Feeding rumen-protected methionine during the peripartum period improved milk fat content and reduced the culling rate of Holstein cows in a commercial herd.

Researchers have reported the benefits of feeding rumen-protected methionine (RPM) during the peripartum on the health parameters of dairy cows. Rumen-protected Met has reportedly improved milk yield, milk components, and liver health, but the literature is scarce on its effects in commercial herds. Therefore, we aimed to determine the effects of feeding RPM (Smartamine M, Adisseo Inc., Antony, France) prepartum (8 g/cow per day) and postpartum (15 g/cow per day) on performance, metabolic profile, and culling rate of Holstein cows in a commercial herd. One hundred sixty-six (n = 166) Holstein cows, 58 nulliparous and 108 parous, were randomly assigned to 1 of 2 dietary treatments, consisting of TMR top-dressed with RPM (RPMet; 2.35% and 2.24% Met of MP for close-up and fresh cows, respectively) or without (control [CON] 2.03% and 1.89% Met of MP for close-up and fresh cows, respectively), fed from 21 ± 6 d prepartum until 16 ± 5 d postpartum. From 17 DIM until dry-off, all cows received RPMet. Daily milk yield was recorded, and milk samples were collected in the first and second weeks after calving to determine their composition. Blood samples were collected before the morning feeding on -14, -7, +1, +7, and +14 d relative to calving. Mortality and morbidity were recorded during the first 60 DIM. Cows supplemented with RPMet had greater milk yield during the first 16 DIM (31.76 vs. 30.37 kg/d; SEM = 1.04, respectively), and had greater milk fat content (4.45 vs. 4.10%; SEM = 0.11, respectively), but not milk total protein (3.47 vs. 3.39%; SEM = 0.04, respectively) and casein contents (2.74 vs. 2.66%; SEM = 0.04, respectively) than CON cows. Cows in RPMet had increased plasma Met concentrations than cows in CON (24.9 vs. 21.0 µmol/L; SEM = 1.2, respectively). Although morbidity was similar between treatments, the culling rate from calving until 60 DIM was lower for RPMet cows than for CON cows (2.4% vs. 12.1%; SEM = 0.02). In conclusion, cows receiving RPMet have greater milk yield, improved milk fat content, and a lower culling rate at 60 DIM than CON cows.

Organic copper, iron, manganese and zinc: digestibility, production parameters and egg quality of layers / [Cobre, ferro, manganês e zinco orgânico: digestibilidade, parâmetros zootécnicos e qualidade dos ovos de poedeiras]

This study examined the replacement of the inorganic minerals (IM) Cu, Fe, Mn and Zn with their organic form (OM) in the diet of 67-week-old Dekalb White laying hens by comparing digestibility, production and egg quality. The experiment involved 240 birds, with 48 birds used per treatment and 12 per replicate. Isoenergetic and isonutrient diets were supplemented with 8mg Cu, 50mg Fe, 70mg Mn and 50mg Zn per kilogram of diet from an inorganic premix (IM100), from an organic premix (OM100), or the latter at the decreasing inclusion levels of 65% (OM65), 45% (OM45) and 35% (OM35). The following variables were evaluated: production, eggs per housed bird (EHB), viability, egg weight and mass, cracked and lost eggs, digestibility and egg physicochemical traits. Birds fed OM35 and OM45 showed lower production rates, and organic minerals provided the highest egg weights, regardless of their inclusion level. Accordingly, egg mass was similar between IM100, OM45 and OM35, and highest values were obtained with OM100 and OM65. Source or level had no influence on digestibility or egg quality. Supplementation with 2.8mg Cu, 17.5mg Fe, 24.5m g Mn and 17.5mg Zn per kilogram of diet (OM35) in the last third of the laying cycle provided relevant economic production indices (EHB, viability, egg weight or mass).(AU)

Estudou-se a substituição dos minerais inorgânicos (MI) Cu, Fe, Mn e Zn por minerais orgânicos (MO) na dieta de poedeiras Dekalb White com 67 semanas, comparando-se índices de produção, digestibilidade e qualidade dos ovos. Utilizaram-se 240 aves, 48 aves por tratamento e 12 por repetição. Dietas isoenergéticas e isonutrientes foram suplementadas com 8mg Cu, 50mg Fe, 70mg Mn e 50mg Zn por kg de ração MI100 e MO100 ou suplementações decrescentes MO65, MO45 e MO35. Avaliou-se produção, ovo por ave alojada (OAA), viabilidade, peso e massa dos ovos, trincados e perdidos, digestibilidade dos nutrientes e características físico-químicas dos ovos. Observaram-se menores índices de produção nas aves dos tratamentos MO35 e MO45 e maiores pesos dos ovos nos tratamentos com minerais orgânicos, independentemente da inclusão. Assim, massas de ovos foram semelhantes para os tratamentos MI100, MO45 e MO35 e maiores para MO100 e MO65. Fontes ou níveis de inclusões não influenciaram a digestibilidade e a qualidade dos ovos. Índices zootécnicos economicamente relevantes (OAA, viabilidade, peso e massa do ovo) foram obtidos com suplementação de 2,8mg Cu, 17,5mg Fe, 24,5mg Mn e 17,5mg Zn por kg de ração (MO35) em poedeiras brancas no último terço do ciclo de postura.(AU)