O. M. Junqueira

Lysine and methionine + cystine for laying hens during the post-molting phase

One experiment was conducted to evaluate the effect of using different lysine and methionine + cystine levels on body weight recovery, performance, and egg quality of laying hens during the post-molting period. In this trial, 432 Isa Brown layers, with 72 weeks of age, were distributed in 54 cages according to a completely randomized design with six treatments and nine replicates of eight birds each. During the resting period, six diets with different digestible lysine and methionine + cystine levels were used, as follows: 0.48% digestible lysine and 0.43% methionine + cystine; 0.48% digestible lysine and 0.47% methionine + cystine; 0.48% digestible lysine and 0.52% methionine + cystine; 0.56% digestible lysine and 0.50% methionine + cystine; 0.56% digestible lysine and 0.56% methionine + cystine; 0.56% digestible lysine and 0.62% methionine + cystine. Data were submitted to analysis of variance and means were compared at by Tukey’s test at 5% probability level. The different lysine and methionine + cystine levels in the diets fed during the resting period significantly influenced layer performance. The diet containing 0.56% lysine and 0.56% methionine + cystine promoted higher egg weight eggs during the second production cycle.

Effects of mycotoxin adsorbents in aflatoxin B 1 - and fumonisin B 1 -contaminated broiler diet on performance and blood metabolite

The present study examined the effect of aflatoxin (AFB1) and fumonisin (FB1) at the levels of 2 mg kg−1 AFB1 and 100 mg kg−1 FB1 and the efficiency of use of different levels of adsorbent based on sodium and calcium aluminosilicate on growth performance, hematological parameters, and biochemical parameters of broilers. A total of 1,440 Cobb broilers were distributed into the following treatments: positive control (PC) - no mycotoxin and adsorbent (AD); PC+3AD - no mycotoxin, with 3 g kg−1 adsorbent in feed; negative control (NC) - only mycotoxin; NC+1AD - with mycotoxin and 1 g kg−1 adsorbent in feed; NC+2AD - with mycotoxin and 2 g kg−1 adsorbent in feed; and NC+3AD - with mycotoxin and 3 g kg−1 adsorbent in feed. The amounts of AFB1 and FB1 added to NC reduced weight gain (35%) and feed intake (50%) compared with PC; however, inclusion of 2 or 3 g kg−1 adsorbent to NC alleviated such losses. Birds fed NC showed anemia, immunosuppression, and impaired liver function, observed by reduced cholesterol and increased gamma glutamyl-transferase activity compared with PC; values returned to normal levels when 2 or 3 g kg−1 of the adsorbent (as fed) were used. Mycotoxins cause adverse effects on most of the parameters studied, and the use of adsorbent at the levels of 2 and 3 g kg−1 of the adsorbent as fed partially negates the adverse effect of mycotoxicosis.

Silicon in broiler drinking water promotes bone development in broiler chickens

Abstract Skeletal abnormalities, bone deformities and fractures cause significant losses in broiler production during both rearing and processing. Silicon is an essential mineral for bone and connective tissue synthesis and for calcium absorption during the early stages of bone formation. Performance was not affected by the addition of silicon. However, broilers receiving silicon showed a significant increase of phosphorus, zinc, copper, manganese and ash in the tibia. In conclusion, broiler performance was not impaired by adding the tested silicon product to the drinking water. In addition, bone development improved, as demonstrated by higher mineral and ash content. Further studies are required to determine the optimal concentration of silicon, including heat stress simulations, to better understand the effects of silicon on bone development.