Jean-François Cabaraux

Comparison of composition and quality traits of meat from young finishing bulls from Belgian Blue, Limousin and Aberdeen Angus breeds

Thirty-six young finishing bulls from three breeds (Belgian Blue, Limousin and Aberdeen Angus) were fattened over five months with finishing diets based either on sugar-beet pulp or on cereals. Nutritional quality traits of meat - fat content and fatty acid composition with emphasis on the n-6 and n-3 polyunsaturated fatty acids - along with some organoleptic quality traits were measured. The Belgian Blue bulls had the lowest intramuscular fat content associated with lower saturated and monounsaturated fatty acid contents. The polyunsaturated fatty acid content did not differ to a large extent between the breeds, the Aberdeen Angus bulls showing slightly higher values. Relative to energy intake, the overall contribution of meat to the n-3 fatty acid recommended intake was small, whatever the breed. By contrast, the contribution of meat to daily fat intake was of greater importance, especially for the Aberdeen Angus bulls. The quality traits of meat varied also according to the breed: compared to the Aberdeen Angus, the Belgian Blue bull meat had the stablest colour, the highest drip and the lowest cooking losses. The meat of Limousin bulls had intermediate characteristics for all the parameters.

Performance, slaughter characteristics and meat quality of young bulls from Belgian Blue, Limousin and Aberdeen Angus breeds fattened with a sugar-beet pulp or a cereal-based diet

Thirty-six young fattening bulls from three breeds (Belgian Blue, Limousin and Aberdeen Angus) were fattened over 5 months with fattening diets based either on sugar-beet pulp or on cereals. Fattening performance as well as carcass and meat characteristics were measured. There were few relevant effects of the diets on the parameters. The breeds also showed similar fattening features. However, the BB had higher killing-out proportion and their carcasses presented better scores in terms of conformation and fattening. The meat quality of the breeds differed, especially in terms of luminosity, redness and cooking losses. There were also significant influences of breed on the chemical composition of meat; fat content was lowest in Belgian Blue and highest in Aberdeen Angus. Such specificities could help to allocate breeds in appropriate niches in Belgium.

Growth patterns of Belgian Blue replacement heifers and growing males in commercial farms

Abstract A survey was carried out to propose models of growth curves in Belgian Blue cattle less than 20 months of age and raised in commercial farms in southern Belgium. Live weight data were recorded between 1993 and 1999 from 1104 breeding heifers, and 924 growing males. The linear, polynomial group, power, logistic, Brody, Gompertz, von Bertalanffy and Richards models were used and compared. A step-wise linear growth model characterized by two periods of linear growth was also evaluated. This last model has been proposed as the reference model to characterize the growth curves of Belgian Blue cattle less than 20 months old. The animals were then ranked and divided in subgroups based on percentiles and quartiles in order to compare their performances. The subgroups performing better presented a greater homogeneity. The males ranked above the 90th percentile presented a growth rate comparable to that of young males selected for artificial insemination. Cattle ranked above the third quartile presented a growth rate comparable to that of licensed animals. When reproduction performances were related to the growth rate, it appeared that the better growing heifers were bred younger and heavier than lesser performing animals.

Effects of available surface on gaseous emissions from group-housed gestating sows kept on deep litter

In the European Union, the group-housed pregnant sows have to have a minimal legal available area of 2.25 m2/sow. However, it has been observed that an increased space allowance reduces agonistic behaviour and consecutive wounds and thus induces better welfare conditions. But, what about the environmental impacts of this greater available area? Therefore, the aim of this study was to quantify pollutant gases emissions (nitrous oxide, N2O, methane, CH4, carbon dioxide, CO2 and ammonia, NH3), according to the space allowance in the raising of gestating sows group-housed on a straw-based deep litter. Four successive batches of 10 gestating sows were each divided into two homogeneous groups and randomly allocated to a treatment: 2.5 v. 3.0 m2/sow. The groups were separately kept in two identical rooms. A restricted conventional cereals based diet was provided once a day in individual feeding stalls available only during the feeding time. Rooms were automatically ventilated. The gas emissions were measured by infra red photoacoustic detection during six consecutive days at the 6th, 9th and 12th weeks of gestation. Sows performance (body weight gain, backfat thickness, number and weight of piglets) was not significantly different according to the space allowance. In the room with 3.0 m2/sow and compared with the room with 2.5 m2/sow, gaseous emissions were significantly greater for NH3 (6.29 v. 5.37 g NH3-N/day per sow; P < 0.01) and significantly lower for N2O (1.78 v. 2.48 g N2O-N/day per sow; P < 0.01), CH4 (10.15 v. 15.21 g/day per sow; P < 0.001), CO2 equivalents (1.11 v. 1.55 kg/day per sow; P < 0.001), CO2 (2.12 v. 2.41 kg/day per sow; P < 0.001) and H2O (3.10 v. 3.68 kg/day per sow; P < 0.001). In conclusion, an increase of the available area for group-housed gestating sow kept on straw-based deep litter seems to be ambiguous on an environmental impacts point of view. Compared with a conventional and legal available area, it favoured NH3 emissions, probably due to an increased emitting surface. However, about greenhouse gases, it decreased N2O, CH4 and CO2 emissions, probably due to reduced anaerobic conditions required for their synthesis, and led to a reduction of CO2 equivalents emissions.

Performances of local poultry breed fed black soldier fly larvae reared on horse manure

In poultry, feed based on maggots, like larvae of black soldier fly (Hermetia illucens) is an attractive option to substitute current ingredients which are expensive and often in direct or indirect competition with human food. Little information is currently available on the utility of these larvae in poultry feed, so goals of this study were to determine whether larvae could be reared on horse manure under traditional farming conditions and to evaluate the growth performances of a local poultry fed these larvae and the fatty acids profiles of their meat. After freezing and thawing, larvae were introduced in the feed of Ardennaise chickens between 30 and 80 days of age. Birds in the control group received a commercial standard feed, while those in the treatment group received the same commercial feed in which 8% was substituted with whole fresh larvae corresponding to 2% on a dry matter basis. Means ± standard errors of larval length and weight were 20.67 ± 2.21 mm and 0.14 ± 0.02 g, respectively. Mean larval percentages of dry matter and of substances extractable in diethyl ether were 24.6% and 23.1%, respectively. Larval fatty acids profiles were predominantly composed of lauric acid (28.1%) and palmitic acid (22.0%). Least squares means of weekly weights of chicken, adjusted for the effects of sex, replication and initial weights, were significantly higher (P < 0.05) by 77.03 ± 53.37 g in larvae-fed than in control chickens. All other measurements were not statistically different between larvae-fed and control chicken, including fatty acid profiles, protein content and ω6/ω3 ratio.

Effects of dietary black soldier fly larvae on performance of broilers mediated or not through changes in microbiota

A total of 40 one-day-old male Ross chickens were individually fed a commercial feed with either 0 or 8% of de-frosted larvae of black soldier flies (BSF; wet weight). We recorded daily body weights and feed intake of each chicken for a period of 13 days. After euthanasia, we visually scored masses of abdominal fat tissues, and lesions and quantity of fat in intestinal villi. We measured percentages of tibia ash. Larvae, their growing substrate, and the caecal content of the chickens were collected for further microbiota characterisation. Statistical analyses included analyses of variance, chi-square tests, partial least square regressions and mediation analyses. We did not observe any significant differences in the overall means of zootechnical measures and in the relative abundances of most bacterial families in the caeca of birds fed insect larvae or not. On the other hand, relative abundances of both Rhodobacteraceae and Bacillaceae were lowest in birds receiving larvae. We identified new, and confirm...

Floor slat openings impact ammonia and greenhouse gas emissions associated with group-housed gestating sows

According to EU legislation, group-housed gestating sows must have a minimum of 2.25 m2 floor area per sow with at least 1.3 m2 of continuous solid floor of which a maximum of 15% is reserved for drainage openings. The aim of the experiment was to quantify the impact of different drainage openings on ammonia and greenhouse gas emissions. Three successive batches of 10 gestating sows were used. Each batch was divided into two groups kept separately in two identical rooms with similar volume and surface. The solid part of the floor presented 15% drainage openings in the first room and 2.5% in the second room. The gas emissions (ammonia (NH3), methane (CH4), nitrous oxide (N2O), carbon dioxide (CO2) and water vapour (H2O)) were measured three times during 6 consecutive days. Gaseous emissions were significantly lower with 15% drainage openings with reductions of 19% for NH3 (12.77 v. 15.83 g/day per sow), 15% for CH4 (10.15 v. 11.91 g/day per sow), 10% for N2O (0.47 v. 0.52 g/day per sow), 9% for CO2 (2.41 v. 2.66 kg/day per sow) and 13% for H2O (3.25 v. 3.75 kg/day per sow). This trial showed the advantage, in an environmental point of view, to use 15% drainage openings on the solid part of partly slatted floors in pens for group-housed gestating sows.