Explore the vast range of titles available.

Under current practices, broiler parent stock (broiler breeders) encounter several welfare problems, such as feed restriction and injury during mating. Intensive selection for production traits, especially growth rate, is associated with increased nutritious requirement and thus feed consumption, but also reproductive dysfunctions and decreased sexual activity in broiler breeders. A resulting serious welfare problem is the subsequent severe feed restriction which is applied during rearing, in order to prevent health problems and to achieve better egg production. This severe feed restriction has negative effects on bird welfare as it causes chronic stress resulting from hunger. Recent research has focused on management practices to alleviate the negative effect of this feed restriction. Using both a more fibrous feed and an appetite suppressant seems most successful. There are welfare concerns involved in the mating of broiler breeders. In many countries mutilations (beak trimming, despurring and toe clipping) are carried out in male broiler breeders as a standard procedure to prevent excessive damage to the hens during mating. It has been reported that broiler breeder males show low libido but, at the same time, may be aggressive and show rough behaviour during mating, which can cause severe injuries to the hens, although some injuries may be caused by over-mating hens. Current studies aim to develop management practices to reduce hen injury due to over-mating and improve the sexual behaviour in both males and females. In the last part of the review, an examination of how breeding companies are taking welfare into consideration in their commercial selection scheme is made. In practice, although for example reduced mortality and some health criteria are included in selection programs and some alternative breeds as used, other welfare issues remain, such as feed restriction during rearing.

The objective of this study was to determine the effects of feed restriction and source of dietary fatty acids during the close-up dry period on postcalving reproductive performance of dairy cattle. Thirty-four days before expected calving, pregnant Holstein cows (n=72; parity 1 to 5) were randomly assigned to 1 of 6 treatments. Treatments were ad libitum (AL) or 24% feed restriction (FR) in combination with 1 of 3 oilseed supplements at 8% of diet dry matter: canola, linola, or flax to enrich the rations with oleic, linoleic, or linolenic fatty acids, respectively. After calving, cows were fed a common lactation diet that contained no oilseeds. Measurements of uterus, corpus luteum, and follicles were obtained by ultrasonography twice weekly from 7±1 d after calving until the first ovulation. Cows (n=66) were subjected to timed artificial insemination (TAI), and pregnancy was determined 32 d later. Feed-restricted cows had lower dry matter intake and lost more body weight prepartum. Energy balance (Mcal/d) was negative in FR cows prepartum but they had a less severe negative energy balance postpartum. The dietary source of fatty acid did not affect energy balance. Cows fed AL had a higher incidence of uterine infections (10/37 vs. 2/35) but tended to have fewer ovarian cysts (2/37 vs. 7/35) than FR cows. Mean (±SE) interval from calving to uterine involution did not differ among dietary treatments (26.8±1.8 d). Interval from calving to first ovulation was longer in cows fed canola than in those fed either linola or flax (34.7±3.1 vs. 23.7±3.2 and 21.0±3.1 d, respectively). A greater percentage of cows fed AL conceived to the first TAI (47.1 vs. 18.8) and tended to have fewer mean days open (157±10.8 vs. 191±10.1) than cows fed FR. In summary, FR cows had a lower incidence of uterine infections, but they were less fertile as reflected by a lower percent pregnancy to first TAI and increased days open. Cows fed diets enriched in linoleic or linolenic fatty acids had a lesser incidence of ovarian cysts and ovulated sooner with no effect on energy balance or fertility.

Despite having huge responsibilities in avian species, published reports on the influence of dietary factors and other possible constraints on the size, development and function of liver are limited. Consideration of the factors that could influence and alter liver function is therefore of critical relevance. In the current review, aspects of liver structure and function, and the influence of feed restriction, anti-nutritional factors, structural components and feed additives on liver are discussed. Effects of feed technology techniques such as thermal treatment and pelleting, feed particle size and whole grain feeding on the liver are also reviewed. A discussion of lipogenesis and lipid storage in poultry is presented to provide a better understanding and to differentiate the normal pathways of lipid metabolism from abnormal (i.e., disordered) pathways. The liver is the main site of fat synthesis in poultry, but under certain conditions, excessive fat can accumulate in the liver and cause problems. Factors contributing to the fatty liver syndrome are also examined.

The objective of the present study was to determine the effect of feed restriction systems, herbal mixture and their interactions on growth performance, carcass traits, and microbial aspects of growing New Zealand White (NZW) rabbit kept from 5 to 13 weeks of age. A 3 × 4 factorial arrangement was performed, including three feed restriction systems (ad-libitum, 90%, and 80% of ad-libitum) and four dietary supplementation levels of herbal mix (0, 0.30%, 0.50% and 0.70%). A total number of 120 rabbits (male and female ratio 1:1) at five weeks of age were randomly allotted into twelve experimental groups (n = 10 each). Results showed a significant decrease in body weight, body weight gain and feed intake in restricted-fed rabbits compared to the control group (ad-libitum). HERBS levels significantly influenced the growth performance and carcass traits of rabbits. The herbal blend had a positive effect on reducing the population of pathogenic microorganisms and increasing the population of lactic acid bacteria. Conclusively, it could be concluded that the feed restriction system has beneficial effects in the improvement of feed conversion ratio (FCR), weight gain, and carcass traits. In addition, HERBS supplementation to the growing rabbits resulted in significant improvements in growth performance, carcass characteristics, and microbial aspects of rabbits kept from 5 to 13 weeks of age. Highlights: This work investigated the effect of feed restriction systems (FRS), herbal mix (HERBS), and their interactions with rabbits. Restricted feed decreased live body weight during all ages studied. Feed conversion ratio, weight gain and carcass traits were improved due to FRS. The HERBS improved the growth, carcass traits, and microbial aspects of rabbits.

The perinatal experiences in broiler chickens can have a significant impact on the phenotypes of offspring and can affect how they interact with their environment, affecting their health, productivity and welfare. This study aimed to evaluate the synergistic effect of early-age feed restriction and thermal conditioning on the physiological responses of broiler chickens in hot tropical environments. Two hundred forty male Marshall broiler chicks were assigned to four treatments with four replicates of fifteen birds each. The treatments comprised: broiler chicks raised conventionally (CO), broiler chicks exposed to 60% feed restriction at days 4, 5 and 6 (FR), chicks thermally-conditioned (38 °C) at day 5(TC) for 24 h and broiler chicks subjected to thermal conditioning at (38 °C) at day five and exposed to 60% feed restriction at 4,5 and 6 (TCFR). A completely randomized design was used for the experiment. The results obtained revealed that the final body weights of TCFR chickens were significantly higher ( P  < 0.05) than TC, which were higher ( P  < 0.05) than FR and CO chickens. The feed conversion ratio of CO chickens was higher ( P  < 0.05) than those of TC, FR and TCFR. A higher ( P  < 0.05)concentration of serum malondialdehyde was recorded in CO chickens than the other treatment groups. Overall, this study has demonstrated that the combination of early feed restriction and thermal conditioning positively affected broiler chickens’ growth performance and antioxidant status in hot tropical environments. The findings of this study suggest that the use of early-age feed restriction and thermal conditioning could be beneficial in alleviating heat stress in broiler chickens.

Ten Sarda dairy ewes (5 with high Body Condition Score: H-BCS, BCS>2.5; BW 48.8±5.4 kg; 5 with low BCS: L-BCS, BCS<2.5; BW 36.2±4.7 kg) were subjected, after 7-day preliminary (Prel) period, to short-term feed restriction (FR, 50% of nutrient requirements) for three days followed by refeeding (Re-Fed, 100% requirements) for three days. Milk yield and composition (protein, fat, lactose, MUN, SCC, fatty acids), and blood parameters (glucose, NEFA, BUN, insulin, GH, IGF-I, leptin) were monitored. Milk yield decreased during FR in both BCS groups: at day 3 it was 38% and 35% of Prel values in H- BCS and L-BCS ewes, respectively, reaching Prel levels at Re-Fed in both groups. Milk fat concentration was influenced by BCS×sampling, increasing in H-BCS ewes during FR, but not varying in L-BCS ewes throughout the trial. During FR, milk protein increased as milk yield decreased. There was no change in milk urea nitrogen concentration during FR, but this decreased in both BCS groups during Re-Fed. FR modified the FA profile of milk fat in both BCS groups, increasing LCFA at the expense of SCFA and MCFA. Some blood parameters (NEFA, GH and IGF-I) were influenced by BCS, whereas almost all parameters were influenced by sampling. There was a rapid return to initial levels in all parameters except milk urea, blood urea and insulin at Re-Fed.

A reduction in daily caloric or nutrient intake has been observed to promote health benefits in mammals and other vertebrates. Feed Restriction (FR), whereby the overall food intake of the organism is reduced, has been explored as a method to improve metabolic and immune health, as well as to optimize productivity in farming. However, less is known regarding the molecular and physiological consequences of FR. Using the model organism, Danio rerio, we investigated the impact of a short-term (month-long) FR on growth, gut morphology and gene expression. Our data suggest that FR has minimal effects on the average growth rates, but it may affect weight and size heterogeneity in a sex-dependent manner. In the gut, we observed a significant reduction in gut circumference and generally lower mucosal heights, whereas other parameters remained unchanged. Gene Ontology (GO), EuKaryotic Orthologous Groups (KOG), and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis identified numerous metabolic, reproductive, and immune response pathways that were affected by FR. These results broaden our understanding of FR and contribute towards growing knowledge of its effects on vertebrate health.

Evaluated different feed forms (FF), (mash or pellets), feeding systems (FS) (ad libitum or controlled) and metabolizable energy levels (ME) (2,900 kcal/kg or 2,750 kcal/kg) in rearing period 1 (7 to 12 weeks) and 2 (13 to 17 weeks). Utilized 400 brown-egg laying pullets a completely randomized design in 2x2x2 factorial arrangement (eight treatments, with five replications). In period 1, feed intake was similar (P > 0,05) between FF and between ME, however pullets fed ad libitum showed 27.5% higher intake than fed with controlled amounts (P < 0,05). Body weight (BW) differed (P < 0.05) in the FS. Feed conversion (FC) was not affected (P > 0.05) by any of the study factors. Flock uniformity was affected (P < 0.05) by FF and by FS, with an interaction between the factors (P < 0.05). The pullets fed the mash feed ad libitum had better uniformity (P < 0.05) than the pullets fed with the controlled mash feed. The pelleted feed caused the worst uniformity. In rearing period 2, feed intake was affected (P < 0.05). That pullets fed mash or pelletized feed ad libitum consumed 8g more (P < 0.05) on average, than those in the controlled FS. In the ad libitum supply, intake was higher (P < 0.05) for the mash feed than for the pelleted feed. BW and FC were not affected by any of the factors (P > 0.05). Uniformity (%) was influenced by the mash or controlled systems (P < 0.05). Between 7 and 17 weeks of age, brown-egg laying pullets need to be fed with a mashed diet in a controlled feeding system, with 2,750 kcal/kg of metabolizable energy. RESUMO: Foram avaliadas diferentes formas de ração (FA), (farelo ou pellets), sistemas de alimentação (SA) (ad libitum ou controlado) e níveis de energia metabolizável (EM) (2.900 kcal/kg ou 2.750 kcal/kg) nos períodos de criação 1 (7 a 12 semanas) e 2 (13 a 17 semanas). Foram utilizadas 400 frangas poedeiras semipesadas em delineamento inteiramente casualizado em arranjo fatorial 2x2x2 (oito tratamentos, com cinco repetições). No período 1, o consumo de ração foi semelhante (P > 0,05) entre FA e entre SA, porém frangas alimentadas ad libitum apresentaram consumo 27,5% maior do que as alimentadas com quantidades controladas (P < 0,05). O peso corporal (PC) diferiu (P<0,05) no SA. A conversão alimentar (CA) não foi afetada (P > 0,05) por nenhum dos fatores do estudo. A uniformidade do lote foi afetada (P < 0,05) por FF e por FS, com interação entre os fatores (P < 0,05). As frangas alimentadas com ração farelada ad libitum apresentaram melhor uniformidade (P < 0,05) do que as frangas alimentadas com ração farelada controlada. A ração peletizada causou a pior uniformidade. No período de recria 2, o consumo de ração foi afetado (P < 0,05). As frangas alimentadas com ração farelada ou peletizada ad libitum consumiram 8g a mais (P < 0,05) em média, do que aquelas no FS controlado. No fornecimento ad libitum, o consumo foi maior (P < 0,05) para a ração farelada do que para a ração peletizada. O PC e o FC não foram afetados por nenhum dos fatores (P > 0,05). A uniformidade (%) foi influenciada pelo sistema farelado ou controlado (P < 0,05). Entre 7 e 17 semanas de idade, as frangas poedeiras de ovos vermelhos precisam ser alimentadas com dieta farelada em sistema de alimentação controlado, com 2.750 kcal/kg de energia metabolizável.

In this study the effects of the diets on semi-heavy laying hens regarding performance and egg quality were evaluated under different forms of presentation - PF (mash x pelleted), feeding systems - FS (ad libitum x controlled), and metabolizable energy levels - ME (2,800 x 2,550 kcal kg-1). The experiment included 400 laying hens, between 18 and 77 weeks of age, in a completely randomized distribution design following a factorial arrangement of 2x2x2 (with 5 replicates of 10 birds). The birds that had been fed pelleted feed, with ad libitum supply and 2,550 kcal kg-1 of EM demonstrated increased intake of feed and feed conversion; a higher uniformity, however, was identified in the controlled system. The best laying index was observed in birds fed ad libitum and 2,550 kcal kg-1; in the control system, birds fed with mash or pelleted diets revealed greater feed conversion, while higher uniformity was noted in the birds fed on and pelleted, ad libitum. The eggs were heavier in hens fed on the pelleted, ad libitum and 2,800 kcal kg-1 diet. The eggshells were thicker and the yield was higher when they were put on mash diets and 2,800 kcal kg-1. In terms of egg quality, hens given a pelleted diet ad libitum and 2,550 kcal kg-1 of ME produced heavier eggs; those provided with mash or pelleted diets in the control system displayed higher Haugh units. Therefore, for semi-heavy laying hens, the diet recommended is mash feed, ad libitum and 2,550 kcal kg-1 of metabolizable energy. RESUMO: Avaliou-se o efeito de dietas com diferentes formas de apresentação - FA (farelada x peletizada), sistemas de alimentação - SA (à vontade x controlado) e níveis de energia metabolizável - EM (2.800 x 2.550 kcal kg-1) sobre o desempenho e qualidade de ovos de poedeiras semipesadas. Foram utilizadas 400 poedeiras de 18 a 77 semanas de idade, distribuídas em um delineamento inteiramente casualizado, em arranjo fatorial 2x2x2 (oito tratamentos, com cinco repetições de dez aves). As aves alimentadas com ração peletizada, fornecimento à vontade e 2.550 kcal kg-1 de EM apresentaram maior consumo de ração e conversão alimentar; maior uniformidade, entretanto, ocorreu no sistema controlado. Nas interações, no sistema à vontade e 2.550 kcal kg-1 o consumo foi maior comparado ao controlado e 2.800 kcal kg-1; melhor índice de postura ocorreu com fornecimento de ração à vontade e 2.550 kcal kg-1; com dietas fareladas ou peletizadas no sistema controlado, as aves apresentaram melhor conversão alimentar; melhor uniformidade foi observada nas aves arraçoadas à vontade e peletizada. Ovos mais pesados foram obtidos com dieta peletizada, à vontade e 2.800 kcal kg-1. A espessura e rendimento de casca foi maior com dietas fareladas e 2.800 kcal kg-1. Nas interações da qualidade de ovos, os mais pesados obtêm-se com dieta peletizada fornecida à vontade e 2.550 kcal kg-1 de EM, sendo que tanto com dieta farelada ou peletizada no sistema controlado apresentaram maior unidade Haugh. Recomenda-se ração farelada, sistema à vontade e 2.550 kcal kg-1 de energia metabolizável para poedeiras semipesadas.

The purpose of this study was to evaluate different feeding programs for the grower phase (14 to 42 days of age) of two strains of meat-type breeding quail. A total of 480 quails (360 females and 120 males) were distributed in a completely randomized design with a 3x2 factorial scheme (three feeding programs and two strains), totaling six treatments. The feeding programs were: P1 - ad libitum; P2 - controlled daily feeding; and P3 - daily feeding with a 10% restriction of the feed offered in P2. In the controlled daily feeding program, 20, 25, 30, and 30g of feed/bird/day were offered at the ages 14 to 21; 22 to 28; 29 to 35; and 36 to 42 days, respectively. The performance of the quails in the grower phase, sexual maturity, breeding performance, egg quality and incubation parameters were assessed. During the grower phase, it was observed that quails with a 10% feed restriction showed lower feed intake, weight gain and average weight at 42 days of age, in comparison to quails from the treatments. Among the strains, there was only difference in weight at 42 days of age. Regarding the sexual maturity indicators, it was found that quails with a 10% feed restriction were four days later in producing the first egg in comparison to the others. During the laying phase, quails subjected to 10% feed restriction consumed less feed and had lower body weight by the end of the experiment, while those fed ad libitum showed higher mortality. For egg quality parameters and incubation parameters, no interaction was observed between the factors strains and feeding programs. It is concluded that the feeding program with 10% feed restriction from 14 to 42 days of age reduces the weight of quails at 42 days of age, delays sexual maturity and reduces feed intake, mortality and body weight at the end of the laying cycle, without affecting the reproductive parameters of the quails, and is therefore, recommended. RESUMO: Com o objetivo de avaliar diferentes programas de alimentação para a fase de crescimento (14 a 42 dias de idade) de duas linhagens de codornas de corte reprodutoras, 360 fêmeas e 120 machos, totalizando 480 animais, foram distribuídos em delineamento experimental inteiramente casualizado em esquema fatorial 3x2 (três programas alimentares e duas linhagens), com seis tratamentos. Os programas de alimentação foram: P1 - alimentação à vontade; P2 - alimentação diária controlada e P3 - alimentação diária com 10% de restrição da ração ofertada no P2. No programa de alimentação diária controlada, 20, 25, 30, e 30g de ração/ave/dia foram oferecidas às aves nas idades de 14 a 21; 22 a 28; 29 a 35; e 36 a 42 dias de idade, respectivamente. Foram avaliados o desempenho das aves na fase de crescimento, a maturidade sexual, o desempenho das matrizes, qualidade dos ovos e parâmetros de incubação. Na fase de crescimento observou-se que as aves com restrição alimentar de 10% apresentaram menor consumo de ração, ganho de peso e peso médio aos 42 dias de idade, em relação às aves dos demais programas de alimentação. E entre as linhagens, houve diferença apenas para o peso aos 42 dias de idade. Nos indicadores de maturidade sexual, verificou-se que as aves com alimentação restrita em 10% foram quatro dias mais tardias para produzir o primeiro ovo em comparação às demais. Na fase de postura, as aves restritas em 10% apresentaram menor consumo durante e menor peso corporal ao final do experimento, enquanto as aves alimentadas à vontade apresentaram maior mortalidade. Para os parâmetros de qualidade dos ovos e parâmetros de incubação, não foi observado interação entre fatores, linhagens e programas de alimentação. Conclui-se que o programa de alimentação de 14 a 42 dias de idade, com restrição em 10% avaliados, diminui o peso das codornas aos 42 dias de idade, atrasa a maturidade sexual e reduz o consumo de ração, a mortalidade e o peso corporal ao final do ciclo de postura, sem causar prejuízos nos parâmetros reprodutivos das matrizes, sendo, portanto, recomendado.