Stocking Rate and Supplementation Effects on Performance of Lambs Grazing Triticale and Ryegrass Sward in Uruguay

An experiment was carried out from 9 June to 2 October 1997, using a Lolium multiflorum Lom. (Ryegrass) and X Triticosecale Wittmack (triticale) sward to evaluate the effect of stocking rate (SR; 20, 30 and 40 lambs/ha), and supplementation (S; with or without) on Corriedale lamb performance. SR had a significant effect on: liveweight gain (160, 130 and 90 g/an/d, P\u3c 0.01); greasy fleece weight (2.8, 2.7 and 2.3 kg, P\u3c 0.01); fiber diameter (28, 27, and 26 microns, P\u3c 0.05); rib eye depth (2.4, 2.1 and 2.0 cm, P\u3c 0.05); fat cover (3.2, 2.1 and 1.5 cm, P\u3c 0.01); hot carcass weight (17.7, 15.6 and 13.5 kg/an, P\u3c 0.01); GR (10.5, 6.6 and 4.2 mm, P\u3c 0.01) and boneless leg weight (1.56, 1.42 and 1.24 kg, P\u3c 0.05), for 20, 30 and 40 lambs per ha, respectively. At the highest SR, lambs increased grazing time (59 vs 52%) and biting rate (29 vs 26 bites/lamb/min). The mayor influence of S on lamb performance was found in grazing behavior variables: (grazing time (63 vs 50%, P\u3c 0.01); biting rate (26.8 vs 28.4 bites/lamb/min, P\u3c 0.01)), carcass characteristics: (hot carcass weight (15.3 vs 16.0 kg, P\u3c 0.05); GR (7.9 and 6.3 mm, P\u3c 0.05)) for with and without supplement, respectively. Over the experimental period (115 days), liveweight production and wool production ranged from 358 to 437 kg/ha for 20 and 30 lambs/ha respectively, and wool production from 55 to 93 kg/ha for 20 and 40 lambs/ha respectively. These results show the potential use of mixed ryegrass and triticale swards to produce high quality lamb meat even at high SRs, and the convenience of using supplements only when sward conditions are not sufficient to maintain an adequate lamb performance, particularly when high lamb SRs are used

Lamb Stocking Rate and Supplementation Effects on Mixed Triticale and Ryegrass Swards Characteristics

An experiment was carried out from 9 June to 22 October 1997, using a Lolium multiflorum L. (ryegrass) and Triticosecale Wittmack (triticale) mixed sward grazed by lambs in a rotational grazing system, to determine the effect of stocking rate (SR; 20, 30 and 40 lambs/ha) and supplementation (S; with or without) on herbage production, composition and nutritive value. SR affected significantly before and after grazing herbage mass and sward height, being higher the values of these variables at the lower SR (3232, 2611 and 2345 kg DM ha-1, P \u3c 0.05; 2557, 1761 and 1612 kg DM ha-1, P \u3c 0.01; 17, 11 and 9 cm, P \u3c 0.01 respectively). Increments in SR had an effect on post grazing sward composition, increasing the proportion of ryegrass (32, 36 and 47 %, P\u3c 0.05) and decreasing triticale contribution (68, 64 and 55 %, P\u3c 0.05) for 20, 30 and 40 lambs/ha. The effect of SR on sward nutritive value was not very clear. Before grazing, S affected significantly herbage mass, being higher the values at the supplemented treatments (2787 vs. 2672 kg DM ha-1, P \u3c 0.10). This experiment showed the high potential of forage production and nutritive value of ryegrass and triticale swards for lamb production in the sandy soil region of Uruguay, and the dominant effect of SR, compared to S, on most of the sward variables considered

Influence of Stocking Rate and Grazing System on Lamb Performance of Mixed Oat and Ryegrass Swards in Uruguay

An experiment was conducted at INIA-Tacuarembó Research Station (Uruguay) during 15 June to 4 October 1998, using a Avena Sativa (oat) and Lolium multiflorum (ryegrass) sward to examine the effect of stocking rate (SR; 25 and 35 lambs/ha) and grazing system (GS; strip and 7 days rotational grazing) on sward and lamb performance. SR had a significant effect on lamb performance, being higher the liveweight gain (LWG; 120 vs 98 g/a/d, P \u3c 0.01), hot carcass weight (HCW; 17.7 vs 16.1 kg/a, P \u3c 0.05) and carcass fat cover (GR; 12 vs 8 mm, P \u3c 0.01) of those lambs managed at the lower SR. At the high SR, lambs increased grazing time (405 vs 376 min., P \u3c 0.05). SG did not affect lamb performance, but strip GS reduces lamb grazing time (367 vs 414 min., P \u3c 0.01) and biting rates (22 vs 24 bites/lamb/min., P \u3c 0.01). Post grazing sward height (SH) was highly associated with LWG (LW = - 101,7 + 32.7 SH – 1.49 SH2, R2 = 0.66). This experiment demonstrated that: (a) the productive potential of ryegrass and oat swards to produce high quality lamb meat, (b) the relative low impact of using strip GS to increase lamb performance and (c) the potential use of post grazing SH as a practical tool to predict lamb LWG in this type of swards

A Sheep and Catlle Diet Selection Study on a Fertilized Native Sward in Uruguay

This study was undertaken during winter, spring and summer 1997, located in the basaltic region of Uruguay to evaluate the effects of stocking rate (SR) and N and P fertilizer application on sward characteristics and on sheep and cattle diet selection and grazing behaviour. The treatments applied were: a) control (C; without fertilizer application using a SR of 0.9 stock units (SU)/ha), b) T1 (with N and P fertilizer application using a SR of 0.9 SU/ha), c) T2 (with N and P fertilizer application using a SR of 1.2 SU/ha) and d) T3 (with N and P fertilizer application using a SR of 1.5 SU/ha). In general, compared with C, fertilized treatments resulted in increments in sward surface height (SSH) and sheep bite weight (BW): a) winter (3, 8, 5 and 5 cm., P \u3c 0.01; 79, 142, 139 and 92 mg DM/bite, P \u3c 0.05), b) spring (3, 8, 5 and 6 cm., P \u3c 0.01; 108, 188, 115 and 215 mg DM/bite, P \u3c 0.01), and c) summer (7, 14, 11 and 8 cm., P \u3c 0.01;146, 199, 182 and 131 mg DM/bite, P \u3c 0.05) for C, T1, T2 and T3, respectively. In general, the nutritive value of diet selected by sheep and cattle was higher than that of the pasture on offer, and higher in sheep than in cattle: a) winter (17, 18 and 16% crude protein, CP, P \u3c 0.05; 39, 37 and 41% acid detergent fiber, ADF, P \u3c 0.05), b) spring (11, 14 and 11% CP, P \u3c 0.05; 42, 33 and 37% ADF, P \u3c 0.01), and c) summer (8, 10 and 9% CP, P \u3c 0.05; 50, 40 and 45% ADF, P \u3c 0.01) for pasture on offer, sheep and cattle diets, respectively. This study demonstrated the importance of fertilizing native swards to improve production, structure, nutritive value, and animal carrying capacity and animal performance. It also shows the important role that diet selection plays in determining the nutritive value of the forage eaten by sheep and cattle, and stresses the greater selective ability of sheep over cattle

A Comparative Grazing Study of Sheep and Cattle Diet Selection on Native Pastures in Uruguay

An experiment was carried out during winter, spring and summer 1997, on native pastures of the basaltic region of Uruguay to evaluate the effects of different herbage mass levels (high, medium and low) on sward characteristics and on sheep and cattle diet selection and grazing behaviour. Higher herbage masses resulted in increments in herbage accumulation and sheep bite weight: winter (1880, 1513 and 610 kg DM ha-1, P \u3c 0.01; 199, 148 and 128 mg DM/bite, P \u3c 0.01), and summer (3046, 2175 and 1172 kg DM ha-1, P \u3c 0.01; 214, 175 and 143 mg DM/bite, P \u3c 0.01) for high, medium and low herbage mass levels respectively. The nutritive value of diet selected by sheep and cattle was higher than that of the herbage on offer, and higher in sheep than in cattle: winter (10.2, 15.9 and 12.5% crude protein, CP, P \u3c 0.05; 49.2, 32.4 and 38.1% acid detergent fiber, ADF, P \u3c 0.01, and summer (7.4, 10 and 9.5% CP, P \u3c 0.05; 51.1, 36.8 and 43% ADF, P \u3c 0.01) for herbage on offer, sheep and cattle diets respectively. These contrasting results found in the nutritive value were closely associated with differences in the proportions of the botanical components recorded, particularly the differential contribution of dead material. This experiment quantified the importance of diet selection in determining the nutritive value of the forage eaten by sheep and cattle on the native pastures of the basaltic region of Uruguay and established some relationships between diet selection and grazing management, involving animal selectivity ability differences (sheep versus cattle) and seasonal effects

Lamb Stocking, Grazing System and Supplementation Effects on Triticale and Ryegrass Swards Performance in Uruguay

An experiment was carried out from 3 of July to 22 of October 1998, using a Lolium multiflorum Lom. (ryegrass) and Triticosecale Wittmack (triticale) sward grazed by lambs, to examine the effect of stocking rate (SR; 25 and 35 lambs/ha), grazing system (GS; strip and 7 days rotational grazing) and supplementation (S; with or without) on sward structure, production, composition and nutritive value. SR affected significantly pre and post grazing herbage mass and sward height, being higher at the lower SR (3211 vs 2832 kg DM ha-1, P \u3c 0.01; 2443 vs 1939 kg DM ha-1, P \u3c 0.01; 19 vs 17 cm, P \u3c 0.01 and 10 vs 8 cm, P \u3c 0.01 respectively), increasing, at the high SR, the proportions of the ryegrass green leaf component, particularly in the uppermost layers of the sward canopy. In comparison with 7 days rotational GS, strip GS resulted in higher post grazing herbage mass, sward height and nutritive value (2387 vs 1996 DM ha-1, P \u3c 0.01; 10 vs 9 cm, P \u3c 0.01; 62 vs 67 % NDF, P \u3c 0.01 and 33 vs 37 % ADF, P \u3c 0.01). S increased post grazing herbage mass and sward height (2347 vs 2035 DM ha-1, P \u3c 0.01 and 10 vs 9 cm, P \u3c 0.01). This experiment showed the high forage productive potential and nutritive value of ryegrass and triticale swards for lamb production in the sandy soil region of Uruguay and the dominant effect of SR on swards variables comparing with GS and S

Influência de diferentes estratégias de alimentação na qualidade da carcaça e qualidade da carne de vacas de descarte alimentadas com pastagem

Animal performance, carcass and meat quality characteristics of beef cull cows under different feeding strategies were evaluated. Cows were allotted to one of four direct grazing treatments combining different levels of forage allowance (FA) and supplementation rate (% of live body weight, BW) using rice bran (RB): T1= FA2%+RB0, T2= FA4%+RB0, T3= FA2%+RB0.8% and T4= FA2%+RB1.6%. Cows from T1 presented lower (P<0.05) slaughter weight (SW) than the other three treatments. Additionally, T1 presented lower weight (P<0.05) for rump and loin, striploin, sirloin, inside round and tri-tip, compared to T2, T3 and T4. Intramuscular fat (IMF), pH (48 h), Warner-Bratzler shear force (WBSF; aged for 7 or 21 days), lean colour, saturated fatty acid (SFA), monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) concentrations did not differ among treatments (P>0.05). A strategic use of low RB supplementation rate grazing on an oats forage crop, improves both carcass and meat qualitry traits of cull cows, adding value and promoting healthy meat production for human consumption from grass-based production systems.Se comparó la producción, las características de la canal y la calidad de la carne de vacas de descarte bajodiferentes estrategias de alimentación fueran evaluadas. Las vacas fueron asignadas a uno de cuatro tratamientos que combinaban diferentes niveles de asignación de forraje (AF) y suplementación con afrechillo de arroz (AA), según el peso vivo (% PV): T1 = AF 2 %, T2 = FA 4 %, T3 = AF 2 % + AA 0.8 % y T4 = FA 2 % + AA 1.6 %. Las vacas de T1 presentaron menor (P < 0.05) peso de faena que los restantes tratamientos. A su vez, T1 presentó menor peso (P < 0.05) para el lomo, bife, nalga de adentro y colita de cuadril, en comparación con T2, T3 y T4. La grasa intramuscular, pH (48 h), fuerza de corte WarnerBratzler (con periodos de maduración de 7 o 21 días), color de la carne y concentración de ácidos grasos (AG) saturados (AGS), monoinsaturados (AGM) y poliinsaturados (AGP) no difirieron entre tratamientos (P > 0.05). Sin embargo, se observaron diferencias en el contenido de los ácidos grasos n6 y n3 (P < 0.05). El uso estratégico de un bajo nivel de suplementación de AA en un verdeo de avena mejoró ciertas características de calidad de la canal y la carne de las vacas de descarte.O desempenho animal, as características de carcaça e a qualidade da carne de vacas de corte (refugo) sobdiferentes estratégias de alimentação foram avaliados. As vacas foram distribuídas em um dos quatro tratamentos de pastoreio direto combinando com diferentes níveis de oferta de forragem (FA) e taxa de suplementação (% do peso vivo, PC) usando farelo de arroz (RB): T1 = FA2 % + RB0, T2 = FA 4 % + RB0, T3 = FA 2 % + RB 0.8 % e T4 = FA 2 % + RB 1.6 %. As vacas do T1 apresentaram menor (P < 0.05) peso de abate (PS) do que os outros três tratamentos. Além disso, T1 apresentou menor peso (P < 0.05) para alcatra e lombo, contrafilé, pernil e tripa, em comparação com T2, T3 e T4. A gordura intramuscular (IMF), o pH (48 h), a força de cisalhamento WarnerBratzler (WBSF; envelhecido por 7 ou 21 dias), a cor da carne, a quantidade de ácido graxo saturado (SFA),monoinsaturados (MUFA) e poliinsaturados (PUFA) não diferiram entre os tratamentos (P > 0.05). No entanto, foram encontradas diferenças entre os tratamentos nos teores de ácidos graxos n6e n3 (P < 0.05). O uso estratégico de baixas taxas de suplementação com farelo de arroz em uma cultura forrageira de aveia melhorou algumas características de qualidade da carne e carcaça de vacas de descarte

Influence of different feeding strategies on carcass and meat quality of grassfed cull cows

Animal performance, carcass and meat quality characteristics of beef cull cows under different feeding strategies were evaluated. Cows were allotted to one of four direct grazing treatments combining different levels of forage allowance (FA) and supplementation rate (% of live body weight, BW) using rice bran (RB): T1= FA2%+RB0, T2= FA4%+RB0, T3= FA2%+RB0.8% and T4= FA2%+RB1.6%. Cows from T1 presented lower (P0.05). A strategic use of low RB supplementation rate grazing on an oats forage crop, improves both carcass and meat qualitry traits of cull cows, adding value and promoting healthy meat production for human consumption from grass-based production systems.info:eu-repo/semantics/publishedVersio

Research to develop nutritional and genetic strategies that optimize the fatty acid content and profile of Uruguayan beef. Review.

Health concerns of consumers are becoming one of the most relevant predictors of food purchases. Thus, differentiation of the meat offered through its nutritional quality plays a key role to improve market competitiveness. This article presents: (1) the nutritional importance of lipids in beef and their relevance for the consumer, (2) scientific information on the characterization of the fatty acid composition of Uruguayan beef, and the factors that affect its composition, and (3) areas where more scientific information is needed to reinforce strategies to improve the nutritional quality of beef. The main production system in Uruguay is based on grazing which results in beef with lower levels of fat and higher levels of n-3 fatty acids and conjugated linoleic acid. Nonetheless, other production systems involving diet supplementation, are also part of a market diversification strategy. More information is needed to evaluate the impact of our forage diversity (native and improved pastures), the duration of supplemental feeding and the type of supplement on the fatty acid composition of beef. The potential for genetic progress through traditional selection and genomics or marker-assisted selection on the fatty acid composition of beef also needs further attention to develop effective strategies that capitalize on the nutritional value of Uruguayan beef