The objective of this study was to evaluate the inclusion of oregano essential oil (OEO) as a phytogenic feed additive in the diet of lambs on the productive performance, ruminal pH, ammoniacal nitrogen production, volatile fatty acids, nitrogen balance, carcass yield, backfat thickness, loin eye (Longissimus dorsi) area, shelf life, and antioxidant activity of the meat. Thirty-nine Suffolk × Hampshire lambs (19 ± 3.7 kg live weight) were used in a completely randomized design with three treatments (n = 13) consisting of 0, 0.02, and 0.04% OEO in the diet. The inclusion of OEO in the diet did not affect (p > 0.05) the productive performance due to the treatments; similarly, no differences (p > 0.05) were observed in the ruminal variables and nitrogen balance. Backfat thickness and loin eye area had similar results (p > 0.05), and the antioxidant activity in meat was improved (p < 0.05) with the inclusion of OEO. Shelf life and crude protein content increased (p < 0.05) with the inclusion of OEO in the diet and with the passing of storage days. Dry matter was affected (p < 0.05) by the storage time, with a decrease observed on day 24. pH, ether extract, and ash were not affected (p > 0.05). It is concluded that the productive performance, ruminal variables, nitrogen balance, loin eye area, backfat thickness, and carcass yield were not affected by the inclusion of OEO. However, crude protein remained stable and antioxidant activity improved, increasing the shelf life of lamb meat.

Choline is an essential nutrient for animals, but dietary choline is degraded in the rumen, and thus, should be offered as rumen-protected choline (RPC) in ruminants. In this article, we investigate the effect of RPC supplementation in feedlot lambs. Forty intact male Saint Croix lambs (average: 20.3 kg, 3–4 months of age) on a high grain-low roughage base feed were randomly assigned to four treatments (0, 0.1, 0.2, and 0.3% RPC on dry-matter basis; n = 10 per group). RPC was offered for 90 days after 15 days of adaptation. RPC supplementation was not associated with significant differences in dry matter intake, weight gain, gain:feed ratio, carcass weights, and the dressing percentages. There was a linear decrease in height to the shoulder (p = 0.013) and longissimus muscle area (p = 0.051) with higher RPC levels, and a higher backfat thickness and yield grade with 0.3% RPC compared to 0.1% RPC (p < 0.05). Blood triglycerides concentrations were higher in control (0% RPC) compared to 0.3% RPC (p = 0.008). The lack of significant effects on growth performance and the results on backfat thickness and yield grade, may indicate undesirable effects associated with RPC supplementation. More research is needed to establish the needs and specific quantities of RPC supplementation in feedlot lambs.

The purpose of this study was to determine how feeding sheep coffee pulp affects carcass characteristics and what changes occur in physicochemical, antioxidant capacity and oxidation of the meat during refrigerated storage. The experiment was carried out in 15 Blackbelly lambs weighing an average 22.86±0.76kg. The animals were assigned to three treatments: T0=control diet, T1=diet with 8% coffee pulp, and T2=diet with 16% coffee pulp. After fattening for 56 days, the sheep were slaughtered and the carcasses assessed. The inclusion of 16% coffee pulp in the diet increased carcass dressing from 48.19 to 50.83% and decreased the amount of fat in rumen and intestines from 3.43 to 2.53% (P

Coffee pulp has been included in ruminant diets; but until now, little has been known about how the addition of ensiled coffee pulp (ECP) affects the growth performance of lambs. This study explores the diet’s antioxidant capacity, tannins, and caffeine concentration and its effect on water intake, growth performance, rumen variables, in vivo digestibility, nitrogen balance, and carcass and meat characteristics of lambs fed ECP. Thirty-six male Pelibuey lambs were distributed randomly to one of three treatments (n = 12): without ECP₀; diet with 10% ECP₁₀, and diet with 20% ECP₂₀. The diets’ antioxidant capacity, tannins, and caffeine concentration were similar (p > 0.05) for all treatments. The diets’ antioxidant compounds and the blood serum’s antioxidant capacity were affected (p < 0.05). Dry matter and water intake, body-weight gain, and feed conversion were not significant (p > 0.05). No differences (p > 0.05) were found in the rumen variables or the nitrogen balance. However, the in vivo digestibility of crude protein was affected (p < 0.05). Carcass and meat quality were not affected (p > 0.05) by the inclusion of ECP, except temperature and redness (a*) at seven days of storage, respectively. Including up to 20% of ECP in the diet of lambs did not affect the growth performance, rumen variables, or nitrogen balance; however, the antioxidant compounds of the diets, the antioxidant capacity in blood serum, and the in vivo digestibility of crude protein were different. There was an increase in the redness (a*) and lower temperature in the Longissimus dorsi muscle, keeping lightness (L*), yellowness (b*), water-holding capacity, and texture at seven storage days.

The effect of duckweed (DW) supplementation was evaluated on dry matter intake (DMI), presence and duration of estrus, percentage of ewes repeating estrus and pregnancy rate, as well as the concentration of progesterone (P4) in multiparous crossbred ewes from Pelibuey, Dorper, and Katahdin breeds, fed with Taiwan grass hay (TWH). Eighteen ewes with 39.7±4 kg mean body weight, kept in individual pens, were randomly assigned to one of the following treatments: T1: TWH, T2: TWH plus 200 g DW, T3: TWH plus 300 g DW. The ewes were synchronized with 40 mg fluorogestone acetate (FGA) and 400 UI equine chorionic gonadotropin (eCG). Data were analyzed as a completely randomized design using the GLM procedure. DW supplementation had no effect on dry matter intake (p>0.05); however, a slight decrease of TWH intake was observed as DW supplementation increased. No differences (p>0.05) were found in the beginning of estrus, percentage of ewes presenting it, its duration, or pregnancy rate. There were no differences (p>0.05) on P4 concentration among treatments, or treatmentxperiod interaction (p>0.05). However the period was significant (p<0.01), since the P4 levels increased as time increased after the removal of the FGA device and eCG application.

Livestock systems can contribute to food security by making use of available resources not suitable for human consumption such as Cucurbita argyrosperma Huber residue (CR). The aim of this pilot study was to evaluate preference and physicochemical characteristics of CR silages and their effect on milk production and milk composition from cows in a dual-purpose system in Campeche, Mexico. Three completely randomized experiments were performed. In experiment 1, physicochemical characteristics of four CR plus hay grass silages were evaluated: CR-77, CR-71, CR-65 and CR-59, containing 77%, 71%, 65% and 59% of CR, with 25%, 30%, 35% and 40% of estimated dry matter (DM), respectively. In experiment 2, silages intake preferences were determined in cattle. In experiment 3, the effect of CR silage or corn silage on milk production and milk composition of grazing cows in a dual-purpose system was evaluated. The results in experiment 1 showed that DM content differed between treatments (p < 0.05), ranging from 27.35% (CR-77) to 41.81% (CR-59) and estimated DM was similar to the actual values. pH and temperature were also different (p < 0.05). pH was different between CR-71 (4.01) and CR-59 (4.43), and temperature between CR-77 (28.87 °C) and CR-65 (29.5 °C). Crude protein (CP) was very low in all silages (<4%), particularly in CR-59 (2.8%) (p < 0.05), and neutral detergent fiber (NDF) was significantly (p < 0.05) higher with CR-65 and CR-59 (average: 79.6%) than CR-77 and CR-71 (average 75.1%). There were no differences in intake preference (experiment 2), milk production (average 3.7 L) or milk composition (average protein: 3.27%, fat: 2.26%, lactose: 5.23%, solids non-fat: 9.17%) (experiment 3) (p > 0.05), but differences in DM intake of silages in experiment 3 were observed (p < 0.05). Even with the limitations of this pilot study, it is feasible to produce silages with CR with a good fermentation process as a feeding alternative for cows in a dual-purpose system in Campeche, Mexico.