Carcass Yield Research Articles

Effects of calcium pidolate on performance, carcass traits, bone biomechanical properties and mineralisation and jejunum histomorphology in broilers

ABSTRACT 1. The current study was conducted to determine the effect of dietary calcium pidolate (CalP) on performance, slaughtering characteristics, bone biomechanical properties, mineralisation and jejunum histomorphology in male broilers. A total of 200 one-day-old Ross 308 male chicks were randomly assigned to one of four treatments as five pen replicates, each containing 10 chicks. The basal diet without CalP was formulated to supply the nutritional needs of broilers and the treatment diets contained 0.30, 0.45 and 0.60 g/kg CalP, with limestone meeting the remaining calcium requirement. 2. The addition of CalP had a quadratic effect on performance (P < 0.05) and the best performance was achieved in the group that included CalP at a dose of 0.45 g/kg but 0.60 g/kg level worsened performance. Supplementing with CalP linearly decreased carcass yield (P < 0.01) and relative breast weight (P ≤ 0.05) but the relative thigh weight increased quadratically (P < 0.05) and reached a maximum at 0.45 g/kg. 3. Tibia shear force and stress linearly increased with the use of CalP in the diet (P < 0.05). Supplementation had a quadratic effect on tibial calcium (P < 0.01), reaching a maximum at 0.30 g/kg, although tibial phosphorus levels decreased linearly (P < 0.01). 4. The effect of CalP on jejunum histomorphology fluctuated and, compared to the unsupplemented control group, the villus height/crypt depth ratio increased, while the other variables decreased (P < 0.05). Decrease in crypt depth with the addition of CalP was significant (P < 0.05). 5. Using Ca-pidolate at a rate of 0.45 g/kg in broiler diets is sufficient to increase performance and tibia strength but 0.60 g/kg level negatively affected performance. In addition, the results of jejunum histomorphology were variable, but the crypt depth decreased with CalP levels and this is an important effect. However, further research is needed to detail the effect of CalP on broilers.

Effect of Incorporating Hibiscus sabdariffa Seed Flour (Red Variety) on Zootechnical Performance of Broilers Chickens Cobb500 Strain

The aim of this study was to evaluate effects of incorporating red Hibiscus sabdariffa seed meal into the feed ration on the growth performance, carcass characteristics and economic margins of broiler chickens in Côte d'Ivoire. To achieve this, 237 broiler chicks of the Cobb500 strain, two (2) weeks old, were divided into three (3) lots of 79 birds each. lot 1 was fed with ration that did not contain Hibiscus sabdariffa red variety (HSR0) seed meal. Lots 2 and 3 were fed respectively by ration HSR 2% and HSR 4% by which contain 2 % and 4 % of Hibiscus sabdariffa seed meal respectively. The results showed that the inclusion of Hibiscus sabdariffa seeds significantly reduced food consumption in subjects fed HSR 2 and HSR 4 compared with ration HSR 0 (control). It varied from 38.71 ± 1.26 g/d to 161 ± 5.08 g/d for lot 2 and from 37.85 ± 1.16 g/d to 148 ± 6.08 g/d for lot 3 compared with 39.8±1.3 g/dr to 172 ± 7.2 g/d for lot 1. On other hand, the subjects in lot 2 achieved better growth performance than the other lots. They recorded an average weight of 2,334±208.6 g compared with 2,213 ± 170.78 g and 1,958 ± 182.57 g for lots 1 and 3 respectively. Over the 4-week period, the highest mortality rate was observed in lot 1, at 10.13 %. No negative effect was observed on the carcass yield of chickens fed Hibiscus sabdariffa meal. In economic terms, incorporation reduced the production cost of broilers. In conclusion Hibiscus sabdariffa seeds can therefore be incorporated up to 2% into chicken rations without causing any significant loss in chicken weight. Studies need to be carried out to improve the organoleptic quality of Hibiscus sabdariffa seeds.

Productivity and economic performance of Nellore young bulls fed diets with increasing fiber content.

Adequate neutral detergent insoluble fiber (NDF) content in the total diet can improve intake efficiency, prevent rumen disorders, and enhance the health and performance of feedlot-finished beef cattle. We hypothesized that an increase in dietary fiber levels would decrease the productive performance but increase the economic performance of young bulls in confinement. Thus, it was aimed to evaluate the effect of increasing fiber levels on feed intake, wastage, and productive and economic performance of Nellore young bulls finished in confinement. We used 20 Nellore cattle, non-castrated males, 30 months old, and average body weight (BW) of 416.35 ± 2.2kg distributed in a completely randomized design, kept in individual stalls. Animals were divided into four treatments consisting of four levels of neutral detergent insoluble fiber (NDF) (25%, 30%, 35%, and 40% NDF) in total DM. Nutrient intake, feed conversion, feed waste, body weight (BW) at slaughter, total weight gain (TWG), average daily gain (ADG), hot carcass weight (HCW), and carcass yield (CR) were evaluated. In addition, economic parameters (revenue, food expenses, and gross margin) were calculated and compared. The dry matter (DMI), organic matter (OMI), crude protein (CPI), and ether extract (EEI) intakes showed quadratic behavior. The DMI maximum estimated was 28.5% NDF in the diet. The NDF and ADF intakes showed a positive linear effect and the starch intake had a negative linear effect. There was a significant positive linear effect (P < 0.05) for the variables total mixed ration (TMR) offered and daily and total RTM intake. Minimum RTM wastage was estimated with a diet containing 30% NDF. The maximum points for BW at slaughter, HCW, and ADG were 29.9%; 29.6%, and 25% NDF, respectively. The costs of concentrate and silage showed a positive linear behavior, as did the ADG costs and the carcass equivalent cost (P < 0.05). The maximum point of the revenue estimate (US$/animal) was 29.9% of NDF, 26.1% of NDF for the total expenditure on food (US$/animal), and 32.5% of NDF for the gross margin (U$/animal). In conclusion, the animals fed a 30% NDF diet showed the best performance and economics, in addition to less food waste. We recommend 25 to 32.5% of NDF in the diet to obtain maximum productive and economic performance when finishing Nellore young bulls in confinement.

Effect of coated calcium feeding on growth performance, carcass traits, immunity, blood biochemistry and tibial bone morphometry in commercial broiler chicken.

The bone abnormalities pose great concern in heavy, rapidly growing broilers, resulting in significant economic loss, and health issues in birds. To address these problems and prevent unnecessary mineral excretion into environment, it is crucial to optimise the inclusion level of dietary calcium in broiler's diet. The calcium utilisation by the bird is also affected by its source, particle size, bioavailability etc. Hence this study aimed to study the effect of partially replacing conventional dietary calcium source with coated calcium on growth performance, immune response, carcass traits, blood calcium and phosphorus, and mineral retention in broilers. About 416 broiler chicks were randomly distributed into four treatments, each with eight replicates of 13 birds and fed with iso-calcium, isocaloric, and isonitrogenous diet for 42 days. The T0 (control) was a basal diet while the T1, T2, and T3, were treatment diets in which conventional calcium source (limestone) was partially replaced with coated calcium by 10, 20, and 30% respectively. The birds of T3 group showed higher (P < 0.05) body weight gain, better feed conversion ratio and higher carcass yields compared to T0, T1, and T2 diet fed birds. Further the treatment groups exhibited higher (P < 0.05) cell-mediated and humoral immune responses and immune organ weights compared to control. The tibial bone weight, length and average diameter was highest (P < 0.05) in T3. Moreover, the T3 diet fed group also showed higher (P < 0.05) calcium and phosphorus content in serum and bone and lowest content of these minerals in the excreta followed by T2, T1 and control. These findings suggest that a 30% conventional calcium source with coated calcium may be used as a high-grade mineral source for broiler chicken feed.

The efficacy of crossbreeding on reproductive and productive performance in New Zealand White and Flemish Giant rabbits

Crossbreeding is a well-established practice in livestock production aimed at improving reproductive and productive traits. This study evaluated the effects of crossbreeding on rabbits, focusing on comparisons between purebred Flemish Giant (n = 10), New Zealand White (n = 23), and their crossbred offspring (n = 27). Various parameters, including litter size, body weight, growth rate, and mortality, were assessed. The results demonstrated that crossbred rabbits presented a 15% faster growth rate than purebred rabbits, along with the lowest mortality rate and highest total meat output. This phenomenon, attributed to hybrid vigour, effectively blends the large frame of the Flemish Giant with the good litter size of the New Zealand White. Furthermore, statistical analyses, including ANOVA and Tukey‒Kramer’s honestly significant test, confirmed the significant effects of breed class on productivity, body weight, and carcass yield. Growth curves estimated using the Gompertz model highlighted the superior performance of crossbred rabbits under semiarid conditions. Notably, crossbreeding resulted in offspring with the highest dressing percentage and overall improved performance, offering potential advantages for rabbit producers worldwide.

Effect of Stocking Density on Growth Performance and Carcass Characteristics of Broilers Grown to 3 Kg under Antibiotic Free Diets1,2

Background: Stocking densities could have a significant impact on birds when reducing or eliminating antimicrobials (antibiotic-free; ABF) in poultry diets. This study investigated the effects of stocking densities on growth performance and carcass characteristics of broilers fed antibiotic-free diets grown to 3 kg. Methods: A total of 888 1-d-old Ross × Ross 708 chicks were randomly distributed into 24 pens. The treatments were four stocking densities including 29, 33, 39 and 42 kg of BW/m2; each treatment was represented by six replicates. Treatments were blocked within the room to account for any variations in room conditions. Treatment assignments were randomized within each block. Used bedding was obtained from commercial farms to simulate commercial conditions and litter microflora. Birds were fed antibiotic-free (ABF) diets and provided a three phase-feeding program (Starter: 0-14 d, Grower: 15-28 d and Finisher: 29-42 d). Feed and water were provided ad libitum. Birds and feed were weighed on 1, 14, 28 and 42 d of age to measure growth performance. On d 43, 10 (5 males and 5 females) birds from each pen were processed to determine weights and yields. Result: The BW and BW gain, live weight, carcass weights and carcass yield percentage were not affected by stocking density. Also, mortality was not affected by stocking density. However, FI and FCR for the starter period were significantly elevated (P less than 0.001 and P less than 0.001, respectively) at lower stocking densities, but were not different for the remainder of the growout. In conclusion, stocking densities evaluated from 29 to 42 kg/m2 with appropriate environmental management has a negligible effect on overall production and processing yield in ABF broilers.

The Productive and physico-chemical performance at two seasons of the year in trout (oncorhynchus mykiss)

The objective of the research was to evaluate the productive and physicochemical performance of trout (Oncorhynchus mykiss) in two seasons of the year. The months of April-June for the rainy season and July-September for the dry season in the Junín region of Peru were considered. The productive performance variables were: length, live weight, carcass weight and yield; on the other hand, the physicochemical variable (pH, water retention, humidity, ash, ethereal extract and protein). The results indicate that no differences (p&gt;0.05) were found between the rainy and dry seasons for: length (cm), moisture (%), ash (%), ethereal extract (%) and protein (%). On the contrary, differences (p&lt;0.05) were found between the rainy and dry seasons for live weight (g) with 239.37 g and 186.30 g respectively, as well as differences for carcass weight (g) in the rainy (186.30 g) and dry (140.77 g) seasons; likewise, differences were found for carcass yield (%), with 88.17 % and 86.89 % for the rainy and dry seasons, respectively. It is evident that in the rainy season there is an increase in their productive behavior. In terms of physicochemical performance, both seasons do not influence the chemical characteristics

Effect of Long-Term Supplementation of AZOMITE (Hydrated Sodium Calcium Aluminosilicate) in Finishing Diets on Growth Performance, Dietary Energy, and Carcass Yield of Hairy Lambs.

The aim of this study was to evaluate growth performance, dietary energy utilization, and carcass characteristics (carcass weight, dressing percentage, and visceral organ mass) of feedlot lambs fed different levels of AZOMITE (AZO), a source of volcanic clay composed of hydrated sodium calcium aluminosilicate, the same as that included in a finishing diet. For this reason, 36 Pelibuey × Katahdin crossbred intact male lambs (18.81 ± 3.04 kg initial weight) were used in a feeding trial lasting 81 d. Lambs were grouped by initial weight and assigned within six weight groupings to 18 pens in a randomized complete block design. Diets, offered ad libitum, were corn-based finishing diets with an 88:12 concentrate-to-forage ratio supplemented as follows: 1) no AZO inclusion (CTRL), 2) AZO inclusion at a 0.75% level (0.75AZO) in diet dry matter, 3) AZO inclusion at a 1.50% level (1.5AZO) in diet dry matter. Cracked corn was replaced by AZO. After the feeding trial was finished, lambs were slaughtered and carcass weight was registered and dressing percentage was calculated. The data were analyzed as a randomized complete block design, with the pen as the experimental unit. Water consumption and dry matter intake were not affected (p ≥ 0.11) by supplemental AZO. The incorporation of AZO into the diet increased gain efficiency and observed dietary net energy (NE), being maximal with 0.75% AZO inclusion (quadratic effect, p = 0.02). The observed-to-expected dietary NE in the control group was as anticipated (1.00) according to the estimated energy based on the ingredient composition in diet, while in the 0.75AZO group, the observed dietary energy was 6% above expected, indicating a greater efficiency in energy utilization destined to growth (quadratic effect, p = 0.006). Lambs that were fed the AZO treatment showed an improvement (linear effect, p = 0.04) in hot carcass weight (HCW), and tended (linear effect, p = 0.06) to improve dressing percentage (DP) as AZO was increased in the diet. Visceral organ mass was not affected by the treatments. It is concluded that AZOMITE clay can be included up to 1.5% in finishing diets for lambs without negative effects on the intake of water and feed. Lambs that received diets supplemented with 0.75% AZO showed greater improvements in feed efficiency and dietary energy utilization, but an inclusion of 1.50% resulted in greater improvements to HCW and DP. This is the first report regarding the effects of AZO supplementation in the dietary energy utilization of fattening hairy lambs. Further research about the effects of AZO supplementation on ruminal and total tract digestion, carcass and meat quality, and the health of lambs is needed in order to more deeply understand the effects of AZO on its productivity performance.

Ultrasound-Based Phenotyping for Genetic Selection of Carcass Traits in Oreochromis niloticus: Integrating Imaging Technology Into Aquaculture Breeding.

Recent years have witnessed a remarkable global surge in fish production, with Nile tilapia (Oreochromis niloticus) emerging as a prominent contributor owing to its high demand as a nutritious food source. However, unlike terrestrial species, maintaining genealogical control and collecting phenotypic data in fish farming poses significant challenges, necessitating advancements to support genetic improvement programmes. While conventional methods, such as body measurements using rulers and photographs are prevalent in data collection, the potential of ultrasound-a less invasive and efficient tool for fish measurement-remains underexplored. This study assesses the viability of ultrasonography for genetically selecting carcass characteristics in Nile tilapia. The investigation encompasses data from 897 animals representing 53 full-sib tilapia families maintained in the genetic improvement programme at the Federal University of Lavras. To measure carcass traits, the animals were sedated with benzocaine and ultrasound images were obtained at three distinct points. Subsequently, the animals were euthanised through medullary sectioning for further carcass processing. After evisceration, filleting and skinning, all weights were meticulously recorded. (Co)variance components and genetic parameters of the measured traits were estimated using the Bayesian approach by Gibbs sampling implemented in MTGSAM (Multiple Trait Gibbs Sampling in Animal Models) software. Heritabilities estimated for the studied carcass traits were moderate, ranging from 0.23 to 0.33. Notably, phenotypes derived from ultrasound images demonstrated substantial genetic correlations with fillet yield (0.83-0.92). In conclusion, this study confirms that indirect selection based on ultrasound images is effective and holds promise for integration into tilapia breeding programmes aimed at enhancing carcass yield.

Prickly pear (Opuntia ficus-indica) dehydrated envelopes and seed cakes in Coturnix coturnix feed: effects on growth performance, carcass characteristics, meat quality and blood biochemical profiles.

The valorization of agro-industrial byproducts in domestic animal feed has the potential to reduce the cost of animal production. This trial was conducted to determine the effect of incorporating prickly pear byproducts (envelopes and cakes) as a partial substitute for corn and soybean meal in the diet of wheat quails (Coturnix coturnix) during their rearing period. Six hundred-day-old Coturnix coturnix quails of equal sex ratio (1:1), weighing on average 7 ± 0.5g, were randomly distributed into four groups, one control group and three experimental groups, according to the rates of incorporation of prickly pear cakes and envelopes, in sequential or nonsequential mode, in the different rearing phases. Each batch (150 subjects) was subdivided into five packs of 30 animals and randomly distributed according to the rate of incorporation (0%, 10%, 20% and 30%) of prickly pear envelopes and cakes. The live weight at 45 days and average daily gain (ADG1 - 45d) increased significantly with the introduction of byproducts in all rearing phases (SFCEPP). The carcass yield increased significantly (p < 0.05) with the introduction of byproducts in the finishing phase (FCEPP) and in all rearing phases (SFCEPP). The mineral content decreased significantly (p < 0.05) in all the experimental groups. The protein content increased significantly by 2 points on average when the two prickly pear byproducts were introduced in all rearing phases. The blood biochemical profile of each experimental batch was not influenced by the incorporated prickly pear byproducts. Prickly pear envelopes and cakes in wheat quail feed improve growth performance and meat quality, particularly when they are introduced in the finishing phase and in all rearing phases.

Advanced chelate technology-based trace minerals reduce inflammation and oxidative stress in Eimeria-infected broilers by modulating NF-kB and Nrf2 pathways

This study investigated the effects of substituting inorganic trace minerals (ITM) with advanced chelate technology-based TM (ACTM) in broiler chicken feed on productive performance, metabolic profile, humoral immunity, antioxidant status, and modulation of NF-kB and Nrf2 signaling pathways in mixed Eimeria species exposure. The study involved 480 newly hatched male broiler chickens, which were divided into 5 treatment groups, each with 6 replicate cages and 16 chickens per replicate. The experimental treatments included an uninfected negative control group fed a basal diet with recommended inorganic TM levels (NC), an infected positive control group fed the same diet (PC), a PC group supplemented with salinomycin (SAL), and two PC groups in which the basal diet was replaced with 50% and 100% ACTM instead of inorganic TM (ACTM50 and ACTM100, respectively). All groups, except for the NC group, were orally challenged with mixed Eimeria species oocysts on day 14. According to the results, the PC group showed lower feed intake, breast yield, low-density lipoprotein-cholesterol concentration, lactobacillus spp. counts, and serum IgG levels, but higher jejunal TGF-β expression versus the NC group. The broilers in the NC, SAL, and ACTM100 groups showed higher body weight gain, carcass yield, and TGF-β expression, but lower serum alkaline phosphatase activity, ileal E. coli count, and jejunal expression levels of IL-1β, IL-6, IFN-γ, Nrf2, and SOD1 compared to the PC group, with the NC group having the highest body weight gain and lowest IL-1β and Nrf2 expression levels. Furthermore, the administration of ACTM100 treatment improved feed efficiency, increased serum iron, zinc, manganese, and copper levels, enhanced total antioxidant capacity and different antioxidant enzyme activities, and reduced malondialdehyde concentration. In conclusion, complete replacement of ITM with ACTM effectively protects broilers from Eimeria infection, with similar positive effects to SAL treatment in terms of productive performance and anti-inflammatory responses and better antioxidant responses and mineral availability.

Insights of dietary electrolyte balance in broilers raised under natural heat stress conditions

ABSTRACT 1. Dietary electrolyte balance (DEB) has been used to minimise problems in broiler chickens raised in warm climates. However, there is a need to determine the most appropriate DEB levels in these animals 2. This study evaluated the influence of five DEB levels (110, 175, 240, 305 and 370 mEq/kg) on water intake (WI), zootechnical performance (feed intake, weight gain and feed conversion ratio), tibiotarsus bone variables (fresh bone weight, dry bone weight, bone length, mineral matter, Seedor index and bone strength) and intestinal histomorphometry (villus height (VH) and width (VW), crypt height (CH) and width (CW), internal and external muscularis) on broilers in two developmental phases (1–21 and 22–42 d of age). Additionally, the haematological profile (blood count and serum biochemistry), carcass yield, cuts and abdominal fat were assessed. 3. Applying 370 mEq/kg DEB increased WI, VW in the jejunum and ileum and number of haemocytes at 21 d, while WI and VW in the duodenum and ileum at 42 d. In contrast, 110 mEq/kg increased chlorine concentrations at 21 d and leukocyte and heterophil numbers at 42 d. 4. In summary, the 370 mEq/kg level was the most appropriate for broiler homoeostasis raised under natural heat stress, as the best results were found on WI and VW variables. Therefore, this DEB level was recommended in broilers aged 21 or 42 d.

Comparative analysis of production performance, carcase traits, and meat quality in yearling beef of Limousine, Sardo-Bruna, and their crosses

The aim of this study was to compare animal performance and meat quality of a local cattle breed of Sardinia Island with specialised meat purebred or obtained by crossbreeding. For this purpose, 10 Sardo-Bruna (SB; 5 males, 5 females), 10 Limousine (L; 5 males, 5 females) and 10 Limousine × Sardo-Bruna crossbreed (L × SB; 5 males, 5 females) were compared simultaneously from 12 to 20 ± 1 (mean ± SEM) months old. During the trial, body weight (BW) was recorded once a month for estimating the average daily gain (ADG). At slaughter, carcase measurements, pH and colour traits were recorded from the left side of the carcase. Proximate composition, fatty acid (FA) profile, cooking and drip losses were evaluated using the Longissimus thoracis et lumborum muscle. The SB group showed a lower cold carcase yield compared to L and L × SB genetic types. Males had a higher ADG, slaughter weight, hot and cold carcase weights, hot and cold carcase yields, and cooking losses than females. Females group showed a higher intramuscular fat content and rib fat thickness compared to males. No relevant differences among genetic types and between sexes were observed for meat and fat colours and pH. Concerning the FA profile, SB genetic type evidenced a higher oleic acid content and a better nutritional index than other genetic types while males had a higher PUFA content than females. In conclusion, the results of this study showed that the Limousine breed can be effectively used to enhance carcase yield of local breed without effects on meat quality.

Genome-wide association analysis identifies candidate genes for carcass yields in Peking ducks.

Poultry meat, particularly Peking ducks, holds a significant global market share, prized for their high meat yield and fat content. However, understanding of the molecular genetic mechanisms influencing carcass yield in ducks is limited. This research aims to use genome-wide association analysis to uncover single-nucleotide polymorphisms influencing carcass yield in Peking ducks, followed by identifying candidate genes linked to carcass traits. In this study, we analyzed seven traits of 643 Peking ducks at age 42 days and identified novel loci associated with these traits. A total of 35 significant loci were detected, with eight SNPs reaching genome-wide significance. KIF20B, AGBL5, SGSM1, MRO, PLAG1, XKR4, and TGS1 were considered as important candidate genes influencing carcass yield in ducks. This study adds to the list of genes affecting Peking duck body traits, aiding marker-assisted breeding and enhancing economic yield.

Evaluating the effectiveness of Toxfin and Novasil as dietary aflatoxin-binding agents in broilers for sustaining hepatic antioxidant capacity and intestinal health status during aflatoxin B1 exposure.

To assess the efficacy of Toxfin and Novasil as aflatoxin-binding agents in broilers exposed to aflatoxin B1 (AFB1) from 11 to 30days, 288 mixed-sex Ross 308 broiler chickens were randomly allocated to four dietary groups: control feed, control feed + 0.25mg/kg AFB1, AFB1 feed + 0.3% Toxfin, and AFB1 feed + 0.3% Novasil. The evaluation encompassed growth performance for the grower (11-20days), finisher (21-30days), and overall (11-30days) phases, carcass characteristics, serum biochemical components, liver function enzymes, hepatic antioxidant capacity, AFB1 residue in the liver and kidney, and ileal morphology at 30days, and apparent nutrient digestibility during 29-30days. Exposure to AFB1 significantly resulted in reduced growth efficiency, lowered carcass yields, liver hypertrophy, impaired metabolic and hepatic functions, liver oxidative stress, disrupted ileum architecture, diminished nutrient digestibility, and accumulated AFB1 in the liver and kidney. Conversely, supplementation of Toxfin or Novasil significantly augmented body weight gain (BWG) and reduced feed conversion ratio (FCR) during the finisher and overall phases, elevated BWG in the grower phase, heightened levels of glucose, hepatic protein, and glutathione peroxidase, declined malondialdehyde content, improved apparent metabolizable energy, and lowered AFB1 residues in the liver and kidney. Furthermore, Toxfin inclusion significantly reduced FCR during the grower phase, enhanced European production efficiency factor during the grower and overall phases, augmented dressing percentage, declined proportional liver weight, elevated concentrations of total protein, albumin, and total antioxidant capacity, heightened villus surface area, and boosted crude protein digestibility. To conclude, incorporating 0.3% Toxfin into broilers' feeds confers a more effectual safeguard than Novasil against the deleterious consequences of AFB1 exposure.

The use of partially slatted floor designs as an alternative to littered systems in broiler chickens. I. The effects on the performance, slaughter and carcass traits.

In this study, the effects of fully littered, slatted and their varying combinations on growth, performance, carcass and meat quality characteristics in broiler chickens were investigated. In the experiment, five treatment groups were formed as fully littered (FL), fully slatted (FS), 1/3 littered + 2/3 slatted (2/3 SF), 1/2 littered + 1/2 slatted (1/2SF), 2/3 littered + 1/3 slatted (1/3 SF). Each treatment group included 5 replicates (24 chicks in each) and a total of 600 male-female mixed fast growing broiler chicks (Ross-308) were used during 6 weeks. Weekly body weight (BW, g), feed intake (FI, g), feed conversion ratio (FCR, g.feed intake/g.weight gain), livability (%) and EPEF (European Production Efficiency Factor) were determined as performance characteristics. Carcass yield (CY, %), and the percentages of abdominal fat (AFP, %), edible internal organs (EIOP, %), gizzard (GP, %), breast (BRP, %) and thigh (TP, %) meat were the carcass characteristics. Meat quality measured by pH and color (L*: lightness, a*: redness, b*: yellowness) of breast and thigh meat, and occurrence of white striping and hemorrhaging in breast meat. The weekly BW differences among the floor treatments were significant (P < 0.01), and 1/3SF broilers were the heaviest at slaughter age (3311.6g). The 6-week FCR in FS broilers was significantly worse than the others (1.471), but FI, livability and EPEF were similar among treatments. AFP tended to be higher in FL birds (P = 0.066), while CY, EIOP, GP, BRP and TP did not differ between groups. Breast pH was similar between treatments, with 1/2SF showing the highest (6.34) and FL the lowest (6.24) breast pH (P < 0.01). The partially slatted systems caused lighter, redder and yellower color values in breast meat (P < 0.01) than the fully littered or slatted systems, but did not change the color of the thigh meat. White striping and hemorrhaging in breast meat were not affected by the floor treatments. This study suggests that the use of partially slatted systems in broiler chickens improves meat color without compromising performance traits (body weight, feed efficiency, EPEF), litter moisture and slaughter traits and these systems could be an alternative to fully littered systems.

Morphological adaptation to environmental stress in small ruminants from the sahelian zones of Niger and potential associations with carcass yield

This study analyses, in the Sahelian zone of Niger, the morphological traits of sheep and goats' responses to environmental stress and the contribution of adaptive traits to herd productivity. The study utilized 2490 adult small ruminants, including 653 red and Sahelian goats and 1837 Peulh (with three varieties: Balami, Oudah and Bali-Bali) and Tuareg (Ara-ara) sheep from 13 sites with a marked aridity gradient within the country's northern latitude. Carcass yield was assessed on a second sample of 1617 adult animals, comprising 876 sheep and 741 goats. Variations in thorax auricular index (ratio of ear length to thorax depth), gracility index (which reflects the subtraction of the animal's body from the ground) and hot carcass yield, according to climate zones and breed, were subjected to an analysis of variance at the 5% risk threshold. Principal Component Analysis was used to analyze correlations between biometric and heat indices. For most breeds, the auricular thorax index and the gracility index were higher for animals in arid zones than those in humid zones. The increase in the average values of the body indices had as a result an increase in the animals' carcass yield and live weight. In all sheep and goat breeds, gracility increases with heat index. Gracility differed (p < 0.05) between breeds, with Bali-Bali and Oudah subgenetics of the Peulh sheep breed being more gracile than the Ara-ara sheep. Also, the auricular thorax index was higher (p < 0.05) in Sahelian goat than in red goat. The importance of biometric indices in terms of animals' adaptability to their environment means that we need to define important heat stress indicators specific to sheep and goats in Sahelian farming systems.

Supplementation with 25-hydroxicolecalciferol increases the nutritional efficiency and carcass growth of grazing Nellore young bulls

We aimed to evaluate the effect of 25-OH Vit D3 (Hy-D, DSM, Brazil) supplementation on the performance, body measures, and carcass characteristics of growing and finishing grazing Nellore young bulls. Two experiments were conducted. In Experiment 1, 150 animals (body weight (BW) of 350 ± 23kg) were separated into 6 treatment groups: protein supplement (PS); protein supplement with monensin (PS+Mon); protein supplement with 25-OH Vit D3 (PS+Vit D3); protein supplement with monensin and 25-OH Vit D3 (PS+Mon+Vit D3); protein-energetic supplement (PE); protein-energetic supplement with 25-OH Vit D3 (PE+Vit D3). In Experiment 2, 240 animals with an initial BW of 390 ± 16kg were separated into the same protein-energetic supplement treatment groups used in Experiment 1 with or without 25-OH Vit D3 (two treatments). Animals in the different treatments of Experiment 1 had similar ADG and final BW values (P > 0.05), except for those that received monensin in PS, which showed lower ADG (P < 0.05). The addition of monensin to the PS inhibited increases in the body measures (P < 0.05) except for the height at withers (P > 0.05). Animals that received PE+Vit D3 showed greater increases in rib width (P < 0.05). In Experiment 2, animals that received 25-OH Vit D3 were 8.0kg heavier than the animals that did not receive this supplement (P < 0.05). The results show that supplementation with 25-OH Vit D3 is a promising and effective method of improving carcass weight and yield in finishing beef cattle during grazing.

Physical attributes and nutritional composition of meat from dual purpose (Sasso C431 and TR51) broiler breeds in Ntabazinduna, Zimbabwe.

The growing animal welfare concerns regarding poultry production have led to the rearing of slow-growing meat type chickens also known as free-range chickens. In Zimbabwe these slow-growing chickens are gaining popularity as an alternative to the commercial broiler chickens owing to their preferred sensory attributes comparatively. Little is known regarding the quality of the meat versus that of the conventional broilers. We evaluated the physical characteristics and nutritional composition of meat from dual purpose slow-growing hybrids, Sasso C431 and TR51 in comparison with the commercial broiler breed Ross 308, under intensive feeding conditions. Birds were fed the standard commercial chicken feed produced by Hamara, a local chicken and chicken feed producing company. Birds were slaughtered on days 42, 56 and 70 of life where carcass and breast yield were measured. The pH, drip loss and cooking losses were determined for all carcasses. Proximate composition (dry matter, ash, protein, fat, carbohydrate) and mineral composition (iron, zinc and phosphorus) were determined for all the meat samples. The fast-growing broiler breed had a higher breast yield; than the slower-growing breeds, Sasso C431 and TR51 breeds (P&lt;0.05). The highest cooking and drip loss were observed in the faster growing breed Ross 308 and the lowest ones for Sasso C431 and TR51 breeds (P&lt;0.05). Shear texture values were higher in the Sasso C431 and TR51 than the Ross 308 breed (P&lt;0.05). The Sasso C431 and TR51 breeds can produce more meat with a lower fat and a higher protein compared to the Ross breeds.

Insertion of agronomy and animal science course students in bovine slaughterhouses, in mato grosso do sul, directs learning: a rural extension perspective

Rural extension is a tool that has become essential for the efficient and rapid implementation of good agricultural and livestock practices, seeking the development of rural properties. Carrying out an internship provides the student with professional and personal growth, as having the opportunity to follow the routine of their future profession allows them to improve their learning. In this context, the article explored the insertion of students from Agronomy and Zootechnics courses in beef production, on properties and in beef slaughterhouses. Describing the targeted experience and learning of students, it can contribute to carcass yield and meat quality, highlighting the importance of the partnership between the University, producers and agribusinesses. During the months of November 2022 to January 2023, students from the Agronomy and Zootechnics courses followed the activities of a company in the state of Mato Grosso do Sul, which carries out technical monitoring of slaughter, and provides consultancy to improve the quality of beef. Given the aspects reported, we can say that carrying out this internship contributed to providing new experiences for these students, especially in rural areas and meat quality. Making it possible to improve and consolidate knowledge about cattle farming, animal nutrition, health management, slaughter and meat quality. By carrying out activities during the internship, it served to influence professional training. The activities proved to be extremely relevant in the construction of theoretical-practical knowledge among those involved, industry, company, students and producers and the suggestions given to producers provided differentiated training as it covered different areas of the beef cattle production chain.