Feeding of Camelina sativa Seeds to Light-Type Gentile di Puglia Lambs: Effect on Productive Performance and Muscle Fatty Acid Composition.

The effect of different amounts of camelina (CAM; Camelina sativa) seeds in lambs of the Gentile di Puglia breed on growth, carcass characteristics, and meat quality was investigated. Up to 70 days of age, twenty-four male lambs (13.0 ± 0.35 kg) were randomly assigned to three isocaloric and isonitrogenous diets. Pelleted total mixed rations (TMR) were created to provide: (1) a control diet (CON), (2) an experimental corn-based diet including 5% camelina (CAM5) seeds, and (3) an experimental corn-based diet containing 10% camelina (CAM10) seeds. The presence of CAM in the diet impacted lamb performance (p < 0.05), according to the results of a growth study. Lambs were slaughtered at the conclusion of the feeding period, and none of the carcass characteristics investigated were significantly affected by dietary treatment, with the exception of brisket and rib weight and carcass lean, which were improved (p < 0.05) in lambs fed the CAM diet. The color of lamb flesh from the Longissimus lumborum muscle was affected by CAM diets (p < 0.05), but the chemical content and physical characteristics did not differ across treatments (p > 0.05). The fatty acid composition of lamb meat in muscle was somewhat regulated by the experimental diets, with CAM feeding improving (p < 0.05) the level of linolenic acid and MUFA while reducing SFA and PUFA. As a result of the current data, it can be stated that camelina seed supplementation may be included in the lamb diet because no negative impacts on productivity, as well as an enhancement in meat quality, have been found.

Physiological dynamics in broiler chickens under heat stress and possible mitigation strategies.

High ambient temperature has emerged as a major constraint for the future development of the poultry industry, especially in the tropics and subtropics. The scarcity of resources coupled with harsh environmental conditions is the most crucial predicaments in the way to rationalize optimum production of broiler. Heat stress disturbs the physiological biochemistry of the broiler which ultimately reduces feed intake and feed efficiency which ultimately results in reduced performance and productivity. Under hot environmental conditions, feed utilization is disturbed by the deposition of fat and oxidative stress. In addition, changes in blood cells, acid-base balance, immune response, liver health, and antioxidant status are some of the major dynamics altered by heat stress. The broilers have a narrow range of temperatures to withstand heat stress. In this review, we have discussed the various physicochemical changes during heat stress, their possible mechanisms, and mitigation strategies to reduce heat stress.

Dietary vitamin D: growth, physiological and health consequences in broiler production.

Vitamins are needed in trace amounts in dietary formulations for poultry; however, they are critical for the health, maintenance, and performance of important body organs. Broilers have a lot of leg issues because of their rapid development and lack of exercise. Because of commercial broilers have limited access to direct sunlight, vitamin D supplementation in the feed is critical to reducing the risk of bone deformation and maximizing development. Vitamin D deficiency causes skeletal abnormalities, which may lead also to financial problems. The latest scientific findings on the source, metabolism, mechanisms of action, and functions of vitamin D in broilers are the subject of this review paper.

Effects of in ovo feeding of vitamin E or vitamin C on egg hatchability, performance, carcass traits and immunity in broiler chickens.

The effect of in ovo feeding of different levels of vitamins C and E on egg hatchability, immune response, growth and carcass traits of broiler chickens were investigated. A total of 672 fertilized eggs were assigned to one of eight experimental groups having three replicates with 28 eggs as follows: (1) negative control (not injected); (2) positive control (injected with 0.2 mL deionized water); (3) vitamin C at 1 mg; (4) vitamin C at 3 mg; (5) vitamin C at 6 mg; (6) vitamin E at 0.5 IU; (7) vitamin E at 0.75 IU; and (8) vitamin E at 1.0 IU. At the end of incubation, the number of chicks hatched, and their individual body weight were recorded. Among hatched birds, a total of 240 mixed chicks were randomly selected (30 subject per group equally shared in three pen floors). Chicks were vaccinated against Avian Influenza, Gumboro, Bronchitis, and Newcastle disease virus. Performance parameters were weekly evaluated until 42 days of age. At days 28 and 42, broiler serum and spleen and Bursa of Fabricius relative weight were assessed as well as on day 42 the carcass traits. From results, in ovo injection with 3 mg of vitamin C or 0.75 IU of vitamin E, increased significantly (p < .05) the embryos hatchability when compared to the negative control. However, body weight at hatch and growth performance parameters showed no differences among treatments. Similarly, in ovo concentrations of vitamins C or E showed no differences on carcass traits, immunity-related organs weight or immune response for anti-Newcastle disease hemagglutination-inhibition and total immunoglobulins against sheep red blood cells (SRBC) when compared to the control groups. Based on findings, it can be concluded that in ovo feeding vitamins E and C supported positively chicken embryos hatchability demonstrating the key-role as antioxidant agents; however, further studies are currently being evaluated.

The effects of peppermint (Mentha piperita L.) and chicory (Cichorium intybus L.) in comparison with a prebiotic on productive performance, blood constituents, immunity and intestinal microflora in broiler chickens.

A total of 320 one-day-old broiler chickens were used in a 42-day feeding trial to evaluate the effects of peppermint (Mentha piperita L.) and chicory (Cichorium intybus L.) in comparison with a prebiotic on-growth performance, blood constitutes, immunity and intestinal microflora. The dietary treatments were as follows: basal diet (control); control + prebiotic (Fermacto™); control + 0.1% peppermint; control + 0.1% chicory, respectively. A significant (p < 0.05) body weight gain and feed intake was found at 21 and 42 days of growth period in broilers fed diet supplemented with 0.1% chicory compared with other groups. Feeding of prebiotic or chicory led to higher (p < 0.05) feed intake. Chickens fed control diet had higher (p < 0.05) abdominal fat compared with the other groups. Serum blood constituents indicated that broilers fed prebiotic or supplemented with peppermint or chicory had reduced (p < 0.05) levels of cholesterol, triglycerides and low-density lipoprotein than control group. Immunity-related parameters showed that chicken fed chicory had lower (p < 0.05) heterophil-to-lymphocyte ratio compared with the other groups. Intestinal microflora revealed that chickens fed prebiotic or herbals had higher count of Lactobacillus and lower E. coli than control. Thus, it can be concluded that broiler dietary supplementation with prebiotic or chicory can improve performance supporting positively health status.

Effect of dietary flaxseed meal supplemented with dried tomato and grape pomace on performance traits and antioxidant status of laying hens.

This study was carried out to determine the effect of dietary flaxseed meal (FSM) supplemented with dried tomato pomace (DTP) and dried grape pomace (DGP) on performance, egg quality, biochemical parameters traits and antioxidant status of laying hens. Birds (1825 ± 87 g of body weight) were divided into 12 dietary groups with six replicates per group (eight birds per replicate), under a completely randomized design with factorial arrangement 2 × 3 × 2 consisted of two levels of DTP (0 and 15%), three FSM levels (0, 4 and 8%) and two levels of DGP (0 and 5%). As a result of this study, there were no significant differences in egg production and weight as well in feed conversion ratio (FCR) among treatments (p > 0.05). Feeding of DGP reduced significantly feed intake and egg mass when compared to control group (p < 0.05). There was no effect (p > 0.05) of dietary treatment on shell thickness and strength, shape index, Haugh unit and egg specific gravity. Hens consuming 15% DTP and 5% DGP revealed a significantly higher yolk color compared to the other dietary treatments (p < 0.05). Moreover, there was no difference among dietary treatments in terms of serum low-density lipoprotein cholesterol (LDL) and high-density lipoprotein cholesterol (HDL) cholesterol, atherogenic index, triglycerides, total cholesterol levels (p > 0.05). Serum antioxidant parameters as glutathione peroxidase (GSH-Px) activity, malondialdehyde (MDA), total superoxide dismutase (TSOD) and total antioxidant capacity (T-AOC) were not influenced by treatments (p > 0.05). Based on findings, FSM and DTP supplements did not significantly impact most of hens' performance indicators and egg quality parameters, whereas significant improvements were observed by feeding of 15% DTP and 5% DGP on egg traits, in particular on egg-yolk color that plays a key-role in consumer's choice. However, the supplementation of FSM and DTP or DGP even in laying hen diet is still controversial and further research is needed.

Effects of different levels of dietary black cumin (Nigella sativa L.) and fenugreek (Trigonella foenum-graecum L.) and their combination on productive traits, selected blood constituents, microbiota and immunity of broilers.

The effects of inclusion of powdered seeds of black cumin (B) (Nigella sativa L.) and fenugreek (F) (Trigonella foenum-graecum L.) on productive traits, selected blood constituents, microbiota and immunity of broilers were studied. A total of 648 day-old chicks were randomly assigned to nine treatments, with four pen replicates, each with 18 birds, including three levels of B seed powder (BSP; 0, 5 or 10 g/kg) and three levels of F seed powder (FSP; 0, 5 or 10 g/kg) in a 3 × 3 factorial arrangement. Neither powder affected feed intake. The FSP increased (p = 0.048) feed conversion ratio (FCR), but decreased daily BW gain (p = 0.02) between days 0 and 21, while BSP increased daily gain between days 22 and 42 and overall (both p = 0.005). Abdominal fat was decreased (p = 0.003) by BSP. Blood constituents were unaffected by either powder, but ileal Escherichia coli were decreased (p = 0.039) at day 42. The BSP increased a range of immunological titers, where BSP affected positively the measured variables. The interactions between BSP and FSP, specifically on broiler carcass cuts, suggested that where BSP is included at 10 g/kg, the inclusion of FSP at the same level may provide no additional benefit. Thus, while either powder could be included separately, the co-inclusion of both at 10 g/kg is not recommended.

Interaction of blood calcium with luteal activity, energy metabolites and somatic cells count in post-partum dairy cows.

The aim of the research was to assess whether there was a link between serum calcium (Ca) after calving and serum progesterone, milk somatic cells count and Ca, and other blood metabolites in Achai and crossbred cows. Based on blood calcium level shortly after calving, thirty cows from both breeds were divided into a moderate group (≤10.0 mg/dl of Ca) and a high group (>10.0 mg/dl of Ca), with samples collected at 0, 7, 14, 21, 28 and 35 days post-partum, respectively. On day 35 of the post-partum, crossbred and Achai cows with high blood Ca recorded significantly (p < .01) higher serum progesterone, glucose, triglyceride and milk Ca compared with moderate blood Ca group; however, serum cholesterol was significantly (p < .01) higher in both breeds under high blood Ca. Incidence of subclinical mastitis was significantly (p < .01) higher in crossbred and Achai cows under high blood Ca. The results showed that blood progesterone (OR=2.095), glucose (OR=1.024), triglyceride (OR=4.571), cholesterol (OR=1.111) and milk Ca (OR=1.141) resulted in a greater concentration in crossbred compared to Achai cows. A significant (p < .01) correlation was found between blood Ca and other blood metabolites (progesterone, glucose, triglyceride and cholesterol) in both breeds. In conclusion, greater serum Ca concentration after calving is associated with greater serum progesterone, glucose, triglyceride and milk Ca in crossbred cows; however, the incidence of subclinical mastitis increased.

Association among metabolic status, oxidative stress, milk yield, body condition score and reproductive cyclicity in dairy buffaloes.

The aim of this study was to determine the metabolic status, stress and ovarian activity through progesterone profile in dairy buffalo as influenced by post-partum days, body condition score (BCS) and lactation number. A total of 45 dairy buffaloes were involved and divided into three factors based on their BCS (2.5, 3.0 and 3.5, respectively), lactation number (1, 2 and 3, respectively), and post-partum intervals (14, 28, 42 and 56, respectively). Based on findings, from day 14 to day 56 after parturition, blood glucose, cholesterol and triglyceride levels increased significantly (p < .01), while malondialdehyde (MDA) and cortisol levels decreased significantly (p < .05) on day 56 of the trial. With increased BCS levels, milk yield, blood metabolites and progesterone improved significantly (p < .05), whereas stress indicators decreased significantly (p < .01). Blood metabolites, progesterone and milk production were significantly (p < .01) higher and stress indicators (MDA and cortisol) were significantly (p < .01) lower in lactation stage. Buffaloes with a greater lactation stage and growing post-partum stage had better blood metabolite and progesterone concentrations and less stress. It was concluded that better BCS and increased lactation stage have significant impact on milk yield, stress reduction and restoration of ovarian activity in buffaloes during post-partum period.

Influence of dietary L-carnitine and lysine-methionine levels on reproductive performance and blood metabolic constituents of breeder ducks.

The present study aimed to evaluate the influence of dietary supplementation of different levels of L-carnitine and/or lysine-methionine (Lys-Met) on reproductive performance of breeder ducks. Three L-carnitine (0, 75 and 150 mg/kg) and three lysine-methionine (100%, 110% and 120% above the NRC (Nutrient requirements of poultry, 1994, National Academy Press) recommendations) levels were fed to 180 breeder ducks (144 females and 36 males) in a completely randomized design for 49 days. Laying performance and reproductive traits were evaluated; additionally, uric acid, total protein total, triglycerides, total cholesterol, low-density lipoprotein, high-density lipoprotein, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were assessed. The Lys-Met above 100% NRC (Nutrient requirements of poultry, 1994, National Academy Press) recommendations with or without L-carnitine improved feed utilization (p < .05). Furthermore, Lys-Met above 100% recommendations without L-carnitine improved egg fertility and hatchability. Fertility and hatchability improved in breeders fed on L-carnitine with 120% Lys-Met (p < .05). Serum glucose increased and total cholesterol reduced on 100% Ly-Met without L-carnitine or 110% Ly-Met with 150 mg L-carnitine (p < .05). Glucose was reduced, while total cholesterol increased on 75 mg L-carnitine and 100% Lys-Met (p < .05). Increasing Lys-Met without L-carnitine reduced serum protein (p < .05). Albumin and ALT increased on 75 mg L-carnitine-100% Lys-Met and reduced on 150 mg L-carnitine-120% Lys-Met (p < .05). There were no interaction effects on globulin, uric acid and AST (p > .05). Thus, based on findings, breeder ducks responded to dietary Lys-Met more efficiently than L-carnitine; however, more research is needed to evaluate also economic aspects related to L-carnitine dietary supplementation.

Effect of dietary sesame (Sesame indicum L) seed meal level supplemented with lysine and phytase on performance traits and antioxidant status of late-phase laying hens.

OBJECTIVE: This study was performed to investigate the effects of supplementing sesame seed meal (SSM) with phytase and lysine on performance, egg quality, blood biochemical and antioxidant status of laying hens. METHODS: A total of 960, 56-wk-old laying hens were divided into 12 dietary groups with eight replicates per group (10 birds per replicate). A completely randomized design with factorial arrangement 2×3×2 consisted of two levels of lysine supplement (0 and 10% over requirement), three SSM levels (0, 10 and 20%) with or without phytase (0 and 300 g/ton). The feeding trial lasted 10 weeks. RESULTS: From findings, birds fed diets with 10% SSM had higher feed intake than groups fed 0 and 20% SSM. The addition of phytase to experimental feeds, improved feed conversion ratio (FCR), increased egg weight and mass (P&lt;0.01). Egg quality criteria was not affected by supplementing phytase; however, supplementing 300 g/ton phytase to hens diet, led to a significant (P&lt;0. 05) increase in egg shell strength. Egg yolk cholesterol and serum low-density lipoprotein cholesterol (LDL-C), atherogenic index and total cholesterol were decreased (P&lt;0.01) by diet containing 20% SSM. The high-density lipoprotein cholesterol (HDL-C) was increased (P&lt;0.05) in serum of hens fed 20% SSM than the other groups. It was also observed that total antioxidant capacity (TAC) and total superoxide dismutase (TSOD) content of hens fed 20% SSM was significantly upper than control group (P&lt;0.05). CONCLUSION: As from results, dietary supplementation of SSM and phytase had no negative effects on laying hens performance or egg quality improving also the egg oxidative stability.

Efficacy and role of inulin in mitigation of enteric sulfur-containing odor in pigs.

BACKGROUND: The efficacy and role of inulin in the mitigation of enteric sulfur-containing odor gases hydrogen sulfide (H2 S) and methyl mercaptan (CH3 SH) in pigs were examined in this study. Twelve Duroc × Landrace × Yorkshire male finisher pigs (60.7 ± 1.9 kg), housed individually in open-circuit respiration chambers, were randomly assigned to two dietary groups, namely basal diet (control) and basal diet supplemented with 1% (w/w) inulin. At the end of the 45 day experiment, pigs were slaughtered and volatile fatty acid (VFA) concentration, sulfate radical (SO42- ) concentration, population of sulfate-reducing bacteria (SRB) and expression of methionine gamma-lyase (MGL) gene were determined in contents from the caecum, colon (two segments) and rectum. Metabonomic analysis was used to compare differences in biochemical composition, and the Illumina MiSeq procedure to investigate differences in bacterial components, in the different parts of the large intestine between inulin-supplemented and inulin-free (control) groups. RESULTS: Inulin decreased (P < 0.05) the average daily enteric H2 S and CH3 SH production by 12.4 and 12.1% respectively. The concentrations of acetate, propionate and butyrate in the large intestinal content were significantly increased (P < 0.05) with inulin treatment, whereas valerate concentration and MGL mRNA expression decreased (P < 0.05). The growth of Lactobacillus, Butyrivibrio, Pseudobutyrivibrio, Bifidobacterium and Clostridium butyricum was stimulated, while that of Desulfovibrio, the dominant SRB, was inhibited, and there was an accumulation of SO42- in the large intestinal content of the inulin-supplemented pigs, suggesting that inulin mitigates H2 S generation from the SO42- reduction pathway by reducing the growth of SRB. CONCLUSION: The results showed that inulin mitigates CH3 SH generation via three methionine degradation metabolic pathways and H2 S generation from two cysteine degradation metabolic pathways, thus resulting in increased synthesis of these two sulfur-containing amino acids in the pig large intestine. © 2016 Society of Chemical Industry.

Dietary high-polyphenols extra-virgin olive oil is effective in reducing cholesterol content in eggs.

BACKGROUND: Extra-virgin olive oil (EVOO) represents an important food in Mediterranean diet due to its favorable effects on human and animal health derived from the consumption of polyphenols. We studied the effects of dietary EVOO differing in polyphenols levels on egg quality. METHODS: A total of 150 laying hens were allotted into three groups over 10 weeks of the experimental period. The three diets were based on wheat-soybean meal with added oils at 2.5%. Hens were fed the following diets: (1) commercial diet containing sunflower oil (Control), (2) diet EVOO from Cima di Bitonto variety (low-polyphenols content; Low-P), and (3) diet EVOO from Coratina variety (high-polyphenols content; High-P). The performance of the hen, the qualitative traits of eggs, and the fatty acid composition and cholesterol content of egg-yolk were measured. RESULTS: None of the egg productive parameters studied were influenced by dietary treatment, except for yolk color score that was enhanced in hens fed the both EVOO diets (P<0.05). Feeding high-polyphenols EVOO reduced serum cholesterol level in hens (P<0.01) and egg-yolk cholesterol levels (as per egg; P<0.05). The dietary supplementation of high-polyphenols EVOO raised the polyunsaturated fatty acids (PUFAs) composition and increased the content of oleic and linolenic acids in egg-yolk. Moreover, the atherogenic index in egg-yolk decreased linearly in accordance with increasing levels of dietary polyphenols (P<0.01). CONCLUSION: In conclusion, a diet for hens consisting of high-polyphenols level from extra-virgin olive oil can improve the fatty acid quality of egg-yolk while lowering the egg-yolk cholesterol level, which could be a beneficial functional food for human health.

Effect of oligosaccharides extract from palm kernel expeller on growth performance, gut microbiota and immune response in broiler chickens.

This study examined the prebiotic effects of oligosaccharides extract from palm kernel expeller (OligoPKE) on growth performance, cecal microbiota and immune response of broiler chickens. A total of ninety 1-day-old broiler chicks (Cobb-500) were randomly allocated to three treatment groups of six pens (replicates) with five birds per pen. Dietary treatments were: (i) basal diet as control, (ii) basal diet plus 0.5% OligoPKE, and (iii) basal diet plus 1% OligoPKE. Birds growth traits (ADG, ADFI and G:F) were measured during the starter (1-21 day), finisher (22-35 day) and the entire experimental periods. Blood and cecal digesta samples were collected from chickens at 21 and 35 days of age (DOA). Microbial quantification of the digesta samples, white blood cells including heterophil, lymphocyte, monocyte, eosinophil, basophil counts and immunoglobulin (IgA and IgM) were also determined. OligoPKE had no effect on ADG and ADFI throughout the study period, but chickens fed OligoPKE supplemented diet had better (P < 0.05) G:F during finisher and overall rearing periods. Supplementing OligoPKE did not significantly alter the birds' microbiota of the cecal digesta. At 21 DOA, blood IgA concentration increased significantly when birds fed 1% OligoPKE in diet recorded compared to the control treatment. Similar observations were also recorded in birds at 35 DOA. Hematological data showed that heterophil and basophil counts of chickens fed OligoPKE supplement were lower than those in control group at 21 DOA. Our findings suggested that OligoPKE improved immune responses in broiler chickens, especially at younger age when the immune system is not still fully developed.

Evaluating pasture and soil allowance of manganese for Kajli rams grazing in semi-arid environment.

The current research on the manganese (Mn) transfer from soil to plant as well as to grazing Kajli rams in the form of sampling periods was carried out under semi-arid environmental conditions. Forage, soil and blood plasma samples were collected during 4 months of the year after a 1-month interval, and Mn concentrations were assessed after wet digestion using an atomic absorption spectrophotometer. Results showed that Mn concentration in soil ranged from 48.28 to 59.44 mg/kg, with incoherent augment and decline across sampling periods, and effect of sampling period on soil Mn was also found to be significant (P < 0.05). The mean levels of Mn in soil appeared higher than the critical value and sufficient for forage crop requirement. The Mn concentration in forage ranged between 24.8 and 37.2 mg/kg, resulting deficient based on the requirement allowance of Mn for livestock grazing animals, therein with almost unchanged forage Mn concentration. The Mn values in blood plasma of rams varied from 0.066 to 0.089 mg/l, with a consistent increase based on sampling period, and the effect of sampling periods on plasma Mn was found to be highly significant (P < 0.05). The Mn levels in ram blood plasma were lesser than the normal level suggesting reasonable need for supplementation. Our study revealed the role of Mn availability in soil and plant species amassing capability on the transport of Mn in the soil-plant-animal system. Results indicated a much higher accumulation rate at the sampling characterized by vegetation dominated by legumes in comparison to grasses, crop residues and mixed pasture and a pronounced seasonal supply of Mn at the four sampling period of grazing land of diverse botanical composition.

Feeding of Dehulled-micronized Faba Bean (Vicia faba var. minor) as Substitute for Soybean Meal in Guinea Fowl Broilers: Effect on Productive Performance and Meat Quality.

The present study aimed to assess the effect of dietary substitution of soybean meal (SBM) with dehulled-micronized faba bean (Vicia faba var. minor) in guinea fowl broilers on their growth traits, carcass quality, and meat fatty acids composition. In this trial, 120 day-old guinea fowl keets were randomly assigned to two treatments which were fed from hatch to 12 weeks of age. Birds were fed two wheat middlings-based diets comprising of a control treatment which contained SBM (78.3 g/kg) and a test diet containing dehulled-micronized faba bean (130 g/kg) as the main protein source. Substituting SBM with faba bean had no adverse effect on growth traits, dressing percentage, or breast and thigh muscles relative weight of the guinea fowls. Conversely, a decrease (p<0.05) of abdominal fat was found in guinea fowls fed the faba bean-diet. Breast muscle of birds fed faba bean had higher L* score (p<0.05) and water-holding capacity (p<0.05) than the SBM control diet. Meat from guinea fowls fed faba bean had less total lipids (p<0.05) and cholesterol (p<0.01), and higher concentrations of phospholipids (p<0.01). Feeding faba bean increased polyunsaturated fatty acid concentrations in breast meat and decreased the saturated fatty acid levels. Moreover, dietary faba bean improved the atherogenic and thrombogenic indexes in guinea fowl breast meat. Results indicated that substitution of SBM with faba bean meal in guinea fowl diet can improve carcass qualitative traits, enhancing also meat lipid profile without negatively affecting growth performance.

Major proteins in goat milk: an updated overview on genetic variability.

Milk and dairy products are very important in Mediterranean diet because of their health promoting and organoleptic properties. In many developing countries, goat rearing has a key role in livestock production. What makes goats so popular is their ability to provide high quality food under diverse climatic conditions and resilience to extreme and capricious environments. In the last years, the interest concerning caprine milk has been increasing also to find a new exploitation for local breeds. To promote the goat dairy products there is a clear need to know the quality and the technological aspects of milk produced. That being so, the purpose of this study was to review the available literature on the major goat milk proteins with a particular attention to recent findings on their genetic variability. Moreover, the main effects of different protein variants on milk yield and composition were also discussed.

Investigating the genetic polymorphism of sheep milk proteins: a useful tool for dairy production.

Sheep is the second most important dairy species after cow worldwide, and especially in the Mediterranean and Middle East regions. In some countries, the difficult environmental conditions require a peculiar adaptation and, in these contexts, sheep are able to provide higher quality protein than cattle. In the least-developed countries, the amount of dairy sheep and ovine milk production is progressively increasing. In order to improve dairy productions, in particular those with local connotations, it is necessary to obtain in-depth information regarding milk quality and rheological properties. The genetic polymorphisms of milk proteins are often associated with quantitative and qualitative parameters in milk and are potential candidate markers that should be included in breeding strategies similar to those already available for cattle. Due to the current and growing interest in this topic and considering the large amount of new information, the aim of this study was to review the literature on sheep milk protein polymorphisms with a particular emphasis on recent findings in order to give scientists useful support. Moreover, the effects of different protein variants on milk yield and composition are discussed.

Effect of rearing system (free-range vs cage) on gut and muscle histomorphology and microbial loads of Italian White breed rabbits.

OBJECTIVE: The growing consumers' interest on animal welfare has raised the request of products obtained by alternative rearing systems. The present study was conducted to assess the influence of housing system on gut and muscle morphology and on microbial load in rabbits reared under free-range (FR) and cage system (CS). METHODS: A total of forty weaned (35 days of age) male Italian White breed rabbits were allotted according to the rearing system, and at 91 days of age were randomly selected and slaughtered for the morphological evaluation of tissue from duodenum and longissimus lumborum. Morphometric analysis of the villus height, villus width, crypt depth, villus height/crypt depth ratio, and villus surface was performed. The microbial loads on hind muscle was determined by total mesophilic aerobic count (TMAC), Escherichia coli and Enterobacteriaceae; whereas, total anaerobic bacteria count (TABC) and TMAC, E. coli and Enterobacteriaceae was determined on caecal content. RESULTS: Rearing system did not interfere with the duodenum and muscle histomorphology in both rabbit groups. Similarly, microbial load of caecal content showed no significant differences on the TABC and TMAC. Conversely, significant difference was found for E. coli strains in caecal content, with the lower counts in FR compared to CS rabbits (p<0.01). Microbiological assay of muscle revealed significant lower TMAC in FR vs CS rabbits (p< 0.05). All rabbit meat samples were negative for E. Coli and Enterobacteriaceae. CONCLUSION: Free-range could be considered a possible alternative and sustainable rearing system in rabbits to preserve gut environment and muscle quality.

Influence of dietary fat source on growth performance responses and carcass traits of broiler chicks.

This study was conducted to determine the effects of three different fat sources and their combination on growth performance, carcass traits and intestinal measurements of broiler chickens reared to 42 d of age. Two hundred day-old male broiler chicks (Ross 308) were randomly assigned to one of five treatments with four replicates of 10 chicks based on a completely randomized design. The dietary treatments consisted of 4% added fat from three different sources and their combination as follows: T, diet containing 4% tallow; CO, diet containing 4% canola oil; SFO, diet containing 4% sunflower oil; TCO, diet containing 2% tallow+2% canola oil; TSFO, diet containing 2% tallow+2% sunflower oil. Dietary fat type affected significantly BW and gain as well as feed efficiency in birds fed the TCO diets compared with those fed the other diets. Dietary fat type also modified meat yield, resulting in a higher breast and drumstick yields in the birds fed TCO and TSFO diets, respectively. Most of internal organ relative weights and small intestine measurements were not influenced by dietary treatments, except for the abdominal fat pad weight that was lower in birds fed SFO and for small intestinal length that was influenced by fat source. Results from the current study suggested that the supplementation with a combination of vegetable and animal fat sources in broiler diet supported positively growth performance and carcass parameters.