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In vivo and carcass measurements were evaluated to predict carcass physical and chemical composition and to list the measurements that best fit the prediction of the composition of growing Santa Inês sheep carcasses. Thirty-three animals were used to measure the loin eye area by ultrasound in vivo (LEAu) and in the carcass. We used 39 animals for biometric measurement in vivo and 42 sheep for morphometric measurement in the carcass. For the physical and chemical compositions of carcasses, dissection of the half left carcass was carried out in 42 animals. The data were submitted to Pearson’s correlation analysis and t test. Simple and multiple linear regressions were performed using a stepwise procedure. All correlations between in vivo measurements and the physical and chemical compositions of carcasses (in kg) were significant, except for LEAu. Biometric measurements and hot (HCW) and cold (CCW) carcass weights were considered as predictors of the carcasses’ physical and chemical compositions. Slaughter body weight (SBW) was the variable that most influenced the equations in the assessment of in vivo measurements and HCW and CCW most influenced the equations for measurements on carcasses. Biometric measurements of Santa Inês sheep can be used together with the SBW to estimate the physical and chemical compositions of carcasses, with emphasis on body compactness index, breast width, wither height, and croup height. The morphometric measurements can be used together with carcass weight to estimate the physical and chemical compositions of carcasses, with emphasis on croup width, carcass compactness index, croup perimeter, external and internal carcass lengths, chest width, and leg length and perimeter. The HCW can be used to predict the physical and chemical composition of carcasses without affecting the accuracy of the prediction model.

Based on low 18:0 contents observed in milk fat of cows fed cactus cladodes (CC), we hypothesized that including Opuntia stricta cladodes in a soybean oil (SO)‐supplemented diet would promote incomplete rumen biohydrogenation of supplemental PUFA, leading to increased trans‐11 18:1 and cis‐9, trans‐11 CLA contents in milk. Twelve Holstein cows were used in a two‐period study: (a) Baseline: all cows received a total mixed ration (TMR) composed of sorghum silage (SS) and a concentrate containing no SO for 14 days; (b) Treatment: cows received one of the following SO‐supplemented diets for 21 days: (1) SS‐TMR: a TMR composed of SS and a SO‐enriched concentrate, (2) CC‐TMR: a TMR containing CC as a partial substitute for SS plus the SO‐enriched concentrate, and (3) CC‐PMR: same diet as in treatment 2, but CC were mixed with the SO‐enriched concentrate and fed as a partial mixed ration (PMR). Both CC diets increased relative abundances of trans‐11 18:1, cis‐9, trans‐11 CLA, and 18:2 n‐6 in milk fat, whereas opposite effects were observed on 18:0 and cis‐9 18:1. Proportion of 18:2 n‐6 increased, and cis‐9, trans‐11 CLA tended to increase with CC‐PMR as compared to CC‐TMR, whereas 18:3 n‐3 was higher with CC‐PMR than with SS‐TMR. Proportions of several odd‐ and branched‐chain fatty acids, certain 18:1 isomers, and trans‐9, cis‐11 CLA changed with CC diets, notably with CC‐PMR. Milk yield and intake of most nutrients (except fibre) increased or tended to increase with the CC diets, whereas gross milk composition was unaltered. Stearoyl‐CoA desaturase‐1 index for C18 (SCD18) was higher with CC‐PMR than with SS‐TMR, and milk n‐6:n‐3 FA ratio and apparent transfer of 18:2 n‐6 to milk increased with CC diets. These results indicate that Opuntia stricta cladodes can be a valuable feed ingredient for improving the nutraceutical value of milk fat.

Crude glycerin is a byproduct of the biodiesel industry and has been widely used in ruminant diets as a source of energy, usually in place of corn, primarily during periods of drought in tropical regions. The objective of this study was to evaluate the effect of including levels of the crude glycerin of low purity (0, 6, 12 and 18%) replacing corn in the diets of goats on the carcass characteristics, tissue composition, meat cuts yield and physicochemical parameters of meat. Forty males castrated without defi ned racial pattern goats an initial average weight of 19.70 ± 2.30 kg were slaughtered after 86 days. Diets content 0 and 6% crude glycerin promoted similar responses to the analyzed variables, except for pH and breast weight. No differences were observed to total digestible nutrients, slaughter body weight, commercial cut yield leg tissue composition and physicochemical parameters of meat. Crude glycerin can be included up to 12% without losses on carcass weight and meat cuts, leg composition, and meat quality. The inclusion of crude glycerin containing 63.06% glycerol and 45.57% lipids could be effective in partial replacement of corn in diets for confi ned goats in tropical areas.