Fatty acid profile and composition of milk protein fraction in dairy cows fed long-chain unsaturated fatty acids during the transition period

Abstract

-The objective of this study was to evaluate the utilization of different sources of unsaturated long-chain fatty acids in diets for dairy cows during the transition period and early lactation on the milk fatty acid profile and composition of the protein fraction. Thirty-six Holstein cows were divided into three groups, fed the following diets: control (C); soybean oil (SO); and calcium salts of long-chain unsaturated fatty acids (CS). The milk samples utilized for analysis were obtained weekly from parturition to twelve weeks of lactation; each one of the samples originated from two daily milkings. Milk composition and total nitrogen, non-protein nitrogen and non-casein nitrogen levels were analyzed. The cows receiving the diet with calcium salts had lower concentrations of non-protein nitrogen (%CP) in milk compared with the animals fed the diet with soybean oil. There was a decrease in concentration of medium-chain fatty acids C12-C16, and a concomitant increase in concentrations of long-chain fatty acids >C18 in milk fat for the animals fed the diets CS and SO when compared with diet C. Soybean oil and CS diets increased milk-fat concentrations of the acids C18: 1 trans-11, C18: 2 cis-9, trans-11 and C18: 2 trans-10 cis-12 in relation to diet C. The utilization of sources of long-chain fatty acids in the diet of dairy cows increases the biological value of milk in early lactation due to higher concentrations of specific fatty acids such as CLA C18: 2 cis-9, trans-11.

Soybean oil and calcium salts of fatty acids as fat sources for Holstein dairy cows in transition period

“…Similar results were observed for body weight (Table 3), data also present in (RENNÓ et al 2013) Interaction effect was significant for Fat corrected milk (FCM) (P<0.05) No difference was observed between the contrasts evaluated. Time effects were observed (P<0.05) for the dry matter intake, milk yield and energy balance (Figure 1).…”

Dietary chitosan improves nitrogen use and feed conversion in diets for mid-lactation dairy cows

“…The inhibiting effect of unsaturated C18 on de-novo synthesis has been known in the past, but precise mechanisms involved in the studies were not yet well understood, even if some 18:2 isomers, such as C18:2 trans-10, cis-12, have been identified (Bauman and Griinari, 2001). Renno et al (2013) also found milk fat depression and short-chain fatty acid concentration decrease in dairy cows fed with long-chain unsaturated fatty acids. In the present study, soybean oil increased milk C18:2 cis-9 trans-11, C18:2 trans-10 cis-12 and decreased short and medium chain fatty acid concentration and chitosan was not able to inhibit linoleic acid biohydrogenation in fat supplemented diets.…”

Perfil de ácidos graxos do leite de vacas Holandês x Gir alimentadas com silagem de milho e concentrado contendo ou não glicerina bruta

“…16,75 15,82 0,3919 0,1155 C18:1 cis-11 0,65 0,62 0,0142 0,1803 C18:1 cis-12 0,33 0,27 0,0094 0,0003 C18:1 cis-13 0,061 0,056 0,0027 0,2582 C18:1 cis-14 0,076 0,079 0,0026 0,4124 C20:1 cis-11 0,096 0,094 0,0064 0,8665 AG C18:1 trans C18:1 trans-4 0,013 0,009 0,0007 0,0057 C18:1 trans-5 0,012 0,008 0,0012 0,0392 C18:1 trans-6 a trans-8 0,15 0,12 0,0051 0,0015 C18:1 trans-9 0,25 0,21 0,0064 0,0001 C18:1 trans-10 0,32 0,27 0,0117 0,0070 C18:1 trans-11 1,06 1,08 0,0456 0,7866 C18:1 trans-12 0,29 0,22 0,0076 <0,0001 C18:1 trans-13 e trans-14 0,42 0,33 0,0172 0,0020 C18:1 trans-16 0,27 0,21 0,0104 0,0015 Σ C18:1 trans 2,78 2,44 0,0807 0,0104 Isômeros conjugados (CLA) e não conjugados (NCLA) do ácido linoleico C18:2 trans-9 trans-12 (NCLA) 0,069 0,053 0,0036 0,0060 C18:2 cis-9 trans-12 (NCLA) 0,066 0,065 0,0040 0,8323 C18:2 trans-9 cis-12 (NCLA) 0,107 0,099 0,0039 0,2010 Σ NCLA 0,24 0,22 0,0103 0,1008 CLA cis-9 trans-11 0,58 0,53 0,0254 0,2310 CLA trans-9 cis-11 0,025 0,022 0,0043 0,7022 CLA trans-10 cis-12 0,014 0,015 0,0020 0,6387 AG de cadeia longa ω-6 e ω-3 C18:2 cis-9 cis-12 (ω-6) 1,82 1,66 0,0641 0,0951 γ-C18:3 cis-6 cis-9 cis-12 (ω-6) 0,024 0,023 0,0015 0,8156 C18:3 cis-9 cis-12 cis-15 (ω-3) 0,22 0,20 0,0077 0,1463 C20:2 cis-11 cis-14 (ω-6) 0,031 0,024 0,0030 0,1370 C20:3 cis-8 cis-11 cis-14 (ω-6) 0,076 0,086 0,0054 0,2139 Araquidônico (C20:4 cis-5 cis-8 cis-11 cis-14) (ω-6) 0,14 0,15 0,0086 0,8573 EPA (C20:5 cis-5 cis-8 cis-11 cis-14 cis-17) (ω-3) 0,044 0,051 0,0032 0,1425 DHA (C20:6 cis-4 cis-7 cis-10 cis-13 cis-16 cis-19) (ω-3) 0,060 0,068 0,0048 0,2385 Σ AG ω-6 cis 2,09 1,93 0,0703 0,1335 Σ AG ω-3 cis 0,32 0,32 0,0132 0,9532 Não houve efeito (P>0,05) da inclusão de GB sobre o teor do ácido esteárico no leite (Tab. 4), cujos valores são similares ao obtido (9,1g/100g de AG) em trabalho realizado no Brasil com vacas alimentadas com silagem de milho e concentrado não lipídico (Rennó et al, 2013). No entanto, os teores de ácido oleico (Tab.…”

“…No entanto, os teores de ácido oleico (Tab. 4) podem ser considerados baixos em relação aos relatados por Rennó et al (2013) Zootec., v.72, n.1, p.243-252, 2020 al., 2015) demonstraram que até ~11% de glicerol na MS da dieta em substituição ao amido não altera o pH, mas modifica a proporção molar de ácidos graxos voláteis no rúmen, com maior concentração de propionato às expensas de acetato.…”