Milk production and hematological and antioxidant profiles of dairy cows supplemented with oregano and green tea extracts as feed additives

We aimed to evaluate the effects of the addition of oregano (Origanum vulgare) or green tea (Camellia sinensis L.) extracts (separately and associated) on feed intake, milk production, and hematological and antioxidant profiles of dairy cows. For that purpose, 16 Holstein and 16 Holstein-Gyr cows with 526.3±10.2 kg and within the first third of lactation were distributed according to a complete block design with measurements repeated in time. Treatments were control (CON), addition of 0.056% of oregano extract (OR), addition of 0.028% of green tea extract (GT), addition of a mixture of OR and GT extract (0.056% each) in the diet (MIX). Hematological and antioxidant profiles were monitored. Data were subjected to ANOVA, with block, treatment, days, and their interactions considered as fixed effects and animal and the residue as random effects. In Holstein cows, GT increased feed intake and milk yield compared with CON; in Holstein-Gyr crossbred cows, OR showed increased intake and GT increased milk yield compared with CON. Compared with CON, GT and OR decreased eosinophils concentration; OR showed the highest neutrophils concentration and neutrophils to leukocyte ratio. Compared with CON, OR presented increased catalase (CAT) activity, while GT increased the reduced glutathione concentration. The MIX treatment reduced CAT activity compared with OR, presented the lowest concentration of oxidized dichlorofluorescein in the erythrocytes (DCFER) and plasma (DCFPLA), and increased eosinophils concentration compared with GT and OR. Extracts differently affected feed intake and milk yield depending on genetic group. Feeding green tea and oregano extracts separately or associated distinctly affects the antioxidant indicators of lactating dairy cows.(AU)

Elevated temperature-humidity index induces physiological, blood and milk alterations in Holstein cows in a more pronounced manner than in ½ and ¾ Holstein × Gir

Bos taurus taurus and Bos taurus indicus cattle subspecies present different capabilities in coping with situations of elevated temperatures, the latter being more tolerant to heat stress. Thus, some breeding programs crossed these subspecies to produce a high producing yet heat-tolerant breed (Girolando). Nineteen Holstein (H100) and 19 Girolando cows [(½ Holstein × Gir (H50) and ¾ Holstein × Gir (H75)] with similar milk production were used in a six-day experiment to evaluate the consequences of heat stress due to shade deprivation on their physiological, blood and milk traits. Cows were exposed to a non-shaded environment between morning (06:00h; GMT -3:00) and evening milking (14:30h; GMT -3:00) with access to water ad libitum. Procedures were conducted before morning and evening milkings. Physiological parameters related to mechanisms of heat dissipation were measured, as well as the milk composition. Blood traits were evaluated. The temperature-humidity index (THI) was calculated. Statistical procedures included analysis of variance, correlation, and principal factors. THI was elevated during the trial and negatively impacted physiological, milk, and blood parameters in H100, H75, and H50. Alterations in physiology, milk stability, milk composition, and blood traits were more pronounced in H100. Holstein cows presented changes in physiological parameters in a more pronounced manner and in some milk and blood traits related to the reduced capability of this breed in dealing with elevated THI. The similarity in milk production levels excludes this parameter as a justification for differences in heat tolerance, with genetic composition being the main reason for these results.(AU)

Elevated temperature-humidity index induces physiological, blood and milk alterations in Holstein cows in a more pronounced manner than in ½ and ¾ Holstein × Gir

Bos taurus taurus and Bos taurus indicus cattle subspecies present different capabilities in coping with situations of elevated temperatures, the latter being more tolerant to heat stress. Thus, some breeding programs crossed these subspecies to produce a high producing yet heat-tolerant breed (Girolando). Nineteen Holstein (H100) and 19 Girolando cows [(½ Holstein × Gir (H50) and ¾ Holstein × Gir (H75)] with similar milk production were used in a six-day experiment to evaluate the consequences of heat stress due to shade deprivation on their physiological, blood and milk traits. Cows were exposed to a non-shaded environment between morning (06:00h; GMT -3:00) and evening milking (14:30h; GMT -3:00) with access to water ad libitum. Procedures were conducted before morning and evening milkings. Physiological parameters related to mechanisms of heat dissipation were measured, as well as the milk composition. Blood traits were evaluated. The temperature-humidity index (THI) was calculated. Statistical procedures included analysis of variance, correlation, and principal factors. THI was elevated during the trial and negatively impacted physiological, milk, and blood parameters in H100, H75, and H50. Alterations in physiology, milk stability, milk composition, and blood traits were more pronounced in H100. Holstein cows presented changes in physiological parameters in a more pronounced manner and in some milk and blood traits related to the reduced capability of this breed in dealing with elevated THI. The similarity in milk production levels excludes this parameter as a justification for differences in heat tolerance, with genetic composition being the main reason for these results.

Behaviors associated with cows more prone to produce milk with reduced stability to ethanol test due to feeding restriction / Comportamentos associados com vacas mais propensas a apresentar leite com reduzida estabilidade ao álcool após restrição alimentar

The experiment was carried out to identify changes in the behaviorr of lactating cows induced by severe feeding restriction and further refeeding that could serve as facilitators for the visual identification of cows more prone to produce milk with reduced stability. Twelve cows were separated into two groups: Control: full diet supply; Restriction: 50% of the full diet. Feed restriction lasted seven days (Period 1), with posterior supply of full diet for seven days (Period 2) for all treatments. Behavior was observed on the first and fifth days in each period from 08h40 to 19h00. Ingestive and social behavior were monitored. Cortisol assessed stress levels. Analysis of variance and multifactorial statistical analyzes were performed. Adequate feed supply reduced stress, improved animals' welfare and milk stability to the ethanol test. Elevation in the incidence of behavior related with hunger, frustration and discomfort is an indicator of cows more prone to produce milk with reduced stability.(AU)

O experimento foi conduzido para identificar alterações comportamentais de vacas lactantes submetidas à restrição alimentar severa e realimentação, as quais podem servir para identificação visual de vacas mais propensas a produzir leite de reduzida estabilidade ao álcool. Doze vacas foram separadas em dois grupos: controle: suprimento de dieta completa; restrição: 50% da dieta completa. A restrição alimentar durou sete dias (Período 1), com posterior suprimento de dieta completa por sete dias (Período 2) a todos os animais. O comportamento foi monitorado no primeiro e quinto dias de cada período, entre as 08h40min e 19h. Comportamentos ingestivo e social foram observados. Os níveis de cortisol foram utilizados para monitorar os níveis de estresse. Análises de variância e multifatorial foram realizadas. O suprimento adequado da dieta reduziu estresse, aumentou o bem-estar animal, bem como a estabilidade do leite ao teste do álcool. Elevação na incidência de comportamentos relacionados à fome, frustração e desconforto é um indicador de vacas mais propensas a produzir leite com reduzida estabilidade.(AU)

Influência da mastite na qualidade do leite e leite instável não ácido em diferentes quartos mamário

Objetivou-se verificar a relação entre a contagem de células somáticas do leite bovino ordenhado separadamente de quartos mamários com a qualidade físico-química do leite, em especial com o leite instável não ácido (LINA). Foram utilizadas 21 vacas das raças Holandês e Jersey, sendo selecionados a partir do teste do CMT os animais que apresentaram pelo menos um quarto mamário normal e os demais quartos com mastite subclínica. Realizou-se análise microbiológica, identificação dos agentes e, durante quatro dias consecutivos, as vacas foram ordenhadas com uma ordenhadeira especial de quartos individuais avaliando a produção, composição química, contagem de células somáticas (CCS) e análise física do leite. O principal agente isolado no leite foi o Corynebacterium sp. (27,38%). Ocorreu diminuição de 21,65% na produção de leite dos quartos com CCS acima de 750.000cél/mL. A instabilidade do leite não apresentou variação significativa dos quartos saudáveis em comparação com os quartos mastíticos. Dentre os componentes químicos do leite, o teor de lactose diminuiu à medida que ocorreu o aumento da CCS e não houve variação significativa nos teores de gordura, proteína bruta, sólidos totais e sólidos desengordurados. Houve variação significativa dos componentes do leite nas diferentes raças. Não houve relação entre a mastite subclínica e o LINA

This study assessed the relationship between milk somatic cell count from different mammary quarters of cows with subclinical mastitis with physical and chemical milk quality, especially unestable non acid milk (UNAM). Twenty-one Holstein and Jersey cows were used which had at least one healthy quarter and the others with subclinical mastitis. Microbiological analysis was performed and the agents were identified. Cows were milked with a special milking machine which separate milk from each quarter for four consecutive days. Milk samples were collected to evaluate production, chemical composition, somatic cell count (SCC) and physical characteristics. The main agent identified in the milk was Corynebacterium sp. (27,38%). There was a decrease of 21,65% in quarter milk production of cows with SCC above 750.000cél/mL. Milk instability did not vary significantly from healthy quarters compared with mastitis. Among milk chemical components, lactose decreased as the SCC increased and there were no significant variation in levels of fat, protein, total solids and non-fat solids. There were significant variations in the components of milk in different breeds. There was no relationship between subclinical mastitis and UNAM