Grãos de girassol ou gordura protegida em dietas com alto concentrado e ganho compensatório de cordeiros em confinamento

Abstract

RESUMO -Avaliaram-se os efeitos de três dietas e dois regimes alimentares sobre o desempenho e as características de carcaça de cordeiros em confinamento. Trinta e seis cordeiros com peso inicial de 18,7 ± 2,4 kg foram distribuídos em delineamento inteiramente casualizado em esquema fatorial 3 × 2 e receberam dietas sem inclusão de lipídio e com inclusão de grãos de girassol ou gordura protegida. Seis cordeiros de cada dieta foram submetidos a restrição alimentar e posterior ganho compensatório, enquanto a outra metade foi alimentada à vontade por todo o período de confinamento. Foram avaliados o consumo de matéria seca, o ganho de peso e a conversão alimentar, os níveis de ureia e colesterol sanguíneos, as características Sunflower grains or protected fat in high concentrate diets and compensatory gain for feedlot lambsABSTRACT -The effects of three diets and two feeding managements were assessed on feedlot lamb performance and carcass. Thirty six lambs with initial 18.7 ± 2.4 kg weight were distributed in a randomized complete block design in a 3 × 2 factorial arrangement and were fed a free-lipid diet, and a sunflower grains-added diet or a protected fat-added diet. Six lambs on each diet were submitted to feeding restriction management and later compensatory gain, while the other half was fed ad libitum throughout the feedlot period. Dry matter intake, weight gain and feed conversion ratio, urea and blood cholesterol, carcass characteristics and slaughter by-products were evaluated. During realimentation period the intake of lambs that underwent feeding restriction did not differ from the freely-fed animals. It was not affected by the diet but at the end of this period, the accumulated intake was 11.8% smaller for those lambs previously submitted to feeding restriction. Feed intake to slaughter weight was not influenced by the feeding management. In the restriction period, the blood cholesterol levels were 24% higher than those without restriction, but there was no difference during the realimentation period. The lipids in the diets increased the cholesterol blood levels in both the restriction and realimentation periods and reduced urea blood levels during the realimentation period. The performance, evaluated at slaughter weight, was damaged by the restriction management. There were no effects of feeding management or diet on the carcass parameters. Lipid sources increased the total fat proportion and decreased the gastrointestinal tract content. The feeding management with restriction damages weight gain and feed conversion ratio in lambs up to slaughter.

Carcaças e componentes não-carcaça de cordeiros terminados em pasto de azevém recebendo suplementação concentrada

“…Foi observada correlação positiva entre a gordura de cobertura da carcaça e gordura mesentérica (r=0,77; P<0,05). No caso da gordura perirenal, a resposta à suplementação não foi obtida, contrariando parcialmente a literatura, que frequentemente relata respostas positivas (GARCIA et al, 2003;HOMEM JR. et al, 2010).…”

Performance, nutrient digestibility, and quantitative carcass traits of lambs fed sunflower seeds and vitamin E

“…At the onset of the experiment, lambs were identified, dewormed, vaccinated against clostridioses, and distributed at random into the following treatments: C = sugarcane + concentrate; CS = sugarcane + concentrate with sunflower seeds; CE = sugarcane + concentrate with 1,000 mg vitamin E kg -1 diet dry matter (DM); and CSE = sugarcane + concentrate with sunflower seeds and 1,000 mg vitamin E kg -1 diet DM. The amount of 1,000 mg vitamin E (α-tocopherol acetate) was used per kg of diet DM, because, according to a study conducted by Lopez-Bote et al (2001), this was the amount of vitamin that provided the best result.…”

Fontes de gordura protegida para novilhas Nelore a pasto

“…Além disso, os suplementos lipídicos, também denominados gorduras protegidas, têm sido desenvolvidas com o intuito de aumentar a concentração energética das dietas, exercendo mínima interferência na fermentação ruminal. Esses lipídios protegidos são degradados no rúmen em pequena proporção e, após hidrólise no abomaso, seus ácidos graxos podem ser absorvidos, reduzindo os efeitos negativos sobre a fermentação da fibra (Homem Jr. et al, 2010). Segundo Jenkins e Jenny (1989), a maior concentração de lipídios no sangue ocorre quando aumenta a gordura absorvida via intestino ou aquela proveniente da lipólise.…”