Influence of rumen protein degradability on productive and reproductive performance in buffalo cows

Abstract

-The present study aimed to ascertain the influence of crude protein (CP) digestibility in the rumen on the quantity and quality of milk production and reproductive performance, blood (BU) and milk (MU) urea, haematological profile and vaginal mucus urea, ammonia and potassium of buffalo cows. Lactating buffaloes (n = 84), 60 days in milk, were randomly subdivided into Group C (control, n = 42) and Group T (fed a diet supplemented with Aspergillus oryzae, n = 42). In three fistulated buffalo, the diet supplemented with Aspergillus oryzae showed a decrease (P < 0.01) in protein digestibility in the rumen (79.3 vs. 45.9%). No differences were registered in productive performance. Nine buffaloes not in oestrus during the dietary treatment (Groups T1 and C1), 30 days in milk, were used to study the haematological profile and to determine milk urea and ammonia in the vaginal mucus. The animals in Group T1 had higher ammonia values in the blood (P < 0.01) but not in the vaginal mucus than Group C1. A relationship was found between MU and BU. MU was influenced by CP intake and dry matter intake. No differences between the treatments were observed in reproductive performance and the conception rate and calving interval were 37.9% and 41.4% (90 trial-day) and 449 and 419 days respectively in Groups T and C. Reproductive performance was not influenced by high levels of BU nor by blood ammonia levels, although the latter were higher in the group fed the diet supplemented with Aspergillus oryzae.buffalo cow / protein digestibility in the rumen / blood / milk / vaginal mucus

Relationship of body condition score and blood urea and ammonia to pregnancy in Italian Mediterranean buffaloes

“…In a study that involved natural mating of buffaloes during a period of increasing day length, blood levels of urea > 6.66 mmol·L -1 did not influence fertility [5]. In the present study, blood levels of urea ≥ 6.83 mmol·L -1 were associated with a significantly reduced likelihood of pregnancy.…”

“…The likelihood of pregnancy for buffaloes with low urea blood level was 2.6 greater than for a high urea level and exposure to a high urea level lowered the probability of pregnancy by about 0.25. A difference between the previous [5] and present studies was the use of frozen semen in the latter. Urea appears to inhibit the citric acid cycle in sperm and compromises motility and fertilising ability, effects that are likely to be more pronounced in cryopreserved sperm [18].…”

“…In the contrast to the quantity of protein, degradability in the rumen has no apparent effects on reproductive performance in buffaloes mated naturally [5]. It has been suggested that the failure of rumen protein degradability to influence fertility in buffaloes is due to a lower uterine diffusion of ammonia in buffaloes compared with cattle [5]. The aim in the present study was to obtain clear relationships between body condition, blood levels of urea and ammonia, and risk for pregnancy in Italian Mediterranean Buffaloes synchronised and mated by AI in the mid-winter.…”

“…Samples were centrifuged at 3000 g for 15 min and serum was stored at -18 °C until required for analyses. Immediately after sampling, the ammonia (NH 3 ) was measured on whole blood with a rapid method (Ammonia kit, Menarini, Florence, Italy) that has a high correlation (r = 0.988) with the enzymatic UV-method [5]. The intra-assay coefficient of variation of the ammonia rapid method was 7.7%.…”

“…Italian Mediterranean Buffaloes fed a diet with protein content 50% greater than requirements had higher incidences of oestrus that were followed by a normal luteal phase and typical inter-oestrous interval [4]. In the contrast to the quantity of protein, degradability in the rumen has no apparent effects on reproductive performance in buffaloes mated naturally [5]. It has been suggested that the failure of rumen protein degradability to influence fertility in buffaloes is due to a lower uterine diffusion of ammonia in buffaloes compared with cattle [5].…”