Natural additives in ruminant diet optimizes animal performance by controlling or modifying the rumen fermentation pattern. The aim of this study was to evaluate the effects of using Saccharomyces cerevisiae products during abrupt changes in dietary starch concentration on ruminal pH maintenance, performance and metabolism of confined sheep. Twenty adult ewes, crossbred Texel x Corriedale(44.7±6.97 Kg BW) were divided into three groups: Control (n=6), Cultron X (yeast culture; n=7) and Cultron Pro (hydrolyzed yeast; n=7), administered at a dose of 5 g/sheep/day (10x1010CFU/g DM). The experiment lasted 20 days divided into four periods, alternating between 40 and 60% concentrate. Blood and ruminal fluid were collected at the end of each period, and daily dry matter intake was measured to determine the average daily gain (ADG). Blood tests included blood count and biochemical parameters such as glucose, urea, total plasma proteins (TPP), liver enzymes, acute phase proteins and minerals. There was an upward trend in ADG in group Cultron X compared to control in period 3. Although, ruminal pH did not differ between groups, protozoan motility was higher in animals supplemented with hydrolyzed yeast. The Cultron Pro group showed an increase in TPP in periods 3 and 4, and AST in periods 2 and 3 compared to the control group. There was no difference in other metabolites. Yeast supplementation is a potential tool in times of feeding challenge, in which yeast culture is the most effective for improving performance of confined sheep being in improving performance of confined sheep.

The aim of this study was to confirm the possible consequences of prepartum lameness on subsequent lactation among Holstein cows. In this research, 27 multiparous cows, were monitored from the 30th to 63rd day, relative to calving. Thirty days prior to parturition, the animals were segregated into two groups based on the locomotion score (LS), where LS 1 is attributed to animals without claudication, LS 2 to those with suspected lameness and LS 3, 4 and 5 to those with mild, moderate and severe lameness, respectively; in the lame cows group (LC) (n=15), the animals displayed LS ≥ 3, whereas in the non-lame cows group (NLC) (n=12) they showed LS 1. Milk production, body condition score (BCS) and blood concentration levels of β-hydroxybutyrate (BHB), urea, phosphorus, calcium aspartate aminotransferase (AST), gamma glutamyl transferase (GGT) and total plasma proteins (PPT) were evaluated. Milk production (17.675 ± 0.31 L of milk/day) and blood calcium concentration (7.42 ± 0.12 mg/dL) were lower in the lame cows in comparison to those without lameness (22.27 ± 0.42 L of milk/day and 9.63 ± 0.13 mg/dL). Besides, the lame cows showed higher BCS loss during the early postpartum period. The metabolites AST, GGT, PPT, urea, BHB and phosphorus revealed no difference between the groups during the period evaluated. The lameness evident in cows during prepartum exerted major negative effects on the milk production and calcemia, making the LS evaluation during these period an important tool in the early diagnosis of losses for future lactation.

The purpose of this research was to confirm the changes occurring in the foot system of the heifers challenged with lipopolysaccharides (LPS), at the clinical, serum and histological levels. We studied 16 clinically healthy heifers, 14 months of age, placed in a confinement system. All the animals were provided with an accelerometer collar to establish their activity. They were categorized into two groups: the LPS group (n=8), or those which were administered two intravenous applications of 2 mL containing 0.5 μg/kg of body weight of LPS, with a 24-hour interval and the Control group (n=8) which were given two infusions of 2 mL of saline solution in the same time interval. General clinical examination and blood collection were done at 0, 4 and 8 hours post the LPS challenges and analyses of the hemograms and paroxonese-1 were performed. The animals were then slaughtered on day 4 and the laminar tissue was collected for histological analysis. The LPS group revealed a lower total leukocyte count with heart rate and greater activity. None of the animals revealed any abnormal signs symptomatic of foot pathology after histological analysis. Hence, the challenge with LPS failed to induce any clinical and histological changes in the foot tissue compatible with laminitis.

This work aimed to compare the efficiency of two commercial recombinant bovine somatotropin (rbST) formulations on productive, metabolic, behavioral, and feeding parameters of mid-lactation Holstein cows. Eighteen secondiparous cows were randomly assigned to two groups to be treated with injectable rbST (rbST-Fast, Boostin ^® , MSD Saúde Animal; and rbST-Slow, Lactotropin ^® , Agener União Saúde Animal). Cows were rbST-treated during five cycles of 14 days each, totaling 70 days. Blood samples were collected thrice in each cycle to assess metabolic markers. Daily, automatic feeders and individual monitoring collars measured behavior and feed intake. Milk samples were collected weekly to evaluate milk composition and somatic cell count. The rbST-Fast group had higher milk production ( p = 0.03) and tended to present greater feed intake ( p = 0.07). In addition, animals treated with rbST-Fast had higher ( p < 0.01) concentrations of non-esterified fatty acids (NEFA) and tended ( p = 0.09) to have lower serum glucose values. As for the variation in body weight, cows treated with rbST-Fast lost approximately three times more weight ( p < 0.01) than rbST-Slow cows. Regarding milk components, cows from the rbST-Fast group produced milk with a higher lactose content ( p = 0.05). In conclusion, rbST-Fast treated cows produced more milk, had higher feed intake, and showed a higher degree of lipid mobilization, demonstrated through the higher body weight loss and higher NEFA concentrations.

The aim of the experiment reported in this research paper was to determine the influence of the bovine appeasing substance (BAS) on milk yield, energy metabolism, inflammation, and stress in cows during the transition period. Twenty-four multiparous Holstein cows (day 28 pre-partum to 21 postpartum) were distributed randomly into two groups: control (n = 12) and BAS (Secure Cattle®; n = 12). Each animal was administered 5 mL of the product on days 28 and 14 pre-partum and on the day of calving. The feed intake was assessed using automated, individual feeders and the milk yield was determined electronically. Six milk samples were obtained from each animal, which were analyzed for chemical composition and somatic cell count. Six blood samples were obtained per animal for future biochemical analyses (free fatty acids, beta hydroxybutyrate, cortisol, myeloperoxidase and paraoxonase 1). The statistical analyses were conducted with the JMP Pro 14 software, with P ≤ 0.05 being considered as statistical significance. BAS-treated cows showed higher milk yield than controls. Dry matter intake (DMI) during the pre- and postpartum periods was greater for the control than treated group. The BAS group exhibited reduced plasma cortisol postpartum. In conclusion, cows treated with BAS showed higher milk yield, lower DMI, and reduced plasma cortisol concentrations than controls.

Cattle are ruminant herbivores with great productive capacity due to a highly efficient digestive system adapted to degrade and take advantage of complex compounds, such as plant structural carbohydrates. The fermentative capacity present in their digestive tract comes from the colonization of microorganisms such as bacteria, fungi and protozoa that transform ingested food into substrates for energy production, while the regulation of consumption comes from environmental and physiological factors, involving the central nervous system and hormone production. The decision to consume or refuse food will be based on sensory perception and metabolic demand. Management errors and diseases are evidenced when there is a decrease in food production and consumption. These can be preemptively corrected with the use of animal monitoring technologies to predict drops in production. As an example of these technologies, animal monitoring collars evaluate rumination, activity, idleness and panting for 24 hours, establishing individual curves and notifying when the animal demonstrates alterations and, based on this diagnosis, it is possible to identify alterations due to environmental or physiological factors. Other technologies such as intelligent consumer feeders allow individual assessment and help identify the quality of the diet offered. Thus, the use of animal monitoring systems, combined with knowledge of their physiology, provides a more efficient breeding system with better animal welfare.