ESTUDO DA CARCAÇA DE MACHOS BRAFORD DESMAMADOS AOS 72 OU 210 DIAS, ABATIDOS AOS CATORZE MESES

O objetivo deste trabalho foi comparar as características de carcaça de machos desmamados em duas idades, aos 72 (T72) e aos 210 (T210) dias. Utilizaram-se 36 terneiros 5/8 Hereford e 3/8 Nelore, não castrados, os quais foram terminados em confinamento e abatidos aos 14 meses de idade. Não houve diferença significativa quanto ao peso de fazenda (T72=424 kg e T210=406 kg), rendimento de carcaça quente (T72=54,7% e T210=54,4%), peso de carcaça quente (T72=232 kg e T210=221 kg) e fria (T72=224 kg e T210=214 kg) entre os dois grupos. Os animais desmamados aos 72 dias apresentaram carcaça com conformação ligeiramente superior (11,8 pontos vs. 11,3 pontos) e maior percentagem de costilhar em relação aos novilhos desmamados aos 210 dias, cujos cortes dianteiro e traseiro não diferiram significativamente. Não houve diferença significativa entre as variáveis comprimento de carcaça, comprimento de perna, comprimento de braço, perímetro de braço e espessura de coxão. A espessura de gordura de cobertura não diferiu significativamente entre os dois grupos de carcaça, sendo 4,6 mm e 4,2 mm, respectivamente para T72 e T210 dias. Os resultados mostraram que animais desmamados aos 72 dias de idade apresentam carcaça comparável aos desmamados com 210 dias, com peso e acabamento dentro dos limites exigidos pelos frigoríficos.

A Study of the Reliability of the ASTM C-666 Freeze-Thaw Test, MLR-72-01 and R-252, 1972

The Iowa State Highway Commission purchased a Conrad automatic freeze and thaw machine and placed it in operation during October 1961. There were a few problems, but considering, the many electrical and mechanical devices used in the automatic system it has always functioned quite well. Rapid freezing and thawing of 4"x4"xl8" concrete beams has been conducted primarily in accordance with ASTM C-29l (now ASTM C-666 procedure B) at the rate of one beam per day. Over 4000 beams have been tested since 1961, with determination of the resulting durability factors. Various methods of curing were used and a standard 90 day moist cure was selected. This cure seemed to yield durability factors that correlated very well with ratings of coarse aggregates based on service records. Some concrete beams had been made using the same coarse aggregate and the durability factors compared relatively well with previous tests. Durability factors seemed to yield reasonable results until large variations in durability factors were noted from beams of identical concrete mix proportions in research projects R-234 and R-247. This then presents the question "How reliable is the durability as determined by ASTM C-666?" This question became increasingly more important when a specification requiring a minimum durability factor for P.C. concrete made from coarse aggregates was incorporated into the 1972 Standard Specification for coarse aggregates for concrete.

Wapello County, Township 72 North Range 12 West

Des Moines River Plat Maps.