Influence of Different Heat-Stress-Reducing Systems on Physiological and Behavioral Responses and Social Dominance of Holstein and Jersey Cows and Heifers on Pasture.

High ambient temperatures and relative humidity affect the behavior and physiology of the animal. This study investigated the influence of different heat-stress-reducing systems on the physiological, behavioral, and preferential responses of Holstein and Jersey cows and heifers on pasture. Experimental treatments were: (1) three heat-stress-reducing systems (sprinklers + artificial shade; showers + artificial shade; and artificial shade); (2) two breeds (Holstein and Jersey); and (3) two physiological stages (lactating cows and pubertal heifers). Physiological and behavioral responses to treatments were measured every 30 min on collection days. The frequency and duration of the use of the systems were recorded continuously 24 h/day for 3 days in each period. The air temperature and the relative humidity were 26 ± 4.1 °C and 74 ± 11.3%, respectively. The experimental treatments affected (p = 0.0354) standing idle, grazing behavior (p = 0.0435), and the frequency and duration of use of the systems by the animals (p < 0.0001). For all treatments, the respiratory rate and the coat surface temperature were highly and significantly correlated (p < 0.05) with the temperature and humidity index. In conclusion, under ambient conditions, dairy cows preferred using sprinklers or showers over artificial shade. These systems were more efficient at reducing the heat load and led to better behavioral and physiological responses.

Skin surface temperature of the mammary gland, measured by infrared thermography, in primiparous Girolando cows fed diets containing different lipid sources.

This research communication describes the influence of diet, mammary quarter position and milking process on the temperature of teats and udder of cows fed diets containing different lipid sources. Five primiparous cows were fed diets containing cottonseed, sunflower seed, soybeans or soybean oil as a source of lipids and a reference diet without the inclusion of lipid sources in a 5 × 5 Latin Square design. Milk yield was determined in the last five days of each period. Milk samples were collected for SCC analysis on the last two days of each experimental period. The images of the mammary gland were obtained using an infrared camera and were analyzed with appropriate computer software. Milk yield was 14.8% higher for cows fed soybeans as a source of lipids. Diets and somatic cell counts did not influence the temperature of teats and udder. The milking process reduced the temperature of teats and udder by 0.79°C. Rear teats and rear quarters had higher surface temperatures than front teats and fore quarters. Changes in temperature of teats and mammary quarters occurred as a function of the milking process and quarter position. However, the diet and the SCC did not influence the temperature of teats and mammary quarters in this experiment.

A new technique for repeated biopsies of the mammary gland in dairy cows allotted to Latin-square design studies.

The objective of this study was to develop a technique for carrying out repeated biopsies of the mammary gland of lactating dairy cows that provides enough material to monitor enzyme activities and gene expression in mammary secretory tissue. A total of 16 Holstein cows were subjected to 4 mammary biopsies each at 3-week intervals for a total of 64 biopsies. A 0.75-cm incision was made through the skin and subcutaneous tissue of the mammary gland and a trocar and cannula were inserted using a circular motion. The trocar was withdrawn and a syringe was plugged into the base of the cannula to create a vacuum for sampling mammary tissue. To reduce bleeding, hand pressure was put on the surgery site after biopsy and skin closure and ice was applied for at least 2 h after the biopsy using a cow bra. The entire procedure took an average of 25 min. Two attempts were usually enough to obtain 800 mg of tissue. Visual examination of milk samples 10 d after the biopsy indicated no trace of blood, except in samples from 2 cows. All wounds healed without infection and subcutaneous hematomas resorbed within 7 d. There was no incidence of mastitis throughout the lactation. This technique provides a new tool for biopsy of the mammary gland repeated at short intervals with the main effect being a decrease in milk production. Although secondary complications leading to illness or death are always a risk with any procedure, this biopsy technique was carried out without complications to the health of animals and with no incidence of mastitis during the lactation.

Cette étude a été conduite avec l'objectif de décrire une technique pour laquelle les biopsies de la glande mammaire des vaches laitières en lactation sont répétées. Un total de 16 vaches Holstein ont été soumises chacune à 4 biopsies de la glande mammaire à un intervalle de 3 semaines pour un total de 64 biopsies. Une incision de 0,75 cm a été faite à travers la peau et le tissu sous-cutané de la glande mammaire, et un trocart et une canule ont été insérés en utilisant un mouvement circulaire. Le trocart a été retiré et une seringue a été attachée à la base de la canule pour créer un vacuum afin d'échantillonner le tissu mammaire. Afin de réduire le saignement, une pression manuelle a été appliquée sur le site de la chirurgie après la biopsie et la suture de l'incision de la peau, et de la glace a été appliquée pour au moins 2 h après la biopsie en utilisant une brassière pour vache. La procédure entière a exigé une moyenne de 25 min et deux essais ont habituellement été suffisants pour obtenir 800 mg de tissu. Un examen visuel des échantillons de lait n'ont indiqué aucune présence de sang 10 jours après la biopsie sauf pour deux vaches. Les plaies ont toutes guéries sans infection, et les hématomes sous-cutanés se sont résorbés à l'intérieur d'une période de 7 jours. Il n'y a eu aucune incidence de mammite durant la lactation. Cette technique décrit un nouvel outil de biopsie de la glande mammaire répété à de courts intervalles où l'effet principal a été une baisse de la production laitière. Bien que les complications secondaires entrainant la maladie ou la mort soient toujours un risque avec toute procédure, cette technique de biopsie a été faite sans complications pour la santé des animaux et il n'y a eu aucune incidence de mammite durant la lactation.(Traduit par les auteurs).

Digestibility of canola seeds treated by autoclaving and/or condensed tannins / Digestibilidad de la canola tratada en autoclave y/o con taninos condensados / Digestibilidade de grãos de canola tratados em autoclave e/ou com tanino condensado

Background: plant proteins are susceptible to rapid degradation in the rumen therefore it is important to explore the best way to improve protein utilization. Objective: to evaluate the effect of heat treatment and/ or condensed tannins on ruminal degradability and in vitro digestibility of crude protein (CP) and dry matter (DM) of canola seeds. Methods: in situ and in vitro DM and CP digestibility of canola seeds treated with water (control; CCL), heat in autoclave (CLE), condensed tannin (CTN), and condensed tannin followed by autoclaving (CTA) were evaluated. Results: the DM effective degradability values (EDDM) by CCL, CLE, CTN, and CTA were 66.8%, 73.6%, 58.5%, and 77.5%, respectively. Effective degradability of crude protein (EDCP) by CCL, CLE, CTN, and CTA at a 5%/h passage rate (k) was 75.2, 77.2, 60.2, and 80.5%, respectively. Addition of condensed tannin and/or autoclaving reduced both DM and CP digestibility. Conclusions: treatment with condensed tannins protected canola seeds DM and CP from ruminal degradability, while treatment with heat or tannins combined with heat showed the opposite effect, increasing degradability of those fractions. Addition of condensed tannins and/or autoclaving decreased in vitro DM and CP digestibility.

Antecedentes: es importante estudiar la mejor manera de utilizar fuentes de proteínas vegetales, ya que son rápidamente degradadas en el rumen. Objetivo: evaluar el efecto del tratamiento térmico y/o adición de taninos condensados sobre la degradabilidad ruminal y digestibilidad in vitro de la proteína bruta (PB) y la materia seca (MS) en granos de canola. Métodos: se evaluó la degradabilidad in situ y la digestibilidad in vitro de la MS y PB en granos de canola tratados con agua (control - CCL), térmicamente utilizando autoclave (CTE), taninos condensados (CTN), y taninos condensados seguido por autoclavado (CTA). Resultados: los valores de degradabilidad efectiva de la materia seca (DEMS) para CCL, CTE, CTN, y CTA fueron 66,8, 73,6, 58,5 y 77,5% respectivamente; y para la degradabilidad efectiva de la proteína bruta (DEPB ) fueron 75,2, 77,2, 60,2 y 80,5%, respectivamente -a una tasa de pasaje (k) de 5%/h. La adición de taninos condensados y/o tratamiento térmico provocó la reducción de los valores de digestibilidad, tanto de la MS como de la PB. Conclusiones: el tratamiento con taninos condensados protegió la MS y la PB de las semillas de canola de su degradación ruminal. Los tratamientos con calor húmedo y asociación taninos más calor mostraron el efecto contrario, promoviendo el aumento de la degradabilidad ruminal de esas fracciones. La adición de taninos condensados y/o el autoclavado resultaron en menores valores de digestibilidad para la MS y PB.

Antecedentes: é importante estudar a melhor maneira de utilizar as fontes de proteína vegetal, uma vez que essas são normalmente degradadas no rúmen. Objetivo: avaliar o efeito do tratamento térmico e/ou a adição de tanino condensado sobre a degradabilidade ruminal in situ e a digestibilidade in vitro da proteína bruta (PB) e da matéria seca (MS) de grãos de canola. Métodos: avaliou-se neste trabalho a degradabilidade in situ e a digestibilidade in vitro da MS e PB de grãos de canola tratados com água (controle - CCL), termicamente em autoclave (CTE), tanino condensado (CTN) e tanino condensado seguido de autoclave (CTA). Resultados: os valores de degradabilidade efetiva da matéria seca (DEMS) para CCL, CTE, CTN e CTA foram 66,8; 73,6; 58,5 e 77,5% respectivamente, e para a degradabilidade efetiva da proteína bruta (DEPB) foram 75,2; 77,2; 60,2 e 80,5%, para taxa de passagem (k) igual a 5%/h. A adição de tanino condensado e/ou tratamento com autoclave provocaram a diminuição da digestibilidade, tanto da MS como da PB. Conclusões: concluiu-se que o tratamento com tanino condensado promoveu efetiva proteção da MS e PB dos grãos de canola frente à degradabilidade no rúmen. Já o tratamento com calor úmido e a associação tanino-calor, mostraram efeito contrário, promovendo aumento da degradabilidaderuminal dessas frações. A adição de tanino condensado e/ ou tratamento com autoclave diminuíram a digestibilidade da MS e da PB.

The interaction of monensin and flaxseed hulls on ruminal and milk concentration of the mammalian lignan enterolactone in late-lactating dairy cows.

Four ruminally fistulated multiparous Holstein cows were assigned to a 4x4 Latin square design with a 2x2 factorial arrangement of treatments to study the effects of dietary supplementation of monensin and flaxseed hulls on ruminal and milk concentration of the mammalian lignan enterolactone (EL) and ruminal and faecal activity of beta-glucuronidase. The hypothesis was that monensin supplementation has no effect on the incorporation of EL into milk when cows are fed flaxseed hulls. Treatments were: 1) control, neither flaxseed hulls nor monensin (CO); 2) diet containing (dry matter basis) 20% flaxseed hulls (FH); 3) diet with monensin (16 mg/kg of dry matter; MO); 4) diet containing 20% (dry matter basis) flaxseed hulls and 16 mg/kg monensin (HM). Intake of dry matter was higher for CO and MO than for FH and HM and monensin had no effect. Milk production decreased in cows fed flaxseed hulls while monensin had no effect. Production of 4% fat-corrected milk and concentrations of milk fat, lactose, urea N, and total solids were similar among treatments. Although there was a decrease in ruminal activity of beta-glucuronidase when feeding flaxseed hulls, the metabolism of plant into mammalian lignans may be increased as shown by enhanced concentration of EL in the rumen and milk. Supplementation with flaxseed hulls then may contribute to favourably change milk composition for better human health by enhancing mammalian lignan EL concentration.