross 308 female broiler chicks. Birds were fed corn-soybean meal all-vegetable diets without growth promoters with 5 treatments and 8 replications in each study. In the first study, treatments were composed of a Negative Control without feed additive and four diets with graded increases of Sangrovit of 12.5, 25, 37.5, and 50 ppm. In the second study, chicks received a similar diet from placement to 21 days of age and subsequently were given feeds with graded reductions in crude protein (CP) as follow: a Negative Control with 19.7% CP without sanguinarine, and then 19.7, 19.2, 18.8 and 18.3% CP supplemented with Sangrovit at 20 ppm. It was demonstrated that body weight was increased when birds were fed 50 ppm of Sangrovit at 21 d when compared to the Negative Control. Also comparatively to the Negative Control, cumulative feed conversion was improved for birds fed with Sangrovit at 37.5 ppm as well as feed intake from placement to 7 days at 12.5 ppm. No differences were observed in feed intake. Birds supplemented with Sangrovit and 18.8% CP had similar body weight gain and feed intake as the Negative Control with 19.7% CP. Mortality in both studies was not correlated with the treatments. Results from both studies indicate benefits of the supplementation of Sangrovit in diets for broilers.

Respostas de frangos de corte fêmeas de duas linhagens a dietas com diferentes perfis protéicos ideais

This study was conducted with the objective of evaluating the performance of two broiler strain crosses fed diets having 3 different ideal protein profiles. One day old Cobb x Cobb 500 and Ross x Ross 308 broiler chicks were in a feeding program of 4 phases from 1 to 7, 7 to 21, 21 to 31 and 31 to 37 days of age and having high (H), medium (M) and low (L) ideal protein profiles. At 21 days of age, half of the replications fed H and L protein diets changed to L and H, respectively, whereas those receiving M remained all the way to the end in the same protein level. The experimental design was completely randomized in a factorial arrangement having 3 ideal protein levels and 2 strain crosses until 21 days of age and 5 ideal protein levels and 2 strains from 21 to 37 days old was used. Cobb broilers had higher body weight at 21 days of age and better feed conversion until the end of the experiment, whereas Ross broilers showed higher feed intake during all the experimental period. At processing, Ross broilers had higher breast meat yield at 31 days old, but Cobb broilers had higher yield of leg quarters both at 31 and 37 days. At 21 days, H and M diets presented similar live performance; however, both were superior when compared to L diets. Differences in body weigh at 31 and 37 days due to feeding programs were not apparent; however birds fed L diets in both periods had poorer feed conversion and higher feed intake than all the other treatments. The only processing difference due to feeding program was an increased proportion of abdominal fat when birds were fed L diets in one of the two periods. It was possible to conclude that Cobb broilers had better feed conversion independently of the feeding program used and that the M ideal protein levels were adequate to support maximum live performance and carcass yields.

Water intake and digestive metabolism of broilers fed all-vegetable diets containing acidulated soybean soapstock

A study was conducted to compare live performance and digestive metabolism of broiler chickens fed all-vegetable diets (All-Veg) compared to a regular diet including animal by-products. Three feeds were formulated and provided to broilers according to the feeding program: pre-starter from 1 to 10 days, starter from 11 to 21 days, and grower from 21 to 35 days. All feeds had corn and soybean meal as major ingredients; however, two of them were all-vegetable diets having either Degummed Soybean Oil (DSO) or Acidulated Soybean Soapstock (ASS) as fat sources. The third diet included poultry by-product and poultry fat. A total number of 360 day-old broiler chicks were allocated to 1m2 battery cages, 10 chicks in each, and 12 replicates per treatment. Live performance was similar between groups of birds receiving the different diets with the exception of weight gain, which was increased for birds fed the All-Veg diet with ASS. Birds fed All-Veg diets had increased water intake and produced more excreta with a concurrent reduced feed metabolizability at both ages, regardless of fat source. Metabolizable Energy was not different for the three diets.

Desempenho de frangos de corte sob suplementação com ácidos lático, fórmico, acético e fosfórico no alimento ou na água

This study was carried out to evaluate the effect of the supplementation of organic acids in the diets and ortho-phosphoric acid in the drinking water on broiler performance. A total of 2,112 broiler chicks was allotted to six treatments, each one with eight replications. The diets, all vegetable, were composed by corn-soybean meal without antibiotic growth promoters or anticoccidials. A control diet did not have organic acids, whereas the other treatments had supplementation of organic acid blends as follow for the feeding phases from 1 to 7, 8 to 21, and 22 to 35 days of age: blend A: lactic acid (52%), formic (1%) and acetic (2%); blend B: lactic acid (76%), formic (2%) and acetic (4%); blend C: lactic acid (50%), formic (8%) and acetic (7%); blend D: formic acid (85%). Blend E contained 40% of lactic acid, 5% of acetic acid and 5% of ortho-phosphoric and was added to drink water. The added doses in diets, for phase, were: 8.0, 4.5, and 2.5 kg/t for blends A, B and C and 2.5, 2.5, and 2.0 kg/t for blend D. Blend E was used in drink water in doses of 3.0, 2.0, and 1.0 kg/1,000 L. A completely randomized design was used. There was a general benefit of the supplementation of the organic acid blend on weight gain of birds. However, no difference was observed for feed conversion at the end of the study. Feed intake was lower for birds fed blend B, whereas water intake was reduced by the blend E added to the drinking water. Relative weight of small intestines sections at 7 days of age was smaller in the birds on the control diet, while at the 21 days of age, was smaller in the birds supplemented with blends A and C. The blend E used in the water determined a reduction in the jejunum length at 7 days of age, while blend B had negative effects on the ileum and small intestine lengths at 21 days of age. In comparison to the control diet, without supplementation of growth promoters antibiotics, the diets supplemented with organic acids were efficient in improving the weight gain of broilers.

Técnicas de pulverização e imersão com distintos desinfetantes sobre ovos incubáveis

Two experiments were conducted with the objective of evaluating different active compounds and methods of egg disinfection. In the first experiment, disinfection was done through spray whereas in the second it was done using immersion. Disinfections were performed at breeder house immediately after laying. In both experiments there were five treatments using the following disinfection solutions for each method: synthetic phenol (1040ppm), chlorexidine digluconate (200ppm), quaternary ammonium (800ppm), quaternary ammonium (400ppm) + urea (600ppm), quaternary ammonium (130ppm) + glutaraldehyde (370ppm). In both experiments there were a control treatment without disinfection and another using disinfection using fumigation with formaldehyde (7.7gm-3). After the disinfection procedures, forty eggs per treatment were evaluated for presence of total mesophiles, mould and yeast, total coliforms, Pseudomonas sp and Aspergillus sp. Embryo diagnosis was driven in no hatched eggs, for determination of embryo mortality period, interior contamination, and it was determined the birth of inappropriate chicks for rear and hatchability. In the experiment in that eggs were disinfected by pulverization, the association between ammonia and glutaraldehyde presented higher contamination for total mesophiles in relation to other treatments, with exception of synthetic phenol treatment, which presented similar contamination to all. Differences were not detected among treatments for mold and yeast, total coliforms, Pseudomonas sp and Aspergillus sp, and for embryo diagnosis results. In experiment in that eggs were disinfected through immersion, higher contamination was verified to total mesophiles in eggs no disinfected in relation to disinfected with the different active components. Eggs without disinfection also presented larger contamination for total coliforms in relation to ammonia and urea treatment, being similar to all other treatments. The analysis of mold and yeast contamination, Pseudomonas sp and Aspergillus sp showed similar results among treatments. Eggs disinfected with formaldehyde had higher embryo mortality, in the period from 4 to 7 days, in relation to those disinfected with quaternary ammonia, being other treatments similar to all. In general, the studied disinfectants presented action capacity in the reduction of microbial contamination of incubated eggs. All disinfectants also demonstrated to be safe to survival of the embryos, without great restrictions.

Live performance and processing yields of broilers fed diets with tiamulin and salinomycin combinations

A study was conducted with the objective of evaluating the combined application of tiamulin (TIA) and salinomycin (SAL) in broiler diets fed from 1 to 42 d of age. One thousand and two hundred Cobb x Cobb 500 male broilers were housed in 48 floor pens and fed corn-soybean meal diets containing 66 ppm of SAL combined or not with TIA at 30 or 20 and 20 or 15 ppm, respectively, in the starter (1-21 d) and grower feeds (22-42 d); however, TIA was withdrawn from the feeds 7 days before slaughter. The experimental design was completely randomized with 3 treatments and 16 replicates of 25 birds each. Broilers were weekly evaluated for live performance whereas carcass yield, abdominal fat and commercial cuts were assessed at 42 d using 6 birds randomly taken from each pen. Results obtained at the end of the study demonstrated that body weight gain was not affected (P > 0.05) by the treatments, whereas feed intake was reduced (P 0.05) by the treatments. Live performance and post-slaughter yields data obtained in this study did not indicate that combinations of TIA with SAL could be detrimental. In fact, an improvement in feed conversion was observed at the lowest dose of TIA.