Relationship between metabolic profile, diseases, productive and reproductive performance in highproducing Holstein cows in the postpartum period / Relação entre o perfil metabólico, doenças, desempenho produtivo e reprodutivo de vacas Holandesas recém-paridas de alta produção

The present study aimed to monitor Holstein cows in the postpartum period, and to evaluate the occurrence of clinical diseases and their relationship with metabolic profile, milk yield and composition, and reproductive performance. One hundred and five Holstein cows, 32 primiparous and 73 multiparous, from two dairy herds in Arapoti, Paraná State, were clinically monitored up to ten days after calving. The clinical occurrences diagnosed were: dystocia, metritis, retained placenta, clinical hypocalcemia, displaced abomasum, mastitis, pneumonia, and digital dermatitis. Blood samples were collected at one, two, five, and ten days postpartum for analysis of non-esterified fatty acids (NEFA), ß-hydroxybutyrate (BHB), and total calcium. Individual milk yield was measured up to 100 days in milk (DIM), and the first test-day was evaluated for milk composition. Statistical analyses were conducted using the MIXED procedure of SAS, and the fixed effects of farm (A and B), parity (primiparous and multiparous), and occurrence of clinical diseases (sick and healthy cows) were included. Forty-eight cows (45.7%) had one or more clinical occurrences. In these sick cows, the BHB concentration at five DIM was higher (P = 0.06) than in healthy cows; 0.78 and 0.57 mmol L-1, respectively. Regarding milk yield, cows with one or more clinical occurrences had lower (P < 0.01) daily milk yield up to 30 DIM, and had a tendency of lower (P = 0.09) accumulated production up to 100 DIM than healthy cows. Sick cows had a tendency to show lower (P = 0.08) milk total solids content than healthy cows; 12.04 and 12.60%, respectively. There were no significant differences between sick and healthy animals in the remaining milk components, or the reproductive parameters assessed. The differences observed for days in the first artificial insemination (AI), AI number, and days open occurred due to the effect of the herd.(AU)

O objetivo deste estudo foi monitorar vacas Holandesas no pós-parto e avaliar a ocorrência de doenças clínicas e sua relação com o perfil metabólico, a produção de leite e sua composição e o desempenho reprodutivo. Foram monitoradas clinicamente durante 10 dias após o parto, 105 vacas da raça Holandesa, 32 primíparas e 73 multíparas, de dois rebanhos leiteiros em Arapoti, Paraná. As ocorrências clínicas diagnosticadas foram: distocia, metrite, retenção de placenta, hipocalcemia clínica, deslocamento de abomaso, mastite, pneumonia e dermatite digital. Amostras de sangue foram coletadas nos dias 1, 2, 5 e 10 após o parto para análises de ácidos graxos não-esterificados (AGNE), ß-hidroxibutirato (BHB) e cálcio total. A produção de leite individual foi mensurada até 100 dias em leite (DEL) e para a composição do leite foi avaliado o primeiro controle leiteiro oficial após o parto. As análises estatísticas foram conduzidas pelo procedimento MIXED do SAS e foram incluídos os efeitos fixos de fazenda (A e B), paridade (primíparas e multíparas) e ocorrência de doenças clínicas (vacas doentes e saudáveis). Quarenta e oito vacas (45,7%) apresentaram uma ou mais doenças clínicas. Nestas vacas doentes a concentração de BHB no 5o dia pós-parto foi superior (P = 0,06) a de vacas saudáveis; 0,78 e 0,57 mmol L-1, respectivamente. Em relação a produtividade, vacas com uma ou mais doenças clínicas apresentaram menores (P < 0,01) produções diárias até 30 DEL e tendência de menores (P = 0,09) produções acumuladas até 100 DEL em relação a vacas sadias. Vacas doentes apresentaram uma tendência de menor (P = 0,08) porcentagem de sólidos totais no leite do que vacas saudáveis; 12,04 e 12,60%, respectivamente. Não houve diferenças significativas entre animais doentes e saudáveis para os outros componentes do leite, bem como nos parâmetros reprodutivos avaliados. As diferenças observadas para dias até a primeira inseminação artificial (IA), número de IA e dias abertos ocorreram devido ao efeito de rebanho.(AU)

Effect of ensiling time on apparent total tract starch digestibility in Southern Brazilian dairy herds

Ensiling corn for longer periods is a strategy used to increase rumen bacteria access to starch. In fact, when corn is ensiled for insufficient periods, starch digestibility decreases, as evidenced by excreted starch. This study investigates the effects of corn silage ensiling time on starch digestibility of dairy cows through fecal starch analysis. The trial was conducted during the spring of 2013 and the fall of 2014 on twenty dairy herds located in the state of Paraná, southern Brazil. Total mixed ration (TMR), whole-plant corn silage (WPCS) and fecal samples were collected for determination of dry matter (DM), neutral detergent fiber (NDF), acid detergent fiber (ADF), lignin and starch. Apparent total tract starch digestibility (ATTSD) was calculated using equations developed by Fredin et al. (2014) and Bal et al. (1997). Data were analyzed using the CORR, REG and GLM procedures of SAS. Spring and fall WPCS were ensiled for 260 and 132 days, respectively (p 0.05) in ATTSD-Fredin from season to season though there was a trend (p = 0.11) towards greater ATTSD-Bal for spring samples. ATTSD-Bal was positively correlated with ensiling days (r = 0.31). Starch digestibility was not negatively affected by WPCS harvesting maturity. Differences in post-ruminal starch digestion, variation between farms in DM intake and diets, limitations of the equations, influence of uncontrolled factors, and the small number of experimental units might have contributed to the absence of significant results. Overall, Bal et al. (1997) equation was more efficient in distinguishing ATTSD from different ensiling periods.

Effect of ensiling time on apparent total tract starch digestibility in Southern Brazilian dairy herds

Ensiling corn for longer periods is a strategy used to increase rumen bacteria access to starch. In fact, when corn is ensiled for insufficient periods, starch digestibility decreases, as evidenced by excreted starch. This study investigates the effects of corn silage ensiling time on starch digestibility of dairy cows through fecal starch analysis. The trial was conducted during the spring of 2013 and the fall of 2014 on twenty dairy herds located in the state of Paraná, southern Brazil. Total mixed ration (TMR), whole-plant corn silage (WPCS) and fecal samples were collected for determination of dry matter (DM), neutral detergent fiber (NDF), acid detergent fiber (ADF), lignin and starch. Apparent total tract starch digestibility (ATTSD) was calculated using equations developed by Fredin et al. (2014) and Bal et al. (1997). Data were analyzed using the CORR, REG and GLM procedures of SAS. Spring and fall WPCS were ensiled for 260 and 132 days, respectively (p < 0.01). There was no difference (p > 0.05) in ATTSD-Fredin from season to season though there was a trend (p = 0.11) towards greater ATTSD-Bal for spring samples. ATTSD-Bal was positively correlated with ensiling days (r = 0.31). Starch digestibility was not negatively affected by WPCS harvesting maturity. Differences in post-ruminal starch digestion, variation between farms in DM intake and diets, limitations of the equations, influence of uncontrolled factors, and the small number of experimental units might have contributed to the absence of significant results. Overall, Bal et al. (1997) equation was more efficient in distinguishing ATTSD from different ensiling periods.(AU)