Inclusion of lemon leaves and rice straw into compound feed and its effect on nutrient balance, milk yield, and methane emissions in dairy goats.

The objective of this experiment was to study the effects of incorporating lemon leaves and rice straw into the compound feed of diets for dairy goats. Ten Murciano-Granadina dairy goats (n = 5 per group) in mid-lactation were used in a crossover design experiment (2 treatments across 2 periods). Goats were fed a mixed ration with barley grain (control, CON) or CON plus lemon leaves [189 g/kg of dry matter (DM)] and rice straw (120 g/kg of DM) in place of barley grain (LRS). Soybean oil (19 g/kg of DM) was added to the LRS diet to make it isoenergetic (17 MJ of gross energy/kg of DM) relative to CON. After 14 d on their respective treatments, goats were allocated to individual metabolism cages for another 7 d. Subsequently, feed intake, total fecal and urine output, and milk yield were recorded daily over the first 5 d. During the last 2 d, ruminal fluid and blood samples were collected, along with individual gas exchange measurements recorded by a mobile open-circuit indirect calorimetry system using a head box. No differences in DM intake were detected, and ME intake in LRS was lower than in CON (1,095 vs. 1,180 kJ/kg of metabolic body weight). No differences were observed in milk production, but milk fat content was greater in LRS (6.4%) than in CON (5.6%). Greater concentrations of monounsaturated (14.94 vs. 11.96 g/100 g of milk fat) and polyunsaturated fatty acids (4.53 vs. 4.03 g/100 g of milk fat) were detected in the milk of goats fed LRS compared with CON. Atherogenicity (2.68 vs.1.91) and thrombogenic (4.58 vs. 2.81) indices were lower with LRS compared with CON. Enteric CH4 emission was lower in LRS (24.3 g/d) compared with CON (31.1 g/d), probably due to the greater lipid content and unsaturated fatty acid profile of lemon leaves and the soybean oil added in the LRS diet. Overall, data suggest that incorporating lemon leaves and rice straw into lactating goat diets is effective in reducing CH4 emissions while allowing improvements in milk fat production and milk thrombogenic index without affecting production performance. Thus, their inclusion in compound feeds fed to small ruminants appears warranted and would have multiple positive effects, as on efficiency of nutrient use, human health, and the environment.

Effect of the rearing system on financial returns from Murciano-Granadina breed goats.

In dairy goats, the kid rearing system can have critical importance in financial returns. Commonly used criteria for the choice of rearing system are not always clear due to the high number of factors involved. The aim of this study was to quantify all those factors to facilitate decision making. So, the effect of two different kid rearing systems, mixed rearing system (MRS) and artificial rearing system (ARS), on milk yield, milk composition and somatic cell count (SCC), milk yield loss at weaning for MRS, kid growth and costs of the different traits on the financial returns in Murciano-Granadina breed goats was studied. Twenty-four goats per group were used. In the MRS, goats reared only one kid, which had free access to goat milk 24 h a day and were weaned at week 6 of lactation, whereas kids in the ARS were separated from their mothers at kidding, colostrum and artificially reared. In both systems, dams were machine-milked once a day throughout lactation and the records took place weekly. Potential milk yield was estimated according to the oxytocin method up to week 12 of lactation, and was similar for both rearing systems, although a 12.3% drop in potential milk yield at weaning was observed for MRS. During the first 6 weeks of lactation, marketable milk was lower for dams in MRS compared to those in ARS (72.1 v. 113.0 l), but similar for the rest of the experiment (101.5 v. 99.4 l, respectively). Marketable milk composition and SCC throughout the 12 weeks of lactation were unaffected by the rearing system. Artificial rearing system entailed an increment in production cost of 22.2€ per kid compared to the rearing by MRS. A similar economic return per goat and kid was obtained from ARS and MRS in this experiment, although, due to one herd's prolificacy of 1.8, the actual results would be 16.2€ per goat in favour of MRS. The real interest of this experiment may be the possibility of extrapolation to different flocks with diverse levels of milk production, prolificacy and prices and costs for incomes and outputs, to estimate the production system that increases returns. In conclusion, the results showed an increase in the cost of €22.2 per kid bred in the ARS, compared to the MRS, and a final return of 16.2€ per goat in favour of the mixed system.

Effect of the inclusion of artichoke silage in the ration of lactating ewes on the properties of milk and cheese characteristics during ripening.

The effect of including artichoke silage in the rations of dairy ewes on milk characteristics and biochemical changes of ripened cheeses was evaluated. Four groups of lactating ewes were fed rations containing 0, 10, 20, or 30% artichoke silage on a dry matter basis. Bulk milk samples were collected 3 times during the feeding period, and semi-hard cheeses were manufactured and sampled during ripening. Milk composition and cheese yield were not affected by diet. Inclusion of 20 and 30% artichoke silage reduced the firmness of the curds at a level only detected by the Gelograph (Gelograph-NT, Gel-Instrumente, Thalwil, Switzerland) probe. Inclusion of artichoke silage in ewes' diet decreased fat and total free fatty acids content of these cheeses and increased total free amino acids content. Despite the effect of diet on cheese ripening characteristics, the overall sensory scores for cheeses corresponding to artichoke silage diets were statistically higher than those for the control cheeses.