Conventional Feed-Grade or Slow-Release Coated Urea as Sources of Dietary Nitrogen for Fattening Lambs.

Twenty-two Assaf male lambs (29.2 ± 0.9 kg live weight and 89 ± 0.2 days of age), distributed in two experimental groups, were used to evaluate the use of either feed-grade conventional urea (Control diet; n = 11) or slow-release urea (SRU diet; n = 11) as sources of dietary nitrogen on animal performance, ruminal fermentation, blood acid-base status, plasmatic metabolic profile, and carcass and meat quality. Animals were housed individually and fed ad libitum. At the end of the fattening period (day 70), the animals were slaughtered to compare the fermentation patterns in ruminal digesta and to evaluate the carcass and meat characteristics. No statistically significant differences (p > 0.05) were observed between treatments in the dry matter intake, final live weight, average daily gain, and feed conversion rate. Regarding the ruminal fermentation parameters, the molar proportion of propionic acid was higher (p < 0.05) and that of butyric acid was lower (p < 0.05) with the SRU than with the Control diet. There were no significant differences (p > 0.05) between experimental treatments in the blood acid-base status and biochemical profile, except for the concentration of urea in plasma, which was significantly (p < 0. 05) greater in SRU than in Control lambs. No statistically significant differences were observed between treatments (p > 0.05) in the carcass and meat characteristics. In conclusion, the use of slow-release urea as a replacement for feed-grade conventional urea in the diet of Assaf fattening lambs, under the experimental conditions of this study, did not improve animal performance and increased the feeding costs.

Banana Pseudo-Stem Increases the Water-Holding Capacity of Minced Pork Batter and the Oxidative Stability of Pork Patties.

Banana pseudo-stem (BPS), which is rich in fibre and polyphenols, is a potential functional ingredient for the food industry. In this study, BPS was added at concentrations of 1.5, 3.0, and 4.5 g/kg to a minced pork batter to evaluate its performance as a filler and to pork burger patties to evaluate its performance as a natural antioxidant. The effects of BPS were compared with those of carrageenan and ascorbate, which are a conventional binder and antioxidant, respectively. The performance of BPS was similar to that of carrageenan in terms of the cooking yield and texture of the cooked batter. BPS reduced the brightness of fresh patties and appeared to reduce oxidative discolouration during the frozen storage of raw patties. Moreover, BPS reduced the levels of thiobarbituric acid reactive substances (TBARS) during the refrigerated and frozen storage of cooked patties. A greater decrease in TBARS formation was observed with 4.5 g BPS/kg compared with 0.5 g sodium ascorbate/kg during refrigerated storage. In contrast to ascorbate, BPS promoted the presence of lipid-derived volatile compounds induced by thermal breakdown in the headspace of cooked patties. Nonetheless, this effect was reduced as the amount of BPS in the patties increased. In cooked minced meat products, BPS could increase cooking yields and lipid oxidative stability during storage and might result in a more intense flavour.

Effects of Birth Weight on Animal Performance, Fattening Traits and Meat Quality of Lambs.

Intrauterine growth restriction (IUGR) is a key developmental programming factor which might impair both the feed efficiency of lambs and meat quality, since it deeply impacts skeletal muscle and adipose tissue development. To determine the effect of birth weight on the growth performance, ruminal parameters, digestibility, non-carcass components, carcass traits, physicochemical characteristics and fatty acid profile of meat, two experimental groups (six animals in each group) of male Merino lambs with different body weights (BW) at birth (low BW (LW; 3.88 ± 0.281 kg) and high BW (HW; 5.80 ± 0.647 kg)) were used. The lambs were penned with their corresponding ewe during the natural suckling period, being weaned at 15 kg. Then, the lambs were penned individually and offered a complete pelleted diet during the fattening period. All the animals were slaughtered when they reached 27 kg of BW. After weaning, both daily dry matter intake (578 vs. 615 g/day; p = 0.021) and average daily gain (141 vs. 190 g/day; p = 0.004) were significantly lower in LW lambs, and a higher feed:gain ratio was recorded for this group (3.98 vs. 3.45; p = 0.008). Carcass traits did not show differences (p > 0.05) between both groups of lambs, except for higher chilling losses for the LW group (3.29 vs. 2.69%; p = 0.012). Additionally, higher amounts of kidney knob and channel fat were observed for LW lambs (85.4 vs. 152 g; p = 0.028). Apart from a higher hardness of meat in LW lambs (152 vs. 189 Newtons, p = 0.040), no other differences (p > 0.05) were observed in the physicochemical traits of this product; however, the meat of LW lambs tended (p = 0.057) to contain more total fatty acid content with a higher (p = 0.041) proportion of saturated fatty acids than the meat of HW lambs. In conclusion, under the conditions of the present study, a low body weight at birth increased the deposition of fat in carcass and non-carcass components during the fattening period of lambs, thus reducing animal performance and worsening the nutritional indexes of the meat. Accordingly, it seems reasonable to try to identify these animals during early life, to be sold as suckling lambs in the meat market instead of being fattened.

Effect of Dietary Crude Protein on Animal Performance, Blood Biochemistry Profile, Ruminal Fermentation Parameters and Carcass and Meat Quality of Heavy Fattening Assaf Lambs.

Thirty Assaf male lambs (30 ± 1.9 kg of body weight) were allocated to three groups fed diets differing in their crude protein (CP) contents (low protein (LP), 134 g CP/kg dry matter (DM); medium protein (MP), 157 g CP/kg DM; and high protein (HP), 173 g CP/kg DM) to test the effect of dietary protein content on animal performance, rumen function, animal health, and carcass and meat quality. Feed intake was recorded daily, and animals were weighed every second week. Lambs were blood-sampled to determine their acid-base status and biochemical profile. After 70 days of trial, lambs were slaughtered, and the ruminal content was collected to assess ruminal fermentation. Finally, carcass and meat quality were evaluated. Dry matter intake and average daily gain increased (p < 0.05) when increasing the level of dietary CP. There were not significant differences (p > 0.05) in the evaluated parameters in the rumen fluid of lambs. There were not significant differences in carcass or meat quality (p > 0.05) and in those parameters related to blood acid-base status. Several biochemical parameters showed differences depending on diet CP level (urea, protein, albumin, glucose, and calcium; p < 0.05). Feeding costs calculated in relation to cold carcass weight decreased when dietary CP decreased. The results suggested that a dietary protein content greater than 157 g/kg DM would be required to maximize growth performance in Assaf male fattening lambs under 50 kg of body weight. However, a protein content beyond that level was not found to improve either carcass or meat quality and could worsen profitability.

Production Significance of Bovine Respiratory Disease Lesions in Slaughtered Beef Cattle.

Bovine respiratory disease (BRD) is still a serious concern in feedlots, where it exerts a negative effect on farm productivity. There is a shortage of studies focused on the evaluation of BRD-associated lesions at the slaughterhouse in clinically healthy animals. The objective of this work was to investigate the prevalence and type of subclinical pneumonic lesions in slaughtered beef cattle, according to the age range and management system, and its impact on carcass weight. A total of 1101 beef cattle intended for human consumption were examined at slaughter. Information on age, sex, management system and carcass weight was recorded. The presence and type of pneumonia were evaluated according to gross and microscopic findings and etiological agents by PCR. Lung pneumonic lesions appeared in 17.9% of animals and were predominant among veal calves. According to the type, chronic catarrhal pneumonia prevailed in the majority of animals, and mixed and extensively reared cattle were more likely to suffer acute fibrinous pneumonia. The presence of pneumonic lesions was associated with a significant decrease in carcass weight that had more of an impact in veal male calves coming from intensive systems. Bacterial infections were the predominant infectious agent and the only cause of acute fibrinous pneumonia, while viruses were infrequent and only found in lesions with chronic catarrhal pneumonia. This study shows the importance of BRD in beef feedlots upon production values and points out the feasibility of slaughterhouse assessment of pneumonia as a method for the evaluation of BRD significance.

The effects of storage and hop extract on aroma and flavour compounds in Balkan-style sausages packed under a CO2-containing anaerobic atmosphere.

Changes in the levels of pH, lactic acid, acetic acid, headspace volatile compounds, and spoilage odour intensity during a 35 day refrigerated storage period in two sets of a Balkan-style fresh sausage, a control sausage (CON) and a sausage containing an aqueous hop extract (HOP), packaged under a 20% CO2 and 80% N2 atmosphere were evaluated. Storage resulted in progressive sausage acidification and increased the levels of acetic acid, 1-methylbutanol, ethyl acetate, ethyl hexanoate, and 2-ethylhexanol; all of which are associated with anaerobic microbial metabolism under sugar restricted conditions. Storage decreased the levels of hexanal, heptanal, pentanol, and garlic-derived organosulfur compounds. Hop extract showed oxygen scavenging abilities, and decreased the levels of the volatile compounds derived from lipid auto-oxidation while contributing to the presence of specific terpene compounds. The use of hop extract did not improve the shelf life of sausages packed under anaerobic atmosphere. The spoilage odour appeared in both types of sausages on the 14th day, and it was considered strong from day 21 onwards.

Replacing Soybean Meal with Urea in Diets for Heavy Fattening Lambs: Effects on Growth, Metabolic Profile and Meat Quality.

Thirty-six Assaf male lambs (29.4 ± 3.10 kg body weight (BW)) were used to study the feasibility of including urea (at 0, 0.6 or 0.95% of dry matter for Control, Urea1, and Urea2 diets, respectively) in substitution of soybean meal in fattening diets. Animals were individually penned and feed intake was recorded daily. Blood samples were taken at days 35 and 63 of the experimental period to determine the acid-base status and the biochemical profile. At the end of the experiment (nine weeks), lambs were slaughtered, ruminal contents were collected and carcass and meat quality were evaluated. There were not differences (p > 0.05) among treatments in dry matter intake, animal performance, ruminal fermentation pattern, and carcass and meat parameters. Serum albumin concentration was higher and concentration of HCO3 and total CO2 in blood were lower in Urea2 compared to Urea1 and Control lambs. These results, together with the tendency to lower (p = 0.065) blood pH in this group might suggest a moderate metabolic acidosis. Partial replacement of soybean meal with urea did not impair growth rate in heavy fattening Assaf lambs (from 29 to 50 kg body weight), reduced feeding costs and had no adverse effects on feed efficiency, rumen fermentation and carcass and meat quality.

Microbial Growth and Biogenic Amine Production in a Balkan-Style Fresh Sausage during Refrigerated Storage under a CO2-Containing Anaerobic Atmosphere: Effect of the Addition of Zataria multiflora Essential Oil and Hops Extract.

Fresh sausages are highly perishable, and the preservatives allowed in these types of meat preparations are limited. Balkan-style fresh sausages were prepared in triplicate without antimicrobials (Control), with an aqueous hops extract (30 mL/kg), with Zataria multiflora Boiss essential oil (1 mL/kg), or a combination of both (15 and 0.5 mL/kg, respectively), and refrigerator-stored under a 20% CO2 and 80% N2 atmosphere. The spoilage microbial growth, i.e., lactic acid bacteria (LAB), Brochothrix thermosphacta, Enterobacteriaceae, Micrococcaceae, molds and yeasts, the pH value, and the production of biogenic amines in the sausages were monitored weekly and compared with a control sausage during a 35-day storage period. Furthermore, 349 colonies of presumptive LAB (isolated from the De Mann, Rogose-Sharpe agar plates) were identified using a MALDI-TOF-based method. Growth levels to ≈ 9 Log colony forming units (CFU) per g were reached by LAB, with a predominance of Lactobacillus sakei. Enterobacteriaceae and B. thermosphacta also showed significant growth (up to 6 Log CFU/g). Biogenic amine levels increased, and tyramine values overcame 250 mg/kg. The study could not demonstrate a significant effect of antimicrobial source treatments in any of the characteristics studied, and thus, the shelf-life of sausages.

Early Feed Restriction Programs Metabolic Disorders in Fattening Merino Lambs.

Early postnatal nutrition may have a significant subsequent impact on metabolic disorders during the entire lifespan of lambs. The aim of the present study was to describe the changes in biochemical, immunological, hepatic, and ruminal parameters of fattening lambs derived from early feed restriction during the suckling phase. Twenty-four merino lambs (average body weight, BW, 4.81 ± 0.256 kg) were used, 12 of them were milk-fed ad libitum (ADL) remaining permanently with their dams, whereas the other 12 lambs (restricted, RES) were subjected to milk restriction. After weaning, all the lambs were fed 35 g/kg BW per day of the same complete pelleted diet to ensure no differences between groups in dry matter intake (603 vs. 607 g/day for ADL and RES lambs, respectively, p = 0.703), and were slaughtered at a BW of 27 kg. Biochemical profiles revealed higher concentrations of ceruloplasmin and low-density lipoproteins, whereas insulin concentration was lower in the RES lambs compared to the ADL group. Liver thiobarbituric acid reactive substances were lower in the RES lambs. No significant differences in ruminal or blood immunological parameters were found. In conclusion, early feed restriction promoted metabolic disorders not related to ruminal acidosis occurrence, which can compromise the health status during the fattening period of merino lambs.

Liver transcriptomic and plasma metabolomic profiles of fattening lambs are modified by feed restriction during the suckling period.

The increasing world population is driving demand for improved efficiency of feed resources of livestock. However, the molecular mechanisms behind various feed efficiency traits and their regulation by nutrition remain poorly understood. Here, we aimed to identify differentially expressed (DE) genes in the liver tissues of fattening Merino lambs and differences in metabolites accumulated in plasma to identify modified metabolic pathways as a consequence of milk restriction during the suckling period. Twenty-four male Merino lambs (4.81 ± 0.256 kg) were divided into 2 groups (n = 12 per dietary treatment). The first group (ad libitum, ADL) was kept permanently with the dams, whereas the other group (restricted, RES) was milk restricted. When they reached 15 kg of live body weight (LBW), all the animals were offered the same complete pelleted diet at the same level (35 g DM/kg LBW per day) to ensure no differences in dry matter intake. All the lambs were harvested when they reached 27 kg of LBW. For transcriptomic analysis, 4 liver samples from each group (8 samples in total) were selected for RNA sequencing (RNA-seq), and plasma samples from all animals (24 samples in total) were used to perform a nontargeted metabolomic analysis on a hybrid quadrupole-time-of-flight mass spectrometer coupled to an ultra-high performance liquid chromatographic system (UHPLC/QTOF-MS). Thirty-eight DE annotated genes were identified by RNA-seq, with 23 DE genes being down-regulated and 15 up-regulated in the liver of RES lambs relative to the ADL group (P < 0.10). Also, the metabolomic assay identified 38 differentially accumulated compounds (P < 0.10). In general, those genes and pathways involved in protein synthesis or protease inhibitors were down-regulated in the RES group, whereas those related to proteolytic degradation were up-regulated, thus suggesting a higher catabolism of proteins in these lambs. RES lambs showed over-expression of xenobiotic metabolism pathways, whereas those genes related to ß-oxidation of fatty acids were down-regulated. According to the data obtained, early feed restriction during the suckling period of Merino lambs promoted long-term effects on both the hepatic transcriptomic profile and plasma metabolic profile, which might have modified fatty acids metabolism, catabolism of proteins, and detoxification of xenobiotics, thus reducing feed efficiency during the fattening period.

Immunohistochemical study and mRNA cytokine profile of the local immune response in cattle naturally infected with Calicophoron daubneyi.

In order to recognize the local immune response of the definitive host to Calicophoron daubneyi natural infection, an immunohistochemical study was carried out in the reticulum and rumen in 49 naturally infected cattle. The role of cytokines (IL-4 and IL-10 interleukins and IFN-γ) in the activation of specific defence mechanisms was evaluated by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) assays to study cytokine mRNA expression. In all infected animals, CD3+ T lymphocytes seemed to be the main element of the inflammatory infiltrate in the reticular and ruminal lamina propria at the point of the parasite adhesion. Intraepithelial globule leukocytes also showed immunolabelling for CD3. Most CD3+ cells also expressed CD4 (T cell helper) antigen although sporadic CD8+-cytotoxic lymphocytes were observed. Local expression of IFN-γ was observed in damaged papillae at the site of parasite attachment and in scattered cells in the lamina propria. B cells (CD79αcy+, CD45+ and IgG+) were found constantly in relation to lymphoid aggregates. MAC387 was expressed in squamous epithelium and in macrophages of the lamina propria of affected papillae. Macrophages in this location also stained positively for CD163 and CD68. Intraepithelial Langerhans cells and macrophages located in the lamina propria showed immunopositivity for MHCII in the affected areas. RT-qPCR analysis confirmed a statistical significant increase of IFN-γ, and IL-10 expression (p<0.01) in the rumen associated with the presence of flukes. These findings suggest a predominant Th1 polarized local immune response with the probable involvement of Th regulatory cells in cattle C. daubneyi natural infection.

Pathological changes in cattle naturally infected by Calicophoron daubneyi adult flukes.

Local host response and parasite distribution were studied in the forestomachs, abomasum, duodenum and regional lymph nodes of cattle suffering from bovine paramphistomosis. The parasites were found attached, by its ventral sucker, to small conical papillae of the rumen and reticulum. Affected papillae, showed morphological changes denoted by very narrow stalks and expanded heads. Histologically, these changes were characterized by epithelial acanthosis-hyperkeratosis of the epithelium. Infiltration of inflammatory cells was often related with the epithelial changes, although it was also found in the duodenal mucosa and submucosa. These cells were arranged as aggregates or follicles but sparse infiltration of eosinophils, globule leukocytes, mast cells or macrophages was also observed in the lamina propria. Tissue damage and inflammatory reaction were more severe in the ruminal atrium, where the largest number of flukes and affected papillae were observed. In contrast, lesions in the ruminal dorsal sac were absent or mild. Statistical correlation between lesion severity and parasite burden was confirmed.