Effects of acid detergent fiber intake on early postpartum milk production and chewing activities in dairy goats fed alfalfa hay

Effect of Supplementation with Organic Selenium or Turmeric and Rosemary Mixture on Beta-Defensin Content in Goat Milk

The present study examines the effects of diet supplementation with an organic selenium or herb-spice mixture on beta-defensin1 (GBD-1) and beta-defensin2 (GBD-2) concentrations in goat milk. Herd-I, consisting of Polish White (PWI) and Fawn Improved (PFI) goats, received supplementation with organic or inorganic selenium (controls). All goats were free from parasites, mastitis, and small ruminant lentivirus infection. Herd-II, consisting of PWI goats, either received a turmeric-rosemary mixture (experimental) or not (controls). The Herd I control group demonstrated higher fat, free fatty acid, and somatic cell levels and lower protein and lactose contents than Herd II controls. The GBD-1 concentration was below the detection limit in both herds. Herd I controls demonstrated higher GBD-2 concentrations in milk than Herd II controls. In addition, lower GBD-2 concentrations were noted in PWI goat milk. Organic selenium or rosemary-turmeric mixture supplementation had no effect on the GBD-2 content in the milk of healthy goats. The higher GBD-2 concentration observed in Herd Ic than in Herd IIc may suggest that the type of basal diet affects defensin secretion.

Effects of Replacing Grass with Foliage on Growth Rate and Feed Intake in Goats-A Systematic Review and Meta-Analysis

Simple Summary

Goats are important as food sources and livelihood in several areas of the world, mainly in low-income countries. Free-range browsing is common, but to increase productivity and improve health, supplemental or complete feeding is increasing. Ruminant feeding has often been using grasses, but as goats are browsers, they may benefit from including foliage in the diet. This systematic review and meta-analysis focuses on the effect of including foliage in goat diets. The results show that foliage was often more nutrient-rich and increased dry matter intake as well as average daily weight gain in goats.

Abstract

Small ruminants such as goats have a higher preference for browse species than cattle and sheep. In a meta-analysis of 42 papers describing 117 experimental treatments found by a search performed in June 2021 in PubMed and Web of Knowledge, we examined the general effect of including foliage in the diet of goats, replacing grasses, on dry matter intake and average daily weight gain. The inclusion requirement for a paper was that it described a controlled trial with a control diet of grass and with grass replaced by foliage in the experimental diet. Publication bias was estimated by calculating the Fail-safe n. Random effects analyses were conducted, using effect size calculated as Hedges’ d. The results showed that inclusion of foliage increased feed intake (Hedges’ d = 1.350, SE = 0.388) and average daily weight gain (Hedges’ d = 1.417, SE = 0.444) compared with a grass-based control. The positive effect of foliage inclusion on dry matter intake was associated with lower neutral detergent fiber (NDF) and higher crude protein (CP) in the foliage than in the grass it replaced. The positive effect on average daily weight gain was associated with higher CP concentration in the foliage than in grass. Foliage inclusion level showed a quadratic relationship with dry matter intake, with maximum dry matter intake achieved at a level of 50–60%. There was wide variation between the studies reviewed, and this variation was not reduced by subgroup analysis based on different kinds of foliage. In conclusion, the addition of foliage to goat diets can increase feed intake and daily weight gain, as an effect of the dietary preferences of goats and of generally higher nutritional value in foliage species compared with natural/semi-natural grass species.

Dietary fiber and milk yield, mastication, digestion, and the rate of passage in goats fed alfalfa hay

Two experiments were conducted to study the effect of intake of fiber on productive performance of high producing dairy goats during early to midlactation. Four dietary treatments were isonitrogenous and consisted of combinations of chopped alfalfa hay and concentrate, yielding 14, 18, 22, and 26% ADF. In Experiment 1, 40 multiparous Alpine does were used in a completely randomized block design. Milk fat content and total chewing time increased, and milk yield tended to decrease, as dietary ADF intake increased. Chewing efficiency [min/(g x kg BW.75)] for DM decreased, whereas that for ADF increased as ADF intake increased. Prediction equations were the following: milk fat yield, g/d = 115.78 - .128 x ADF intake, g/d + .00021 X (ADF intake)2 (r = .55); total chewing time, min/d = 345.33 + .32 x ADF intake, g/d (r = .60). In Experiment 2, 20 does were used in a completely randomized design. Apparent digestibilities of DM and energy decreased as dietary ADF intake increased. Rumen turnover rate and transit time of liquid were affected by ADF intake. Transit time of hay decreased as ADF intake increased. Intake of ADF affected pH and ammonia, acetate, and butyrate concentrations in the rumen. Acetate to propionate ration increased with ADF intake. No apparent trends were observed in whole blood beta-hydroxybutyrate or in plasma NEFA concentrations related to ADF intake. It appeared that DMI and milk fat yield leveled at 22% ADF or 43% NDF. For lactating dairy goats producing more than 3.5 kg/d of milk, calculated fat output reached a plateau when they consumed 587 g/d of ADF and spent 512 min/d chewing.