Effects of Supplementing Milk Replacer with Sodium Butyrate on Dairy Calves.

Diarrhea and respiratory diseases pose significant challenges in the rearing of pre-weaned calves, motivating the investigation of tools to improve gastrointestinal tract development, health, and overall performance in young calves. Consequently, the primary objective of this study was to assess the effectiveness of an additive incorporated into milk replacer to promote the development and health of the animals. Forty-six dairy calves were randomly assigned into two treatments: control (CON, n = 23; with 15 females and 8 males), and sodium butyrate (SB, n = 23; with 15 females and 8 males). The calves in the SB treatment group were supplemented with 4 g/d of unprotected sodium butyrate (Adimix, Adisseo, China), added to the milk replacer from 4 to 60 days of age. Water and starter were fed ad libitum. The study evaluated several parameters, including feed intake, nutrient digestibility, ruminal pH, ammonia and volatile fatty acids, blood metabolites (glucose, insulin-like growth factor type 1, urea, ß-hydroxybutyrate), hemogram, health scores, performance, and feed efficiency. Bull calves were euthanized at 60 days of age for organ comparison, while heifer calves were assessed for carryover effects up to 90 days of age. Data were analyzed independently using linear mixed models using the nlme package in R, and the Artools package for non-parametric categorical outcomes. Although the feed intake and performance variables exhibited differences within weeks, no divergence was observed between treatment groups. Notably, a positive treatment-by-week interaction was identified for starter feed intake (p = 0.02) and total dry matter intake (p = 0.04) during pre-weaning for CON animals. Ruminal parameters, blood metabolites, and hemogram values such as glucose, urea, insulin-like growth factor type 1, mean corpuscular value, lymphocytes, and neutrophils displayed differences within weeks during the pre-weaning stage, but similar results within groups. No differences between supplemented and non-supplemented calves were found across nutrient digestibility, organ development, and histology. Regarding health scores, differences were noted within weeks for fecal and respiratory scores during the pre-weaning stage, and only the respiratory score during the post-weaning stage. Consequently, butyrate supplementation did not elicit improvements or negative effects in the body development or health status of dairy calves.

Residual Feed Intake as an Efficiency Metric for Pre-Weaning Dairy Calves: What Do We Know?

Dairy cattle systems have targeted improvements in feed efficiency by selecting animals that can convert less feed into more products. Residual feed intake (RFI) has been the index of choice when selecting dairy cattle for feed efficiency. Nonetheless, RFI studies have focused on lactating cows, and the crucial importance of pre-weaning efficiency on farm profitability and cow productivity has been mostly neglected. This review discusses the current knowledge of how RFI divergence relates to nutrient metabolism in pre-weaning dairy calves, including the advantages and limitations of evaluating RFI in this phase. Existing literature indicates that nutrient utilization, energy metabolism, protein metabolism, vitamin metabolism, intestinal development, and hindgut bacterial populations may be implicated in RFI divergence between pre-weaning calves. Techniques developed to date to evaluate RFI in this phase are still evolving to better adapt to the unique characteristics of this phase, and more research is needed to fill in the gaps in our current understanding of early-life feed efficiency divergence in cattle. However, current results suggest great potential for selecting high-efficiency calves while in pre-weaning to accelerate the progress of genetic selection in dairy cattle.

Adoption of Precision Technologies by Brazilian Dairy Farms: The Farmer's Perception.

The use of precision farming technologies, such as milking robots, automated calf feeders, wearable sensors, and others, has significantly increased in dairy operations over the last few years. The growing interest in farming technologies to reduce labor, maximize productivity, and increase profitability is becoming noticeable in several countries, including Brazil. Information regarding technology adoption, perception, and effectiveness in dairy farms could shed light on challenges that need to be addressed by scientific research and extension programs. The objective of this study was to characterize Brazilian dairy farms based on technology usage. Factors such as willingness to invest in precision technologies, adoption of sensor systems, farmer profile, farm characteristics, and production indexes were investigated in 378 dairy farms located in Brazil. A survey with 22 questions was developed and distributed via Google Forms from July 2018 to July 2020. The farms were then classified into seven clusters: (1) top yield farms; (2) medium-high yield, medium-tech; (3) medium yield and top high-tech; (4) medium yield and medium-tech; (5) young medium-low yield and low-tech; (6) elderly medium-low yield and low-tech; and (7) low-tech grazing. The most frequent technologies adopted by producers were milk meters systems (31.7%), milking parlor smart gate (14.5%), sensor systems to detect mastitis (8.4%), cow activity meter (7.1%), and body temperature (7.9%). Based on a scale containing numerical values (1-5), producers indicated "available technical support" (mean; σ2) (4.55; 0.80) as the most important decision criterion involved in adopting technology, followed by "return on investment-ROI" (4.48; 0.80), "user-friendliness" (4.39; 0.88), "upfront investment cost" (4.36; 0.81), and "compatibility with farm management software" (4.2; 1.02). The most important factors precluding investment in precision dairy technologies were the need for investment in other sectors of the farm (36%), the uncertainty of ROI (24%), and lack of integration with other farm systems and software (11%). Farmers indicated that the most useful technologies were automatic milk meters systems (mean; σ2) (4.05; 1.66), sensor systems for mastitis detection (4.00; 1.57), automatic feeding systems (3.50; 2.05), cow activity meter (3.45; 1.95), and in-line milk analyzers (3.45; 1.95). Overall, the concerns related to data integration, ROI, and user-friendliness of technologies are similar to those of dairy farms located in other countries. Increasing available technical support for sensing technology can have a positive impact on technology adoption.

Effects of vaccination against brucellosis and clostridia on the intake, performance, feeding behavior, blood parameters, and immune responses of dairy heifers calves.

The aim of this study was to identify possible effects of different vaccination strategies (concomitantly or not) against brucellosis and clostridia on intake, performance, feeding behavior, blood parameters, and immune responses of dairy heifers calves. Fifty heifers calves were enrolled [38 Gyr (Zebu, Bos taurus indicus) and 12 5/8 Holstein × Gyr]. At 120 d of age, animals were randomly distributed among 3 groups: B (n = 18), vaccinated against brucellosis; C (n = 14), vaccinated against clostridia and CB (n = 18), vaccinated concomitantly for both. Rectal and thermographic temperatures were evaluated on days -1, 0, 1, 2, 3, 5, 7,10, 14, and 28 relatives to the vaccination day. Feed and water intake, body weight (BW), and feeding behavior were monitored daily by an electronic feeding system. Blood was sampled on days 0, 3, 7, 14, and 28, relative to the vaccination day for determination of glucose and ß -hydroxybutyrate (BHBA) concentrations. Blood sampled on day 0 (prevaccination) and on days 28 and 42 were used to evaluate the immune response against Brucella abortus and clostridia. There was an increase in rectal temperature between the first and the third day postvaccination in the 3 groups. The thermography revealed an increase of local temperature for 7 d on groups B and CB. Group C had increased local temperature for a longer period, lasting for up to 14 d. Dry mater intake was reduced for groups B and CB, but no alteration was observed for group C. No alterations regarding initial BW, final BW, average daily weight gain, and feed efficiency were observed. No differences were observed for the 3 vaccination groups for blood parameters throughout the evaluation period. The concomitant vaccination against brucellosis and clostridia led to lower neutralizing antibody titers against epsilon toxin of Clostridium perfringens and botulinum toxin type C of C. botulinum (C > CB > B). When cellular proliferation assay and serological tests to B. abortus were evaluated, no differences were observed between groups B and CB. The present results indicate that the concomitant vaccination against brucellosis and clostridia has no relevant impact on the intake, performance, and feeding behavior of dairy calves. However, the concomitant vaccination of vaccines against these 2 pathogens impacts animal immunity against clostridial infections.

Extract of Mangifera indica L. leaves may reduce biofilms of Staphylococcus spp. in stainless steel and teatcup rubbers.

Human ingestion of antimicrobial residues in dairy products is a problem of public health. In this study we evaluated antibacterial effectiveness of aqueous and ethanolic leaf extracts of Mangifera indica L. as a natural alternative for reduction of Staphylococcus spp. biofilms. Eight Staphylococcus spp. strains from cows with mastitis and the Staphylococcus aureus strain (ATCC 25923) were evaluated. High performance liquid chromatography indicated the presence of phenolic compounds in the aqueous extract. Agilent Technologies gas chromatography revealed the presence of phenolic compounds, carbohydrates, and gallic acid in ethanolic extract. The tannin contents were 2.27 ± 0.01 and 2.67 ± 0.01% for ethanolic extract and aqueous extract, respectively. Extracts were evaluated in agar diffusion test and the size of inhibition zones were compared. The ethanolic extract was the most effective, showing minimum inhibitory concentrations and minimum bactericidal concentrations between 1.8-7.5 and 15.1-45.3 mg/ml, respectively. After tannin removal, the extracts were less effective, indicating these secondary metabolites as one of the main antibacterial compounds. The ethanolic extract at 45.3 mg/ml reduced mature biofilms in teat rubber (average: 3.91 log reduction) and stainless steel (average: 3.87 log reduction) after 5 min of contact. The extracts of M. indica leaves represent natural alternatives against Staphylococcus spp. strains and the ethanolic extract shows potential as a natural sanitizer.

Avaliação do perfil metabólico de vacas da raça Holandesa durante o período de transição / Evaluation of the metabolic profile of Holstein cows during the transition period

O período de transição é um momento de grande desafio para vacas de aptidão leiteira, uma vez que, a maioria dos problemas metabólicos ocorre nesta fase podendo prejudicar toda a expectativa de produção durante a lactação, resultando em impacto econômico significativo para fazendas de produção de leite. Este trabalho teve como objetivo avaliar o perfil metabólico de vacas da raça Holandesa durante o período de transição. Doze vacas Holandesas foram avaliadas, três semanas pré-parto até três semanas pós-parto, em sistema free-stall, localizado em Inhaúma, Minas Gerais, no período de outubro a dezembro de 2012. Avaliou-se o perfil metabólico através da concentração sérica de ácidos graxos não esterificados (AGNE), beta hidroxibutirato (BHBA), colesterol (COLES), proteína total (PT), albumina (ALB), cálcio, fósforo, magnésio bem como a atividade sérica das enzimas aspartato transaminase (AST) e lactato desidrogenase (LDH). As concentrações séricas de AGNE e BHBA foram diferentes entre o pré-parto e pós-parto (p<0,05). Observou-se diminuição na concentração de COLES com a aproximação do parto com posterior aumento (p<0,05). As concentrações séricas dos minerais, PT e ALB não apresentaram diferenças (p>0,05) no período avaliado. A atividade enzimática de AST e LDH foram maiores no período pós-parto (p<0,05). A avaliação do perfil metabólico é uma importante ferramenta de monitoramento e, na situação estudada, demonstrou alterações do perfil energético das vacas entre os períodos pré e pós-parto, relacionadas provavelmente a diminuição da ingestão de alimentos. A luz dos resultados do perfil metabólico, o rebanho avaliado possui pequeno risco para a ocorrência de enfermidades no pós-parto relacionadas ao período de transição.

The transition period is a time of great challenge for dairy cows, since most metabolic problems occur at this time and can compromise the entire lactation, resulting in a significant economic loss to commercial farms. This study evaluated the metabolic profile of dairy cows during the transition period. Twelve Holstein cows between three weeks pre-calving until three weeks postpartum was used in this study. They remained in a free-stall system, located in Inhaúma, Minas Gerais, during October to December 2012. The metabolic profile were composed by non-esterified fatty acids (NEFA), beta-hydroxybutyrate (BHBA), cholesterol (COLES), total protein (TP), albumin (ALB), calcium, phosphorus, magnesium as well as the activity serum enzymes aspartate transaminase (AST) and lactate dehydrogenase (LDH). There were differences in serum NEFA and BHBA between prepartum and postpartum (p<0.05). Observed a decrease in the concentration of COLES with the approaching birth with subsequent increase (p<0.05). Serum concentrations of minerals, PT and ALB did not differ (p>0.05). The enzymatic activity of AST and LDH were higher in the postpartum period (p<0.05). The evaluation of the metabolic profile is an important monitoring tool. Changes in the metabolic profile of cows during the transition period are motivated by energetic changing. Cows that were evaluated have a small risk of developing postpartum diseases related to the transition period.

Estudo longitudinal da infecção por enteropatógenos em bezerros neonatos, com diarreia, sob diferentes estratégias de aleitamento / Longitudinal study of infection by enteropathogens in newborn calves with diarrhea under different feeding strategies

Foram utilizados 17 bezerros, recém nascidos, da raça Holandesa, com o objetivo de avaliar a influência do volume de sucedâneo nos principais patógenos causadores de diarreia neonatal. [...] Foram coletadas amostras de sangue dos bezerros com cinco dias de idade para dosagem da proteína total. A média da proteína total foi 6,33 e 6,21g/dL nos grupos 1 e 2 respectivamente. O grupo 2 apresentou tendência (p<0,1) de maior consumo de sucedâneo no período avaliado. A quantidade de sucedâneo oferecida aos animais não influenciou a incidência de diarreia e sua etiologia, ou seja, não foi observada diferença (p>0,05) na frequência das amostras positivas para cada agente entre os grupos. A frequência dos enteropatógenos nas amostras foi de 100 e 75 por cento para Cryptosporidium spp.; 28,5 e 43,7 por cento para Salmonella spp.; 28,5 e 15,6 por cento para patotipos de E. coli; 3,5 e 6,2 por cento para Rotavírus e 10,7 e 9,4 por cento para Giardia sp. nos grupos 1 e 2 respectivamente. Foram encontrados os sorotipos de Salmonella infantis e muenster. Os patotipos de E. coli isolados foram classificados como E. coli enterohemorrágica, enteropatogênica, enterotoxigênica e produtoras de toxinas Shiga 1 e 2. Foi observada associação entre o Cryptosporidium spp. e os patotipos de E. coli em 30 por cento das amostras do grupo 1 e Cryptosporidium spp. e Salmonella spp. em 45,5 por cento no grupo 2. Os resultados do presente trabalho demonstraram que o fornecimento de diferentes volumes de sucedâneo não apresentou influência sobre a incidência e etiologia da diarreia neonatal. A avaliação longitudinal dos enteropatógenos durante o período de patência da diarreia demonstrou que a associação entre eles ocorre a partir do primeiro dia da doença e destacou a importância da infecção pelo Cryptosporidium spp. agente encontrado em todos os momentos e animais.

Seventeen Holstein newborn calves were used with the objective of evaluating the influence of milk replacer volume in the pattern of pathogens causing neonatal diarrhea. […] Were collected blood samples from calves with five days of age for determination of total protein. The average total protein was 6.33 and 6.21g/dL in groups 1 and 2, respectively. The group 2 tended (p<0.1) higher consumption of milk replacer during the study period. The volume of milk replacer did not influenced the incidence of diarrhea and the frequency of positive samples for each etiologic agent between the two groups (p>0.05). Also, there was no difference (p>0.05) on the pattern of the frequency of positive samples for evaluated pathogens. The frequency of pathogens in the samples was 100 and 75 percent for Cryptosporidium, 28.5 and 43.7 percent for Salmonella spp., 28.5 and 15.6 percent for E. coli pathotypes, 3.5 and 6.2 percent for Rotavirus and 10.7 and 9.4 percent for Giardia in groups 1 and 2, respectively. Serotypes of Salmonella infantis and muenster were found. The isolated pathotypes of E. coli isolates were classified as Escherichia coli enteropathogenic, enterotoxigenic and Shiga-toxin-producing 1 and 2. Associations between Cryptosporidium spp. and E. coli pathotypes, and between Cryptosporidium spp. and Salmonella spp. were found in 30 percent of the samples in group 1 and in 45.5 percent in group 2, respectively. Our results showed that the different volumes of milk replacer did not influence the incidence and etiology of neonatal diahrrea. Longitudinal evaluation of enteropathogens during patency demonstrated that the association between the etiologic agents starts from the first day of disease. This result highlighted the great importance of the infection by Cryptosporidium spp. which was present in every moments and animals evaluated.

Perfil sanguíneo e peso de órgãos internos de bezerros leiteiros criados em diferentes sistemas de aleitamento / Blood profile and weight of internal organs of dairy calves in different nursing systems

Objetivou-se avaliar o perfil sanguíneo e o tamanho absoluto e relativo dos órgãos internos de bezerros em sistema de aleitamento convencional ou fracionado. Foram utilizadas 10 fêmeas, com peso corporal inicial médio de 37,53 kg (±2,36) e 12 machos com peso corporal médio de 81,6 kg (±8,6), ambos da raça Holandesa. O aleitamento convencional constituiu-se de quatro litros de leite fornecidos diariamente durante 54 dias de avaliação e o fracionado, de seis litros do 6º ao 25º dias de idade, quatro litros do 26º ao 45º dias de idade e dois litros do 46º ao 59º dias de idade, além de concentrado, feno de Cynodon sp., água e suplemento mineral fornecidos ad libitum. O delineamento experimental foi inteiramente ao acaso, com cinco repetições para os parâmetros sanguíneos e seis repetições para o desenvolvimento dos órgãos internos. As coletas de sangue foram realizadas nas fêmeas nos dias sete, 21, 28, 42, 49 e 56 de idade. Para a avaliação dos órgãos internos os machos foram abatidos aos dois meses de idade, após jejum de 16 horas. Não foram observadas diferenças para os valores de proteínas totais, albumina, globulina, creatinina, ureia, colesterol e β-hidroxibutirato nas idades avaliadas (p>0,05). Entretanto, para a concentração de glicose houve interação entre os sistemas de aleitamento e os períodos avaliados, podendo ser observado que com 21 dias de idade a concentração foi maior nas bezerras mantidas em sistema fracionado, quando comparadas aos animais do grupo convencional. O sistema de aleitamento não alterou o peso corporal final, peso corporal final vazio e o peso dos órgãos internos, exceto para o coração, demonstrando que o sistema de aleitamento fracionado não altera as avaliações dos órgãos internos...

The objective was to evaluate the blood profile together with the relative and absolute size of the internal organs of calves in conventional or fractionated feeding system. Ten females were used, with an average initial body weight of 37.53 kg (±2.36), and 12 males with a mean body weight of 81.6 kg (±8.6), both Holstein breed. The conventional feeding consisted of four liter milk supplied daily for 54 days of evaluation, and fractioned six liter milk was given from 6 to 25 days of age, four liter from 26 to 45 days of ager, and two liter from 46 to 59 days of age. Cynodon sp. hay, water and mineral supplement was provided ad libitum. The experimental design was completely randomized with five replicates for blood parameters and six replicates for the development of internal organs. Blood collections were performed in females on days seven, 21, 28, 42, 49 and 56 of age. For the evaluation of internal organs males were slaughtered at two months of age, after 16 hours of fasting. No differences occurred in the values of total protein, albumin, globulin, creatinine, urea, cholesterol and β-hydroxybutyrate in ages evaluated (p>0.05). However, for the concentration of glucose no interaction was found between lactation systems and periods evaluated. It can be noted that at 21 days of age the concentration was higher in calves kept in the fractionated system, when compared with animals of the conventional group. The feeding system did not affect the final body weight, the empty body weight or the weight of the internal organs, except for the heart, demonstrating that the fractional feeding system does not alter the assessment of the internal organs...