Performance and carcass quality of forage-fed steers as an alternative to concentratebased beef production

This paper studies the performance and carcass quality of Parda de Montaña cattle under different management systems to find alternatives to concentrate feed indoor beef production. Treatments were: i) Control, with 8 bulls (216±34.3 kg initial weight; 282±45.6 days) fed concentrate and straw ad libitum during winter housing period until reaching 500 kg; ii) G-supp, with 8 steers (204±31.2 kg initial weight; 271±47.5 days) fed a total mixed ration (TMR) (50% alfalfa hay, 10% straw, 40% corn) ad libitum during winter housing period (from mid-April steers rotationally grazed on a mountain meadow supplemented with 1.8 kg dry matter corn/d until reaching 500 kg); iii) TMR, with 8 steers (200±42.5 kg initial weight; 261±39.0 days) managed as G-supp steers until mid-July, when they were housed and fed TMR ad libitum until reaching 500 kg.Control bulls had 45% greater weight gain than TMR and G-supp steers during housing period (P<0.001). In the finishing period, TMR had 31% greater weight gain than steers finished on pasture (P<0.01). At slaughter, Controls were 97-127 days younger than others (P<0.001). Steers finished on TMR had worse conformed carcasses, greater fat and fewer edible meat proportions than G-supp and Control (P<0.01). Total cost of TMR and G-supp was greater than Control, with a similar income for G-supp and Control. TMR steers were paid less because of their worse carcass quality. Hence, finishing of steers on pasture with a supplement can be a feasible alternative to fattening bulls on concentrates, depending on the relative availability and price of feedstuff

Effects of whole linseed and rumen-protected conjugated linoleic acid enriched diets on beef quality

Instrumental assessments and sensory tests were performed to evaluate the effects of diet and postmortem ageing time (1, 7 and 21 days) on beef quality. A total of 48 Friesian calves were randomly allocated to four dietary treatments: control, whole linseed (10% linseed), conjugated linoleic acid (CLA) (2% protected CLA), and whole linseed+CLA (10% linseed and 2% protected CLA). Animals were slaughtered at 458±16.6 kg live weight and 11 months of age. Ageing was more significant than diet on most instrumental parameters. Meat from linseed enriched diets had greater drip loss (P=0.001) and intramuscular fat (P=0.01) than meat from animals fed CLA. Beef aged for 7 and 21 days had lower cooking losses (P=0.01) and shear force (P=0.001) than beef aged for 1 day. Lightness was affected only by display time. The addition of CLA in the diet increased hue and yellowness, whereas the inclusion of linseed decreased these values, as well as increased redness. Linseed in the diet decreased fat odour (P=0.05), but increased beef (P=0.01) and liver (P=0.05) flavours. Meat aged for 21 days was significantly more rancid (P=0.001), even under vacuum storage. Several organoleptic properties were improved with the inclusion of linseed in the diet, whereas they remained unaffected by the inclusion of CLA

ISPst9, an ISL3-like insertion sequence from Pseudomonas stutzeri AN10 involved in catabolic gene inactivation

A novel insertion sequence (IS), ISPst9, from Pseudomonas stutzeri AN10 was cloned and characterized. ISPst9 is a typical bacterial IS, consisting of a 2472-bp element flanked by 24-bp perfect inverted repeats that generates 8-bp AT-rich target duplications upon insertion. The sequence also contains a gene that encodes an active transposase (TnpA) with significant amino acid identity to members of the ISL3 family. Southern blot analysis of digested genomic DNA of strain AN 10 and its 4-chlorosalicylate-degrading derivative strain AN142 demonstrated that native ISPst9 transposes in multiple copies, with one of them responsible for the nahH insertional inactivation observed in strain AN142. Precise excision of ISPst9 yielded NahH+ revertants of AN142 at high frequencies (up to 10-6). In vivo transposition, mainly in multiple copies, of an ISPst9 derivative containing a KmR cassette cloned into a suicide vector was also demonstrated. Hybridization experiments carried out with different strains of P. stutzeri and with 292 phylogenetically distinct environmental isolates suggested that the presence of an ISPst9-like IS occurs in diverse bacteria together with the presence of aromatic hydrocarbon-degrading determinants (Journal)Funds were obtained from projects VEM2003-20565 and CTM2005-01783 from MEC, and project PRIB2004-10152 from CAIBPeer Reviewe

Effect of production system before the finishing period on carcass, meat and fat qualities of beef

Twenty Gascon young bulls that had been reared either in intensive conditions (INT) (n = 10) with early weaning at 3 to 4 months, or in a traditional extensive (EXT) system (n = 10) with weaning at 7 months, were subjected to the same conditions during the 145-day finishing period. Production system before the finishing period did not affect conformation, dressing percentage or morphology of the carcass; nevertheless, tissue composition differed somewhat between the two groups. Display had a stronger effect on meat colour than did production system. Percentage of myoglobin was highest in INT (P ⩽ 0.001), although meat texture and sensory quality did not differ between rearing conditions. EXT animals had darker, more yellow fat, a higher percentage of n-3 fatty acids (P ⩽ 0.001), a lower percentage of saturated fatty acids (P ⩽ 0.05) and a lower n-6/n-3 index (P ⩽ 0.001) than did the INT-reared animals. Production system before the fattening period might modify some of the characteristics of commercial beef, especially those associated with fat.This research was financed by European Project Programmes POCTEFA-OTRAC I 2009/010. The authors thank the OTRAC consortium members and the local government (DGA) for the PhD scholarship.info:eu-repo/semantics/publishedVersio

IS Pst9, an ISL3-like insertion sequence from Pseudomonas stutzeri AN10 involved in catabolic gene inactivation

A novel insertion sequence (IS), ISPst9, from Pseudomonas stutzeri AN10 was cloned and characterized. ISPst9 is a typical bacterial IS, consisting of a 2472-bp element flanked by 24-bp perfect inverted repeats that generates 8-bp AT-rich target duplications upon insertion. The sequence also contains a gene that encodes an active transposase (TnpA) with significant amino acid identity to members of the ISL3 family. Southern blot analysis of digested genomic DNA of strain AN10 and its 4-chlorosalicylate-degrading derivative strain AN142 demonstrated that native ISPst9 transposes in multiple copies, with one of them responsible for the nahH insertional inactivation observed in strain AN142. Precise excision of ISPst9 yielded NahH+ revertants of AN142 at high frequencies (up to 10-6). In vivo transposition, mainly in multiple copies, of an ISPst9 derivative containing a KmR cassette cloned into a suicide vector was also demonstrated. Hybridization experiments carried out with different strains of P. stutzeri and with 292 phylogenetically distinct environmental isolates suggested that the presence of an ISPst9-like IS occurs in diverse bacteria together with the presence of aromatic hydrocarbon-degrading determinants

Using machine learning procedures to ascertain the influence of beef carcass profiles on carcass conformation scores

In this study, a total of 163 young-bull carcasses belonging to seven Spanish native beef cattle breeds showing substantial carcass variation were photographed in order to obtain digital assessments of carcass dimensions and profiles. This dataset was then analysed using machine learning (ML) methodologies to ascertain the influence of carcass profiles on the grade obtained using the SEUROP system. To achieve this goal, carcasses were obtained using the same standard feeding regime and classified homogeneous conditions in order to avoid non-linear behaviour in grading performance. Carcass weight affects grading to a large extent and the classification error obtained when this attribute was included in the training sets was consistently lower than when it was not. However, carcass profile information was considered non-relevant by the ML algorithm in earlier stages of the analysis. Furthermore, when carcass weight was taken into account, the ML algorithm used only easy-to-measure attributes to clone the classifiers decisions. Here we confirm the possibility of designing a more objective and easy-to-interpret system to classify the most common types of carcass in the territory of the EU using only a few single attributes that are easily obtained in an industrial environment

Near-infrared reflectance spectroscopy for predicting the phospholipid fraction and the total fatty acid composition of freeze-dried beef

Research on fatty acids (FA) is important because their intake is related to human health. NIRS can be a useful tool to estimate the FA of beef but due to the high moisture and the high absorbance of water makes it difficult to calibrate the analyses. This work evaluated near-infrared reflectance spectroscopy as a tool to assess the total fatty acid composition and the phospholipid fraction of fatty acids of beef using freeze-dried meat. An average of 22 unrelated pure breed young bulls from 15 European breeds were reared on a common concentrate-based diet. A total of 332 longissimus thoracis steaks were analysed for fatty acid composition and a freeze-dried sample was subjected to near-infrared spectral analysis. 220 samples (67%) were used as a calibration set with the remaining 110 (33%) being used for validation of the models obtained. There was a large variation in the total FA concentration across the animals giving a good data set for the analysis and whilst the coefficient of variation was nearly 68% for the monounsaturated FA it was only 27% for the polyunsaturated fatty acids (PUFA). PLS method was used to develop the prediction models. The models for the phospholipid fraction had a low R2 p and high standard error, while models for neutral lipid had the best performance, in general. It was not possible to obtain a good prediction of many individual PUFA concentrations being present at low concentrations and less variable than other FA. The best models were developed for Total FA, saturated FA, 9c18:1 and 16:1 with R2 p greater than 0.76. This study indicates that NIRS is a feasible and useful tool for screening purposes and it has the potential to predict most of the FA of freeze-dried beef. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

The reactivity of cyclopropyl cyanide in titan's atmosphere: a possible pre-biotic mechanism

Cyclopropyl cyanide and other simple nitriles detected in Titan's atmosphere could be precursors leading to the formation of organic macromolecules in the atmosphere of Saturn's largest satellite. Proposing a thermodynamically possible mechanism that explains their formation and supports experimental results represents a difficult challenge. Experiments done in the Atomic and Molecular Physics Laboratory at the University of Trento (AMPL) have studied the ion-molecule reaction between cyclopropyl cyanide and its protonated form, with reaction products being characterized by mass spectrometry. In addition to the expected ion-molecule adduct stabilized by non-covalent long-range interactions, in this work we prove that another distinct species having the same mass to charge ratio (m/z) of 135 is also produced. Moreover, from a previous study of the neutral cyclopropyl cyanide potential energy surface (PES) which shows a partial biradical character it has been possible to characterize the formation through the bimolecular reaction of a new covalent cyclic organic molecule. Calculations have been carried out at the ab initio Møller-Plesset (MP2) level of theory, ensuring the connectivity of the stationary points by using the intrinsic reaction coordinate (IRC) procedure. In order to characterize the reaction transition state, multireference calculations were done using a complete active space involving six electrons and six molecular orbitals [CAS (6 e, 6 m.o.)]. This study opens the possibility of exploring the formation of new organic molecules by gaseous phase ion-molecule interaction schemes, with such molecules having relevance in interstellar space and in astrobiology (and may be involved in prebiotic molecular evolution)