Victor Pinheiro

Effect of Dietary Dehydrated Pasture and Citrus Pulp on the Performance and Meat Quality of Broiler Chickens

Some feedstuffs containing significant levels of fiber may be a good source of bioactive compounds that may contribute to improving broiler meat quality. However, high fiber level can have a negative impact on broiler performance. A study was undertaken to investigate the impact of incorporating citrus pulp (5 or 10%) or dehydrated pasture (5 or 10%) on the performance, carcass yield, and characteristics of broiler chickens. A diet containing neither citrus pulp nor dehydrated pasture was used as control. The results on growth performances showed that daily weight gain was reduced by 26% in birds of the 10% citrus pulp treatment (P<0.05). Compared with the control treatment, increases in feed intake occurred in birds consuming diets with 5 or 10% citrus pulp, which resulted in significantly higher feed conversion rates with the 10% level. Under the same incorporation rate, dehydrated pasture had effects less evident on the performances of broiler chicken. In addition, diets containing citrus pulp, displaying higher percentages of soluble nonstarch polysaccharides, increased small intestine relative length, and reduced carcass yield. Inclusion of 10% dehydrated pasture in diets resulted in improved breast skin yellowness (P<0.05). Finally, the results revealed that incorporation of the nonstarch polysaccharide-rich feedstuffs had a major impact on the fatty acid profile (affected 16 of 21 fatty acids) of broiler meat. Polyunsaturated fatty acids content in meat was higher in birds consuming the highest levels of both citrus pulp and dehydrated pasture, leading to increased ratios of polyunsaturated to saturated fatty acids. Together, the results suggest that incorporation of moderate levels of dehydrated pastures in poultry diets has a minor impact on broiler performance and can contribute significantly to improve breast skin yellowness and fatty acid composition of meat.

Effects of the dietary incorporation of olive leaves on growth performance, digestibility, blood parameters and meat quality of growing pigs.

BACKGROUND In a preliminary study the oxidative stability and tocopherol content of pork meat were shown to be improved by olive leaf (OL) feed supplementation at 50 and 100 g kg(-1) . However, growth performance was affected negatively. Therefore the objective of the present study was to assess the influence of OL supplementation at a lower level on feed digestibility, growth performance and meat quality. RESULTS Pigs were fed a basal diet (control), a basal diet with 25 g OL kg(-1) (OL2.5) or a basal diet with 50 g OL kg(-1) (OL5). The incorporation of OL significantly decreased growth rates (P = 0.010) and backfat thickness (P = 0.035) and increased feed/gain ratio (P = 0.032) in the OL5 group. Feed/gain ratio increased more for females (P = 0.001). The incorporation of OL decreased the crude fat (P = 0.006) and protein (P = 0.037) digestibility of both OL diets. Nevertheless, OL was effective in increasing the tocopherol content of meat (P = 0.009). However, meat from pigs fed the OL diets showed similar conjugated diene content, pH and colour parameters to that from pigs fed the control diet, even after 6 days of storage at 4 °C. CONCLUSION The data indicate that olive leaves may be included in pig diets at 25 g kg(-1) in order to improve the tocopherol content of meat without excessively compromising growth performance.

The value of in vivo real time ultrasonography in assessing loin muscularity and carcass composition of rabbits

Sixty nine growing rabbits were scanned over the lumbar region using a real time ultrasonography (RTU) machine to estimate loin muscularity and carcass composition. Longissimus thoracis et lumborum muscle (LM) depth, width and area were taken. Animals were weighed (LW), slaughtered and carcass composition was determined. Equivalent measurements to those taken by RTU in vivo were taken on the carcass and muscularity indices were calculated on carcass and in vivo. Simple correlations between the two types of measurements were determined and carcass composition was estimated by simple and multiple regressions. The LW varied from 1200 to 3410g. The simple correlations between carcass and in vivo RTU LM measurements were high (P<0.001) and the LM area was the trait with the highest correlation (r=0.92). Simple correlations between muscularity indices measured by RTU and in carcass were significant (P<0.001). In vivo RTU measurements explained a large amount of the variation of the carcass meat weight (MW) and bone weight (r(2) range from 0.49 to 0.77; P<0.001). Using multiple regression equations to estimate carcass composition, the best fit was obtained with the LW and one or more in vivo RTU measurement. The LW explained 90.6% of the variation of MW in the carcass. In vivo RTU is able to estimate loin muscularity and carcass composition of rabbits with accuracy. The usefulness of in vivo RTU and LW to predict carcass composition of rabbits using multiple regressions was also shown.

Prediction of carcase and breast weights and yields in broiler chickens using breast volume determined in vivo by real-time ultrasonic measurement.

1. The use of in vivo real-time ultrasonic (RTU) to predict breast and carcase weights and yields in 103 male broiler chickens was evaluated. Breast area (mm2), thickness (mm) and volume (cm3) were measured by RTU in three identified sites. After RTU measurements, the broiler chickens were weighed (live weight, LW, g) and slaughtered. Carcase and breast weights (g) and physical measures of breast area (mm2), and thickness (mm) corresponding to the three identified sites, and volume (cm3) were recorded. 2. The best simple correlation between RTU and carcase measurements was obtained for breast volume. Breast and carcase weights were well predicted by LW. Furthermore, breast volume measured in carcase or by RTU was better in predicting breast weight and breast and carcase yields. 3. Multiple regression equations were fitted using LW (g) and RTU measurement of breast volume to predict breast and carcase weights and yields. The coefficients of determination were 0·52 and 0·65 for breast and carcase yields, respectively, and 0·92 and 0·99 for breast and carcase weights, respectively.

Effects of rye, wheat and xylanase supplementation on diet nutritive value and broiler chicken performance

Tres experimentos foram realizados para avaliar os efeitos de dietas formuladas com 53% de trigo ou centeio, suplementadas ou nao com a enzima xilanase (0,06%), sobre a digestibilidade de nutrientes e a energia metabolizavel das dietas e sobre o desempenho e desenvolvimento do trato digestivo de frangos de corte. Como testemunha foi usada uma dieta com 53% de milho. No primeiro experimento, as digestibilidades da materia seca, materia orgânica e gordura e energia metabolizavel corrigida para o nitrogenio (EMAn) das dietas com centeio foram menores que daquelas com trigo (2.556 kcal/kg vs 2.842 kcal/kg) e menores no conjunto dessas dietas que na dieta com milho (2.684 kcal/kg vs 3.010 kcal/kg). A digestibilidade da materia orgânica e a EMAn das dietas com centeio tambem foi inferior as da dieta com trigo. A suplementacao com xilanases nao afetou a utilizacao digestiva das dietas com centeio ou com trigo. No segundo experimento, nos frangos alimentados com as dietas com centeio, o menor ganho de peso e consumo de EMAn e a pior conversao alimentar ocorreram entre os 8 e os 35 dias de idade. A conversao alimentar foi de 2,17 para as dietas com centeio e 1,88 para a dieta com milho. A adicao de xilanases as dietas com centeio ou trigo nao melhorou a conversao alimentar. Nos frangos alimentados com as dietas com centeio durante 31 dias, o duodeno-jejuno e ileo foram maiores e o rendimento de carcaca menor que nos frangos alimentados com a dieta testemunha (71,6% vs 74,4%). As dietas com trigo nao afetaram essas caracteristicas. Os pesos do pâncreas e do figado tambem nao foram alterados pelas dietas.Three trials with were conducted to evaluate the effects of diets with 53% rye (diet C) or 53% wheat (diet T) supplemented or not with xylanase enzymes (0.06%) on nutrient digestibility and metabolizable energy and the performance and development of the broiler chicken digestive tract. A diet with 53% corn was used as control. In trial 1, dry matter, organic matter and apparent fat digestibilities corrected for nitrogen (EMAn) were lower in rye diets than in wheat diets (2556 kcal/kg vs 2842 kcal/kg) and were lower in the set of these diets than in the control diet. The organic matter digestibility and EMAn in the rye were also lower than those of the wheat diets. Xylanase supplementation did not affect the digestive use of the rye or wheat diets. In trial 2, growing broiler chickens fed the rye diets showed the lowest weight gain and EMAn intake and the worst feed conversion ratio between 8 and 35 days of age. The feed conversion ratio was 2.17 with rye diets and 1.88 with the corn diet. Xylanase supplementation on rye or wheat based diets did not improve feed conversion. In trial 3, birds fed on rye diets for 31 days showed longer duodenum-jejunum and ileum and lower carcass yield than birds fed the control diet (71.6% vs 74.4%). The wheat based diets did not affect these parameters. Pancreas and liver weights were not affected by the feeds.

Strategies for mitigation of nitrogen environmental impact from swine production

This work presents strategies that can be implemented in order to minimize the environmental impact of swine slurry on soil, water, and air. This reduction can be achieved through decrease in nitrogen excretion and ammonia emissions. The correct feed formulation according to animal requirements, the increase in diet digestibility and improvement in animal performance can reduce nitrogen excretion. The use of additives either in the diet or in the manure as well as some equipment rearrangements can reduce ammonia emission.

Potential use of cowpea (Vigna unguiculata (L.) Walp.) stover treated with white-rot fungi as rabbit feed

BACKGROUND Lignin inhibitory effects within the cell wall structure constitute a serious drawback in maximizing the utilization of fibrous feedstuffs in animal feeding. Therefore treatments that promote efficient delignification of these materials must be applied. This study evaluated the potential of white-rot fungi to upgrade the nutritive value of cowpea stover for rabbit feeding. RESULTS There was an increase in the crude protein content of all substrates as a result of fungi treatments, reaching a net gain of 13% for Pleurotus citrinopileatus incubation. Overall, net losses of dry and organic matter occurred during fungi treatments. Although the fiber content remained identical, higher consumption of cell wall contents was measured for P. citrinopileatus incubation (between 40 and 45%). The incubation period did not influence lignin degradation for any of the fungi treatments. Differences within the fungal degradation mechanisms indicate that P. citrinopileatus treatment was most effective, enhancing in vitro organic matter digestibility by around 30% compared with the control. CONCLUSION Treatment of cowpea stover with P. citrinopileatus led to an efficient delignification process which resulted in higher in vitro organic matter digestibility, showing its potential in the nutritional valorization of this feedstuff.

A novel feedstuff: ensiling of cowpea (Vigna unguiculata L.) stover and apple (Malus domestica Borkh.) mixtures. Evaluation of the nutritive value, fermentation quality and aerobic stability

BACKGROUND Agro-industrial by-products are of low economic value as foods for human consumption but may have potential value as animal feedstuffs. This study evaluated a novel feedstuff, ensiled discarded apple (85%) and cowpea stover (15%) mixtures with two different ensiling periods (45 and 60 days), regarding the nutritive value, fermentation quality and aerobic stability. RESULTS Generally, no differences (P > 0.05) were observed between ensiling periods for nutritive value and fermentation characteristics. Silages were stable after ensiling, presenting high lactic acid (77.3 g kg-1 dry matter (DM)) and acetic acid (54.7 g kg-1 DM) and low ethanol (15.7 g kg-1 DM) and NH3 -N (105.6 g kg-1 total N) concentrations. No butyric acid was detected in silages, and they were aerobically stable for up to 216 h. Lactic acid bacteria numbers were high at silo opening (7.14 log colony-forming units (CFU) g-1 ), while Enterobacteriaceae were not detected and yeasts/moulds were low (2.44 log CFU g-1 ). Yeast/mould and Enterobacteriaceae numbers grew considerably during 12 days of air exposure. CONCLUSION A mixture of low calibre discarded apples with cowpea stover can be used as animal feed after the ensiling process owing to its nutritive value and long aerobic stability.

Real-time ultrasound to predict rabbit carcass composition and volume of longissimus dorsi muscle

Real-time ultrasonography (RTU) was used to measure the longissimus dorsi muscle (LM) volume in vivo and to predict the carcass composition of rabbits. For this, 63 New Zealand White × Californian rabbits with 2093±63 g live weight were used. Animals were scanned between the 6th and 7th lumbar vertebrae using an RTU equipment with a 7.5 MHz probe. Measurements of LM volume were obtianed both in vivo and on carcass. Regression equations were used for the prediction of carcass composition and LM volume using the LM volume measured obtained with RTU (LMVU) as independent variable. Carcass meat, bone and total dissectible fat weights represented 780, 164 and 56 g/kg of the reference carcass weight, respectively. Regression equations showed a strong relationship between LMVU and the correspondent volume in carcass. Furthermore, LMVU was also useful in predicting the amounts of carcass tissues. It is possible to predict LM volume in the carcass using the LM volume measured in vivo by RTU. The amount of carcass tissues can be predicted by the LM volume measured in vivo by RTU.