Yuridia Bautista-Martínez

This study aimed to evaluate the effects of milk replacer (MR) feeding on carcass characteristics, meat quality, and fatty acid profile in suckling goat kids through a meta-analysis. The electronic databases Scopus, Web of Science, PubMed, and Google Scholar were used to identify the articles required for the meta-analysis using the PRISMA methodology. The data used in this meta-analysis were obtained from 13 English-language articles published in peer-reviewed journals between January 2005 and May 2026. All data were analyzed using random-effects models. Feeding with MR did not affect (p > 0.05) body weight at slaughter, hot carcass weight, or hot carcass yield of suckling kids. However, a lower renal fat weight (p < 0.05) was observed in kids fed MR. On the other hand, feeding with MR did not affect (p > 0.05) meat pH at 24 h, lightness (L*), redness (a*), yellowness (b*), Chroma (C*), Hue (H°), Warner-Bratzler shear force, or the moisture, protein, fat, collagen, and ash content in the meat of suckling kids. Nevertheless, a lower water-holding capacity (p < 0.05) was observed in the meat of kids fed MR. Feeding with MR did not affect (p > 0.05) the concentration of caproic, caprylic, lauric, myristic, myristoleic, palmitoleic, heptadecanoic, oleic, alpha-linolenic, arachidonic acid, behenic acids, total saturated fatty acids, total monounsaturated fatty acids, and total polyunsaturated fatty acids. However, lower concentrations (p < 0.05) of capric, pentadecanoic, palmitic, stearic, and arachidic acids were observed in the meat of suckling kids fed MR. In contrast, higher concentrations (p < 0.05) of linoleic acid were observed in the meat of suckling kids fed MR. In conclusion, the use of milk replacer in suckling kids preserves growth, carcass traits, and most meat quality attributes, while reducing renal fat deposition and selectively modifying the fatty acid composition toward a higher linoleic acid content.

Background and Aim: Palmitic acid (PA) (C16: 0) is a rumen-inert long-chain fatty acid (FA) widely used in dairy cattle to increase dietary energy density and milk fat synthesis; however, its effects in dairy goats remain poorly characterized. This study evaluated whether supplementing 3% or 6% PA in the diet of mid-lactation goats could improve milk yield, composition, FA profile, and whole-animal energy balance under semi-arid Mexican production conditions. Materials and Methods: Twenty-one multiparous crossbred goats (45.8 ± 1.2 kg; 21 ± 3 days in milk) were randomly assigned to three treatments for 6 weeks after a 2-week adaptation: (1) Control diet (without PA), (2) diet + 3% PA, and (3) diet + 6% PA on a dry-matter (DM) basis. Diets were isoenergetic and isoproteic before PA addition. Individual DM intake (DMI), milk yield, and composition were measured daily; milk FA profiles and energy balance were determined on days 0, 21, and 42. Data were analyzed using a mixed-model with repeated measures, and means were compared using the Tukey test (p ≤ 0.05). Results: PA inclusion did not affect DMI, body weight, or milk yield. However, milk fat concentration and yield increased significantly (p < 0.01) in both PA treatments, with the highest fat concentration observed at 6% PA. The milk FA profile shifted toward greater C16: 0 and C16: 1 proportion (p < 0.0001) and decreased short-chain (C16) FA fractions. Energy-corrected milk yield rose by ~40% in PA-fed goats, and energy balance improved markedly from week 3 onward, particularly in the 3% group (p < 0.01), indicating superior dietary energy utilization without intake suppression. Conclusion: Moderate PA supplementation (~3% DM) effectively enhances milk fat synthesis and energy efficiency in goats while maintaining stable intake and yield. Increasing PA beyond 3% confers minimal additional benefit and may overly saturate milk fat. These findings provide species-specific evidence that rumen-inert fat inclusion can be an efficient strategy to support metabolic status and product quality in mid-lactation goats under variable forage systems. Keywords: dairy goats, energy balance, fatty acid profile, milk composition, palmitic acid, rumen-inert fat.

Energy is an important component in total mixed rations (TMR) for ruminants, most commonly sugars (as sugarcane molasses, SCM) and animal fats (rendered beef fat, RBF) are often included in finishing lambs. The effects of feeding TMR with RBF, SCM or control were determined on lamb performance. Lambs (103) were divided into three groups by sex and fed the three rations; rations were iso-proteinaceous and iso-energetic. Lambs were allotted by sex, breed and weight, and lambs were weighed every 14 days. Data was analyzed using a general linear model for average daily gain (ADG), feed intake (FI), feed conversion (FC) and scrotal circumference (SC) to determine the effects of sex, ration, breed, nandrolone and their interactions. Sex affected ADG (P<0.05), ram lambs gained more (159.8 g) than ewe lambs (119.1 g); the lambs fed RBF gained more (150.0 g) than control (138.8 g) or SCM (129.4 g) rations. Lambs fed SCM consumed more (P<0.05) than the lambs fed RBF or control rations. Main factors studied, sex, TMR and nandrolone affected (P<0.05) FC. The interactions sex*ration, sex*nandrolone and ration*nandrolone were significant (P<0.05) for ADG, whereas sex*breed, sex*ration, sex*nandrolone and ration*nandrolone were significant (P<0.05) for FI and sex*ration and ration*nandrolone were significant (P<0.05) for FC. Lambs fed RBF gained more weight than lambs fed the other rations, ram lambs also gained more weight than the ewe lambs and also lambs treated with nandrolone gained more weight than the non-treated lambs.

The objective of this study was to evaluate the impact of incorporating palmitic acid into the diet of dairy goats on the physicochemical characteristics, nutritional value, and fatty acid profile of goat kid meat. For this, 28 Creole local kids were used, divided into the following treatments: grazing, kids fed milk from grazing goats; base diet, kids fed milk from goats in confinement with a total mixed ration; base diet + 3PA, kids fed milk from goats in confinement that consumed the base diet plus 3% palmitic acid; and base diet + 6PA, kids fed milk from goats in confinement fed with the base diet plus 6% palmitic acid. The feeding period was conducted over a 30‐day period. Live weight, average daily gain, carcass weight, and carcass yield were higher ( p ≤ 0.01) in kids from the base diet + 6PA treatment than in the other treatments. The proportion of stearic, elaidic, linoleic, CLA, oleic, and docosahexaenoic fatty acids was higher ( p ≤ 0.05) in meat from kids fed with grass‐fed milk. In contrast, kids from the base diet + 3PA and base diet + 6PA treatments had a higher ( p ≤ 0.05) proportion of palmitic and palmitoleic acids. The addition of palmitic acid to goat feed improves growth rate and carcass yield and modifies the fatty acid profile in kid meat.

Conjugated linoleic acid (CLA) is a constituent of bovine milk that has been shown to possess protective effects against various diseases, including cancer. Therefore, there is a compelling rationale for increasing the content of CLA in milk. The feeding of cows in pastures has been demonstrated to increase CLA, as pastures typically have higher concentrations of linoleic and α–linolenic acids, which serve as precursors of CLA in the process of ruminal biohydrogenation. The enhancement of linoleic and α–linolenic acids can be achieved through management techniques that promote rapid vegetative growth, such as nitrogen fertilization. An experiment was conducted on a ranch in the state of Tabasco, Mexico, to determine the effect of nitrogen fertilization on the chemical composition and fatty acid profile of grass and bovine milk. The experimental design involved two plots, one of which was fertilized with urea (150 kg·ha-1), while the other served as a control. Each plot was assigned a group of five cows in production, utilizing a randomized complete block design. An intensive rotational grazing system was used, and grass and milk samples were taken on days 14, 21, and 28 of the experimental periods. Nitrogen fertilization of the grass increased (P≤0.01) more than 100% forage production and 15.75% the crude protein content in the grass. In milk, nitrogen fertilization of the grass increased (P≤0.05) the fat content by 31.68% but did not affect (P>0.05) the protein and lactose content or the content of CLA. A positive linear relationship was found (P≤0.05) between the concentration of linoleic acid in grass and the concentration of CLA in milk. The nitrogen fertilization of Cayman Blend grass increases forage production, the crude protein content in the grass, and the fat content in milk without affecting the content of conjugated linoleic acid and other fatty acids.

Para producir 1 kg de queso fresco y madurado en el sistema caprino, se necesitan aproximadamente 6 L y 8 L de leche respectivamente.

Introduction According to the Mexican Meat Council, chicken meat is one of the most consumed proteins globally, ranking second in preference with 268,566,000 tons in 2022. In Mexico, the approximate consumption in 2022 was 4,842,000 tons, placing it

Few studies have evaluated the impact of a lipid-rich diet with palmitic acid (PA) in ruminal fermentation. The objective was to evaluate the in vitro bath culture of the protected PA on the ruminal fermentative variables. Four diets were used: (a) without protected PA (nPA) and (b) inclusion of protected PA at three levels: PA3 = 3%, PA6 = 6%, and PA9 = 9% dry matter (DM). The maximum gas production occurred without including protected PA and the low gas production given with the inclusion of protected PA9 (p ≤ 0.05). Meanwhile, the inclusion with 3 and 6% of protected PA showed a higher level of gas production kinetics than the other treatments (p ≤ 0.05). DM and organic matter degradation after 72 h of incubation linearly decreased (p ≤ 0.05) with a high level of protected PA. The level of C16:0 in the protected AP increased with the higher level of supplemented AP (p ≤ 0.05). The best efficiency in propionic acid, decrease in methane, and increase in biohydrogenation (79%) occurred with the inclusion of protected PA3 (p ≤ 0.05). In conclusion, supplements with protected PA at 3 and 6% increased PA availability. The results indicate good benefits of protected PA on fermentative variables, and these doses seem ideal for future research in lactating goats.

El objetivo del presente estudio fue evaluar el efecto de la edad de rebrote sobre la producción de forraje en cultivares de Urochloa (Cobra, Convert 330, Camello I y Camello II) en Güemes, Tamaulipas. El experimento se realizó en condiciones de temporal, de septiembre a noviembre de 2018. Las variables evaluadas fueron: altura de planta (AP; cm), rendimiento (kg ha^-1) de materia seca de hoja (MSh), materia seca de tallo (MSt) y radiación interceptada (RI; %). El diseño estadístico fue completamente al azar, con tres repeticiones, se aplicó la prueba de comparación de medias de Tukey (p= 0.05). En general, la acumulación de materia seca incrementa en función de la edad de rebrote. Durante la octava semana de rebrote se obtuvieron los mayores rendimientos y fue mayor el rendimiento de hoja respecto al de tallo. Los mayores rendimientos de MSh se obtuvieron en la octava semana de rebrote (p≤ 0.05), independientemente del cultivar, con rendimientos de 1 625.3, 3 183.7, 3 032.7 y 4 227.7 kg ha^-1 MS para Cobra, Convert 330, Camello I y Camello II, respectivamente. La octava semana es el momento óptimo para aprovechar el forraje de los híbridos en las condiciones climáticas que fueron evaluados.

The concentration of conjugated linoleic acid (CLA) in dairy products derived from ruminants, such as cow’s milk, is mainly influenced by the dietary lipid profile. The current study aimed to establish the relationship between fatty acid (FA) profiles in various diets and the concentration of...