Bioelectrical impedance analysis (BIA) is a method based on the different levels of opposition to the flow of an ionic current through the different body tissues. Results are expressed by primary measures of resistance (Rs) and reactance (Xs). From such measures, equations are applied to determine the phase angle (PA) and impedance (Z). Bioimpedance analysis has been indicated as a reliable and precise method to determine the body composition and nutritional status in humans. BIA has recently been adapted to be applied on animal production. Therefore, the aim of this review is to provide an analysis on the potential use of bioelectrical impedance on zootechnical production. Through BIA, correlations among bioelectrical measures and tissue composition of swine, bovine, ovine, bubaline and fish carcasses can be established. In this regard, a growing number of demands were led by more precise and cost-effective methods to evaluate the body composition in the zootechnical sector, in which the analysis of bioelectrical impedance proved to be a promising and minimally invasive technology to replace traditional methods.

This study aimed to evaluate the storage time effects on whole‐plant sorghum silage nutrients fermentation profile, fermentation losses, mycotoxin concentrations and aerobic stability. Sixteen experimental silos (cylindrical bag with 32 cm i.d. and six kg of silage) were used in a completely randomised design to evaluate the following storage times: 45, 90, 180 and 360 days. Storage time linearly increased silage Ammonia‐N, propionic and butyric acid concentrations. In addition, treatments had a quadratic effect on silage pH and concentrations of lactic and acetic acids. Storage time did not affect fermentation losses, dry matter recovery and zearalenone concentration. However, storage time linearly decreased silage dry matter concentration and linearly increased deoxynivalenol silage content. Aflatoxin and fumonisin were not identified in silage samples. Storage time linearly increased silage pH regardless of evaluation period, and temperature, 24 h after aerobic exposure. Thus, the storage time of whole‐plant sorghum silage affects the fermentation profile, has no effect on fermentation losses, increases deoxynivalenol content and reduces silage aerobic stability.

With the aim to evaluate the effects of the use of additives (milk whey and inoculant containing Lactobacillus casei and Lactobacillus acidophillus) in sorghum silage, an experiment was conducted in which the productive parameters, fermentative and the nutritional quality of silage were analyzed. The experimental design was completely randomized, testing different levels of inclusion of whey and live Lactobacillus strains based on forage green matter, constituting the following treatments: 1) Sorghum without inclusion of additives (CON); 2) Sorghum + 5 x 102 cfu/g L. casei and L. acidophillus (LAC); 3) Sorghum 5 x 102 cfu g-1 whey (SL); 4) Sorghum + 5x102 cfu/g-1 L. casei and L. acidophillus and 5x102 cfu/g whey (LAC + SL). When Lactobacillus was included the mixture used was 50 ml of water and 10 grams of Lactobacillus. To measure silage fermentation, pH, dry matter recovery, gas and effluent losses, ammonia nitrogen, buffer power and density were estimated. The addition of whey and Lactobacillus inoculant in sorghum silage did not significantly change the bromatological values of silage when compared to the original material. The inclusion of additives increased (P <0.05) the effluent losses during fermentation. The use of whey presents a viable alternative for producers, as it does not compromise the fermentation and chemical composition of sorghum silage and assists in the reduction of dairy residues in nature.

Use of electrical bioimpedance analysis to evaluate the quality of bovine raw milk

The objective of this study was to, through a meta-analysis of published data, evaluate the effects of dietary supplementation on the performance of beef cattle grazed on Brachiaria pastures during the rearing and finishing phases of growth. Data from 15 Brazilian studies were analyzed, totaling 462 animals given different types and levels of supplementation. Animals were divided into two categories: 319 in the rearing phase, and 143 in the finishing phase. The reviewed studies evaluated the effects of protein, energy, and protein/energy supplementation on animal performance parameters. Daily weight gain and final live weight were analyzed using forest plots. Daily weight gain during the rearing phase was similar across all supplement types used. Animals given supplementation gained an average of 119 g more per day compared to those who received no supplementation. Specifically, protein supplementation resulted in an increase of 28.22 kg. Animals given supplementation of any kind, represented by the subgroups shown in the plots, gained an average of 24.47 kg more compared to the control group.

The experiment evaluated the effects on the chemical composition (fermentation, kinetic parameters, and protein and carbohydrate fractions) of corn silage after various storage durations (45, 90, 180, and 360 days). Experimental mini silos of the corn plants were made and opened after various storage periods. The experimental design was completely randomized with four treatments and four replications per treatment. Variables such as pH, lactic acid and acetic acid showed a quadratic effect, whereas effluent and gas losses increased linearly with prolonged storage. Proteolysis was observed with an increase in storage, resulting in a rise in ammonia-N, soluble N, and non-protein N concentration and reduction in true protein. The soluble carbohydrate fractions were reduced, and digestible and indigestible fibre were increased. For the kinetic degradation parameters of the silages obtained through in vitro gas methodology, the highest fermentation rate occurred in the first 12 hours of incubation, and the highest volume of gas produced within 96 hours was obtained for silages with shorter storage (45 days). The increase in storage resulted in greater losses and lower ruminal degradability in vitro, causing a decrease in protein quality and nutritional value.