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

Abstract

Efeitos de níveis de energia na dieta utilizando sais de cálcio de ácidos graxos sobre o valor nutritivo das dietas e qualidade do leite em cabras leiteiras no periparto ABSTRACTPeripartum 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.Index terms: Digestibility, calcium soap, fatty acid, Lactoplus ® , protected fat. RESUMOO 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...

Effect of calcium salts of fatty acids on the nutritive value of diets, feeding behavior, and serum blood parameters of lactating Saanen goats grazing on stargrass

“…These values were close to the 0.63 g g −1 and 0.65 g g −1 observed by Silva et al (2007) and Molina (2013) NDF) and 0, 900, or 1200 g kg −1 DM of a rumen-inert fat in the concentrate; and Souza et al (2014), who fed goats corn silage and 0, 28.7, 54.6, or 80.5 g kg −1 DM of CSFA. The higher digestibility of dry matter reported by Sanz Sampelayo et al (2002) and Souza et al (2014) may be related to the forages used. It is usually known that maize silage and alfalfa hay are more digestible than grass pastures or hay (oat and Tifton).…”

“…The addition of CSFA to the concentrate for multiparous and primiparous goats changed the neutral detergent fiber digestibility coefficient (NDFD); this result shows that forms of rumen-inert lipids cannot decrease cell wall digestibility, as previously shown by Sanz Sampelayo et al (2002), Souza et al (2014), and Molina (2013).…”

“…It is usually known that maize silage and alfalfa hay are more digestible than grass pastures or hay (oat and Tifton). Another reason could be the lower amount of CSFA in this study, which conferred a diet with lower energy values than those provided by Sanz Sampelayo et al (2002) and Souza et al (2014).…”

“…Molina (2013) evaluated the effect of adding CSFA to the diet of Saanen goats, with no observed interference with blood glucose, with an average of 50.98 mg dL −1 . Similarly, Souza et al (2014) did not observe changes in serum blood glucose when CSFA rich in polyunsaturated fatty acids was added to increase the dietary energy in the diet of Saanen goats.…”

“…Among the benefits of CSFA is the possibility of increasing the energy content of the diet without influencing fiber digestibility, thereby allowing high levels of inclusion in ruminant diets (Baldin et al, 2013). In this sense, CSFA is interesting, because it does not change ruminal fermentation (Sirohi et al, 2010) and also improves milk quality (Souza et al, 2014). Thus, CSFA is an energy supplement that in combination with other foods can increase the dry matter intake providing good availability of nutrients for satisfactory responses in females for milk production.…”