Efeito de diferentes níveis de proteína bruta na ração sobre o desempenho e as características de carcaça de cordeiros terminados em creep feeding

Abstract

RESUMO -O experimento foi realizado com os objetivos de avaliar o efeito dos níveis de proteína bruta (15, 20 e 25%) na ração concentrada sobre o desempenho e as características de carcaça de cordeiros Suffolk alimentados em creep feeding e analisar economicamente esse sistema de produção. Foram utilizados 15 cordeiros inteiros, nascidos de partos simples, alimentados ad libitum com as rações experimentais duas vezes ao dia. Estimaram-se o consumo de médio diário de ração, pelo cálculo da quantidade fornecida e das sobras; o ganho de peso, pela pesagem dos animais a cada 14 dias; o peso vivo ao abate (PVA) dos cordeiros em jejum (16 horas); e o rendimento de carcaça quente, após abate e evisceração. O ganho médio diário foi influenciado pelos níveis de proteína, quando considerada a idade de abate como covariável. Não houve efeito significativo dos níveis de proteína sobre as características de carcaça. No sistema de alimentação e terminação de cordeiros Suffolk em creep feeding, a ração deve ser balanceada com 25% de proteína bruta, uma vez que esse nível proporcionou maior ganho de peso médio diário e não alterou as características de carcaça.Palavras chave: comedouro seletivo, idade de abate, ganho diário, ovinos Effects of Feeding Different Crude Protein Levels on Production and Carcass Traits of Suffolk Lambs in Creep FeedingABSTRACT -This trial was carried out to evaluate the effects of different concentrate crude protein levels (15, 20 or 25%) on production and carcass traits of Suffolk lambs in creep feeding. An economical analysis of the production system was also performed. Fifteen single birth lambs fed ad libitum twice a day were used in this study. The average daily intake was measured by subtracting the orts from the amount of feed offered to the animals. Lambs were weighed every fourteen days to determine body weight gain. To measure slaughter body weight (SW) animals were fasted for 16 h and then weighted. After evisceration both hot carcass weight and yield were obtained. To determine cold carcass yield and cooling losses, carcasses were placed in a refrigerator at 5°C for 24 hours and weighted again. The different concentrate crude protein levels affected the daily weight gain only when the slaughter age was used as the covariable. Conversely, crude protein levels did not significantly change carcass traits in the present trial. It can be concluded that the concentrate with 25% of crude protein is recommended to Suffolk lambs in creep feeding because of the higher daily weight gain and maintenance of carcass traits.Key Words: creep feeding, daily weight gain, sheep, slaughter age IntroduçãoOs cordeiros, desde que atendidas suas exigências nutricionais, constituem a categoria ovina que apresenta maior eficiência para ganho de peso e qualidade de carcaça nos primeiros meses de vida. Portanto, é necessário o correto manejo nutricional logo nos primeiros dias de vida, destacando-se a utilização do creep feeding, que consiste na suplementação dos animais com alimento concentrado em local inacessí-ve...

Performance and carcass characteristics of lambs fed on diets supplemented with glycerin from biodiesel production

“…Nevertheless, the results of Ortiz et al (2005) concerned with the total fat value of 2.52% remain higher than those found in this study, which varied from 1.70 to 1.92%. This effect might have occurred due to possible changes related to the proportion of volatile fatty acids, which may possibly alter fat deposition on the carcass and possibly the meat fatty acid profile (Abo El-Nor, 2010).…”

“…Crude protein levels were considered high, when compared with those found by Ortiz et al (2005), 19.66%. Nevertheless, the results of Ortiz et al (2005) concerned with the total fat value of 2.52% remain higher than those found in this study, which varied from 1.70 to 1.92%.…”

Fatty acid profile and lambs’ meat quality fed with different levels of crude glycerin replacing corn

“…Moisture content was 69.9 g 100 g -1 which is below the findings of Zeola et al (2004), who found 75.6 g 100 g -1 , but close to the findings of Barros et al (2015), who also evaluated increasing levels of crude glycerin on diet and found values ranging from 67.7 to 72.2 g 100 g -1 . The total lipids and crude protein levels averaged 3.47 and 20.05 g kg -1 , respectively (Table 3) and are close to the values obtained by Ortiz et al (2005), being consistent with good quality meat, and considered acceptable in the literature. According to Osório and Osório (2003), the high total lipids can negatively affect meat product, once consumers have certain restrictions on the ruminants fat, mainly sheep, due to the high levels of saturated fatty acids.…”

Influence of pre and postnatal energy restriction on the productive performance of ewes and lambs

“…However, this gain was similar to that observed by Carvalho et al (1999), for ¾ Texel lambs (0.316 kg/day) and lower than that reported DM -dry matter; n: number of animals; R 2 -coefficient of determination; CV -coefficient of variation; ADMP -average daily milk production. by Ortiz et al (2005), who worked with increasing levels of creep feeding and reported average gains of 410 g/day. Lambs nursed by ewes from the 2.4 Mcal ME/kg DM group showed a daily gain difference of 160 g in relation to lambs from the severe restriction group and of 70 g in relation to the moderate restriction group.…”