Alberto Sartori

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.

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.

Dietary Spirulina (Arthrospira platensis) and Thyme (Thymus vulgaris) supplementation to growing rabbits: Effects on raw and cooked meat quality, nutrient true retention and oxidative stability

The study evaluated the effect of Spirulina and Thyme dietary supplementation on rabbit meat quality, nutrient true retention and protection against oxidative stress. Rabbits in the control group (C-C) received a non-supplemented pellet throughout the experiment (5-11weeks of age). In the other groups, the pellet contained 5% Spirulina (S), 3% Thyme (T), or both (ST) for either the entire (groups S-S, T-T, ST-ST) or only the final part of the growing period (8-11weeks: groups C-S, C-T, C-ST). Spirulina supplementation increased the γ-linolenic acid content of rabbit meat, whereas Thyme improved the oxidative stability of raw and freeze-dried meat.

Application of computed tomography to assess the effect of egg yolk ratio on body composition in chickens of different genotype and gender at hatch and during the rearing period.

1. Computed tomography was used for the in vivo determination of yolk ratio in 7000 domestic hen eggs, originated from two markedly different genotypes, in order to examine the effect of egg yolk ratio, gender and genotype on the development of hatched chicks. 2. Eggs with extremely low, average and extremely high yolk ratio were chosen for further investigation (n = 350 in each group in both genotypes). After incubating the selected eggs, hatched birds were reared and slaughtered at 11 weeks of age. 3. The yolk ratio of eggs significantly affected the body composition of the chickens at hatching and during rearing to 8–9 weeks of age. 4. Chickens of a genotype selected partly for weight gain had significantly higher live weight from hatching to the end of the rearing period and had better slaughter characteristics than those of the dual purpose TETRA-H genotype. 5. At hatching, only the dry matter content of the body was affected by the gender of the birds. The effect of gender on the live weight and body composition of chickens was evident from the 5th week of age to the time of slaughter. 6. It was concluded that eggs with a low yolk ratio were most beneficial for broiler production, because chickens hatched from these eggs had the highest slaughter weight and muscle index and the lowest fat index for their body mass.

Increasing dietary starch to ADF ratio in phase feeding programs for early weaned rabbits

Riassunto Programmi alimentari con diete a rapporto crescente amido/ADF in conigli svezzati precocemente - Allo scopo di valutare l’effetto di programmi alimentari a rapporto crescente amido/ADF su stato di salute, prestazioni produttive e qualità della carcassa e della carne, 240 conigli ibridi sono stati alimentati da 25 a 42 d di età con le diete L1 (amido: 10,9%, ADF: 19,5%) o M1 (amido: 14,6%; ADF: 17,8%), da 42 a 56 d con le diete L2 (amido: 10,7%; ADF: 20,1%), M2 (amido: 15,9%; ADF: 17,6%) o H2 (amido: 17,1%; ADF: 15,7%) e da 56 d alla macellazione (75 d) con una dieta unica, F3 (amido: 22,0%; ADF 13,6%). L’aumento del rapporto amido/ADF nelle diete del secondo periodo ha migliorato la conversione alimentare (da 2,92 a 2,86; P<0,05), senza effetti sullo stato di salute e la qualità della carcassa e della carne.

Effect of starch to ADF ratio and grinding procedure in diets for growing rabbits

Riassunto Effetto del rapporto amido/ADF e delle modalità di macinazione della dieta in conigli in accrescimento – Allo scopo di valutare l’effetto del rapporto amido/ADF e della modalità di macinazione, 216 conigli sono stati alimentati da 32 a 76 giorni di età con 6 diete ottenute a partire da 2 diete a basso o alto rapporto amido/ADF (0,70 e 1,04) macinando tutte le materie prime con griglia da 3 mm o da 6 mm o macinando le materie prime fibrose con griglia da 6 mm e le altre con griglia da 3 mm prima della pellettatura della dieta. L’aumento del rapporto amido/ADF ha migliorato la digeribilità della dieta e la conversione alimentare e ha stimolato la produzione di butirrato e valerato nel cieco, senza effetti sullo stato di salute. La modalità di macinazione ha modificato la granulometria della dieta, soprattutto per la frazione maggiore di 0,60 mm, ma non ha influenzato le prestazioni produttive e l’attività fermentativa ciecale.