Unraveling the genetic diversity of creole breeds is central to understanding their value and importance for conservation and improvement in diverse production environments in America. In most of its countries, information on attributes of many livestock breeds is scanty and do not support well-informed decision-making upon relevant management strategies. This study aimed at investigating the “Paisanita” cattle breed, a landrace breed adapted to different ecological regions of Guatemala. For this purpose, a total of 47 adult females belonging to 4 different geographical areas of the country were analysed on the basis of 24 quantitative traits. Results showed no differences between areas and so, the possible presence of ecotypes was discarded. This conclusion helps the objectives of conservation, and future monitoring of “Paisanita” cattle.

Cow milk is rich in proteins, fats, carbohydrates, and minerals, and its nutrient content depends on various factors. We tested differences in fatty acid and protein contents of milk from seven breeds and regions, including three dairy breed samples: Holstein milk from Beijing, China (BH); Holstein milk from Hebei province, China; Jersey milk (JS); and four dairy/meat cow samples: Sanhe milk, Xinjiang brown milk (XH), Simmental milk, and Shu Xuanhua milk. Breed significantly affected total fat, fatty acid, and protein contents. The region significantly affected the contents of different fatty acids, α-lactalbumin, and lactoferrin. JS had the highest total fat, most fatty acids, and casein contents. XH performed well with significantly higher unsaturated fatty acid content than BH, which was not significantly different from JS, and its protein composition of low β-lactoglobulin and high lactoferrin was more similar to breast milk, which may thus be favorable to the growth and development of children. Our results may inform the development of dairy products from different cow breeds and advance the process of accurate breed identification.

Forty-five of intact three sheep breeds (Awassi, Harri, and Najdi) were used in this study (15 animals of each breed), with weight ranged from 23.40 to 25.87 kg. Five animals from each group at the end of growth trial were used for digestibility and nitrogen balance trials. The three groups of sheep had effect (p > 0.05) in the final live weight (FLW). Average daily feed intake (ADI), average daily gain (ADG) and feed conversion ratio (FCR) were significantly (p < 0.05) different among the three groups. For digestibility coefficients, the three breeds of sheep had no effect (p > 0.05) in dry matter (DM), organic matter (OM), crude protein (CP), crude fiber (CF), nitrogen free extract (NFE), neutral detergent fiber (NDF) and acid detergent fiber (ADF). In the similar approach, no significant differences were founds among three breeds of sheep in digestible organic matter, digestible of crude protein, total digestible nutrients and nitrogen retention. The current study concluded that the sheep breeds affected average daily feed intake, average daily gain and feed conversion ratio (FCR). Awassi breed showed the best of average daily gain and feed conversion ratio followed by Najdi then Harri breeds. The breed of sheep had no effect on digestibility coefficients and nitrogen retention.

The sustainability of agroecological systems, biodiversity protection, animal welfare and consumer demand for higher-quality products from alternative and extensive farming methods, have reinforced interest in local breeds that are well adapted to low-input environments. However, food safety needs to be safeguarded to reinforce consumer confidence. The aim of this study was to conduct a preliminary investigation on the occurrence of Salmonella spp. in eggshells, hen’s cloaca and litter materials from autochthonous Portuguese laying hens raised in a semi-extensive system for small-scale production. A total of 279 samples were obtained, with 63 samples from the “Preta Lusitânica” breed, and 72 samples each from the remaining autochthonous breeds, namely “Branca”, “Amarela” and “Pedrês Portuguesa”. None (0%) of the samples analyzed were positive for Salmonella spp.. To the best of our knowledge, these are the first results of Salmonella evaluation from hen’s cloaca, eggshells, and litter materials in autochthonous Portuguese chickens, suggesting that a semi-extensive production system can contribute to better food security and a lower risk to public health and the environment.

One of the main factors that influence the fertility of cattle in grazing systems in hot tropical climates is heat stress. The objective of this study was to evaluate the effect of season, breed, hormonal and physiological condition on the quantity and quality of cumulus-oocyte complexes (COCs) and embryos produced in vitro, from Romosinuano (RM) and Tropical Milking (TM) donors. Three ovum pick-up and in vitro fertilization (OPU-IVF) were performed, one per season; hot dry (HD; 10, 10), hot humid (HH; 9, 9) and fresh dry (FD; 7, 10) in RM and LT donors. Serum levels of cortisol, insulin and glucose were measured, in addition to heart rate (HR), respiratory rate (RR) and rectal temperature (RT). Effect of season x genotype interaction (p≤0.05) was observed in all COCs variables and only in cleavage embryos (CLI) (p≤0.05). Body weight (BW) affected all COCs variables (p≤0.01), except unviable (UNV) although affected degenerated embryos (DEG) (p≤0.01) and total blastocysts (BLAST) (p≤0.01). Cow age only affected viable COCs (VIAB) (p ≤ 0.05), code one blastocysts (BC1) and BLAST (p≤0.01). Cortisol affected total COCs (COCsT), VIAB and total matured in vitro (TMIV) (p≤0.01), as well as CLI, BC1 (p≤0.01) and BLAST (p≤0.05). Insulin affected COCsT (p≤0.01), UNV (p≤0.05), denuded oocytes (DE) (p≤0.01), BC1 and code two blastocysts (BC2) (p≤0.01). Glucose affected all COCs variables (p≤0.01), except UNV and all embryo variables except BC2. HR affected COCsT, DE, TMIV (p≤0.01), CLI, BLAST and DEG (p≤0.05). RR affected COCsT, UNV, VIAB, CLI (p≤0.05), BC1, BLAST and DEG (p≤0.01). RT only affected DE, VIAB (p≤0.01) and BLAST (p≤0.05). The seasonal climatic year variation of Veracruz and changes in physiological and hormonal variables have diverse effects on the cumulus-oocyte complexes and embryos produced by RM and TM donors.

Meat tenderness, water holding capacity (WHC) and colour attributes of six muscles (Longissimus thoracis et lumborum (LTL), Semimembranosus (SM), Biceps femoris (BF), Supraspinatus (SS), Infraspinatus (IS), Semitendinosus (ST)) from large frame Indigenous Veld Goats (IVG) and Boer Goats (BG) were studied. Weaner male Boer Goats (BG; n = 18; 10 bucks and 8 wethers) and large frame Indigenous Veld Goats (IVG; n = 19; 9 bucks and 10 wethers) were raised on hay and natural grass, and on a commercial pelleted diet to a live weight of 30 - 35 kg. All goats were slaughtered at a commercial abattoir and the dressed carcasses chilled at 4°C within 1-hour post-mortem. The muscles were dissected from both sides 24-hours post-mortem and aged for 1-day and 4-days. Variations in meat characteristics such as ultimate pH, WHC, percentage purge, myofibril fragment length, intramuscular fat, connective tissue characteristics, and Warner-Bratzler shear force. Bucks had higher L* and Hue-angle values, whereas wethers had increased a* and Chroma values. The muscle baseline-data will allow informed decisions to support muscle-specific marketing strategies, which may be used to improve consumer acceptability of chevon.

This study investigates the correlation between gut microbiota diversity and various hematological and meat quality parameters in different cattle breeds, including Angus, Simmental, Braunvieh, Brahman and F1(SMxBR). Using 16S rRNA and 18S rRNA gene sequencing, microbial communities were profiled to discern breed-specific impacts on gut microbiota. Significant correlations were identified between gut microbiota diversity and health parameters, emphasizing the role of microbial diversity in influencing skin condition, fat deposition, and muscle quality. Key bacterial genera such as Blautia, Christensenellaceae_R-7_group, and Coprococcus exhibited significant correlations with meat quality traits. In fungi, genera like Rhodotorula exhibited positive correlations with muscle quality, while protist genera such as Cryptosporidium negatively correlated with meat quality parameters. These findings suggest that host genetics significantly shape the gut microbiota and highlight the potential for targeted microbiota management to optimize gut health, enhance feed efficiency, and improve meat quality in livestock.