Can a blend of integrated feed additives modulate ruminal fermentation patterns and performance of growing lambs? In vitro and in vivo assessments.

Two in vitro and in vivo experiments were accomplished to investigate the impacts of integrated feed additives (IFA, combination of protected fat, lysine, and methionine plus yucca extract, eucalyptus essential oil, and direct-fed microbial) on gas production (GP), ruminal fermentation and degradability parameters and lamb performance, digestibility, and nitrogen balance. In the in vitro experiment, responses of graded doses (0, 25, 50, 75, 100, and 125 g IFA/kg DM) were evaluated. In the in vivo experiment, 15 Barki male lambs (30.43 ± 0.74 kg BW ± SE) were individually allotted in complete randomized design into three treatments (five animal/treatment) as control (basal diet without additive), low dose (50 g/kg DM) and high dose (100 g/kg DM) for 120 days. In vitro results showed that both doses (100 and 125 g/kg DM) quadratically decreased (p < 0.001) GP and ammonia nitrogen (NH-3N) concentration. In vivo experiment revealed that dry matter intake was increased (p = 0.016) with low dose compared to high dose. Inclusion of high dose decreased blood serum glucose concentrations (p > 0.05) and ruminal protozoal populations (p = 0.094) compared with low dose and control diet. Both doses of IFA increased (p < 0.05) serum urea, creatinine, and triglyceride concentrations, while decreased (p < 0.001) ruminal NH3-N concentrations. These results suggested that, although IFA was effective to modify in vitro ruminal fermentation process and feed degradability, such aspects did not improve in vivo performance of growing lambs.

Intake, digestibility, ruminal parameters, and performance in lamb fed with increasing levels of red propolis extract.

The objective of this study was to examine the effect of increasing levels of red propolis extract (RPE) on the intake, digestibility, feeding behavior, rumen parameters, metabolic parameters, and performance of feedlot lambs. Thirty-five uncastrated male Santa Inês lambs with an initial weight of 17.08 ± 2.36 kg were used in a completely randomized design with five treatments (0, 7, 14, 21, or 28 mL RPE/animal/day). The animals were confined for 68 days. Red propolis extract induced a negative quadratic response (P < 0.05) in the intakes of dry matter, organic matter, crude protein, ether extract, neutral detergent fiber, non-fibrous carbohydrates, and metabolizable energy. The apparent digestibility coefficients of dry matter, organic matter, and neutral detergent fiber, as well as the rumen concentration of NH3-N, also responded quadratically (P < 0.05) to RPE. Feeding efficiency increased linearly (P < 0.05) with the inclusion of RPE, whereas rumination efficiency was maximum (P < 0.05) at the RPE level of 16 mL/day. Red propolis extract induced a linear response (P < 0.05) in serum total protein, albumin, creatinine, and gamma-glutamyl transpeptidase. There was a quadratic effect on final body weight and average daily gain with minimum values for inclusion of RPE of 12.89 mL/day and 10.93 mL/day respectively. Feed efficiency rose linearly (P < 0.05) with the increasing concentrations of RPE in the diet. The inclusion of 21 mL RPE/day (8.5 mg total flavonoids/mL) in the diet of feedlot lambs is recommended to reduce the rumen NH3-N production and increase the animals' performance.

The effect of varying levels of purified condensed tannins on performance, blood profile, meat quality and methane emission in male Bapedi sheep fed grass hay and pellet-based diet.

This study determined the effect of purified condensed tannin inclusion levels in a diet on production, haematological indices, blood biochemical components, meat quality and methane emission by yearling indigenous male Bapedi sheep on a grass hay and sheep pellet-based diet in a 28-day trial. The diets contained similar (P > 0.05) nutrients but with different (P < 0.05) purified condensed tannin supplementation levels. A complete randomized design was used. Twenty-four yearling male Bapedi sheep were assigned to four dietary treatments having different purified condensed tannin levels of 0 (GH80P20PCT0), 30 (GH80P20PCT30), 40 (GH80P20PCT40) and 50 (GH80P20PCT50) g/kg DM. A quadratic type of equation was also used to determine condensed tannin supplementation levels for optimal performance and methane emission reduction by sheep. Supplementing diets with purified condensed tannins did not affect (P > 0.05) diet intake, digestibility and live weight gain of male Bapedi sheep. Supplementing diets with purified condensed tannins did not affect (P > 0.05) blood components of male Bapedi sheep. Inclusion of condensed tannins in the diets did not affect (P > 0.05) Bapedi sheep meat pH and sensory attributes. However, supplementing diets with purified condensed tannins decreased (P < 0.05) methane emission by 51 to 60%. A 49.08 g supplementation level with purified condensed tannins per kg DM diet was calculated, with the use of quadratic equations, to result in the lowest methane emission by male Bapedi sheep. The meat of male Bapedi rams on diets containing 30, 40 or 50 g of purified condensed tannins per kg DM contained higher (P < 0.05) antioxidant activities than those from rams fed a diet without purified condensed tannins. These results indicate that purified condensed tannin supplementation levels of 0, 30, 40 or 50 g/kg DM diet had no adverse effects on growth performance, blood profiles and meat sensory attributes of male Bapedi sheep. However, supplementation levels of 30, 40 or 50 g of purified condensed tannins per kg DM diet reduced methane emission by 51 to 60%, and increased sheep meat antioxidant activity values. Supplementing diets with purified condensed tannins has the potential to reduce methane production and emission by sheep. However, long-term studies are recommended to ascertain the present findings.

The inclusion of detoxified castor bean meal in sugarcane silage increases the carcass weight and the content of unsaturated fatty acids in lamb meat.

The aim of this study was to evaluate the performance and meat quality of lambs fed sugarcane silage containing increasing levels of detoxified castor bean meal (DCBM). Twenty-four Santa Inês male sheep were used, with initial body weight of 25.34 ± 2.57 kg, distributed in a completely randomized design with four treatments (0, 70, 140, and 210 g/kg of DCBM in the sugarcane silage). Intake and digestibility of dry matter (DM) and crude protein (CP) were positively influenced (P < 0.05) by the levels of DCBM. There was a linear increase (P < 0.05) on the intake and digestibility of neutral detergent fiber with the inclusion of DCBM. The daily and total gains showed a quadratic effect (P < 0.05) with the inclusion of DCBM, with a maximum point of 241.64 g/d and 18.12 kg at the level of 161.9 g/kg of DCBM. There was a linear increase (P < 0.01) on the hot carcass with the inclusion of DCBM. The inclusion of DCBM did not influence (P > 0.05) the levels of total lipids (2.1%) in lamb meat, but the levels of oleic acid (C18:1 n-6c) and total monounsaturated fatty acids presented a quadratic effect (P < 0.05). It is recommended to include 160 g/kg of detoxified castor bean meal in sugarcane silage.

Sheep production as a Senecio spp. control tool / Ovinocultura, ferramenta de controle de Senecio spp

Since poisoning by Senecio spp. is one of the main causes of cattle death in southern Brazil, control of these plants is a priority for the local livestock production. After the pasture has been mowed, grazing by 16 sheep was efficient for controlling Senecio brasiliensis and Senecio madagascariensis populations in a 5.5-hectare area that had long been severely infested with these species. A total of 28,629 plants among S. brasiliensis (flower-of-souls, 10,122) and S.madagascariensis (fireweed, 18,507) were almost completely eliminated in a two-year period. The number of sheep was kept at 3.0 stock units/ha, but a variable number of cattle were temporarily stocked according to pasture availability. The major sanitary practice applied to the sheep was anthelmintic administration. Liver biopsies taken from sheep and cattle before and after experimental period didn't reveal any change associable with seneciosis. The performance levels of the sheep were comparable to those observed in flocks managed under traditional extensive grazing systems in southern Brazil.

As intoxicações por Senecio spp. estão entre as principais causas de morte de bovinos no sul do Brasil; portanto, o controle dessas plantas é prioridade para a pecuária local. Depois de uma roçada, o pastejo por 16 ovinos controlou, eficientemente, populações de Senecio brasiliensis e Senecio madagascariensis em uma área de 5,5 hectares, a qual havia se mantido, por oito anos consecutivos, severamente, infestada por essas espécies. Um total de 28.629 plantas, entre S. brasiliensis (10.122) e S.madagascariensis (18.507) foi, virtualmente, eliminado em um período de dois anos. O número de ovelhas foi mantido em três unidades /hectare, mas variáveis lotações de bovinos foram associadas com a disponibilidade de forragem. As principais práticas de manejo sanitário aplicadas aos ovinos foram administrações de anti-helmínticos. Biópsias hepáticas, colhidas antes e após o período de estudo, não revelaram qualquer alteração associável com seneciose. Os níveis de desempenho dos ovinos foram comparáveis aos observados em rebanhos manejados em sistemas extensivos tradicionais no sul do Brasil.