Effects of the percentage of concentrate on rumen fermentation, nutrient digestibility, plasma metabolites, and milk composition in mid-lactation goats

Abstract

The aim of this work was to study the effects of the dietary percentage of concentrate on patterns of intake, the evolution of rumen fermentation characteristics and plasma metabolites after a meal, nutrient digestibility, and milk production and composition in a medium-term trial in dairy goats. These effects have been well studied in dairy cattle but seldom in goats. Thirteen ruminally and duodenally cannulated dairy goats (95±4 d in milk) fed ad libitum were used in this study. Goats were assigned to 1 of 2 dietary treatments: high-concentrate (70% concentrate on dry matter basis) or a low-concentrate (35%) total mixed rations. The experiment was conducted over a period of 10 wk, including 3 wk of adaption to the diets. Patterns of intake, rumen fermentation characteristics, and plasma metabolites after a meal and fatty acids profile of milk fat were compared at the onset and at the end of the experiment. The increase in dietary percentage of concentrate decreased rumen pH, acetate to propionate ratio, ammonia-N concentration, and plasma urea concentration. The percentage of concentrate did not affect total volatile fatty acid concentrations. The high-concentrate diet increased the rate of intake during the morning meal at the onset of the experiment, whereas it decreased total dry matter intake and the rate of intake during the morning meal at the end of the experiment. The high-concentrate diet resulted in greater organic matter digestibility. Raw milk yield and protein yield were greater in goats fed the high-concentrate diet, whereas fat yield was not affected by dietary treatments. The milk fat content was lower in goats fed the high-concentrate diet. Proportions of the trans-C18:1 isomer relative to total fatty acids in milk were higher with the high-concentrate diet, but no modification of the proportion of total trans-C18:1 was detected, in particular no shift from trans-11 C18:1 to trans-10 C18:1 was observed. Further, the isomer trans-10,cis-12 C18:2 was not detected. Data from this study could be used for a new modeling approach or to improve existing models.

Effects of Sulla forage (Sulla coronarium L.) on the oxidative status and milk polyphenol content in goats

“…The increased levels of BHBA in the goats that were supplemented with cereals compared with the goats that received no supplement are in accordance with the findings of Fernàndez et al (2007). The increases in the BHBA levels and reductions in the NEFA levels in the supplemented groups are in agreement with lactation phase (86 DIM) findings that were previously reported by Serment et al (2011) for midlactation goats that were fed different percentages of concentrates. Furthermore, a positive correlation between BHBA and milk production was found (r = 0.30; P < 0.05).…”

Pengaruh Tingkat Penggunaan Pakan Penguat Terhadap Performa Induk Kambing Bligon Di Peternak Rakyat

“…Berdasarkan hasil penelitian Ramadhan et al (2013) dengan perlakuan imbangan hijauan konsentrat yang berbeda didapatkan konsumsi BK masing-masing 1,718; 1,482; dan 1,366 kg/ekor/hari berturut-turut untuk penggunaan pakan penguat 17, 35, dan 52%, sedangkan nilai konsumsi BK pada penelitian Serment et al (2011) yang menggunakan kambing Saanen dengan perlakuan konsentrat 35%, yaitu sebesar 2,68 kg/ekor/hari. Terlihat bahwa terdapat beberapa faktor yang menyebabkan perlakuan perbaikan pakan tidak mempengaruhi konsumsi BK.…”

“…Menurut Purbowati et al (2003) pemberian konsentrat yang terlalu banyak akan menyebabkan konsentrasi energi ransum meningkat, sehingga dapat menurunkan tingkat konsumsi, selanjutnya dilaporkan bahwa peningkatan aras konsentrat justru menurunkan konsumsi BK pakan. Hasil yang sama juga disampaikan oleh Serment et al (2011) bahwa konsumsi BK tidak dipengaruhi oleh persentase konsentrat. Ditambahkan Arora (1995) bahwa konsumsi BK pakan dipengaruhi oleh bobot badan, temperatur lingkungan, dan karakteristik pakan yang meliputi kecernaan, palatabilitas, dan keseimbangan nutrien dalam ransum.…”

“…Hal ini sesuai dengan pendapat Tillman et al (1998) yang menyatakan bahwa pakan penguat merupakan bahan pakan ternak yang mudah dicerna sehingga laju aliran pakan dalam saluran pencernaan lebih cepat dan memungkinkan ternak untuk menambah konsumsi pakan. Hasil penelitian di atas tidak sama dengan hasil penelitian Purbowati et al (2003) dan Serment et al (2011) yang menunjukkan bahwa konsumsi BK pakan tidak dipengaruhi oleh persentase konsentrat.…”

Relationships between ruminal Gram-positive bacteria and methane from lactating dairy cows supplemented with monensin and tallow, alone or in combination

“…During lactogenesis, cows require more energy than they consume (28); therefore, it is common to feed dairy cows a high-concentrate diet to increase the net energy for lactation (NE L ) (2). However, these diets cause a drop in pH (31), which affects the rumen microbial populations and fermentation processes (36). To enhance the fermentation processes and to change the microbial populations and profile of fermentation end-products in the rumen, supplements can be added to the cow diet (22).…”