RESUMO Com o objetivo de avaliar o efeito da adição de sais de cálcio de ácidos graxos de cadeia longa (SCAG) na ingestão e na digestibilidade de rações foram utilizadas 25 cabritas, alojadas em gaiolas individuais e em câmara climática a uma temperatura constante de 32ºC. As cabritas foram distribuídas em delineamento em blocos casualizados com cinco tratamentos: controle (sem inclusão de SCAG) e com 6,25; 12,50; 18,75 e 25,00 g de SCAG kg-1 de MS. A inclusão de SCAG nas rações não influenciou as ingestões de água (3,08 L dia-1), matéria seca (0,66 kg dia-1), matéria orgânica (0,62 kg dia-1), proteína bruta (0,12 kg dia-1), fibra em detergente neutro (0,27 kg dia-1) e carboidratos totais (0,47 kg dia-1). Os resultados das digestibilidade da matéria seca (0,66 kg kg-1), matéria orgânica (0,67 kg kg-1), proteína bruta (0,78 kg kg-1), fibra em detergente neutro (0,47 kg kg-1) e carboidratos totais (0,63 kg kg-1) não foram alterados. Houve efeito linear positivo na ingestão e digestibilidade de extrato etéreo. Portanto, a adição de sais de cálcio de ácidos graxos de cadeia longa em rações de cabritas sob estresse térmico de 32ºC não influencia a ingestão e digestibilidade da matéria seca e dos nutrientes, com exceção do extrato etéreo que é intrínseco ao produto adicionado nas rações.

ABSTRACT This study aimed to evaluate the effect of the addition of calcium salts of long chain fatty acids (CSFA) on the intake and digestibility of diets. Twenty-five female goat kids housed in digestibility cages and subjected to heat stress of 32°C in a climatic chamber, were used. The female kids were distributed in a randomized block design with five treatments: control (without inclusion of CSFA) and 6.25; 12.50; 18.75 and 25.00 g CSFA kg-1 of DM. The inclusion of CSFA in rations did not influence water intake (3.08 L day-1), dry matter (0.66 kg day-1), organic matter (0.62 kg day-1), crude protein (0.12 kg day-1), neutral detergent fiber (0.27 kg day-1) and total carbohydrate (0.47 kg day-1). The results of the digestibility of dry matter (0.66 kg kg-1), organic matter (0.67 kg kg-1), crude protein (0.78 kg kg-1), neutral detergent fiber (0.47 kg kg-1) and total carbohydrate (0.63 kg kg-1) were not affected by the treatments. However, there was a positive linear effect on the intake and digestibility of ether extract. Therefore, the addition of calcium salts of long chain fatty acids in the diets for female kids under heat stress of 32°C does not influence the intake and digestibility of dry matter and nutrients, except for ether extract, which is intrinsic to the product added to the rations.

RESUMO: O objetivo foi avaliar a substituição do farelo de soja por levedura seca inativa (Saccharomyces cerevisiae) de cana-de-açúcar sobre o valor nutritivo de dietas para cabras Saanen no periparto. Vinte e quatro cabras Saanen (nove primíparas, 55,35 ± 4,55 kg e quinze multíparas, 73,12 ± 8,51 kg) durante os períodos pré-parto e pós-parto, foram distribuídas em delineamento inteiramente casualizado, com arranjo fatorial 3 × 2 (dieta × ordem de parto). As dietas foram compostas por farelo de soja, farelo de soja e levedura seca ou levedura seca como fonte de proteína e os demais ingredientes: milho moído, suplemento mineral e calcário. A fonte de volumoso utilizada foi a silagem de milho de planta inteira (40% da ração total). As dietas foram avaliadas quanto a ingestão de matéria seca e digestibilidade dos nutrientes. A dieta com inclusão total de levedura seca promoveu redução na ingestão de extrato etéreo (pós-parto) e na digestibilidade de extrato etéreo (pós-parto e pré-parto), devido ao seu menor teor de extrato etéreo quando comparada as demais dietas. As cabras multíparas apresentaram maiores ingestões de matéria seca, nutrientes e nutrientes digestíveis totais, em ambos os períodos avaliados, devido a sua maior capacidade de ingestão. As cabras primíparas em pós-parto apresentaram melhores coeficientes de digestibilidade para matéria seca, matéria orgânica, proteína bruta e carboidratos totais, e, portanto, maior valor energético, atribuído aos nutrientes digestíveis totais, comparado as multíparas. A levedura seca pode substituir o farelo de soja sem alterar o valor nutritivo das dietas para cabras Saanen.

ABSTRACT: The aim was to evaluate the replacement of soybean meal by inactive dry yeast (Saccharomyces cerevisiae) from sugar cane on nutritive value of diets for Saanen goats in the peripartum. Twenty-four Saanen goats (nine primiparous, 55.35 ± 4.55 kg and fifteen multiparous, 73.12 ± 8.51 kg) in prepartum and postpartum periods were distributed in a completely randomized design with a 3 × 2 (diet × parturition order) factorial arrangement. Diets were composed of soybean meal, soybean meal plus dry yeast or dry yeast as protein source, and other ingredients: ground corn, mineral supplement and limestone. The roughage source used was the whole plant corn silage (40% of the total diet). Diets were evaluated as dry matter intake and digestibility of nutrients. The diet with total dry yeast inclusion promoted a reduction on the ether extract intake (postpartum) and ether extract digestibility (prepartum and postpartum), due its lower ether extract content when compared to the other diets. Multiparous goats presented higher intakes for dry matter, nutrients and total digestible nutrients in both evaluated periods due their higher intake capacity. Primiparous goats in postpartum had better coefficients of digestibility for dry matter, organic matter, crude protein and total carbohydrates, and so a higher energetic value, attributed to total digestible nutrients compared to multiparous ones. Dry yeast can replace soybean meal with no changes on nutritive value of diets for Saanen goats.

De acordo com a fonte de gordura incluída na dieta de cabras, a produção de leite pode ser aumentada e a composição de ácidos graxos do leite pode ser melhorada. Este estudo foi conduzido para avaliar a inclusão de gordura protegida (SCAG - sais de cálcio de ácidos graxos) nas dietas de cabras Saanen lactantes, sobre a produção e composição do leite. Cinco cabras Saanen (63,23 ± 9,08 kg de peso corporal e 105 ± 3 dias de lactação) foram distribuídas em delineamento quadrado Latino (5 × 5) em cinco dietas: controle (sem adição de SCAG) e os demais, dietas com: 6,25; 12,50; 18,75 e 25 g de SCAG por kg de matéria seca (g/kg MS), respectivamente. A ingestão de matéria seca (IMS) e a produção de leite (PL) foram avaliadas. Amostras de leite foram coletadas para determinar a composição e o perfil de ácidos graxos. A eficiência alimentar (EA) foi estimada. A suplementação de SCAG em até 25 g/kg MS não influencia a IMS, PL e a EA. A produção de componentes do leite (g/d) não foi influenciada pela inclusão de SCAG na dieta, no entanto,houve redução linear de 0,87 g de proteína por kg de leite para cada 1% de inclusão de SCAG na dieta. A concentração de ácido linolênico (18:3n-3) no leite aumentou com o ponto de máxima de 24 g de SCAG por kg de MS. A gordura protegida pode ser incluída na dieta de cabras Saanen em lactação, em até 25 g/kg MS sem interferir na IMS e PL.

According on the fat source included in the diets for goats, the milk production can be increased and milk fatty acid composition can be improved. This study was conducted to evaluate the inclusion of protected fat (CSFA - calcium salts of fatty acids) in the diets of lactating Saanen goats on milk production and composition. Five Saanen goats (63.23 ± 9.08 kg body weight and 105 ± 3 days of lactation) were distributed in a Latin square design (5 × 5) with five diets: control (without the addition of CSFA) and the other diets with: 6.25, 12.50, 18.75 and 25.0 g CSFA per kg dry matter (g/kg DM), respectively. Dry matter intake (DMI) and milk production (MP) were evaluated. Milk samples were collected to determine milk composition and fatty acid profile. Feed efficiency (FE) was estimated. The supplementation of CSFA up to 25 g/kg DM did not influence the DMI, MP and FE. Milk components production (g/d) was not influenced by the inclusion CSFA in the diet; however, there was a linear reduction of 0.87 g protein per kg of milk for each 1% CSFA included in the diet. The concentration of linolenic acid (18:3n-3) in milk was improved with a maximum point of 24 g of CSFA per kg DM. CSFA can be included in the diets of lactating Saanen goats up to 25 g/kg DM with no interference on DMI and MP.

Foram utilizadas 24 cabras Saanen em lactação (15 multíparas e nove primíparas) do parto até 200 dias de lactação, distribuídas no delineamento inteiramente casualizado em arranjo fatorial (3 rações x 2 ordens de parto). As rações foram constituídas por farelo de soja (FS), farelo de soja + levedura seca (FSLV) ou levedura seca (LV) como fonte de proteína. Para análise da produção de leite, do peso corporal e da ingestão de matéria seca foi utilizada a metodologia Bayesiana. E, para construir as curvas de lactação foi utilizada o modelo não-linear de Wood. A inclusão de levedura seca nas rações diminuiu a taxa de acréscimo da produção de leite até o pico de lactação para as primíparas, porém para as multíparas foi observado efeito inverso. Para as cabras primíparas, a ração FSLV diminuiu a taxa de decréscimo da produção após o pico, embora para as multíparas a inclusão de levedura seca nas rações aumentou a taxa de decréscimo da produção após o pico. A levedura seca pode ser utilizada em substituição ao farelo de soja em rações para cabras Saanen multíparas em lactação.

Twenty-four Saanen goats (fifteen multiparous and nine primiparous) during their lactation period were used, from the kidding until the 200th day of lactation; and were distributed in a completely randomized design and in a factorial arrangement (3 diets x 2 parity orders). The diets were composed of either soybean meal (SBM), soybean meal plus inactive dry yeast (SMDY) or inactive dry yeast (DY) used as the protein source. The analyses of milk yield, body weight and dry matter intake (DMI) were made through the Bayesian methodology. For construct the lactation curves were used the Wood's nonlinear model. The inclusion of inactive dry yeast in the diets reduced the rate of yield increase until the lactation peak for primiparous goats, but for multiparous goats the reverse was noted. The SMDY diet reduced the rate of yield decline after peak for primiparous goats, whereas for multiparous goats the inclusion of inactive dry yeast in the diet increased the decline of the rate of yield during this period. It was observed that inactive dry yeast can be used to replace soybean meal in diets used for multiparous Saanen goats.

O periparto é um período crítico para cabras leiteiras, onde a ingestão de matéria seca (IMS) não é suficiente para suprir os requerimentos energéticos para o crescimento fetal e lactação subsequente. Neste estudo, objetivou-se avaliar o uso de sais de cálcio de ácidos graxos (SCAG), para aumentar o nível de energia na dieta de cabras leiteiras no periparto e seus efeitos sobre o valor nutritivo das dietas e qualidade do leite. Vinte cabras multíparas (63,5±10,3 kg) foram distribuídas em delineamento inteiramente casualizado, em quatro tratamentos com os seguintes níveis de energia na dieta: 2,6 Mcal de energia metabolizável por kg de matéria seca (EM/kg de MS) - dieta controle; 2,7; 2,8; e 2,9 Mcal de EM/kg de MS - com adição de gordura protegida. As cabras foram confinadas em baias individuais e avaliadas durante o período do periparto, acompanhando o peso corporal (PC), IMS, digestibilidade da matéria seca e dos nutrientes da dieta, concentração bioquímica sanguínea, produção e qualidade do leite. O aumento no nível de energia da dieta até 2,9 Mcal de EM/kg de MS não teve efeito sobre PC e não limitou a IMS. A suplementação com SCAG aumentou a ingestão de nutrientes digestíveis totais, sem afetar a digestão da fibra. As concentrações sanguíneas de colesterol e triglicerídeos aumentaram com a adição de SCAG. Não houve efeito dos tratamentos sobre a produção e composição do leite, entretanto, a suplementação lipídica alterou o perfil dos ácidos graxos da gordura do leite, sendo observados maiores teores de ácidos graxos poli-insaturados e essenciais. Concluindo, cabras leiteiras no periparto, alimentadas com a elevação do nível de energia na dieta para 2,9 Mcal de EM/kg de MS, utilizando a suplementação com SCAG, têm maior suprimento de nutrientes digestíveis totais e alteração na concentração dos ácidos graxos da gordura do leite.

Peripartum is a critical period for dairy goats, as dry matter intake (DMI) is not enough to supply the energy requirement for foetal growth and subsequent lactation. The objective of this study was to evaluate the use of calcium salts of fatty acids (CSFA) to increase dietary energy level of peripartum dairy goats and its effects on nutritive value of diets and milk quality. Twenty multiparous Saanen goats (body weight 63.5±10.3 kg) were distributed in a completely randomised design in four treatments at the following dietary energy levels: 2.6 Mcal of metabolisable energy per kg of dry matter (Mcal ME/kg DM) - control diet; and 2.7, 2.8, and 2.9 Mcal/kg DM - with added CSFA. Goats were housed in individual stalls and evaluated in the peripartum period, by measuring body weight (BW), DMI, dry matter and nutrient digestibility of diets, blood composition, and milk quality and yield. Increasing dietary energy level to 2.9 Mcal ME/kg DM had no effect on BW and did not limit DMI. CSFA supplementation increased intake of total digestible nutrients and did not affect fibre digestion. Blood triglycerides and cholesterol concentration increased with CSFA addition. The treatments had no effect on milk yield and composition; however, CSFA supplementation changed the fatty acid concentration of milk fat, increasing levels of polyunsaturated and essential fatty acids. In conclusion, peripartum dairy goats supplemented with CSFA to increase dietary energy level up to 2.9 Mcal ME/kg DM had a greater supply of total digestible nutrients and showed altered fatty acid concentration of milk fat.

The objective of this study was to evaluate the use of calcium salts of fatty acids (CSFA) to increase the dietary energy levels for Saanen goats and their effects on the lactation curve, dry matter intake, body weight, and economic results of the goats. Twenty multiparous goats, weighing an average of 63.5±10.3 kg, were randomly assigned to one of four treatment groups, each receiving one of the following dietary energy levels: a control diet consisting of 2.6 Mcal of metabolizable energy per kg of dry matter (Mcal ME/kg DM) or a test diet supplemented with CSFA (Lactoplus®) to obtain 2.7, 2.8, or 2.9 Mcal ME/kg DM. Goats were housed in individual stalls and were fed and milked twice daily. The animals were evaluated until 180 days in milk by measuring dry matter intake and milk yield. These measurements were used to calculate feed efficiencies and the cost-benefit ratio of diet and lactation curves using Wood's nonlinear model. Increasing dietary energy levels showed no effect on body weight. Supplementation with CSFA did not limit dry matter intake; however, it changed the shape of the lactation curve by promoting a late peak lactation with a longer duration. Milk yields at 180 days in milk had a quadratic increase with a maximum energy level at 2.85 Mcal ME/kg DM. Increasing the dietary energy level for Saanen goats using CSFA changes their lactation curves, with the best milk production achieved with a 2.85 Mcal ME/kg DM diet; however, the greatest economic results were obtained with a 2.7 Mcal ME/kg DM diet.

Twenty-four Saanen goats (15 multiparous and 9 primiparous) from 21 days prepartum to 200 days in lactation were used to evaluate milk yield and composition. Animals were randomly distributed in a 3 × 2 factorial arrangement (3 diets × 2 parity orders) and fed a 40:60 forage:concentrate diet composed of soybean meal, soybean meal + dry yeast or dry yeast as protein source, plus ground corn, mineral supplement and corn silage. The protein source did not influence the body weight of pre and postpartum goats. Prepartum, postpartum and postpeak dry matter intake (DMI) were not altered by diets. However, goats fed the diet containing dry yeast as protein source had lower DMI in late lactation. Milk yield and feed efficiency were not affected by diets. Milk components, acidity and somatic cell count were not influenced by diets during all lactation phases. However, fat and total solid contents postpartum were higher for primiparous goats and somatic cell count postpeak was lower for multiparous goats. Dry yeast can be used to replace soybean meal in diets for lactating Saanen goats.

The effects of inactive dry yeast (Saccharomyces cerevisiae) from sugar cane were studied in 18 primiparus Saanen dairy goats (51.07±1.43) on dry matter intake and digestibility, milk production and quality. Animals were distributed in a completely randomized design during 90 days (from day 60 of milking). Diets were composed of soybean meal; soybean meal + dry yeast; or dry yeast, as protein sources, and ground corn, mineral supplement and corn silage (40%). Animals fed the dry yeast diet showed lower intake of dry matter (DM), organic matter (OM), crude protein, ether extract and neutral detergent fiber. Diets did not influence milk yield; however the milk production efficiency (kg of milk produced/kg of crude protein ingested) was better in goats fed the dry yeast diet. Acidity, somatic cell counts and milk urea nitrogen values were not affected by treatments. Animals fed the soybean + dry yeast diet had higher fat and total solids than those fed the dry yeast diet. The digestibility of DM, OM and total carbohydrate was lower for soybean only and soybean + dry yeast diets. Total digestible nutrients were higher for dry yeast and soy bean diets than soybean + dry yeast diet. Dry yeast from sugar cane is a good alternative protein source for feeding lactating dairy goats and can be recommended because it maintains the production performance.