An experiment was conduced with the objective of evaluating the effects of diet formulation methods and supplementation of ractopamine (RAC) on the performance and carcass characteristics of finishing barrows. Sixty commercial hybrid swines were used, distributed in a randomized experimental block design, in a 2 x 3 factorial arrangment, with two levels of RAC and three methods of diet formulation. Supplementation with RAC improved the final weight, daily weight gain (DWG) and feed conversion (FC) of the finishing barrows. Addition […]

The objective of this study was to investigate the flow and absorption of amino acids (AA) in steers fed diets supplemented with different protein sources. Twenty-one Holstein steers averaging eight months of age and 187 kg of body weight were used. Animals were fitted with abomasal caanulas and fed diets with a forage to concentrate ratio of 40:60. The experimental diets contained Rhodes grass hay, corn, molasses, minerals, and one of the following protein sources: cottonseed meal, yeast, or urea. […]

This experiment was conduced to determine the level of CP with amino acid supplementation in diets to gilts under high environmental temperature in finishing phase. Thirty-five crossbreed gilts (Landrace x Large White) with an average initial weight of 60.3 kg were allotted in a randomized experimental design with five diets (17.3, 16, 14.7, 13.4, and 12.1% CP) seven replications and one animal by experimental unity. The experimental diets were supplied ad libitum until the end of the experiment when the […]

The present experiment was conducted to evaluate the effect of the different levels of soybean oil on endogenous losses, apparent and true ileal digestibility of amino acids in growing pigs diets. Four isoprotein corn and soybean meal based diets meeting the nutritional requirements for this phase, supplemented with crescent levels of soybean oil, (0.0, 1.5, 3.0, and 4.5) were evaluated. Chromic oxide (0.25%) was added to serve as digestibility marker. Sixteen cannulated pigs (simple T-cannula), with weight of 48.0 ± […]

The effect of increasing dietary digestible lysine levels, based on the ideal protein concept, on performance and carcass characteristics of forty barrows with high genetic potential for lean gain averaging initial and final body weights of 30.02 ± 1.38 kg and 60.44 ± 1.81 kg, respectively, was evaluated in this experiment. The animals were assigned to a randomized blocks design, with four treatments, five replicates and two animals per experimental unit. The treatments consisted of a basal diet (18.08% of […]

Forty barrows with high genetic potential for lean gain in the carcass averaging initial and final body weights of 60.43 ± 1.56 kg and 96.66 ± 3.22 kg, respectively, were used to evaluate the effect of dietary digestible lysine levels based on the ideal protein concept, on performance and carcasss characteristics. The animals were assigned to a randomized blocks design, with four treatments, five replicates and two animals per experimental unit. The treatments consisted of a basal diet formulated to […]

Seventy commercial hybrid barrows with high genetic potential for lean deposition in the carcass averaging initial and final body weight of 60.0 ± 1.34 kg and 95.0 ± 0.97 kg, respectively, were used to evaluate the effects of dietary digestible tryptophan levels on performance and carcass characteristics. The experiment was analyzed as a randomized experimental block design with five treatments (0.128, 0.136, 0.144, 0.152, and 0.160%) of digestible tryptophan, that is correspondent to the digestible tryptophan:lysine ratios of 16, 17, 18, […]

The effect of different methionine + cystine (Met+Cis):total lysine (Lis) ratios on performance and egg quality for semi-heavily laying hens was evaluated. One hundred and twenty Lohmann Brown hens with 44 weeks old were allotted to a completely randomized design with with five replicates and four treatments, as follows: T1= 0.76 Met+Cys:total Lys ratio or 0.70% of Met+Cys and 0.92% of total Lys; T2 = 0.83 Met+Cys: total Lis ratio or 0.71% of Met+Cys and 0.85% of total Lys; T3 […]

A trial was conducted to evaluate the effect of reduced CP, amino acid-supplemented diets on performance of castrated males swines on high environmental temperature (32ºC). A total of sixty crossbred piglets (Landrace x Large White) averaging initial weight of 15.2 kg was allotted to completely randomized experimental design with five treatments (18, 17, 16, 15, and 14% of CP), six replications and two animals per experimental unit. The experimental diets were fed to swine ad libitum until the end of […]

Fourty barrows with high genetic potential for lean gain averaging initial and final body weights of 15.76 + 0.93 kg and 30.23 + 1.56 kg, respectively, were used to evaluate the effect of digestible lysine levels, using the ideal protein concept, on the performance and carcass composition. The treatments were composed of a basal diet containing 19.46% crude protein and 3,280 kcal of ME/kg, that were supplemented with different levels of HCl-L-Lysine, resulting in diets with 0.90, 1.00, 1,10, and […]