A. A. Pinheiro

Crude glycerin in supplement to primiparous lactating cows grazing on tropical pasture: nutritional and productive characteristics

The objective of this study was to evaluate the nutritional and productive characteristics of primiparous lactating cows grazing on tropical pasture, using different levels of crude glycerin in the supplement. The experiment was conducted at Rancho Santana farm, located in Jequie city, Bahia, Brazil, in the period from December 21, 2010 to March 16, 2011. Ten ¾ Holstein × ¼ Dairy Gyr lactating primiparous cows, with 109±24 days of lactation and a mean age of 30±6 months and mean body weight of 426.2±68.29 kg were distributed into five treatments, using two simultaneous 5 × 5 latin squares. Treatments consisted of inclusion levels (0, 94, 191, 289, 389 g/kg dry matter basis) of crude glycerin in the supplement. Intake, digestibility, milk production and composition were measured. Results were statistically analyzed by analysis of variance and regression at 0.05 probability. For all consumption variables no significant differences were found between the levels of crude glycerin. Except for the digestibility of ether extract, all digestibility values were similar between treatments. The fat content and yield showed quadratic effect between treatments. No significant differences were observed for protein, lactose, total solids, nonfat dry extract, fat:protein ratio, milk urea nitrogen and somatic cell count between treatments. For primiparous lactating cows grazing on tropical pasture, up to 389 g of crude glycerin/kg of dietary supplement can be included without nutritional and productive interference.

Correlation between intake and ingestive behaviour of confined Holstein-Zebu crossbred heifers.

The aim of the study was to evaluate the correlation between variables referring to feed intake and behaviour of confined Holstein-Zebu crossbred heifers. The experiment was conducted at the dairy Original Research Article Silva et al.; AJEA, 6(1): 15-21, 2015; Article no.AJEA.2015.060 16 unit of the Southwest Bahia State University, campus Itapetinga, Brazil. Sixteen 3⁄4 Holstein x 1⁄4 Zebu heifers with average of 12 months old and initial weight of 150 kg were randomly distributed into four treatments, with four repetitions. A moderate positive correlation was observed between feeding time and NDF and NFC intake variables. The feeding efficiency of NDF was highly correlated with DMI. The variables referring to time of feeding, rumination and boluses per day were observed to be highly correlated with the intake variables, thus showing great potential to draw up predictive equations.

Correlation between intake and feeding behavior of Holstein calves fed diets supplemented with pellets and mash.

The objective was to evaluate the correlation between behaviour al and intake variables of Holstein calves fed pellets and meal. Twelve pure Holstein calves with initial average age of 10 days and weight of 27.5 kg were used; The experimental design used in this study was a 2 x 2 factorial Original Research Article Silva et al.; AJEA, 7(6): 382-388, 2015; Article no.AJEA.2015.138 383 design (two types of feed and two feeding stages lactation and post-lactation periods), with six repetitions. Was found significant effects the time allocated to eating, rumination and resting. The data concerning the efficiency of feeding and rumination, total chewing time, number of ruminal boluses, rumination time/bolus and the number of chews per cud/bolus and discretization of the time series. There was a moderate positive correlation between the variable behaviour: dry matter per bolus, number of discrete eating and resting periods and the variable of dry matter intake (DMI). There was a strong positive correlation between the variables of behaviour: total chewing time, NDF/BOLUS, ADF/ BOLUS and neutral detergent fiber (NDF) and acid detergent fiber (ADF) intake variables. There was a negative moderate correlation between the behaviour variable TRP (time resting period) and the NDF and ADF intake variables. According to the correlations found in this study, between the behaviour aspects and intake of NDF and ADF can support studies aimed to the formulation of diets supplemented based the understanding on behaviour of food intake by animals.