Sheila Cristina Bosco Stivanin

Water consumption may vary depending on climate, dry matter intake (DMI) as well as genetic group and physiological state of the cows. Little is published for other genetic groups besides Holstein. Understanding the need for water intake (WI) as well as drinking behaviour in critical periods could help producers develop adjusted management practices. This study aimed to investigate the drinking and water consumption behaviour of Holstein, Gyr and Girolando-F1 (½ Holstein ½ Gir) cows during the transition period. Thirty-six cows were distributed into three groups (n = 12 each) according to their genetic group. WI and water drinking behaviour were monitored from 10 days before parturition until 21 days of lactation using electronic drinkers. During pre-calving, a positive correlation was observed between WI and DMI only for Holstein (r = 0.31; p < 0.05) and Girolando-F1 (r = 0.34; p < 0.05) cows. Holstein cows ingested the highest amount of water daily and per 100 kg of body weight (BW) (30.9 kg and 4.5 kg). Holstein cows had higher WI per BW^0.75 than Gyr cows (0.23 kg vs. 0.12 kg). Furthermore, Holstein cows remained longer and spent more active time at the drinker (85.4 min; 81.2 min) than Gyr (13.5 min; 12.1 min) and Girolando-F1 cows (36.8 min; 34.4 min; p < 0.05), respectively. Holstein and Girolando-F1 cows had a higher daily number of active visits to the drinker than Gyr cows (4.2, 4.2, and 2.8 times, respectively). In the post-calving period, WI was positively correlated with DMI in all genetic groups, but it was correlated with milk yield (MY) only in Holstein (r = 0.21; p < 0.05) and Girolando-F1 (r = 0.42; p < 0.05) cows. The WI per MY and per BW^0.75 was lower for Girolando-F1 cows in relation to the Holstein and Gyr cows on the first day post-calving and highest for Gyr cows on the seventh day post-calving. WI per kg of BW^0.75 was higher for Holstein cows than for Gyr cows during the first 21 days of lactation, while WI per kg BW^0.75 of Holstein cows was higher than that of Girolando-F1 cows on days 3 and 4 and from days 7 to 21. The genetic groups differed in WI and drinking behaviour and were mainly modulated by DMI and THI in the pre-calving period and by MY and DMI in the post-calving period.

O objetivo do estudo foi avaliar o desempenho de novilhas de corte do desmame ao fim do período reprodutivo aos 13/15 meses de idade submetidas a três sistemas alimentares nos meses de inverno após o desmame: pastagem de aveia preta (Avena strigosa Schreb.) e azevém (Lolium multiflorum Lam.); pastagem de aveia preta e azevém mais suplementação com 1% do peso corporal com farelo de trigo (FT); e pastagem de aveia preta e azevém mais suplementação de 1% de peso corporal com farelo de trigo e 200 ml/cabeça/dia de glicerina bruta (FTG). As suplementações não afetaram a taxa de prenhez das novilhas púberes anteriormente ao período reprodutivo, mas determinaram mais novilhas púberes e maior concepção nos primeiros 21 dias do acasalamento. Novilhas prenhes, independentes dos tratamentos, possuem melhores características fenotípicas de conformação, precocidade, musculatura e tamanho já ao desmame, maior ganho diário médio e condição corporal ao início e fim dos sistemas alimentares e início da temporada reprodutiva, o que permite uma seleção prévia, a idades menores, das bezerras a serem postas em sistemas alimentares para prenhez aos 13/15 meses de idade. Rebanhos com prenhez estabilizada aos dois anos de idade necessitam de seleção para maior precocidade sexual e prenhez aos 13/15 meses de idade, podendo o peso ao desmame ser um bom preditor.

Objetivou-se avaliar o desempenho de cordeiras em pastagem de azevém (Lolium multiflorum Lam.), relacionando a estrutura da pastagem em três estádios fenológicos: vegetativo, pré-florescimento e florescimento, com diferentes suplementos. Os tratamentos incluíram pastejo exclusivo, pastejo com grão de milho moído, farelo de arroz integral (FAI) ou grão de arroz. O método de pastejo foi intermitente, com intervalo de 187 graus-dia. Os suplementos eram oferecidos individualmente por uma hora, e as sobras recolhidas para cálculo de ingestão. O ganho médio diário (GMD) das cordeiras foi calculado pela diferença de peso entre o início e o final do período, dividido pelo número de dias entre as pesagens. O delineamento foi inteiramente casualizado com parcelas subdivididas: sistemas alimentares nas parcelas principais e estádios fenológicos nas subparcelas. Os resultados foram analisados por teste de normalidade e variância, com comparações pelo teste Tukey, usando o programa SAS 9.2. O consumo de suplemento das cordeiras que receberam grão de milho não diferiu das que ingeriram o grão de arroz, mas foi 32,14% superior àquelas que receberam FAI. Cordeiras que receberam grão de milho como suplemento apresentaram maior GMD (0,238 kg) e maior eficiência na conversão de pasto, enquanto as que permaneceram exclusivamente em pastagem tiveram o menor GMD (0,167 kg). O GMD das cordeiras que receberam arroz ou FAI não diferiu significativamente dos outros tratamentos. O consumo de suplemento foi maior para cordeiras que receberam grão de milho em comparação às que receberam FAI. Conclui-se que a suplementação com grão de milho proporciona maior GMD em ovinos em pastagem de azevém.

This study aimed to evaluate the effects of the separate provision of green and oregano tea extracts on the biomarkers of the redox state and health condition in pre-weaned Jersey calves from birth to 60 days of life. Two experiments following the complete randomized design with measures repeated in time were carried out using 38 Jersey calves (17 and 21 calves in experiments 1 and 2, respectively). Calves were distributed according to date of birth into one of three groups: control (CON) - with no addition of extracts; oregano extract (OE) - addition of 70 mg of oregano extract/kg of body weight (BW) and green tea extract (GT) - addition of 35 mg of green tea extract/kg of BW. Eight biomarkers of the redox state were evaluated on days 1, 30, and 60 after birth, and variables measured on day 1 were used as covariates. Body temperature and occurrence of diarrhea were evaluated every two days. Regarding the main results, the supply of oregano extract reduced the concentration of oxidizing biomarkers, such as DCFP (oxidation of dichlorofluorescein in plasma) and carbonyl, and increased the activity of antioxidant enzymes, such as GPx and catalase. Green tea extract only reduced DCFP and tended to improve catalase activity. Calves remained healthy (no fever and only a few days with diarrhea), and plant extracts did not improve their health condition. The addition of green tea and oregano extracts into the diet has a positive effect on redox status in pre-weaned Jersey calves. Este estudo teve como objetivo avaliar os efeitos do fornecimento separado de extratos de chá verde e orégano sobre os biomarcadores do estado redox e condição de saúde em bezerras Jersey durante o seu aleitamento, desde o nascimento até 60 dias de vida. Foram realizados dois experimentos seguindo o delineamento completamente casualizado com medidas repetidas no tempo, utilizando 38 bezerros Jersey (17 e 21 bezerros nos experimentos 1 e 2, respectivamente). Os bezerros foram distribuídos de acordo com a data de nascimento em um dos três grupos: controle (CON) - sem adição de extratos; extrato de orégano (OE) - adição de 70 mg de extrato de orégano/kg de peso corporal (PV) e extrato de chá verde (GT) - adição de 35 mg de extrato de chá verde/kg de peso corporal. Oito biomarcadores do estado redox foram avaliados nos dias 1, 30 e 60 após o nascimento. A temperatura corporal e a ocorrência de diarreia foram avaliadas a cada dois dias. Quanto aos principais resultados, o fornecimento de extrato de orégano reduziu a concentração dos biomarcadores oxidantes, como DCFP (oxidação da diclorofluoresceína no plasma) e carbonila, e aumentou a atividade das enzimas antioxidantes, como GPx e catalase. O extrato de chá-verde reduziu apenas DCFP e tendeu a melhorar a atividade da catalase. Os bezerros permaneceram saudáveis (sem febre e apresentando diarreia por apenas alguns dias) e os extratos de plantas não melhoraram sua condição de saúde. A adição de extrato de chá verde e de orégano na dieta exerceu efeito positivo no status redox em bezerros Jersey em aleitamento.

This study aimed to evaluate intake, energy and nitrogen balance as well as methane emission in Holstein and 1/2 Holstein 1/2 Gyr (Girolando-F1) cows during the transition period. Twenty-four cows (12 Holstein and 12 Girolando-F1) were used to evaluate feed intake, apparent digestibility, heat production and methane emission, carried out in two periods: from 28 to 19 days pre-calving and from 15 to 23 days post-calving. A completely randomised design was used and data were analysed by ANOVA within periods (pre- and post-calving) considering the main effect of genetic groups. Girolando-F1cows presented greater body condition score (BCS) compared with Holstein. During pre-calving, there were no differences between genetic groups, except for highest heat production per kilogram of metabolic body weight for Holstein cows. After calving, Holstein cows had greater intake of DM, nitrogen, NDF per kg of BW and produced more heat per kg of metabolic body weight. Holstein cows yielded more milk and fat-corrected milk (FCM4%) compared with Girolando-F1 cows. Holstein cows presented higher methane emission per unit of BW and of metabolic weight. Emissions of enteric methane per kilogram of milk and per kilogram of FCM4% tended to be lower for Holstein compared with Girolando-F1 cows. Nitrogen and energy retention were similar for both Holstein and Girolando-F1 at pre- and post-calving. Despite differences in BCS, DMI, and milk yield, Girolando-F1 and Holstein cows present overall similar energy efficiency, albeit Holstein cows tended to present less methane emission per kg of eligible product (milk).

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), [...] ABSTRACT 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),

The objective was to investigate the effects of available shaded area on behavioural characteristics of lactating cows during the warm season in the subtropics. Twelve Holstein cows were divided into groups, with 2 (SH2) or 10 m² (SH10) of available shade per cow (six cows per treatment). The behaviour was recorded when animals were grazing from 09.00 to 16.00 h (GMT −02.00 h) throughout the trial. Data considered in the statistical analysis were restricted to the five days when the maximum temperature was ≥ 25 °C. Cows in the SH10 group had lower panting score, but higher proportions of time in shade and lying down and stayed more time per visit in the shaded area than cows in the SH2 group. Cows in the SH10 group had less events of competition near the water trough and in the shaded area than cows in the SH2 group. The solar radiation threshold that triggered the use of the shade was lower in SH10 than in SH2 group. Hourly proportion of time spent grazing or ruminating differed between shaded areas at specific times. The 2 m² of available shaded area per cow is sufficient for all cows to enter the shaded area at the same time. In spite of that, 2 m² of available shaded area per cow negatively affects the proportion of time spent lying and in the shaded area; in addition, it enhances agonistic behaviours between cows when compared with 10 m² of shade per cow.