Dietary yeast supplementation may improve the digestive efficiency of ruminants, but responses depend on the yeast strain and the diet composition. Corn silage and citrus pulp are usual carbohydrate sources for dairy cows in southeast Brazil. This study evaluated the supplementation of dairy cows fedding on corn silage-citrus pulp-based diets with Saccharomyces cerevisiae CNCM I-1077 (Lallemand SAS, Toulouse, France). Twenty multiparous, midlactation Holstein cows were assigned to two treatments in crossover design. Treatments were: live yeast on oyster meal capable of supplying a daily minimum of 1 × 10(10) CFU per cow or oyster meal top-dressed at 10 g to the morning meal. Diet contained (% of dry matter): 16.8% crude protein, 30.9% neutral detergent fiber, 43.9% corn silage, 2% tifton hay, 14.4% steam flaked corn, 16.9% citrus pulp and 21.7% soybean meal. Yeast supplementation increased daily yields of milk (29.4 vs. 28.5 kg, p = 0.11), protein (0.939 vs. 0.908 kg, p = 0.05), and lactose (1.294 vs. 1.241 kg, p = 0.06), but did not affect milk fat contents (p = 0.59). Daily dry matter intake was 21.4 with yeast and 20.7 kg for the control (p = 0.11). Total tract apparent digestibility of the neutral detergent fiber was 48.1% with yeast and 43.2% for the control (p = 0.08). There was a trend for increased intake of digestible organic matter with yeast supplementation (p = 0.07). The positive milk protein yield response to yeast supplementation may have resulted from the increased fiber digestibility, but the response mechanism could not be elucidated.

The inappropriate use of antimicrobials in dairy animals can lead to residues in raw milk and in dairy products. Foods containing residues of this nature, whether in the short, medium, or long term, cause serious health harm. Absence of these compounds in foods should be a premise for declaring safety. This systematic review aimed to identify the antibiotic residues most frequently found in raw bovine milk and the methodologies used to detect such residues over the ten years from 2013 to 2023. PRISMA guidelines for systematic reviews were followed, by searching the Web of Science, PubMed Central, Scopus, and Springer databases. The search strategy identified 248 articles, and after applying the selection and quality assessment criteria, 16 studies were selected. The number of samples analyzed was 411,530, of which 0.21% tested positive for some type of antibiotic. Eight classes and 38 different types of antibiotics were identified. The most common class was tetracycline, with emphasis on sulfonamides and quinolones, which have shown increasing prevalence among residues in milk in recent years. A total of 56.25% of the studies employed rapid kits to detect residues, 18.75% chromatography, and 25% both techniques. Antibiotic residues in bovine raw milk should be a great concern for animal, environmental, and human health.

The main challenge in milk production has been to maintain a focus on efficient processes that enhance production outcomes while aligning with animal welfare and sustainability and being valued by society. As an alternative to improve cow welfare in production and provide better handling of the waste generated by the activity, the system called the compost-bedded pack barn (CBP) has been widely adopted in countries with temperate climates and higher milk production. This CBP has been attracting global interest, including from countries with tropical and subtropical climates, such as Brazil, where many producers have started to use it due to the response in terms of milk productivity. A CBP can be designed either in (a) an open facility with natural ventilation or a positive-pressure ventilation system or (b) totally closed facilities, equipped with negative-pressure ventilation systems and permanent thermal control. The latter system is being implemented in Brazil, despite insufficient knowledge about its efficiency. The objective of this study was, through a review, to gather and describe the most recent information on the use of open and closed CBP systems for dairy cattle housing, mainly covering how it is applied in tropical climate regions. To achieve the proposed objective, this review study included the following topics related to CBPs: (i) implementation, (ii) bedding, (iii) general construction and architectural characteristics, and (iv) ambient thermal conditioning. Knowledge gaps and directions for future research are also identified here.

The main challenge in milk production has been to maintain a focus on efficient processes that enhance production outcomes, while aligning with animal welfare and sustainability and being valued by society. As an alternative to improve cow welfare in production and provide better handling of the waste generated by the activity, the system called compost-bedded pack barn (CBP) is an alternative that has been widely adopted in countries with temperate climates and higher milk production. This CBP has been attracting global interest, including from countries with tropical and subtropical climates, such as Brazil, where many producers have started to use it due to the response in terms of milk productivity. A CBP can be designed either in a) an open facility with natural ventilation or positive pressure ventilation system or b) totally closed facilities, equipped with negative pressure ventilation systems and permanent thermal control. The latter system is being implemented in Brazil, despite insufficient knowledge about its efficiency. The objective of this study was, through a review, to gather and describe the most recent information on the use of open and closed CBP systems for dairy cattle housing, mainly how it is applied in tropical climate regions. To achieve the proposed objective, this review study included the following topics related to CBPs: (i) implementation; (ii) bedding; (iii) general construction and architectural characteristics; iv) ambient thermal conditioning. Knowledge gaps and directions for future research are also identified.

Improving livestock nutrition with natural supplements can enhance productivity and meat quality. This study evaluated whether a clayey micromineral compound (CMC) in lamb diets improves feed efficiency, health, and meat traits. Twenty-four 60-day-old Dorper/Santa Inês crossbred lambs (28.41 ± 4.147 kg initial weight) were randomly assigned to four CMC doses (0%, 0.4%, 0.8%, or 1.2% of dry matter intake/day) for 90 days, following a 15-day adaptation. The lambs were individually housed, with daily feed intake monitoring, weekly weight measurements, and blood analyses at the start and end. On day 89, rumen fluid was sampled for digestion analysis, and post-mortem evaluations were used to assess meat quality and rumen health. The results showed that 0.8% CMC optimized fat and fiber digestion (p < 0.05), while higher doses linearly improved meat color intensity (p < 0.05). Blood tests indicated better liver function at intermediate doses (p < 0.05). However, the CMC did not affect overall growth, feed intake, or carcass traits. The supplement was safe but provided selective benefits. These findings suggest that CMCs could enhance feed efficiency and meat appeal, although further research is needed to refine dosing for maximum impact.

The objective of this study was to assess the impact of incorporating vegetable oils into the in vitro fermentation of a tropical grass on the kinetics and digestibility of the fibrous fraction by rumen microorganisms. Treatments consisted of different inclusion levels (0, 2, 4, and 6% dry matter) of lipid sources, namely soybean oil, canola oil, and baru oil, mixed with tropical forage (Pennisetum purpureum Schum cv. Cameroon). A completely randomized design was employed, featuring a 3 × 4 [...] ABSTRACT The objective of this study was to assess the impact of incorporating vegetable oils into the in vitro fermentation of a tropical grass on the kinetics and digestibility of the fibrous fraction by rumen microorganisms. Treatments consisted of different inclusion levels (0, 2, 4, and 6% dry matter) of lipid sources, namely soybean oil, canola oil, and baru oil, mixed with tropical forage (Pennisetum purpureum Schum cv. Cameroon). A completely randomized design was employed, featuring a 3 × 4