Óxido de cromo e n-alcanos na estimativa do consumo de forragem de vacas em lactação em condições de pastejo

Morenz, Mirton José Frota; Silva, José Fernando Coelho da; Aroeira, Luiz Januário Magalhães; Deresz, F.; Vásquez, Hernán; Paciullo, Domingos Sávio Campos; Lopes, Fernando César Ferraz; Elyas, Ana Cristina Wyllie; Detmann, Edênio

doi:10.1590/s1516-35982006000500036

Cited by 12 publications

(11 citation statements)

References 23 publications

(40 reference statements)

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“…This result resembles those obtained with forage plants of tropical grassland environments (Carvalho et al 2005, Morenz et al 2006, Flores et al 2011, for the period of spring and summer. The DWG of heifers did not change (p>0.05) with the mineral mix provided (Table 3), but was influenced by season, with higher values in spring and summer (0.52 kg/ UA) than in winter (0.25 kg/UA).…”

Section: Resultssupporting

confidence: 88%

Performance of dairy heifers raised on Xaraés palissadgrass (Brachiaria brizantha cv. Xaraés) pasture supplemented with two types of mineral mixture

et al. 2014

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The effects of selective (e.g. mineral supplement formulated on the basis of nutritional and clinical examination of the herd) or commercial mineral supplementation of crossbred dairy heifers (Holstein-Mantiqueira), on daily weight gain (DWG), body condition score (BCS), age at first mating (AFM) and the intake of mineral mixture (IMM) managed on Xaraés palissadgrass pasture (Brachiaria brizantha cv. Xaraés) were evaluated from February 2006 to March 2008. Structural characteristics, forage allowance and nutritional value of Xaraés palissadgrass were also evaluated. The structural variables of pasture, allowances and nutritive value of forage, besides the DWG were only affected (p<0.05) by season, with highest results for spring and summer. Throughout the experimental period (730 days), no sign of mineral deficiency was detected in heifers that ingested the selective supplement. The DWG and AFM were not influenced by the mineral mixture offered (0.52 and 0.33 kg/day during the spring/summer and in fall/winter for DWG, respectively, and 813 days of AFM). The IMM was higher for commercial mineral mixture than for selective (61.6 and 51.0g/day respectively). The BCS was slightly higher for selective (3.17) than for the commercial (3.02) mineral mixture. Thus, the selective mineral supplement was a strategy to prevent mineral deficiency in this herd and resulted in similar performance at lower costs (e.g. due to less IMM) of crossbred heifers when compared with the commercial mineral supplementation.INDEX TERMS: Palissadgrass, Brachiaria brizantha cv. Xaraés, dairy heifers, forage allowance, selective mineral supplementation, mineral mixture intake.

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Section: Resultssupporting

confidence: 88%

Performance of dairy heifers raised on Xaraés palissadgrass (Brachiaria brizantha cv. Xaraés) pasture supplemented with two types of mineral mixture

et al. 2014

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“…Other comparisons of markers, mainly Cr v. n-alkanes, were performed at grazing, only allowing a relative comparison of different methods. In most of these grazing studies, as in our experiment, pasture intake was greater when estimated using Cr 2 O 3 than using n-alkanes (15% to 19%; Piasentier et al, 1995;Malossini et al, 1996;Morenz et al, 2006). However, the opposite result has also been observed (212% for Cr 2 O 3 v. n-alkanes; Dove et al, 2000).…”

Section: Discussionsupporting

confidence: 43%

“…No previous comparison of Yb and n-alkanes was made. By comparing Cr and n-alkanes on grazing dairy cows, Malossini et al (1996) and Morenz et al (2006) observed greater within-day and between-day variability in the faecal concentration of Cr than of n-alkanes. Ferreira et al (2004), however, found no effect of faecal sampling time on intake estimated from both n-alkanes and Cr.…”

Section: Discussionmentioning

confidence: 93%

“…This is, however, the only means of determining the accuracy of a method because of the precise measurement of actual intake, a good estimation of the composition of the selected food and the possible total faecal collection enabling the determination of faecal marker recovery. Although marker comparisons have already been conducted on dairy cows at pasture (Malossini et al, 1996;Morenz et al, 2006), no comparative studies on dairy cows have been conducted indoors. The ability of the n-alkanes technique, alone or combined with the 13 C technique, to estimate pasture and maize silage proportions when maize silage intake is unknown has been tested by García et al (2000).…”

Section: Introductionmentioning

confidence: 99%

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N-alkanes v. ytterbium/faecal index as two methods for estimating herbage intake of dairy cows fed on diets differing in the herbage : maize silage ratio and feeding level

Pérez-Ramírez

Peyraud

Delagarde

2012

Animal

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The aim of this study was to compare the n-alkanes and the ytterbium (Yb)/faecal index techniques as two methods for estimating the herbage intake of dairy cows fed indoors on different herbage : supplement ratios and feeding levels. The supplement was a mixture of maize silage and soyabean meal (ratio of 87 : 13 on a dry matter (DM) basis). In all, four treatments were studied. The herbage : supplement ratio in the diet was 25 : 75, 50 : 50, 75 : 25 and 50 : 50 for treatments 1, 2, 3 and 4, respectively. Animals were offered for treatments 1, 2 and 3, 100% of ad libitum intake measured before the experiment and 70% of ad libitum intake for treatment 4. Cows were fed herbage in the morning and supplement in the evening. A total of six lactating Holstein dairy cows were used in a 4 3 4 Latin square with four 14-day periods. Herbage and supplement intakes, faecal output (FO), in vivo organic matter (OM) digestibility and faecal recovery of markers were measured on the last 5 days of each period. Intake was estimated with the two methods and from two faecal sampling techniques, that is, total faecal collection v. grab sampling during milking. Mean herbage intake as fed, or estimated from n-alkanes or from the Yb/faecal index was 7.7, 8.1 and 10.2 kg DM, respectively. The mean prediction error, expressed as a fraction of actual herbage intake, was 0.10 and 0.50 for the n-alkanes and Yb/faecal index methods, respectively. The n-alkanes method clearly showed much better accuracy than the Yb/faecal index method for estimating intake, irrespective of the faecal sampling method, herbage : silage proportion or feeding level. For the nalkanes method, herbage intake was slightly overestimated (7%) when herbage proportion in the diet was high, due to a ratio of faecal C 33 : C 32 recovery .1. The high bias for the Yb/faecal index was due to the cumulative effect of overestimation of FO (mean recovery of Yb 5 0.92) and underestimation of the diet indigestible fraction (28%). Between-treatment variations of FO were on average well estimated by Yb. Between-treatment variations of OM digestibility estimated using the faecal index technique were lower than those observed in vivo. It is concluded that intake of grazing dairy cows receiving high levels of maize silage supplement should be estimated using the n-alkanes method.

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“…A utilização de óxido de cromo como marcador externo para estimativas de consumo de forragem com herbívoros em pastejo é uma técnica amplamente difundida e possui vantagens como o baixo custo, a relativa simplicidade dos procedimentos analíticos (MORENZ et al, 2006) e a fácil obtenção do marcador.…”

Section: Introductionunclassified

Consumo de forragem por cordeiras suplementadas em pastagem de milheto

Camargo¹,

Rocha²,

Kozloski³

et al. 2008

Cienc. Rural

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III RESUMOEste trabalho foi conduzido para avaliar a influência de níveis de suplemento (0,0; 0,5; 1,0 INTRODUÇÃOO rebanho de ovinos do Rio Grande do Sul é o maior do país, com aproximadamente quatro milhões de cabeças, cerca de 23,53% do rebanho brasileiro (ANUALPEC, 2006). Esse rebanho está distribuído em grande número de propriedades rurais do Estado, sendo que o sistema criatório é feito de forma extensiva. Durante o ano, a maior parte do rebanho permanece em pastagem nativa, com restrita disponibilidade de área, o que limita o desempenho de categorias nutricionalmente exigentes.A pastagem de milheto (Pennisetum americanum (L.) Leeke), no verão, é uma alternativa para o uso da pastagem nativa. Essa espécie produz até cinco vezes mais forragem que o campo nativo (RIZO et al., 2004) e permite incrementar o ganho de peso vivo por área e a taxa de lotação. Em pastejo, o valor bromatológico do milheto varia no decorrer do seu ciclo e o valor dos ganhos de peso realizados pelos animais não se mantém constante (SANTOS et al., 2005). Nessas condições, a suplementação pode ser

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Óxido de cromo e n-alcanos na estimativa do consumo de forragem de vacas em lactação em condições de pastejo

Cited by 12 publications

References 23 publications

Performance of dairy heifers raised on Xaraés palissadgrass (Brachiaria brizantha cv. Xaraés) pasture supplemented with two types of mineral mixture

Performance of dairy heifers raised on Xaraés palissadgrass (Brachiaria brizantha cv. Xaraés) pasture supplemented with two types of mineral mixture

N-alkanes v. ytterbium/faecal index as two methods for estimating herbage intake of dairy cows fed on diets differing in the herbage : maize silage ratio and feeding level

Consumo de forragem por cordeiras suplementadas em pastagem de milheto

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