The Association between Socioeconomic Profiles, Attitudes, and Knowledge of Dairy Farmers Regarding Somatic Cell Count and Milk Quality.

The primary objective of this study was to investigate the association between the bulk tank somatic cell count (SCC) and dairy farmers' knowledge about milk quality, mastitis control, and their socioeconomic characteristics. Additionally, we estimated the association between the bulk tank SCC and bulk tank milk hygienic quality in dairy herds. Bulk tank milk samples from 120 dairy herds enrolled in the milk quality payment program were collected for the determination of the SCC, the total bacterial count (TBC), the preliminary incubation count (PIC), the laboratory pasteurization count (PC), and the coliform count (CC). Based on the bulk tank SCC results, 63 herds were selected and categorized into three groups: (a) low SCC: ≤250,000 cells/mL (n = 16); (b) medium SCC: >250,000 ≤ 400,000 cells/mL (n = 24); and (c) high SCC: >400,000 cells/mL (n = 23). Socioeconomic profiles, attitudes, and knowledge of somatic cell count and milk quality were assessed using previously tested questionnaires, which were used to interview the herd managers of the 63 selected dairy herds. Among the findings, 87.0% of the dairy herds had an SCC < 400 × 103 cells/mL, and presented milk production as the main economic activity of the farm, whereas only 47.0% of dairy herds with an SCC > 400 × 103 cells/mL had milk production as the main economic activity of the farm (p < 0.031). In a total of 95% of the selected herds (n = 60), milking machines were used, with pipeline milking machines being more predominant, accounting for 70.8% in herds with a medium somatic cell count (SCC) and 78.3% in herds with a high SCC, as opposed to herds with a low SCC at 50% (p < 0.031). The frequency of dairy producers' awareness of the maximum legal requirements for the bulk tank SCC and TBC was higher in herds with a higher SCC than in herds with a medium SCC. In conclusion, the results of this study indicate a significant association between the bulk tank somatic cell count (SCC) and dairy farmers' knowledge about milk quality, mastitis control, and socioeconomic characteristics. These findings emphasize the importance of knowledge and the socioeconomic profiles of dairy farms in maintaining and enhancing milk quality in dairy herds.

Effects of exogenous amylase on the in vitro digestion kinetics of whole-crop maize silages made from flint or dent grain type at different phenological stages grown in tropical condition.

The effect of exogenous amylase on the in vitro rumen digestion kinetics of whole-crop maize silage made from dent (RB9004) or flint grain type (RB9308) was evaluated at different phenological stages: soft dough (SOD), early dent (EAD), ½ milkline (½M) and ¾ milkline (¾M). Forage was harvested from 70 to 110 days after sowing. Two rumen-cannulated cows receiving or not exogenous amylase (0.7 g/kg dry matter-DM, provided to achieve 396 kilo Novo units of amylase activity/kg of TMR DM) were used as donor of ruminal fluid. The in vitro gas production kinetics was evaluated according to a dual-pool logistic model. The chemical composition and gas production kinetics were affected by the hybrid and phenological stages. The flint hybrid had lower range for chemical analysis among physiological stages. Harvesting at ½M and ¾M improved DM content, bromatological composition and silage quality parameters compared to dent or flint types. Amylase (i) increased methane (CH4 ) production and in vitro dry matter digestibility (IVDMD) in ½M stage, (ii) improved digestion kinetics by reducing lag time and increasing total gas production and fermentation rates of non-fibrous carbohydrates (NFC) and fibrous carbohydrates (FC), and (iii) increased extent and fermentation rate of NFC and increased fermentation rate of FC fraction in whole-crop maize silages produced from dent or flint types in all phenological stages. Harvesting between ½M and ¾M is the best phenological stage to improve chemical composition and silage quality parameters. Exogenous amylase showed improvements on fibre digestion of silages at ½M and ¾M phenological stages in both grain types of corn.

Herd characteristics and management practices associated with bulk tank milk quality of dairy herds in southeastern Brazil.

This study identified the association of management practices and herd characteristics with milk quality of bulk tanks in southeastern, Brazil. Milk samples were collected weekly during 8 weeks from 63 dairy herds. Bulk tanks were evaluated for total bacteria (TBC), preliminary incubation (PIC), pasteurization (PC), coliform (CC), and somatic cell counts (SCC). Associations found were type of milking system utilized in the farm with TBC, PIC, and SCC; the use of gloves for milking with TBC and PIC; sanitation of milking equipment prior to milking with PC and CC; strip cup testing of cows with PC; teat washing prior to milking with SCC; pre-milking teat disinfection with TBC and CC; post-dipping with TBC and SCC; and the alkaline-acid washing procedure of milking equipment with PIC and PC. The regression analysis explained the variation of bulk tank PC (- 0.47 log cfu/mL) due to the adoption of strip cup test (P = 0.036) and, by 0.366 log cfu/mL due to alkaline and acid washing of milking equipment (P = 0.036). Herringbone milking systems adopted on farms represented a change of - 0.11 log cfu/mL on the log SCC (P = 0.048). Findings may provide a guideline to prioritize efforts aimed at improving milk quality at the farm level in Brazil.

Effect of somatic cell count on composition and hygiene indicators of bulk tank milk / Efeito da contagem de células somáticas sobre a composição e indicadores de higiene do leite de tanque

This study evaluated the effect of somatic cell count (SCC) on composition and hygienic quality of dairy herd bulk tank milk ­ specifically, the effect of SCC of bulk tank of dairy herds on composition (fat, protein, total solids, nonfat dry solids) and on total bacterial count (TBC), psychrotrophic count (PC) and coliform count (CC) were evaluated. A total of 230 dairy herds located south of Minas Gerais and west of São Paulo were selected based on SCC geometric mean obtained from five monthly analyses preceding the start of the sampling. The dairy farms were classified according to SCC in three groups: low (< 250,000 cells/mL, n = 84), medium (> 250,000 and < 750,000 cells/mL, n = 79) and high SCC (> 750,000 cells/mL, n = 67). After herd selection, bulk tank milk samples were collected every 14 days for three months totaling 1380 samples, which were subjected to analysis of composition, TBC, PC, and CC. A decrease of TBC and CC was observed in herds with low SCC; however, herds with medium and high SCC had an increase in fat, crude protein, and total solids contents. A medium correlation was observed between TBC and PC (r = 0.6215), and also between PC and CC (r = 0.3692). Based on hygiene indicators and milk composition, a low and negative correlation between TBC and fat (r = -0.0585), PC and fat (r = -0.0585), and PC and total solids (r = -0.0662) was observed. Dairy herds with SCC < 250,000 cells/mL had higher bulk tank milk hygienic quality; however, considering the composition, herds with higher SCC produced higher milk fat and protein concentration.(AU)

Este trabalho avaliou o efeito da contagem de células somáticas (CCS) na composição e na qualidade higiênica do leite de tanque de rebanhos leiteiros. Especificamente, foram avaliados o efeito da CCS do tanque de rebanhos leiteiros na composição (gordura, proteína, sólidos totais, extrato seco desengordurado) e nas contagens bacteriana total (CBT), de psicrotróficos (CP) e de coliformes (CC). Um total de 230 rebanhos leiteiros localizados no sul de Minas Gerais e oeste de São Paulo foram selecionados com base na média geométrica da CCS obtida de cinco análises mensais anteriores ao início das coletas das amostras. As fazendas foram classificadas de acordo com a CCS em três grupos: baixa (< 250.000 células/mL, n = 84), média (> 250.000 e < 750.000 células/mL, n = 79) e alta CCS (> 750.000 células/mL, n = 67). Após a seleção dos rebanhos, amostras de leite do tanque foram coletadas a cada catorze dias durante três meses, totalizando 1.380 amostras, as quais foram submetidas às análises de composição, CBT, CP e CC. Uma redução da CBT e da CC foi observada em rebanho com baixa CCS; entretanto, rebanhos com média e alta CCS tiveram aumento nos teores de gordura, proteína bruta e sólidos totais. Uma média correlação foi observada entre CBT e CP (r = 0,6215) e também entre CP e CC (r = 0,3692). Com base nos indicadores de higiene e na composição do leite, foi observada uma correlação baixa e negativa entre CBT e gordura (r = -0,0585), CP e gordura (r = -0,0585) e CP e sólidos totais (r = -0,0662). Os rebanhos leiteiros com CCS < 250.000 células/mL apresentaram maior qualidade higiênica do leite de tanque; entretanto, considerando a composição, rebanhos com maior CCS tiveram maiores concentrações de gordura e proteína.(AU)

Randomized clinical trial comparing ceftiofur hydrochloride with a positive control protocol for intramammary treatment of nonsevere clinical mastitis in dairy cows.

The objective of this study was to compare ceftiofur hydrochloride with a positive control protocol for intramammary treatment of nonsevere clinical mastitis in dairy cows. A total of 264 clinical mastitis cases on 11 commercial dairy farms were treated with intramammary infusions, once a day for 4 d using 1 of 2 treatments: (1) ceftiofur hydrochloride 125mg; or (2) control: tetracycline 200mg + neomycin 250mg + bacitracin 28mg + prednisolone 10mg. Streptococcus agalactiae was the most frequently isolated gram-positive pathogen from clinical mastitis, followed by Staphylococcus aureus. Klebsiella spp. and Escherichia coli were the most isolated gram-negative bacteria from clinical mastitis. No significant differences were observed between treatments regarding the overall clinical cure, bacteriological cure, and new infection. No effect of treatment regimen was observed when the bacterial group (gram-positive vs. gram-negative) was evaluated. The overall clinical cure was 0.79 for ceftiofur-treated cows and 0.74 for control-treated cows, whereas the overall bacteriological cure was 0.79 for ceftiofur-treated cows and 0.76 for control-treated cows. Furthermore, the new intramammary infection was 0.10 for cows treated with ceftiofur and 0.11 for cows treated with control. In conclusion, the use of intramammary ceftiofur hydrochloride for treatment of nonsevere clinical mastitis has similar efficacy as a treatment regimen with a combination of antimicrobial agents (tetracycline + neomycin + bacitracin).

Staphylococcus aureus intramammary infection affects milk yield and SCC of dairy cows.

Staphylococcus aureus (S. aureus) is the most prevalent infectious microorganism affecting dairy cattle worldwide, and its pathogenic characteristics facilitate its spread in dairy herds. S. aureus intramammary infections (IMI) are mainly subclinical, and associated losses can exceed average herd losses where the pathogen is not isolated. However, the extent it affects milk composition at udder and quarter levels is still unknown, and cow composite milk losses may be underestimated due to the dilution effect. The aim of this study was to investigate the effects of S. aureus subclinical mastitis on mammary quarter milk yield and composition. In order to determine the effects of the pathogen on milk yield and composition at quarter level, a pairwise comparison of infected and non-infected mammary quarters (n = 28) from two dairy herds was carried out. Quarters were individually milked, and milk production and composition were assessed. S. aureus has increased somatic cell counts at quarter level; however, no effect of S. aureus IMI on milk lactose, fat, and protein contents was observed. Fat yield from infected quarters decreased, but losses due to the infection caused by S. aureus were not associated with quarter positioning in cows.

Prediction of bovine milk true protein content by mid-infrared spectroscopy / Estimativa do teor de proteína verdadeira do leite bovino por espectroscopia na região do infravermelho médio

The aim of this study was to estimate the concentration of milk true protein (TP) by mid-infrared absorbance method (MIR) in samples from bulk tank of dairy herds, and to determine the correlation between the results of TP of milk determined by Kjeldahl and MIR. Forty nine dairy herds were selected (17 Holstein, 6 Jersey and 26 Girolando) for monthly collections of samples from bulk tanks during the period of one year (284 samples). Fat, lactose, crude protein and total solids were firstly determined by MIR, and then analyzed for total and true protein by Kjeldahl method. The regression equation to estimate TP contents based on MIR crude protein determination was as follows: TP=0.0021+(1.0104xCP), where: TP is the content of true protein, CP is the crude protein content determined by the MIR method, and 0.0155 is the model error term.

O objetivo deste estudo foi estimar o teor de proteína verdadeira (PV) do leite por meio de metodologia de espectroscopia na região do infravermelho médio (IVM), em amostras de tanque de rebanhos leiteiros comerciais, e determinar a correlação entre os resultados de proteína verdadeira do leite determinados pelo método de Kjeldahl e por IVM. Foram selecionados 49 rebanhos leiteiros (17 da raça Holandesa, seis da raça Jersey e 26 da raça Girolando) para coletas mensais de amostras de leite de tanque durante o período de um ano, totalizando 284 amostras analisadas. As amostras de leite foram analisadas inicialmente em relação aos teores de gordura, lactose, proteína bruta e sólidos totais por IVM, sendo em seguida analisadas quanto ao teor de PB e PV pelo método de Kjeldahl. A equação de regressão para estimativa do teor de PV com base nos teores de proteína bruta foi a seguinte: PV=0,0021+(1,0104xPB); em que: PV é o teor de proteína verdadeira estimado; PB é o teor de proteína bruta pelo método IVM e 0,0155 é o erro apresentado pelo modelo.