Feed Conversion Index Research Articles

PATURAGE VERSUS ENSILAGE POUR LA PRODUCTION LAITIERE

Timothy and Ladino-timothy pastures (Phleum pratence L. et Trifolium repens L.) were compared to corn (Zea mays) and alfalfa-timothy silages (Medicago sativa L. and Phleum pratence L.) for forage and milk production. Three groups of 10 Holstein cows were used over three summers. Concentrate feeding was done according to the amount of milk fat produced. The grazing season extended from 29 May to 7 Oct., and the stoking rate was 3.09 cows per hectare. Cows fed silage were kept in confinement. Forage dry matter yields were 8677 kg/ha for the timothy pasture, 6574 kg/ha for the Ladino-timothy pasture, 7040 kg/ha for the alfalfa-timothy silage and 8740 kg/ha for the corn silage. Milk production per hectare was highest from fields harvested for silage: 11 891 kg/ha from silage compared to 8147 kg/ha from pasture. The forage-producing area required per cow was 0.15 ha for the silage crop and 0.28 ha for the pastures. Daily fat corrected milk production per cow was 21.8 kg on Ladino-timothy pasture, 21.6 kg on timothy pasture and only 18.2 kg per cow fed silage. The feed conversion index was 1.16 kg of dry matter per kilogram of milk for cows on pasture and 0.88 for those receiving silage. Milk produced from timothy pasture contained more protein than milk produced from silage; other milk constituents were not affected by treatments. A high concentration of urea was found in the blood serum of cows grazing on pasture due to the high amount of nitrogen contained in the herbage.

Influence of the Implantation of Lactobacillus Acidophilus in Chicks on the Growth, Feed Conversion, Malabsorption of Fats Syndrome and Intestinal Flora

Three experiments have been carried out with broilers and Leghorn chicks to ascertain the influence of Lact. acidophilli implantation (during the first five days of life) on the weight gain, feed conversion index, fat digestibility, nitrogen retention, ceca and feces weight and the lactic and Enterococci flora in chickens up to 15 days of age.The results have shown that, in comparison to the presence and effects of antibiotics, the Lactobacilli implantation resulted in a similar effect, manifested by increasing weight gain and better feed efficiency in chicks grown in an “old” environment. Although not significant, the differences in fat digestibility and nitrogen retention were also most apparent when the environment was “old.”The implantation of Lact. acidophilus resulted in lower weights of the ceca and feces and a remarkable change in the bacterial flora of the ceca and the small intestine. At nine days of age of the chick, a marked increase in colonies of Lactobacilli was accompanied by an almost total disappearance of the Enterococci organisms.

Effects of protein sources on performance, carcass composition, blood parameters and meat quality in Charolais heifers

The aim of the present study was to evaluate the effects of feeding faba bean and sweet lupin as alternative protein sources to soybean on productive performance, blood parameters, carcass composition, and chemical-physical characteristics of meat and its fatty acid (FA) profile in Charolais heifers. Twenty-four heifers were divided into three homogenous groups and fed with durum wheat straw and three iso-energetic and isonitrogenous pelleted complete diets containing 14% (on as-fed basis) soybean meal; 28% faba bean; and 20% sweet lupin seed. The animals were slaughtered after a 168 day feeding period, and the Longissimus lumborum muscle was sampled for meat quality measurements. The feed conversion index was better in the heifers fed faba bean compared with the soybean treatment group (6.71 versus 7.17). No differences were found among treatment groups in productive performance, slaughtering data and physical features. The concentration of linoleic acid in the meat of the soybean group differed significantly from that in the lupin group (2.38 versus 2.11%). Feeding lupin seed increased the concentrations of C20:3 n-6 (0.09%) and C20:4 n-6 (0.20%) in meat significantly, compared with the soya- and faba bean treatments (0.06–0.07% and 0.12–0.13%, respectively). No differences were found among groups for blood parameters, except for urea concentration, which was lower in the lupin group compared with the concentrations in the serum of heifers receiving the soya bean treatment (31.29 as opposed to 37.56 mg/dL). In conclusion, since faba bean and lupin seed did not affect any of the parameters negatively, these legume grains can be included successfully as alternative protein sources in beef cattle diet.Keywords: Faba bean, lupin seed, soybean, beef cattle, feeding