Gerolamo Xiccato

Effect of parity order and litter weaning age on the performance and body energy balance of rabbit does

Abstract This study aimed to evaluate the effects of doe parity order and litter weaning age on reproductive performance and lactation and body energy balance of rabbit does from one kindling to the following. To this aim, 138 lactating does of three parity orders (first, second and third kindling: K1, K2 and K3) were remated 11 days after kindling. Their litters were weaned at 21, 26 and 32 days of age in a 3×3 factorial arrangement (three parity orders by three weaning ages). Thirty does at initial kindling and 69 pregnant does at final kindling were slaughtered to determine body tissue and energy balance. When increasing parity order, milk production, feed and digestible energy intake during lactation increased linearly while body energy deficit decreased (from −20.5% of the initial content in K1 does to −9.2% in K3 does). When weaning age was decreased from 32 to 21 days, body energy deficit decreased (−19.4% to −8.0%). Significant interactions between parity order and weaning age were recorded in energy balance and reproductive performance. According to these results, multiparous does showed a lower but still relevant energy deficit than primiparous does. Early weaning permitted us to reduce body energy deficit, especially at lower parity orders.

Effect of dietary energy level, addition of fat and physiological state on performance and energy balance of lactating and pregnant rabbit does

The effects of dietary energy level and added fat were studied by comparative slaughter on 60 primiparous rabbit does in different reproductive states. Nine does were slaughtered immediately after their first parturition (preliminary slaughter group) to estimate initial empty body composition. The 51 remaining does were divided into three groups and given diets differing in digestible energy (DE) content: M (11·28 MJ/kg dry matter (DM); H (12·16 MJ/kg DM); F (11·93 MJ/kg DM, obtained by the inclusion of 25 g/kg of animal fat). Thirty-six does (12 per group) were remated 3 to 4 days after parturition, after which 20 does were concurrently pregnant and lactating (LP) and gave birth a second time. At the second parturition these does were slaughtered with their new-born litters. The non-mated or non-pregnant lactating does (LN) were slaughtered at the same time. All litters from the first parturition were weaned at the 30th day of age. The diets influenced the DE intake (3·11 v. 3·31 and 3·36 MJ/day, P v. 180 v. 191 glday, P 0·05) (average of LP and LN does). The maternal diet significantly influenced the weight of the sucking litters (first parturition) at 20 days (2409 and 2454 v. 2629 g, P The LP does showed lower DE intake, milk yield (from 10 to 30 days) and litter weaning weights than LN does. Between the first and the second parturition, the LP does had a loss of empty body weight and a negative protein balance (-0·06 of the initial content), while the LN does had an increase in live weight and empty body weight and a positive protein balance (+0·11 of the initial content). Both LP and LN does had a negative energy balance (−0·24 v. −0·25, respectively; P

Advances in research on poultry and rabbit meat quality

Abstract – Main force and weakness points of poultry and rabbit production chains are presented and meat quality discussed in relation to nutritional and technological issues. An analysis of the most important poultry and rabbit meat quality traits and their major relationships with production factors (genotype, feeding, housing, pre-slaughter handling, slaughtering, and processing) is provided. Most recent research advancements are presented in view of the consumer’s demand for healthy and safe products obtained respecting animal welfare.

Nitrogen excretion in dairy cow, beef and veal cattle, pig, and rabbit farms in Northern Italy

Abstract Reference values for N excretion of different livestock production systems are required for the application of the Nitrate Directive (91/676/EC). A survey aimed to estimate N excretion from on-farm measurements of feed consumption and performance of dairy cows (104 herds, 9,984 cows), growing cattle (40 farms, 40,157 young bulls), veal calves (34 farms, 49,206 calves), growing pigs (39 farms, 161,278 pigs) and rabbits (54 farms, 65,664 reproducing does) was conducted in Veneto from 2002 to 2003. N excretion was computed as the difference between N consumption and N retained in animal products. Dairy cow yielded 8,366 ± 1,646 kg/year of milk, consumed 6,600 ± 928 kg/year of DM, containing 2.45 ± 0.2 % DM of N, and excreted 116 ± 25 kg of N/year. No significant correlation was found between milk yield and N excretion, but the correlation between dietary N concentration and N excretion was significant (r=0.66). For growing cattle, the following mean values were achieved: daily gain 1.25 ± 0.19 kg/d; feed conversion ratio 6.9 ± 0.9 kg of DM/kg, rounds/year 1.66 ± 0.38. Nitrogen consumed, retained and excreted were, respectively, 68.7 ± 5.4, 11.4 ± 1.9 and 57.3 ± 4.9 kg/place/year. For veal calves, N consumed was 24.1 ± 1.9 kg/place/year, 12.1 ± 0.8 kg of which were retained in the body and 12.0 ± 1.5 kg were excreted. For heavy pig production, N consumed, per place and per year, averaged 19.0 ± 1.9 kg, N retained was 5.2 ± 0.5 kg and N excreted was 13.8 ± 0.4 kg. In the close-cycle rabbit farms, the doe and the relative growing rabbits (43 sold per year) consumed 11.2 ± 2.2 kg, retained 3.8 ± 0.7 kg and excreted 7.4 ± 1.5 kg N/doe/year. Nitrogen excretion estimated in this work can be considered as representative of some of the main animal production systems of the North-East of Italy. These values should not be considered as fixed, otherwise the implementation of the various strategies to reduce N excretion would not be possible. They should be considered as guidelines in the assistance both to public institutions and private enterprises in the evaluation of N excretion at farm level, favouring a more accurate quantification of the excretions, an increase of N retention efficiency and a better knowledge of the requirements of agricultural land. Moreover, a major extension of the agricultural land to be fertilised with manure should be promoted.

Energy and protein utilization and partition in rabbit does concurrently pregnant and lactating

Changes in body composition during lactation in 40 primiparous rabbits were studied by comparative slaughter. The results were used to determine the utilization of digestible energy (DE) and digestible protein (DP) and their partitioning between maternal body, milk and foetal tissues. Twelve does were slaughtered immediately after their first parturition (first slaughter group) to estimate initial body composition. The 28 remaining does were remated 1 to 3 days after parturition and divided into two groups offered a pelleted diet at different levels: group L, fed ad libitum and group R, fed 0·75 of ad libitum. The 19 does that were pregnant (10 of L group, 9 of R group) were kept in individual metabolism cages until their second parturition. They were then slaughtered with their litters. Milk yield was higher (147·0 v. 117·2 g/day, P The DE requirement for maintenance was estimated to be 468 kj/day per kg M 0·75 and the efficiencies of utilization of DE and body energy for milk production were 0·63 and 0·76, respectively. The efficiency of utilization of DE for foetal tissue synthesis was estimated to be 0·27 throughout pregnancy. The DP requirement for maintenance was 3·80 g/day per kg M 0·75 and the efficiency of utilization of DP for milk protein production was 0·76 and of body protein 0·61. The efficiency of utilization of DP for foetal protein synthesis was 0·46.

Rearing veal calves with respect to animal welfare: effects of group housing and solid feed supplementation on growth performance and meat quality

Abstract This study aims to evaluate how rearing techniques that improve veal calf welfare affect growth performance and carcass and meat quality, by comparing both traditional rearing in individual stalls with group rearing in collective pens and exclusive milk feeding with maize grain supplementation. Eighty male calves were raised from 60 days-of-age (live weight 76.4±5.5 kg) until slaughter (at 182 and 189 days-of-age). Both group rearing and maize grain supplementation significantly improved growth performance (final live weight: +7 kg in group-reared calves compared to individually reared calves; and +10 kg in maize-supplemented calves compared to exclusively milk-fed calves) and carcass conformation, with no differences in dressing percentage. Group rearing increased blood packed cell volume value. Neither the type of housing nor the feeding system significantly modified carcass or meat colour or the main physical and sensory traits of the meat. Carcass fatness and meat ether extract concentration were higher in the calves reared in individual stalls or supplemented with maize grain. Our results suggest that rearing veal calves in pens and providing solid feed supplements may improve growth performance without impairing carcass and meat quality.

Reproductive rhythm and litter weaning age as they affect rabbit doe performance and body energy balance

Abstract One hundred and twenty multiparous does were synchronized to give birth the same day (initial kindling). The trial lasted until the successive (final) kindling. Immediately following initial kindling, 22 does were selected for comparative slaughter. The remaining does were assigned to three reproductive rhythms and mated 2 (R2), 11 (R11) or 26 (R26) days post partum. Within each rhythm, the does were further divided into two groups with litters weaned at 21 (W21) or 25 (W25) days of age. A total of 54 does were pregnant and were slaughtered soon after final kindling. By increasing the kindling-to-mating interval from 2 to 26 days, total milk production was increased (5590 to 6065 g for R2 and R26, respectively; P P P P P P P P P P P P P

Effect of age, diet and sex on muscle energy metabolism and on related physicochemical traits in the rabbit.

Muscle energy metabolism and related physicochemical traits of the meat were studied in 84 Provisal hybrid rabbits of both sexes. From weaning (30 days) to 55 days of age, the rabbits were divided into 4 groups which were given ad libitum one of the following diets: H diet with high digestible energy (DE) level, L diet with low DE level, F diet with high DE level, obtained by supplementing with animal fats, and W diet with moderate DE level. The H, L and F diet were suitable for lactating does and weaning rabbits; the W diet for weaned young rabbits. From 55 days to slaughter age, the rabbits were given a G diet suitable for growing and fattening. The rabbits were slaughtered at 55 days (23 rabbits), 80 days (31 rabbits) or 87 days (30 rabbits) of age. The activity of a representative enzyme of the glycolytic (fructose-1,6-diP aldolase) and oxidative (NADP-isocitrate dehydrogenase: ICDH) energy metabolism pathways and two related physicochemical traits, namely lightness (L (∗)) and ultimate pH (pH(u)), were determined in the biceps femoris (BF) and longissimus lumborum (LL) muscles. The chemical composition of whole longissimus dorsi (LD) and total hindleg (HL) muscles was also determined. In BF and LL muscles, the activity of the glycolytic energy metabolism increased during the fattening period, as a result of metabolic differentiation. The increase stopped earlier in BF than in LL muscle. Variations in pH(u) values followed the same trend. The dietary effect on biochemical and physicochemical traits was moderate. A slight decrease in muscle pH(u) was observed under the less energetic diets. Aldolase activity was significantly higher in females. The significant correlations between metabolic and physicochemical traits confirmed that as glycolytic energy metabolism increases, the protein content increases, whereas pH(u) decreases. Slaughter weight was positively correlated to glycolytic energy metabolism.

Effect of genotype, gender and feed restriction on growth, meat quality and the occurrence of white striping and wooden breast in broiler chickens

Due to their importance for the control of meat quality in broiler chickens, the present study aimed at identifying the factors associated with the occurrence of myopathies and characterizing the meat properties when affected by myopathies. To this aim, a total of 768 broiler chickens were reared until slaughter (46 d) to evaluate the effect of genotype, gender, and feeding regime (ad libitum vs. restricted rate, 80% from 13 to 21 d of age) on performance and meat quality. Standard broilers were heavier (3,270 vs. 3,139 g; P<0.001) and showed lower feed conversion (1.56 vs. 1.61; P<0.001) than the high-yield broilers. Males showed higher final live weight (3,492 vs. 2,845 g) and lower feed conversion (1.54 vs. 1.63) than females (P<0.001). Feed restriction decreased final live weight (3,194 vs. 3,142 g; P<0.01) and feed conversion (1.60 vs. 1.57; P<0.01) compared to ad libitum feeding. At gross examination, feed restriction tended to increase white-striped breasts (69.5 vs. 79.5%; P<0.10), whereas females showed less wooden breasts than males (8.0 vs. 16.3%; P<0.05). White-striped fillets had higher pHu (5.87 vs. 5.83), and lower a* (-0.81 vs. -0.59) and b* color indexes (13.7 vs. 14.5) (P<0.05), whereas wooden breast fillets exhibited higher cooking losses (25.6 vs. 22.1%) and AK-shear force (4.23 vs. 2.84 kg/g) compared with normal fillets (P<0.001). At histological examination, 3.1% of pectoralis major were normal, 26.6% mildly degenerated, 45.3% moderately degenerated, and 25.0% severely degenerated. In conclusion, genotype had a moderate effect on growth without modifying myopathy occurrence. In contrast, gender and feed restriction affected performance, meat quality, and breast abnormalities.

Nutritive evaluation and ingredient prediction of compound feeds for rabbits by near-infrared reflectance spectroscopy (NIRS)

Near-infrared reflectance spectroscopy (MRS) was used to predict the nutritive characteristics of 66 compound rabbit feeds from three countries (Belgium, Spain and Italy) and the main ingredient inclusion rate in 59 of these feeds of known ingredient composition. Principal component analysis (PCA) was performed to classify the compound feeds according to their origin. The coefficient of multiple determination (R-2) for crude protein concentration (CP) was ca. 0.88 in both, calibration and validation with standard errors of calibration (SEC) and prediction (SEP) equal to 7.5 and 7.7 g (kg DM)(-1), respectively. NIRS prediction of gross energy (GE) and digestible energy (DE) concentrations was more precise, with high R-2 (0.90) and low SEP (0.26 and 0.37 MJ (kg DM)(-1), respectively). Satisfactory results were also obtained for both, the dry matter digestibility (DMd) and gross energy digestibility (GEd) prediction. The CP-correlated wavelengths were observed to be associated with the bond vibrations of the protein functional groups, while the wavelengths correlated with GE, DE, DMd and GEd were linked with starch, protein and crude fiber structure. The calibration on absorbance data to estimate the inclusion rate of the main ingredients demonstrated a fair correlation for alfalfa meal, barley and wheat bran, intermediate for sunflower meal and weak for soybean meal. In validation, the precision of the NIRS estimate remained satisfactory for alfalfa and sunflower meal but decreased for barley and wheat bran. The calibration of the spectra transformed in second derivative appeared to improve the quality of estimation by reducing the number of optimal factors from 9-15 to 2-4; moreover, the estimate precision of soybean and sunflower meal inclusions improved (R-2: 0.90 and 0.86, respectively) with the reduction of SEC (13.0 and 12.9 g kg(-1), respectively). In validation, however, the estimate precision for all raw materials became weaker than the degree achieved using absorbance data. PCA on the transformed spectra grouped the compound rabbit feeds according to their country of origin and indicated the possibility of identifying the presence of specific ingredients (i.e. full-fat rapeseed)