Effects of dietary energy levels using calcium salts of fatty acids on nutritive value of diets and milk quality in peripartum dairy goats

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

INCLUSION OF PROTECTED FAT IN DIETS ON THE MILK PRODUCTION AND COMPOSITION OF SAANEN GOATS

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

Nutritional value of feed used in diets for Saanen goats

This study was performed to characterize feed used in diets for Saanen goats. The feedstuffs were: Tifton 85 hay (Cynodon spp.), soybean meal, ground corn, soybean hulls, ground ear corn and dried cassava residue. Contents were determined for dry matter, ash, crude protein, ether extract, neutral detergent fiber, acid detergent fiber, physically effective fiber and lignin, and organic matter, total carbohydrates and non-fiber carbohydrates were estimated. Carbohydrates were divided into fractions A + B1 (rapidly degradable), B2 (potentially degradable) and C (non-degradable); and the protein in fractions A (soluble), B1 (rapid ruminal degradation), B2 (intermediate degradation), B3 (slow degradation) and C (indigestible). To determine the gas production an automatic technique in vitro was used, modified by Ankom®. Significant differences were observed among feed for the parameters A, B, C, E and A + D of ruminal degradation kinetics, and feed with high non-fibrous carbohydrates content presented higher fraction A (rapid degradation), and the hay showed longer lag time (fraction C). The total gas production was higher for ground corn, ground ear corn and dried cassava residue.

Digestibidade e desempenho produtivo em cabritos mestiços ½ Boer x ½ Saanen alimentados com dietas contendo gordura protegida

 Objetivou-se com este trabalho, avaliar a ingestão, os parâmetros de desempenho produtivo, a digestibilidade da matéria seca e dos nutrientes de dietas com concentrações crescentes de energia metabolizável contendo gordura protegida, e a análise econômica das dietas para cabritos mestiços ½ Boer x ½ Saanen terminados em confinamento. Foram utilizados 28 cabritos, machos não castrados com peso inicial de 19,02 ± 2,20 kg e idade de 88 ± 5,77 dias, distribuídos em delineamento inteiramente casualizado Com quatro dietas: controle com 2,5 Mcal de EM/kg MS e os demais com 2,6; 2,7 e 2,8 Mcal de EM/kg de MS, onde se utilizou a gordura protegida (Lactoplus®) como suplemento energético. Os animais foram mantidos no experimento até atingirem peso aproximado de 32 kg. Para as estimativas de digestibilidade foi utilizado o FDAi como indicador interno. Houve efeito das dietas sobre as ingestões de matéria seca, matéria orgânica, extrato etéreo e carboidratos não fibrosos. Foi observado efeito quadrático das dietas sobre os parâmetros de ganho de peso diário e conversão alimentar. Não houve efeito das dietas sobre as digestibilidades da matéria seca, matéria orgânica, fibra em detergente neutro e da energia bruta. A digestibilidade dos carboidratos não fibrosos e dos carboidratos totais apresentou decréscimo linear e da proteína bruta apresentou aumento linear. Observou-se comportamento quadrático da digestibilidade do extrato etéreo, resultante da inclusão de gordura protegida nas dietas. O nível sérico de colesterol aumentou linearmente de acordo com as dietas. A avaliação econômica se mostrou favorável, com maior valor de renda líquida para a dieta com 2,5 Mcal de EM/kg de MS. A elevação da densidade energética da dieta de cabritos mestiços ½ Boer x ½ Saanen, por meio da inclusão de gordura protegida afeta negativamente a ingestão de matéria seca, e a digestibilidade dos carboidratos não fibrosos e dos carboidratos totais, sem proporcionar melhoria do desempenho produtivo dos animais. </p

Lactation curves and economic results of Saanen goats fed increasing dietary energy levels obtained by the addition of calcium salts of fatty acids

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