Nutritional values and chemical composition of tropical pastures as potential sources of α-tocopherol and condensed tannin

Corrêa

et al. 2022

Preprint

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Tropical erect grass pastures have high forage production potential in subtropical and tropical regions of the world. However, in this kind of pasture, the body weight gain of weaned lambs is usually below of their potential. We determined the effect of pasture height of an erect tropical grass, consequently its structure, on intake and performance of young lambs. The experiment was repeated in two years. Thirty young weaned lambs (4-5 months) were assigned, each year, to three Panicum maximum pasture heights: 1) Tall-75 cm; 2) Medium-50 cm and 3) Short-25 cm. Herbage mass, pasture height, plant morphological composition, pasture nutritional quality, lamb’s average daily gain, gain per hectare and herbage intake were measured. The experiment was installed in a completely randomized design, evaluated in two periods each year. The Short treatment presented, on average and for longer, the highest leaf:stem ratio (1.3 ± 0.23) and average daily gain (91 ± 10 g/day) in relation to the Medium and Tall treatments (68 ± 10 and 40 ± 13 g, respectively). There was a significant interaction between treatment*period for herbage intake. The Tall treatment showed a marked decrease in intake from the first to the second period. The pasture height management interferes in the speed at which the number of stems increases of a tropical erect grass, in relation to leaves. For a better performance of weaned young lambs during summer-autumn period, it is important to manage tropical erect grass pastures at lower height than is generally recommended, lower than 25 cm.

Section: Discussionsupporting

confidence: 77%

Section: Introductionmentioning

confidence: 99%

Pasture Height of A Tropical Erect Grass Affecting Young Lamb Herbage Intake And Performance

Irigoyen

Corrêa

et al. 2022

Preprint

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“…The decrease in quality with advancing stage of pasture maturity is well documented when analyzing the entire forage structure [36, 41–44]. Our data show that CP content did not change over time and energy values, represented by the TDN, but varied according to the sward.…”

Section: Discussionsupporting

confidence: 68%

Influence of tropical pastures on grazing behavior parameters of young lambs

Hampel

et al. 2020

Preprint

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Tropical sward characteristics can alter lamb ingestive behavior. Our study evaluated the ingestive behavior of young lambs in different tropical pastures to identify which variables interfere in their grazing activity. Two years of study were carried out with 54 weaned lambs distributed in three different swards: 1) monoculture of a upright grass, guinea grass (Panicum maximum; GG); 2) monoculture of a shrubby legume pigeon pea (Cajanus cajan; PP) and 3) contiguous areas with half the paddock with GG and half with PP (GP). The experiment was set out in a randomized complete block design. Lamb ingestive behavior was observed from sunrise to sunset with records every 5 minutes. To identify the main variables that affected with the lamb grazing activity, a multivariate analysis of the Decision Tree was performed. Our results showed that there was no difference in the ingestive behavior parameters of young lambs in different swards (P > 0.05). There was interaction among the swards and the experimental periods for the variables idleness time and biting rate (P ≤ 0.05). Grazing time of the animals increased 40% with experimental period progression. The Decision Tree identified leaf:stem ratio as the variable that most influenced lamb grazing time in GG and GP swards while in the PP sward grazing time was directly related to the pasture height. The behavior of young lambs on tropical pasture is variable as there is a change in the behavioral response over time. In addition, the grazing time of these animals can be estimated by means of variables related to pasture structural characteristics (leaf:stem ratio and height) together with chemical variables.

“…There is interest by the industry to reduce the oxidative processes in meat, which can be accomplished by feeding diets rich in antioxidants, as pasture (Wood et al, 2008;Realini et al, 2004). Previous experiments in our lab (Tontini et al, 2019) show that tropical grass and legume forages have considerable concentration of alpha-tocopherol, and tropical legumes can also have appreciable amount of condensed tannins (CT).…”

Section: Introductionmentioning

confidence: 99%

Tropical grass and legume pastures may alter lamb meat physical and chemical characteristics

Hampel

Joy

et al. 2021

Trop Anim Health Prod

The present study assessed the influence of the type of the tropical pastures on lamb body weight (BW) gain and meat quality. Fifty-four lambs were allocated to three grazing pastures: (1) AG -Aruana grass (Panicum maximum cv. IZ-5); (2) PPpigeon pea legume (Cajanus cajan cv. Anão); and (3) CS -contiguous swards, half of the paddock with AG and half with PP. After 92 days of grazing, the lambs were slaughtered. Carcasses were evaluated and the longissimus muscle was collected to determine color, lipid profile, tocopherol concentrations, and lipid oxidation. Although the pastures present differences in the characteristics of nutritional quality, the animals did not show difference in BW gain. The results show that all forage presented similar concentration of alpha-tocopherol (137 ± 14.37 mg kg −1 of fresh matter), whereas total and condensed tannin contents were greater in PP, intermediate in CS, and the lowest in AG treatment (P = 0.0001). Meat α-tocopherol content was similar among treatments (P = 0.1392), with an average concentration close to the optimal level to reduce the meat oxidation. Meat from AG treatment had 45 and 25% lower n-6/n-3 ratio than meat from PP and CS treatments, respectively. The legume increases the unsaturated fatty acids and the grass can reduce the n6/n3 ratio. The level of condensed tannin concentration did show to have important effect on meat characteristics. Both tropical pastures studied can provide a high amount of alpha-tocopherol, generating a great potential to increase the concentration of this antioxidant in lamb's meat.