Kg For Animals Research Articles

Características de carcaça e análise do custo de sistemas de produção de cordeiras ½ Dorset Santa Inês

Um experimento foi realizado com os objetivos de avaliar as características de carcaça de cordeiras ½ Dorset Santa Inês e comparar o custo de produção e o retorno econômico de dois sistemas de terminação. Após o desmame, 44 cordeiras foram divididas em dois sistemas de terminação: confinamento - ração (4% PV) com 15,56% de PB e 4,32 Mcal de EB/kg MS; e pastagem + suplementação (1,5% de ração, com base no peso vivo), com 27,01% PB e 4,51 Mcal de EB/kg MS. Os custos da ração e do suplemento foram de R$0,39 e R$0,54, respectivamente. Os animais foram abatidos ao atingirem peso corporal médio de 30 kg. Os valores médios para os pesos da carcaça quente e fria foram de 14,33 e 14,11 kg e 13,91 e 13,6 kg, os rendimentos verdadeiros médios de 55,81 e 55,61% e os comerciais de 46,39 e 46,04%, respectivamente, para confinamento e pastagem + suplementação. As médias para condição corporal e índices de compacidade da carcaça e da perna das cordeiras terminadas em confinamento e pastagem + suplementação foram, respectivamente, de 3,03 e 2,96; 0,21 e 0,20 kg/cm e 0,43 e 0,44 cm/cm. As características idade ao abate, condição corporal, pesos da carcaça quente e fria, rendimentos verdadeiro e comercial da carcaça e índices de compacidade da carcaça e da perna não diferiram entre os tratamentos. Portanto, cordeiras ½ Dorset Santa Inês podem ser terminadas em confinamento ou em pastagem + suplementação, porém, considerando-se a análise econômica, recomenda-se a terminação em pastagem + suplementação.

Associação de diferentes fontes energéticas e protéicas em suplementos múltiplos na recria de novilhos mestiços sob pastejo no período da seca

Dois experimentos foram realizados com o objetivo de avaliar diferentes fontes protéicas e energéticas em suplementos múltiplos para bovinos. No primeiro experimento, estudou-se o desempenho de novilhos em fase de recria em pastagem de Brachiaria brizantha, no período da seca. Utilizaram-se 20 novilhos mestiços Holandês x Zebu, não-castrados (17 meses de idade e 265±18 kg de peso vivo inicial), distribuídos em quatro piquetes de 1,5 ha. Os suplementos foram fornecidos diariamente na proporção de 0,75% do PV. Empregou-se como fonte protéica grão de soja (GS) ou caroço de algodão (CA) inteiros e farelo de trigo (FT) ou farelo de arroz (FA) como fonte de energia, em esquema fatorial 2 x 2. Não foram verificadas diferenças no ganho médio diário (GMD), no peso vivo final (PVF) e no ganho de peso total (GPT). A suplementação propiciou aos animais GMD de 0,589; 0,530; 0,620 e 0,606 kg/dia, respectivamente, nos tratamentos GS/FT, GS/FA, CA/FT e CA/FA. No segundo experimento, determinaram-se as frações dos carboidratos da pastagem e dos ingredientes utilizados na formulação dos suplementos e estimaram-se as respectivas taxas de digestão das frações pela técnica de produção de gás. A forragem apresentou altos teores da fração indigestível (C) e baixos da potencialmente digestível (B2). Entre os concentrados, o FA apresentou menor fração C. O GS e o FT destacaram-se pela elevada proporção de CNF. O CA, embora tenha demonstrado fração C superior aos demais, apresentou rápida taxa de digestão da fração B2. As taxas de digestão dos CNF foram 35,06; 14,86; 17,83 e 58,80, respectivamente, para FA, FT, GS e CA. A opção por uma das fontes protéicas ou energéticas estudadas depende, portanto, do preço e da disponibilidade no mercado, pois não influenciou o desempenho dos animais. Os carboidratos estruturais (B2 e C) são responsáveis pelo alto teor de carboidratos totais presentes na Brachiaria brizantha no período da seca, pois correspondem a aproximadamente 80% de sua composição. Observaram-se variações entre as frações dos carboidratos, assim como na taxa de degradação das fontes energéticas e protéicas estudadas.

Effects of different energy levels during indoor rearing on performance of Norwegian dairy goats

In three consecutive years, 97 female dairy goat kids from 10 to 20 wk of age of the Norwegian breed were supplemented with low (L = 0.2 kg/kid/d) and high (H = 0.5 kg/kid/d) levels of concentrate (13.3 MJ ME/kg DM and 15% DCP). Average initial BW and age were 13.3 kg and 71 d, respectively. The L-group received an average 0.25 kg DM/head/d less concentrate than the H-group during the initial indoor period, and consumed 0.11 kg (41%) DM/head/d more roughage. Average daily energy intake during this period was 6.70 MJ ME in the L-group (806 kJ ME/kg W 0.75) and 8.86 MJ ME in the H-group (1064 kJ ME/kg W 0.75). BWG was 28% less in the L-group, with average BWG during the first indoor period beeing 107 g/d and 77 g/d in H- and L-group, respectively. Average difference of 1.7 kg in BW at 20 wk of age between H- and L-group animals was reduced to 1.0 kg by the end of the grazing period. Low levels of concentrate prior to pasturing resulted in higher forage DMI in 2 of 3 years during the second indoor feeding period. The daily energy intake during this period was 10.3 MJ ME/head/d in the L-group and 10.1 MJ ME/head/d in the H-group. BW at kidding was 40.2 kg and 40.3 kg for L- and H-groups, respectively. Thirty-eight and 18% of the animals were culled in the L- and H-group, respectively, for failure to conceive. Age at first kidding was 389 for the L- and 385 d for the H-group. Average daily milk yield for 222 d in the first lactation was 1.93 kg for animals in the L- and 1.71 kg ( P = 0.08) in the H-group. No significant difference in milk composition was shown. Different amounts of concentrate offered to pregnant goats in 1989 during indoor feeding, 0.2 kg/d in the LL- and HL-subgroups vs. 0.5 kg/d in LH- and HH-subgroups, resulted in 0.13 kg/d higher forage DMI in L-subgroups compared to H-subgroups, but the difference did not affect subsequent forage DMI or milk production in the first lactation. Moderate energy supplementation is recommended during the rearing period for dairy goats under Norwegian conditions.

An evaluation through lactating cattle of a bacterial inoculant as an additive for grass silage

AbstractThree silages were prepared from herbage treated with either an inoculant (Ecosyl, Imperial Chemical Industries plc) at 3.21 t−1, formic acid (850 g kg−1, Add F BP Chemicals International Ltd) at 2·3 1 t−1, or no additive (control). The herbage used was the first regrowth from perennial ryegrass swards. It was ensiled unwilted, and had mean dry matter and water soluble carbohydrate concentrations at ensiling of 154 and 24·1 g kg−1 respectively. Time course studies showed only minor effects of additive treatment on fermentation patterns within the silo and all three silages had good fermentations. Over an 88 d feeding period, commencing on day 7 of lactation, forty‐eight British Friesian cows were used to evaluate the silages in a three‐treatment, randomized‐block design experiment. The animals were stalled individually, offered the silages ad libitum, and in addition received 5 kg d−1 of a supplement containing 196 g kg−1 crude protein. On the basis of the data recorded during the final 28 d on treatment the animals receiving the inoculant‐treated silage consumed 12 and 10% more silage dry matter and produced 2·1 and 2·3 kg d−1 more milk than those given the control and formic acid‐treated silages respectively. Over the total experimental period the milk yields were 1957, 1894 and 2094 (±41·3) kg for animals receiving the control, formic acid‐ and inoculant‐treated silages respectively. Animals offered the formic acid treated silage produced milk of significantly higher fat concentration than those given the other two silages. Total ration digestibility studies, conducted with three cows per treatment, indicated no significant differences in digestibility coefficients, nitrogen utilization or metabolizable energy concentrations of the three treatment diets. It is concluded that the higher milk yield recorded with the inoculant‐treated silage, and the higher milk fat concentration with the formic acid‐treated silage, over that obtained with the control silage, were due to the increases in ME intake of 5 and 16 MJ d−1 for the formic acid and inoculant‐treated silages respectively.

Impairment of hemodynamics with increasing mean airway pressure during high-frequency oscillatory ventilation.

We investigated the effects of changes in mean airway pressure (Paw), oscillatory frequency and lung compliance on cardiac output (CO) and pulmonary vascular resistance in seven adult cats (3.0 +/- 0.6 kg) during high-frequency oscillatory ventilation (HFOV). The cats were anesthetized with chloralose and urethane and ventilated with a high-frequency oscillator at Paw of 4, 8, 12, and 16 cm H2O and frequencies of 3, 6, 12, 16, and 20 Hz. Saline lavage was used to reduce lung compliance. CO was continuously recorded with an electromagnetic flow probe placed around the aorta and pulmonary vascular resistance was calculated from left atrial and pulmonary artery pressures. Lung lavage reduced static compliance of the respiratory system but did not change CO during pressure-limited ventilation. During HFOV, CO was higher in animals after lung lavage at each Paw. As Paw was raised from 4 to 16 cm H2O during HFOV, CO decreased from 133 +/- 36 to 87 +/- 31 ml/min kg in animals with normal lungs and decreased from 153 +/- 33 to 107 +/- 19 ml/min kg after lung lavage (both p less than 0.001). Increasing Paw was also associated with an increase in pulmonary vascular resistance both before and after lung lavage (both p less than 0.005). Changes in frequency did not significantly alter CO or pulmonary vascular resistance. We conclude that the interaction between the heart and lungs during HFOV is largely mediated by Paw and compliance of the respiratory system. Furthermore, regardless of the degree of lung compliance, cardiac function may be impaired during HFOV as Paw is elevated.

Effect of level, source and duration of feeding of supplemental energy in sow diets of metabolic and hormonal traits related to energy utilization in the baby pig.

In each of two trials, 30 sows were assigned to six energy-supplemented diets for 5 (trial 1) or 35 d (trial 2) before farrowing, and the effects on sow milk and pig survival characteristics were examined. Treatments consisted of 1.6 kg/d of a basal diet plus .09, .18 or .27 kg of animal fat/d or .20, .39 or .58 kg of cornstarch/d. Two pigs were killed at birth after blood samples were taken and before suckling. Two pigs per litter were fasted to 24 h and two to 48 h of age. Blood glucose was increased (P less than .05) at birth in pigs from sows fed fat in the 35-d feeding, whereas blood glucose was not different in pigs in the short-term feeding of diets Beta-hydroxybutyrate was highest in blood from pigs in the fat-fed groups after a 48-h fast, which was an indication of increased fat metabolism. Beta-hydroxybutyrate was also higher (P less than .05) after a 24 h fast in livers of pigs from sows fed the highest level of fat in both trials than in livers of pigs from sows fed the same level of cornstarch. There were also treatment differences (P less than .05) in liver glycogen content, oxidation of palmitate to CO2, oxidation of glucose to CO2, number of pigs born dead, birth weight and colostrum total lipids and energy content. No treatment-related differences in levels of FFA, triiodothyronine, thyroxine or glucagon in blood of the offspring were observed.

Kinetics of the phagocytosis of radiogold colloids by the reticuloendothelial system in the rat

The kinetics of the phagocytosis of radiogold colloids by the reticuloendothelial system of the rat has been studied theoretically and experimentally, assuming a Michaelis-Menten type kinetics and stating equations which allow the analysis of the phenomenon from a more general point of view. In order to investigate the process with dispersions stabilized by an agent other than gelatine, we determined the disappearance curves from the blood stream of polyvinylpyrrolidone (PVP) protected radiogold colloids with mean particle sizes ranging from 25 to 195 Å, by continuous measurement of the radioactivity of the blood, using an extracorporeal blood circulation technique. The results of 114 experiments show that the plot of the half-time of disappearance ( T) against the number of injected particles per kg of animal ( N op ) gives a straight line. They also show that the maximal rate of phagocytosis is (4.13 ± 0.20) × 10 14 particles per kg of animal per minute and that K s has a value of (2.08 ± 0.16) × 10 15 particles per kg of animal. When these results are compared with those obtained with gelatine protected gold colloids, we observe that, in the case of PVP stabilized dispersions, T is generally much shorter for the same value of ( N op). These differences suggest that T is not only influenced by ( N op), but also by the nature of the protective agent. On the other hand, it can be shown that the values of T are not specifically modified by the mean size of the colloidal particles. We discuss these observations and we tentatively explain them as due to the different physicochemical properties of the protective agents which will change ther at of adsorption of the particles on the surface of, and its rate of entrance into, the reticuloendothelial cell.

Management of closed-system marine aquariums

1. The major changes which take place in a captive body of sea water include decreases in alkaline reserve, pH, and dissolved oxygen. Inorganic nitrogen compounds, carbon dioxide, phosphates, dissolved organic compounds and bacteria increase in concentration. 2. Methods which have been applied to reduce the rates of these changes in semiclosed systems include buffers, nitrification by bacteria, ozonation, ion-exchange resins, protein foaming, ultraviolet light, microfiltration and dilution of the culture medium. 3. Design criteria for a basic culture system include, forOctopus bimaculatus: (a) 500 liters of medium per kg of animal; (b) a 0.1 m3 filter bed consisting of 2–5 mm grains of magnesium — bearing calcium carbonate; (c) a flow rate of 80 l per m2 of filter bed per min; and (d) replacement of 25% of the culture medium per month. 4. Similar systems will support heavier loads of hardier animals, e.g. up to 7 kg ofHomarus americanus.

Rumen pH as a Factor for Controlling Feed Intake in Ruminants

Four rumen fistulated steers, in a 4×4 Latin-square design, received intraruminal infusions of a) water, b) phosphoric acid, c) lactic acid, or d) citric acid, to study the effect of rumen pH on daily hay consumption. Steers were fed chopped hay ad libitum for a 6-hr period daily. To lower and maintain the rumen pH at about 6.0, the dilute acid solutions were infused on the day of the experiment with a prime dose 30min before feeding, followed by successive infusions during feeding. Daily air-dry hay intake dropped (P<0.01) from 12.3kg in the control animals (water infused) to 6.0, 6.3, and 8.0kg in the animals receiving phosphoric acid, lactic acid, and citric acid solutions, respectively. In control animals, hourly rumen pH fell gradually through the hours of feeding from 7.03 before infusion to 6.58, 6 hr later. In acid-infused animals, rumen pH dropped from 7.08 to about 6.0, where it was maintained during the feeding period. Blood urea values showed a nonsignificant drop in the acid-infused groups. Blood glucose levels remained constant. Blood ammonia made slight shifts during acid infusion. Blood volatile fatty acids were lower in the acid-infused group.

Renal Clearance of -Hydroxybutyric Acid in a Dog

ConclusionTwo renal clearance experiments in a dog indicate that dl-β-hydroxy-butyrate is excreted by the kidney in a fashion resembling many amino acids. The maximum rate of tubular reabsorption (TmβB) appears to lie between 2 and 3 mg per minute per kg of animal. An appreciable excretion of β-hydroxybutyrate occurs at a plasma level of 8 mg %.